Challenges to the CO2 Global Warming Hypothesis: (1) A New Take on the Carbon Cycle

Central to the dubious belief that humans make a substantial contribution to climate change is the CO₂ global warming hypothesis. The hypothesis is that observed global warming – currently about 1 degree Celsius (1.8 degrees Fahrenheit) since the preindustrial era – has been caused primarily by human emissions of CO₂ and other greenhouse gases into the atmosphere. The CO₂ hypothesis is based on the apparent correlation between rising worldwide temperatures and the CO₂ level in the lower atmosphere, which has gone up by approximately 47% over the same period.

In this series of blog posts, I’ll review several recent research papers that challenge the hypothesis. The first is a 2020 preprint by U.S. physicist and research meteorologist Ed Berry, who has a PhD in atmospheric physics. Berry disputes the claim of the IPCC (Intergovernmental Panel on Climate Change) that human emissions have caused all of the CO₂ increase above its preindustrial level in 1750 of 280 ppm (parts per million), which is one way of expressing the hypothesis.

The IPCC’s CO₂ model maintains that natural emissions of CO₂ since 1750 have remained constant, keeping the level of natural CO₂ in the atmosphere at 280 ppm, even as the world has warmed. But Berry’s alternative model concludes that only 25% of the current increase in atmospheric CO₂ is due to humans and that the other 75% comes from natural sources. Both Berry and the IPCC agree that the preindustrial CO₂ level of 280 ppm had natural origins. If Berry is correct, however, the CO₂ global warming hypothesis must be discarded and another explanation found for global warming.

Natural CO₂ emissions are part of the carbon cycle that accounts for the exchange of carbon between the earth’s land masses, atmosphere and oceans; it includes fauna and flora, as well as soil and sedimentary rocks. Human CO₂ from burning fossil fuels constitutes less than 5% of total CO₂ emissions into the atmosphere, the remaining emissions being natural. Atmospheric CO₂ is absorbed by vegetation during photosynthesis, and by the oceans through precipitation. The oceans also release CO₂ as the temperature climbs.

Berry argues that the IPCC treats human and natural carbon differently, instead of deriving the human carbon cycle from the natural carbon cycle. This, he says, is unphysical and violates the Equivalence Principle of physics. Mother Nature can't tell the difference between fossil fuel CO₂ and natural CO₂. Berry uses physics to create a carbon cycle model that simulates the IPCC’s natural carbon cycle, and then utilizes his model to calculate what the IPCC human carbon cycle should be.

Berry’s physics model computes the flow or exchange of carbon between land, atmosphere, surface ocean and deep ocean reservoirs, based on the hypothesis that outflow of carbon from a particular reservoir is equal to its level or mass in that reservoir divided by its residence time. The following figure shows the distribution of human carbon among the four reservoirs in 2005, when the atmospheric CO₂ level was 393 ppm, as calculated by the IPCC (left panel) and Berry (right panel).

A striking difference can be seen between the two models. The IPCC claims that approximately 61% of all carbon from human emissions remained in the atmosphere in 2005, and no human carbon had flowed to land or surface ocean. In contrast, Berry’s alternative model reveals appreciable amounts of human carbon in all reservoirs that year, but only 16% left in the atmosphere. The IPCC’s numbers result from assuming in its human carbon cycle that human emissions caused all the CO₂ increase above its 1750 level.

The problem is that the sum total of all human CO₂ emitted since 1750 is more than enough to raise the atmospheric level from 280 ppm to its present 411 ppm, if the CO₂ residence time in the atmosphere is as long as the IPCC claims – hundreds of years, much longer than Berry’s 5 to 10 years. The IPCC’s unphysical solution to this dilemma, Berry points out, is to have the excess human carbon absorbed by the deep ocean alone without any carbon remaining at the ocean surface.

Contrary to the IPCC’s claim, Berry says that human emissions don’t continually add CO₂ to the atmosphere, but rather generate a flow of CO₂ through the atmosphere. In his model, the human component of the current 131 (= 411-280) ppm of added atmospheric CO₂ is only 33 ppm, and the other 98 ppm is natural.

The next figure illustrates Berry’s calculations, showing the atmospheric CO₂ level above 280 ppm for the period from 1840 to 2020, including both human and natural contributions. It’s clear that natural emissions, represented by the area between the blue and red solid lines, have not stayed at the same 280 ppm level over time, but have risen as global temperatures have increased. Furthermore, the figure also demonstrates that nature has always dominated the human contribution and that the increase in atmospheric CO₂ is more natural than human.

Other researchers (see, for example, here and here) have come to much the same conclusions as Berry, using different arguments.

Next: Challenges to the CO2 Global Warming Hypothesis: (2) Questioning Nature’s Greenhouse Effect

Science vs Politics: The Precautionary Principle

Greatly intensifying the attack on modern science is invocation of the precautionary principle – a concept developed by 20th-century environmental activists. Targeted at decision making when the available scientific evidence about a potential environmental or health threat is highly uncertain, the precautionary principle has been used to justify a number of environmental policies and laws around the globe. Unfortunately for science, the principle has also been used to support political action on alleged hazards, in cases where there’s little or no evidence for those hazards.

The origins of the precautionary principle can be traced to the application in the early 1970s of the German principle of “Vorsorge” or foresight, based on the belief that environmental damage can be avoided by careful forward planning. The “Vorsorgeprinzip” became the foundation for German environmental law and policies in areas such as acid rain, pollution and global warming. The principle reflects the old adage that “it’s better to be safe than sorry,” and can be regarded as a restatement of the ancient Hippocratic oath in medicine, “First, do no harm.”

Formally, the precautionary principle can be stated as:

When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically.

But in spite of its noble intentions, the precautionary principle in practice is based far more on political considerations than on science. It’s the “not fully established scientifically” statement that both embraces the principle involved and, at the same time, leaves it open to manipulation and subversion of science.

A notable example of the intrusion of precautionary principle politics into science is the bans on GMO (genetically modified organism) crops by more than half the countries in the European Union. The bans stem from the widespread, fear-based belief that eating genetically altered foods is unsafe, despite the lack of any scientific evidence that GMOs have ever caused harm to a human.

In a 2016 study by the U.S. NAS (National Academy of Sciences, Engineering and Medicine), no substantial evidence was found that the risk to human health was any different for current GMO crops on the market than for their traditionally crossbred counterparts. This conclusion came from epidemiological studies conducted in the U.S. and Canada, where the population has consumed GMO foods since the late 1990s, and similar studies in the UK and Europe, where very few GMO foods are eaten.

The precautionary principle also underlies the UNFCCC (UN Framework Convention on Climate Change), the 1992 treaty that formed the basis for all subsequent political action on global warming. In another post, I’ve discussed the lack of empirical scientific evidence for the narrative of catastrophic anthropogenic (human-caused) climate change. Yet Irrational fear of disastrous consequences of global warming pushes activists to invoke the precautionary principle in order to justify unnecessary, expensive remedies such as those embodied in the Paris Agreement or the Green New Deal.

One of the biggest issues with the precautionary principle is that it essentially advocates risk avoidance. But risk avoidance carries its own risks.

Dangers, great and small, are an accepted part of everyday life. We accept the risk, for example, of being killed or badly injured while traveling on the roads because the risk is outweighed by the convenience of getting to our destination quickly, or by our desire to have fresh food available at the supermarket. Applying the precautionary principle would mean, in addition to the safety measures already in place, reducing all speed limits to 10 mph or less – a clearly impractical solution that would take us back to horse-and-buggy days.  

Another, real-life example of an unintended consequence of the precautionary principle is what happened in Fukushima, Japan in the aftermath of the nuclear accident triggered by a massive earthquake and tsunami in 2011. As described by the authors of a recent discussion paper, Japan’s shutdown of nuclear power production as a safety measure and its replacement by fossil-fueled power raised electricity prices by as much as 38%, decreasing consumption of electricity, especially for heating during cold winters. This had a devastating effect: in the authors’ words,

“Our estimated increase in mortality from higher electricity prices significantly outweighs the mortality from the accident itself, suggesting the decision to cease nuclear production caused more harm than good.”

Adherence to the precautionary principle can also stifle innovation and act as a barrier to technological development. In the worst case, an advantageous technology can be banned because of its potentially negative impact, leaving its positive benefits unrealized. This could well be the case for GMOs. The more than 30 nations that have banned the growing of genetically engineered crops may be shutting themselves off from the promise of producing cheaper and more nutritious food.

The precautionary principle pits science against politics. In an ideal world, the conflict between the two would be resolved wisely. As things are, however, science is often subjugated to the needs and whims of policy makers.

Next: Challenges to the CO₂ Global Warming Hypothesis: (1) A New Take on the Carbon Cycle

Absurd Attempt to Link Climate Change to Cancer Contradicted by Another Medical Study

Extreme weather has already been wrongly blamed on climate change. More outlandish claims have linked climate change to medical and social phenomena such as teenage drinking, declining fertility rates, mental health problems, loss of sleep by the elderly and even Aretha Franklin’s death.

Now the most preposterous claim of all has been made, that climate change causes cancer. A commentary last month in a leading cancer journal contends that climate change is increasing cancer risk through increased exposure to carcinogens after extreme weather events such as hurricanes and wildfires. Furthermore, the article declares, weather extremes impact cancer survival by impeding both patients' access to cancer treatment and the ability of medical facilities to deliver cancer care.

How absurd! To begin with, there’s absolutely no evidence that global warm­ing triggers extreme weather, or even that extreme weather is becoming more frequent. The following figure, depicting the annual number of global hurricanes making landfall since 1970, illustrates the lack of any trend in major hurricanes for the last 50 years – during a period when the globe warmed by ap­proximately 0.6 degrees Celsius (1.1 degrees Fahrenheit). The strongest hurricanes today are no more extreme or devastating than those in the past. If anything, major landfalling hurricanes in the US are tied to La Niña cycles in the Pacific Ocean, not to global warming.

And wildfires in fact show a declining trend over the same period. This can be seen in the next figure, displaying the estimated area worldwide burned by wildfires, by decade from 1900 to 2010. While the number of acres burned annually in the U.S. has gone up over the last 20 years or so, the present burned area is still only a small fraction of what it was back in the 1930s.

Apart from the lack of any connection between climate change and extreme weather, the assertion that hurricanes and wildfires result in increased exposure to carcinogens is dubious. Although hurricanes occasionally cause damage that releases chemicals into the atmosphere, and wildfires generate copious amounts of smoke, these effects are temporary and add very little to the carcinogen load experienced by the average person.

A far greater carcinogen load is experienced continuously by people living in poorer countries who rely on the use of solid fuels, such as coal, wood, charcoal or biomass, for cooking. Incomplete combustion of solid fuels in inefficient stoves results in indoor air pollution that causes respiratory infections in the short term, especially in children, and heart disease or cancer in adults over longer periods of time.

The 2019 Lancet Countdown on Health and Climate Change, an annual assessment of the health effects of climate change, found that mortality from climate-sensitive diseases such as diarrhea and malaria has fallen as the planet has heated, with the exception of dengue fever. Although the Countdown didn’t examine cancer specifically, it did find that the number of people still lacking access to clean cooking fuels and technologies is almost three billion, a number that has fallen by only 1% since 2010.

What this means is that, regardless of ongoing global warming, those billions are still being exposed to indoor carcinogens and are therefore at greater-than-normal risk of later contracting cancer. But the cancer will be despite climate change, not because of it – completely contradicting the claim in the cancer journal that climate change causes cancer.

Because climate change is actually reducing the frequency of hurricanes and wildfires, the commentary’s contention that extreme weather is worsening disruptions to health care access and delivery is also fallacious. Delays due to weather extremes in cancer diagnosis and treatment initiation, and the interruption of cancer care, are becoming less, not more common.

It makes no more sense to link climate change to cancer than to avow that it causes hair loss or was responsible for the creation of the terrorist group ISIS.

Next: Science vs Politics: The Precautionary Principle

Why Both Coronavirus and Climate Models Get It Wrong

Most coronavirus epidemiological models have been an utter failure in providing advance information on the spread and containment of the insidious virus. Computer climate models are no better, with a dismal track record in predicting the future.

This post compares the similarities and differences of the two types of model. But similarities and differences aside, the models are still just that – models. Although I remarked in an earlier post that epidemiological models are much simpler than climate models, this doesn’t mean they’re any more accurate.     

Both epidemiological and climate models start out, as they should, with what’s known. In the case of the COVID-19 pandemic the knowns include data on the progression of past flu epidemics, and demographics such as population size, age distribution, social contact patterns and school attendance. Among the knowns for climate models are present-day weather conditions, the global distribution of land and ice, atmospheric and ocean currents, and concentrations of greenhouse gases in the atmosphere.

But the major weakness of both types of model is that numerous assumptions must be made to incorporate the many variables that are not known. Coronavirus and climate models have little in common with the models used to design computer chips, or to simulate nuclear explosions as an alternative to actual testing of atomic bombs. In both these instances, the underlying science is understood so thoroughly that speculative assumptions in the models are unnecessary.

Epidemiological and climate models cope with the unknowns by creating simplified pictures of reality involving approximations. Approximations in the models take the form of adjustable numerical parameters, often derisively termed “fudge factors” by scientists and engineers. The famous mathematician John von Neumann once said, “With four [adjustable] parameters I can fit an elephant, and with five I can make him wiggle his trunk.”

One of the most important approximations in coronavirus models is the basic reproduction number R0 (“R naught”), which measures contagiousness. The numerical value of R0 signifies the number of other people that an infected individual can spread the disease to, in the absence of any intervention. As shown in the figure below, R0 for COVID-19 is thought to be in the range from 2 to 3, much higher than for a typical flu at about 1.3, though less than values for other infectious diseases such as measles.

It’s COVID-19’s high R0 that causes the virus to spread so easily, but its precise value is still uncertain. What determines how quickly the virus multiplies, however, is the incubation period, during which an infected individual can’t infect others. Both R0 and the incubation period define the epidemic growth rate. They’re adjustable parameters in coronavirus models, along with factors such as the rate at which susceptible individuals become infectious in the first place, travel patterns and any intervention measures taken.

In climate models, hundreds of adjustable parameters are needed to account for deficiencies in our knowledge of the earth’s climate. Some of the biggest inadequacies are in the representation of clouds and their response to global warming. This is partly because we just don’t know much about the inner workings of clouds, and partly because actual clouds are much smaller than the finest grid scale that even the largest computers can accommodate – so clouds are simulated in the models by average values of size, altitude, number and geographic location. Approximations like these are a major weakness of climate models, especially in the important area of feedbacks from water vapor and clouds.

An even greater weakness in climate models is unknowns that aren’t approximated at all and are simply omitted from simulations because modelers don’t know how to model them. These unknowns include natural variability such as ocean oscillations and indirect solar effects. While climate models do endeavor to simulate various ocean cycles, the models are unable to predict the timing and climatic influence of cycles such as El Niño and La Niña, both of which cause drastic shifts in global climate, or the Pacific Decadal Oscillation. And the models make no attempt whatsoever to include indirect effects of the sun like those involving solar UV radiation or cosmic rays from deep space.

As a result of all these shortcomings, the predictions of coronavirus and climate models are wrong again and again. Climate models are known even by modelers to run hot, by 0.35 degrees Celsius (0.6 degrees Fahrenheit) or more above observed temperatures. Coronavirus models, when fed data from this week, can probably make a reasonably accurate forecast about the course of the pandemic next week – but not a month, two months or a year from now. Dr. Anthony Fauci of the U.S. White House Coronavirus Task Force recently admitted as much.

Computer models have a role to play in science, but we need to remember that most of them depend on a certain amount of guesswork. It’s a mistake, therefore, to base scientific policy decisions on models alone. There’s no substitute for actual, empirical evidence.

Next: How Science Is Being Misused in the Coronavirus Pandemic

Does Planting Trees Slow Global Warming? The Evidence

It’s long been thought that trees, which remove CO₂ from the atmosphere and can live much longer than humans, exert a cooling influence on the planet. But a close look at the evidence reveals that the opposite could be true – that planting more trees may actually have a warming effect.

This is the tentative conclusion reached by a senior scientist at NASA, in evaluating the results of a 2019 study to estimate Earth’s forest restoration potential. It’s the same conclusion that the IPCC (Intergovernmental Panel on Climate Change) came to in a comprehensive 2018 report on climate change and land degradation. Both the 2019 study and IPCC report were based on various forest models.

The IPCC’s findings are summarized in the following figure, which shows how much the global surface temperature is altered by large-scale forestation (crosses) or deforestation (circles) in three different climatic regions: boreal (subarctic), temperate and tropical; the figure also shows how much deforestation affects regional temperatures.

Trees impact the temperature through either biophysical or biogeochemical effects. The principal biophysical effect is changes in albedo, which measures the reflectivity of incoming sunlight. Darker surfaces such as tree leaves have lower albedo and reflect the sun less than lighter surfaces such as snow and ice with higher albedo. Planting more trees lowers albedo, reducing reflection but increasing absorption of solar heat, resulting in global warming.

The second main biophysical effect is changes in evapotranspiration, which is the release of moisture from plant and tree leaves and the surrounding soil. Forestation boosts evapotranspiration, pumping more water vapor into the atmosphere and causing global cooling that competes with the warming effect from reduced albedo.

These competing biophysical effects of forestation are accompanied by a major geochemical effect, namely the removal of CO₂ from the atmosphere by photosynthesis. In photosynthesis, plants and trees take in CO₂ and water, as well as absorbing sunlight, producing energy for growth and releasing oxygen. Lowering the level of the greenhouse gas CO₂ in the atmosphere results in the cooling traditionally associated with planting trees.

The upshot of all these effects, plus other minor contributions, is demonstrated in the figure above. For all three climatic zones, the net global biophysical outcome of large-scale forestation (blue crosses) – primarily from albedo and evapotranspiration changes – is warming.

Additional biophysical data can be inferred from the results for deforestation (small blue circles), simply reversing the sign of the temperature change to show forestation. Doing this indicates global warming again for forestation in boreal and temperate zones, and perhaps slight cooling in the tropics, with regional effects (large blue circles) being more pronounced. There is strong evidence, therefore, from the IPCC report that widespread tree planting results in net global warming from biophysical sources.

The only region for which there is biogeochemical data (red crosses) for forestation – signifying the influence of CO₂ – is the temperate zone, in which forestation results in cooling as expected. Additionally, because deforestation (red dots) results in biogeochemical warming in all three zones, it can be inferred that forestation in all three zones, including the temperate zone, causes cooling.

Which type of process dominates, following tree planting – biophysical or biogeochemical? A careful examination of the figure suggests that biophysical effects prevail in boreal and temperate regions, but biogeochemical effects may have the upper hand in tropical regions. This implies that large-scale planting of trees in boreal and temperate regions will cause further global warming. However, two recent studies (see here and here) of local reforestation have found evidence for a cooling effect in temperate regions.

But even in the tropics, where roughly half of the earth’s forests have been cleared in the past, it’s far from certain that the net result of extensive reforestation will be global cooling. Among other factors that come into play are atmospheric turbulence, rainfall, desertification and the particular type of tree planted.

Apart from these concerns, another issue in restoring lost forests is whether ecosystems in reforested areas will revert to their previous condition and have the same ability as before to sequester CO₂. Says NASA’s Sassan Saatchi, “Once connectivity [to the climate] is lost, it becomes much more difficult for a reforested area to have its species range and diversity, and the same efficiency to absorb atmospheric carbon.”

So, while planting more trees may provide more shade for us humans in a warming world, the environmental benefits are not at all clear.

Next: Why Both Coronavirus and Climate Models Get It Wrong

The Futility of Action to Combat Climate Change: (2) Political Reality

In the previous post, I showed how scientific and engineering realities make the goal of taking action to combat climate change inordinately expensive and unattainable in practice for decades to come, even if climate alarmists are right about the need for such action. This post deals with the equally formidable political realities involved.

By far the biggest barrier is the unlikelihood that the signatories to the 2015 Paris Agreement will have the political will to adhere to their voluntary pledges for reducing greenhouse gas emissions. Lacking any enforcement mechanism, the agreement is merely a “feel good” document that allows nations to signal virtuous intentions without actually having to make the hard decisions called for by the agreement. This reality is tacitly admitted by all the major CO₂ emitters.

Evidence that the Paris Agreement will achieve little is contained in the figure below, which depicts the ability of 58 of the largest emitters, accounting for 80% of the world’s greenhouse emissions, to meet the present goals of the accord. The goals are to hold “the increase in the global average temperature to well below 2 degrees Celsius (3.6 degrees Fahrenheit) above pre-industrial levels,” preferably limiting the increase to only 1.5 degrees Celsius (2.7 degrees Fahrenheit).

It’s seen that only seven nations have declared emission reductions big enough to reach the Paris Agreement’s goals, including just one of the largest emitters, India. The seven largest emitters, apart from India which currently emits 7% of the world’s CO₂, are China (28%), the USA (14%), Russia (5%), Japan (3%), Germany (2%, biggest in the EU) and South Korea (2%). The EU designation here includes the UK and 27 European nations.

As the following figure shows, annual CO₂ emissions from both China and India are rising, along with those from the other developing nations (“Rest of world”). Emissions from the USA and EU, on the other hand, have been steady or falling for several decades. Ironically, the USA’s emissions in 2019, which dropped by 2.9% from the year before, were no higher than in 1993 – despite the country’s withdrawal from the Paris Agreement.

As the developing nations, including China and India, currently account for 76% of global emissions, it’s difficult to imagine that the world as a whole will curtail its emissions anytime soon.

China, although a Paris Agreement signatory, has declared its intention of increasing its annual CO₂ emissions until 2030 in order to fully industrialize – a task requiring vast amounts of additional energy, mostly from fossil fuels. The country already has over 1,000 GW of coal-fired power capacity and another 120 GW under construction. China is also financing or building 250 GW of coal-fired capacity as part of its Belt and Road Initiative across the globe. Electricity generation in China from burning coal and natural gas accounted for 70% of the generation total in 2018, compared with 26% from renewables, two thirds of which came from hydropower.

India, which has also ratified the Paris Agreement, believes it can meet the agreement’s aims even while continuing to pour CO₂ into the atmosphere. Coal’s share of Indian primary energy consumption, which is predominantly for electricity generation and steelmaking, is expected to decrease slightly from 56% in 2017 to 48% in 2040. However, achieving even this reduction depends on doubling the share of renewables in electricity production, an objective that may not be possible because of land acquisition and funding barriers.

Nonetheless, it’s not China nor India that stand in the way of making the Paris Agreement a reality, but rather the many third world countries who want to reach the same standard of living as the West – a lifestyle that has been attained through the availability of cheap, fossil fuel energy. In Africa today, for example, 600 million people don’t have access to electricity and 900 million are forced to cook with primitive stoves fueled by wood, charcoal or dung, all of which create health and environmental problems. Coal-fired electricity is the most affordable remedy for the continent.

In the words of another writer, no developing country will hold back from increasing their CO₂ emissions “until they have achieved the same levels of per capita energy consumption that we have here in the U.S. and in Europe.” This drive for a better standard of living, together with the lack of any desire on the part of industrialized countries to lower their energy consumption, spells disaster for realizing the lofty goals of the Paris Agreement.

Next: Science on the Attack: Cancer Immunotherapy

The Futility of Action to Combat Climate Change: (1) Scientific and Engineering Reality

Amidst the clamor for urgent action to supposedly combat climate change, the scientific and engineering realities of such action are usually overlooked. Let’s imagine for a moment that we humans are indeed to blame for global warming and that catastrophe is imminent without drastic measures to curb fossil fuel emissions – views not shared by climate skeptics like myself.

In this and the subsequent blog post, I’ll show how proposed mitigation measures are either impractical or futile. We’ll start with the 2015 Paris Agreement – the international agreement on cutting greenhouse gas emissions, which 195 nations, together with many of the world’s scientific societies and national academies, have signed on to.

The agreement endorses the assertion that global warming comes largely from our emissions of greenhouse gases, and commits its signatories to “holding the increase in the global average temperature to well below 2 degrees Celsius (3.6 degrees Fahrenheit) above pre-industrial levels,” preferably limiting the increase to only 1.5 degrees Celsius (2.7 degrees Fahrenheit). According to NASA, current warming is close to 1 degree Celsius (1.8 degrees Fahrenheit).

How realistic are these goals? To achieve them, the Paris Agreement requires nations to declare a voluntary “nationally determined contribution” toward emissions reduction. However, it has been estimated by researchers at MIT (Massachusetts Institute of Technology) that, even if all countries were to follow through with their voluntary contributions, the actual mitigation of global warming by 2100 would be at most only about 0.2 degrees Celsius (0.4 degrees Fahrenheit).

Higher estimates, ranging up to 0.6 degrees Celsius (1.1 degrees Fahrenheit), assume that countries boost their initial voluntary emissions targets in the future. The agreement actually stipulates that countries should submit increasingly ambitious targets every five years, to help attain its long-term temperature goals. But the targets are still voluntary, with no enforcement mechanism.

Given that most countries are already falling behind their initial pledges, mitigation of more than 0.2 degrees Celsius (0.4 degrees Fahrenheit) by 2100 seems highly unlikely. Is it worth squandering the trillions of dollars necessary to achieve such a meager gain, even if the notion that we can control the earth’s thermostat is true?     

Another reality check is the limitations of renewable energy sources, which will be essential to our future if the world is to wean itself off fossil fuels that today supply almost 80% of our energy needs. The primary renewable technologies are wind and solar photovoltaics. But despite all the hype, wind and solar are not yet cost competitive with cheaper coal, oil and gas in most countries, when subsidies are ignored. Higher energy costs can strangle a country’s economy.

Source: BP

And it will be many years before renewables are practical alternatives to fossil fuels. It’s generally unappreciated by renewable energy advocates that full implementation of a new technology can take many decades. That’s been demonstrated again and again over the past century in areas as diverse as electronics and steelmaking.

The claim is often made, especially by proponents of the so-called Green New Deal, that scale-up of wind and solar power could be accomplished quickly by mounting an effort comparable to the U.S. moon landing program in the 1960s. But the claim ignores the already mature state of several technologies crucial to that program at the outset. Rocket technology, for example, had been developed by the Germans and used to terrify Londoners in the UK during World War II. The vacuum technology needed for the Apollo crew modules and spacesuits dates from the beginning of the 20th century.

Such advantages don’t apply to renewable energy. The main engineering requirements for widespread utilization of wind and solar power are battery storage capability, to store energy for those times when the wind stops blowing or the sun isn’t shining, and redesign of the electric grid.

But even in the technologically advanced U.S., battery storage is an order of magnitude too expensive today for renewable electricity to be cost competitive with electricity generated from fossil fuels. That puts battery technology where rocket technology was more than 25 years before Project Apollo was able to exploit its use in space. Likewise, conversion of the U.S. power grid to renewable energy would cost trillions of dollars – and, while thought to be attainable, is currently seen as merely “aspirational.”

The bottom line for those who believe we must act urgently on the climate “emergency”: it’s going to take a lot of time and money to do anything at all, and whatever we do may make little difference to the global climate anyway.

Next: The Futility of Action to Combat Climate Change: (2) Political Reality

Australian Bushfires: Ample Evidence That Past Fires Were Worse

Listening to Hollywood celebrities and the mainstream media, you’d think the current epidemic of bushfires in Australia means the apocalypse is upon us. With vast tracts of land burned to the ground, dozens of people and millions of wild animals killed, and thousands of homes destroyed, climate alarmists would have you believe it’s all because of global warming.

But not only is there no scientific evidence that the frequency or severity of wildfires are on the rise in a warming world, but the evidence also clearly shows that the present Australian outbreak is unexceptional.

Although almost 20 million hectares (50 million acres, or 77,000 square miles) nationwide have burned so far, this is less than 17% of the staggeringly large area incinerated in the 1974-75 bushfire season and less than the burned area in three other conflagrations. Politically correct believers in the narrative of human-caused climate change seem unaware of such basic facts about the past.

The catastrophic fires in the 1974-75 season consumed 117 million hectares (300 million acres), which is 15% of the land area of the whole continent. Because nearly two thirds of the burned area was in remote parts of the Northern Territory and Western Australia, relatively little human loss was incurred, though livestock and native animals such as lizards and red kangaroos suffered.

The Northern Territory was also the location of major bushfires in the 1968-69, 1969-70 and 2002-03 seasons that burned areas of 40 million, 45 million and 38 million hectares (99 million, 110 million and 94 million acres), respectively. That climate change wasn’t the cause should be obvious from the fact that the 1968-69 and 1969-70 fires occurred during a 30-year period of global cooling from 1940 to 1970.

Despite the ignorance and politically charged rhetoric of alarmists, the primary cause of all these terrible fires in Australia has been the lack of intentional or prescribed burning. The practice was used by the native Aboriginal population for as long as 50,000 years before early settlers abandoned it after trying unsuccessfully to copy indigenous fire techniques – lighting fires so hot that flammable undergrowth, the main target of prescribed burns, actually germinated more after burning.

The Aboriginals, like native people everywhere, had a deep knowledge of the land. They knew what types of fires to burn for different types of terrain, how long to burn, and how frequently. This knowledge enabled them to keep potential wildfire fuel such as undergrowth and certain grasses in check, thereby avoiding the more intense and devastating bushfires of the modern era. As the Aboriginals found, small-scale fires can be a natural part of forest ecology.

Only recently has the idea of controlled burning been revived in Australia and the U.S., though the approach has been practiced in Europe for many years. Direct evidence of the efficacy of controlled burning is presented in the figure below, which shows how bushfires in Western Australia expanded significantly as prescribed burning was suppressed over the 50 years from 1963 to 2013.

Bushfires have always been a feature of life in Australia. One of the earliest recorded outbreaks was the so-called Black Thursday bushfires of 1851, when then record-high temperatures up to 47.2 degrees Celsius (117 degrees Fahrenheit) and strong winds exacerbated fires that burned 5 million hectares (12 million acres), killed 12 people and terrified the young colony of Victoria. The deadliest fires of all time were the Black Saturday bushfires of 2009, also in Victoria, with 173 fatalities.    

Pictures of charred koala bears, homes engulfed in towering flames and residents seeking refuge on beaches are disturbing. But there’s simply no evidence for the recent statement in Time magazine by Malcolm Turnbull, former Australian Prime Minister, that “Australia’s fires this summer – unprecedented in the scale of their destruction – are the ferocious but inevitable reality of global warming.” Turnbull and climate alarmists should know better than to blame wildfires on this popular but erroneous belief.

Next: The Futility of Action to Combat Climate Change: (1) Scientific and Engineering Reality

No Evidence That Snow Is Disappearing

“Let It Snow! Let It Snow! Let It Snow!”

- 1945 Christmas song

You wouldn’t know it from mainstream media coverage but, far from disappearing, annual global snowfall is actually becoming heavier as the world warms. This is precisely the opposite of what climate change alarmists predicted as the global warming narrative took shape decades ago.

The prediction of less snowy winters was based on the simplistic notion that a higher atmospheric temperature would allow fewer snowflakes to form and keep less of the pearly white powder frozen on the ground. But, as any meteorologist will tell you, the crucial ingredient for snow formation, apart from near-freezing temperatures, is moisture in the air. Because warmer air can hold more water vapor, global warming in general produces more snow when the temperature drops.

This observation has been substantiated multiple times in recent years, in the Americas, Europe and Asia. As just one example, the eastern U.S. has experienced 29 high-impact winter snowstorms in the 10 years from 2009 though 2018. There were never more than 10 in any prior 10-year period.

The overall winter snow extent in the U.S. and Canada combined is illustrated in the figure below, which shows the monthly extent, averaged over the winter, from 1967 to 2019. Clearly, total snow cover is increasing, not diminishing.

In the winter of 2009-10, record snowfall blanketed the entire mid-Atlantic coast of the U.S. in an event called Snowmaggedon, contributing to the record total for 2010 in the figure above. The winter of 2013-14 was the coldest and snowiest since the 1800s in parts of the Great Lakes. Further north in Canada, following an exceptionally cold winter in 2014-15, the lower mainland of British Columbia endured the longest cold snap in 32 years during the winter of 2016-17. That same winter saw record heavy Canadian snowfalls, in both British Columbia in the west and the maritime provinces in the east. 

The trend toward snowier winters is reflected in the number of North American blizzards over the same period, depicted in the next figure. Once again, it’s obvious that snow and harsh conditions have been on the rise for decades, especially as the globe warmed from the 1970s until 1998.  

But truckloads of snow haven’t fallen only in North America. The average monthly winter snow extent for the whole Northern Hemisphere from 1967 to 2019, illustrated in the following figure, shows a trend identical to that for North America.

Specific examples include abnormally chilly temperatures in southern China in January 2016, accompanying the first snow in Guangzhou since 1967 and the first in nearby Nanning since 1983. Extremely heavy snow that fell in the Panjshir Valley of Afghanistan in February 2015 killed over 200 people. During the winters of 2011-12 and 2012-13, much of central and eastern Europe experienced very cold and snowy weather, as they did once more in the winter of 2017-18. Eastern Ireland had its heaviest snowfalls for more than 50 years with totals exceeding 50 cm (20 inches).

Despite all this evidence, numerous claims have been made that snow is a thing of the past. “Children just aren’t going to know what snow is,” opined a research scientist at the CRU (Climatic Research Unit) of the UK’s University of East Anglia back in 2000. But, while winter snow is melting more rapidly in the spring and there’s less winter snow in some high mountain areas, the IPCC (Intergovernmental Panel on Climate Change) and WMO (World Meteorological Organization) have both been forced to concede that it’s now snowing more heavily at low altitudes than previously. Surprisingly, the WMO has even attributed the phenomenon to natural variability – as it should.

The IPCC and WMO, together with climate alarmists, are fond of using the term “unprecedented” to describe extreme weather events. As we’ve seen in previous blog posts, such usage is completely unjustified in every case – with the single exception of snowfall, though that’s a concession few alarmists make.

Next: When Science Is Literally under Attack: Ad Hominem Attacks

No Evidence That Marine Heat Waves Are Unusual

A new wrinkle in the narrative of human-induced global warming is the observation and study of marine heat waves. But, just as in other areas of climate science, the IPCC (Intergovernmental Panel on Climate Change) twists and hypes the evidence to boost the claim that heat waves at sea are becoming more common.

Marine heat waves describe extended periods of abnormally high ocean temperatures, just like atmospheric heat waves on land. The most publicized recent example was the “Blob,” a massive pool of warm water that formed in the northeast Pacific Ocean from 2013 to 2015, extending all the way from Alaska to the Baja Peninsula in Mexico as shown in the figure below, and up to 400 meters (1,300 feet) deep. Sea surface temperatures across the Blob averaged 3 degrees Celsius (5 degrees Fahrenheit) above normal. A similar temperature spike lasting for eight months was seen in Australia’s Tasman Sea in 2015 and 2016.

Recent Marine Heat Waves

The phenomenon has major effects on marine organisms and ecosystems, causing bleaching of coral reefs or loss of kelp forests, for example. Shellfish and small marine mammals such as sea lions and sea otters are particularly vulnerable, because the higher temperatures deplete the supply of plankton at the base of the ocean food chain. And toxic algae blooms can harm fish and larger marine animals.

Larger marine heat waves not only affect maritime life, but may also influence weather conditions on nearby land. The Blob is thought to have worsened California’s drought at the time, while the Tasman Sea event may have led to flooding in northeast Tasmania. The IPCC expresses only low confidence in such connections, however.   

Nevertheless, in its recent Special Report on the Ocean and Cryosphere in a Changing Climate, the IPCC puts its clout behind the assertion that marine heat waves doubled in frequency from 1982 to 2016, and that they have also become longer-lasting, more intense and more extensive. But these are false claims, for two reasons.

First, the observations supporting the claims were all made during the satellite era. Satellite measurements of ocean temperature are far more accurate and broader in coverage than measurements made by the old-fashioned methods that preceded satellite data. These cruder methods included placing a thermometer in seawater collected in wooden, canvas or insulated buckets tossed overboard from ships and hauled back on deck, or in seawater retained in ship engine-room inlets from several different depths; and data from moored or drifting buoys.

Because of the unreliability and sparseness of sea surface temperature data from the pre-satellite era, it’s obvious that earlier marine heat waves may well have been missed. Indeed, it would be surprising if no significant marine heat waves occurred during the period of record-high atmospheric temperatures of the 1930s, a topic discussed in a previous blog post.

The second reason the IPCC claims are spurious is that most of the reported studies (see for example, here and here) fail to take into account the overall ocean warming trend. Marine heat waves are generally measured relative to the average surface temperature over a 30-year baseline period. This means that any heat wave measured toward the end of that period will appear hotter than it really is, since the actual surface temperature at that time will be higher than the 30-year baseline. As pointed out by a NOAA (U.S. National Oceanic and Atmospheric Administration) scientist, not adjusting for the underlying warming falsely conflates natural regional variability with climate change.  

Even if the shortcomings of the data are ignored, it’s been found that from 1925 to 2016, the global average marine heatwave frequency and duration increased by only 34% and 17%, respectively – hardly dramatic increases. And in any case, the sample size for observations made since satellite observations began in 1982 is statistically small.

There’s no evidence, therefore, that marine heat waves are anything out of the ordinary.

Next: No Evidence That Snow Is Disappearing

Ocean Acidification: No Evidence of Impending Harm to Sea Life

Apocalyptic warnings about the effect of global warming on the oceans now embrace ocean acidification as well as sea level rise and ocean heating, both of which I’ve examined in previous posts. Acidification is a potential issue because the oceans absorb up to 30% of our CO₂ emissions, according to the UN’s IPCC (Intergovernmental Panel on Climate Change). The extra CO₂ increases the acidity of seawater.

But there’s no sign that any of the multitude of ocean inhabitants is suffering from the slightly more acidic conditions, although some species are affected by the warming itself. The average pH – a measure of acidity – of ocean surface water is currently falling by only 0.02 to 0.03 pH units per decade, and has dropped by only 0.1 pH units over the whole period since industrialization and CO₂ emissions began in the 18th century. These almost imperceptible changes pale in comparison with the natural worldwide variation in ocean pH, which ranges from a low of 7.8 in coastal waters to a high of 8.4 in upper latitudes.

The pH scale sets 7.0 as the neutral value, with lower values being acidic and higher values alkaline. It’s a logarithmic scale, so a change of 1 pH unit represents a 10-fold change in acidity. A decrease of 0.1 units, representing a 26% increase in acidity, still leaves the ocean pH well within the alkaline range.    

The primary concern with ocean acidification is its effect on marine creatures – such as corals, some plankton, and shellfish – that form skeletons and shells made from calcium carbonate. The dissolution of CO₂ in seawater produces carbonic acid (H₂CO₃), which in turn produces hydrogen ions (H⁺) that eat up any carbonate ions (CO₃^2-) that were already present, depleting the supply of carbonate available to calcifying organisms, such as mussels and krill, for shell building.

Yet the wide range of pH values in which sea animals and plants thrive tells us that fears about acidification from climate change are unfounded. The figure below shows how much the ocean pH varies even at the same location over the period of one month, and often within a single day.

In the Santa Barbara kelp forest (F in the figure), for example, the pH fluctuates by 0.5 units, a change in acidity of more than 200%, over 13 days; the mean variation in the Elkhorn Slough estuary (D) is a full pH unit, or a staggering 900% change in acidity, per day. Likewise, coral reefs (E) can withstand relatively large fluctuations in acidity: the pH of seawater in the open ocean can vary by 0.1 to 0.2 units daily, and by as much as 0.5 units seasonally, from summer to winter.

A 2011 study of coral formation in Papua New Guinea at underwater volcanic vents that exude CO₂ found that coral reef formation ceased at pH values less than 7.7, which is 0.5 units below the pre-industrial ocean surface average of 8.2 units and 216% more acidic. However, at the present rate of pH decline, that point won’t be reached for at least another 130 to 200 years. In any case, there’s empirical evidence that existing corals are hardy enough to survive even lower pH values.

Australia’s Great Barrier Reef periodically endures surges of pronouncedly acid rainwater at the low pH of about 5.6 that pours onto the Reef from flooding of the Brisbane River, which has occurred 11 times since 1840. But the delicate corals have withstood the onslaught each time. And there have been several epochs in the distant past when the CO₂ level in the atmosphere was much higher than now, yet marine species that calcify were able to persist for millions of years.

Nonetheless, advocates of the climate change narrative insist that marine animals and plants are headed for extinction if the CO₂ level continues to rise, supposedly because of reduced fertility and growth rates. However, there’s a paucity of research conducted under realistic conditions that accurately simulates the actual environment of marine organisms. Acidification studies often fail to provide the organisms with a period of acclimation to lowered seawater pH, as they would experience in their natural surroundings, and ignore the chemical buffering effect of neighboring organisms on acidification.

Ocean acidification, often regarded as the evil twin of global warming, is far less of a threat to marine life than overfishing and pollution. In Shakespeare’s immortal words, the uproar over acidification is much ado about nothing.

Next: No Evidence That Marine Heat Waves Are Unusual

Ocean Heating: How the IPCC Distorts the Evidence

Part of the drumbeat accompanying the narrative of catastrophic human-caused warming involves hyping or distorting the supposed evidence, as I’ve demonstrated in recent posts on ice sheets, sea ice, sea levels and extreme weather. Another gauge of a warming climate is the amount of heat stashed away in the oceans. Here too, the IPCC (Intergovernmental Panel on Climate Change) and alarmist climate scientists bend the truth to bolster the narrative.

Perhaps the most egregious example comes from the IPCC itself. In its 2019 Special Report on the Ocean and Cryosphere in a Changing Climate, the IPCC declares that the world’s oceans have warmed unabated since 2005, and that the rate of ocean heating has accelerated – despite contrary evidence for both assertions presented in the very same report! It appears that catastrophists within the IPCC are putting a totally unjustified spin on the actual data.

Argo float being deployed.

Ocean heat, known technically as OHC (ocean heat content), is currently calculated from observations made by Argo profiling floats. These floats are battery-powered robotic buoys that patrol the oceans, sinking 1-2 km (0.6-1.2 miles) deep once every 10 days and then bobbing up to the surface, recording the temperature and salinity of the water as they ascend. When the floats eventually reach the surface, the data is transmitted to a satellite. Before the Argo system was deployed in the early 2000s, OHC data was obtained from older types of instrument.

The table below shows empirical data documented in the IPCC report, for the rate of ocean heating (heat uptake) over various intervals from 1969 to 2017, in two ocean layers: an upper layer down to a depth of 700 meters (2,300 feet), and a deeper layer from 700 meters down to 2,000 meters (6,600 feet). The data is presented in alternative forms: as the total heat energy absorbed by the global ocean yearly, measured in zettajoules (10²¹ joules), and as the rate of areal heating over the earth’s surface, measured in watts (1 watt = 1 joule per second) over one square meter.

Examination of the data in either form reveals clearly that in the upper, surface layer, the oceans heated less rapidly during the second half of the interval between 1993 and 2017, that is from 2005 to 2017, than during the first half from 1993 to 2005.

The same is true for the two layers combined, that is for all depths from the surface down to 2,000 meters (6,600 feet). When the two lines in the table above are added together, the combined layer heating rate was 9.33 zettajoules per year or 0.58 watts per square meter from 2005 to 2017, and 10.14 zettajoules per year or 0.63 watts per square meter from 1993 to 2017. Although these numbers ignore the large uncertainties in the measurements, they demonstrate that the ocean heating rate fell between 1993 and 2017.

Yet the IPCC has the audacity to state in the same report that “It is likely that the rate of ocean warming has increased since 1993,” even while correctly recognizing that the present heating rate is higher than it was back in 1969 or 1970. That the heating rate has not increased since 1993 can also be seen in the following figure, again from the same IPCC report.

Ocean Heat Content 1995-2017

The light and dark green bands in the figure show the change in OHC, measured in zettajoules, from the surface down to 2,000 meters (6,600 feet), relative to its average value between 2000 and 2010, over the period from 1995 to 2017. It’s obvious that the ocean heating rate – characterized by the slope of the graph – slowed down over this period, especially from 2003 to about 2008 when ocean heating appears to have stopped altogether. Both the IPCC’s table and figure in the report completely contradict its conclusions.

This contradiction is important not only because it reveals how the IPCC is a blatantly political more than a scientific organization, but also because OHC science has already been tarnished by the publication and subsequent retraction of a 2018 research paper claiming that ocean heating had reached the absurdly high rate of 0.83 watts per square meter.

If true, the claim would have meant that the climate is much more sensitive to CO₂ emissions than previously thought – a finding the mainstream media immediately pounced on. But mathematician Nic Lewis quickly discovered that the researchers had miscalculated the ocean warming trend, as well as underestimating the uncertainty of their result in the retracted paper. Lewis has also uncovered errors in a 2019 paper on ocean heating.

In a recent letter to the IPCC, the Global Warming Policy Foundation has pointed out the errors and misinterpretations in both the 2018 and 2019 papers, as well as in the IPCC report discussed above. There’s been no response to date.

Next: Ocean Acidification: No Evidence of Impending Harm to Sea Life

No Convincing Evidence That Greenland Ice Sheet Is Melting Rapidly

When Greenland’s ice sheet lost an estimated 11.3 billion tonnes (12.5 billion tons) of ice on a single warm day this August, following back-to-back heat waves in June and July in western Europe, the climate doomsday machine went into overdrive. Predictions abounded of ever-accelerating melting of both Greenland and Antarctic ice sheets, and the imminent drowning of cities such as London and Miami by rising seas.

But all this hype is unnecessary fear-mongering. As discussed in the previous post, the massive Antarctic ice sheet may not be melting at all as the world warms. And the much smaller Greenland ice sheet isn’t melting any faster on average now than it was 15 years ago. While this year’s summer melt was above average, it was no more than seen seven years before, in 2012.

Melting takes place only during the short Greenland summer, the meltwater running over the ice sheet surface into the ocean, as well as funneling its way down through thick glaciers, helping speed up their flow toward the sea. Although some of the ice lost in summer is normally ice gained over the long winter from the accumulation of compacted snow, last winter’s low snowfall quickly disappeared this year in an early start to the melt season.   

The figure to the left shows that at the peak of the 2019 event, over 60% of the ice sheet surface melted; on July 30 and 31, NOAA (the U.S. National Oceanic and Atmospheric Administration) reported that even the very highest point of the ice sheet liquefied briefly – a rare occurrence. The ice sheet, 2-3 km (6,600-9,800 feet) thick, consists of layers of compressed snow built up over at least hundreds of thousands of years. In addition to summer melting, the sheet loses ice by calving of icebergs at its edges.

The figure below depicts the daily variation, over a full year, of the estimated mass of ice in the Greenland ice sheet, relative to its average value from 1981 to 2010. The loss of ice during the summer months of June, July and August is clearly visible, the biggest recent losses having occurred in 2012 and 2019.

This year’s total ice loss has been estimated at 329 billion tonnes (363 billion tons), somewhat lower than the record 458 billion tonnes (505 billion tons) that melted in 2012. Despite the high 2012 loss, however, the average loss from 2012 through 2016 of 247 billion tonnes (272 billion tons) per year was essentially the same as the 2002 through 2011 average loss of 263 billion tonnes (290 billion tons) per year, according to the IPCC (Intergovernmental Panel on Climate Change).

So, while the average annual loss of 258 billion tonnes (284 billion tons) between 2002 and 2016 is a big jump from the average 75 billion tonnes (83 billion tons) of ice lost yearly during the 20th century, it appears that the Greenland ice sheet has at least stabilized since 2002. The 21st-century increase in summer melt rate may arise partly from dominance of the negative phase of the natural North Atlantic Oscillation since about 2000.

Little known about Greenland is that the ice sheet was smaller than it is today over most of the period since the end of the last ice age. During the long interglacial epoch, as human civilization developed and thrived, there were several periods when it was warmer on average in Greenland than at present, as illustrated in the next figure. This has been deduced by analyzing ice cores extracted from the Greenland ice sheet; the cores carry a record of past temperatures and atmospheric composition. 

One of the warm spells was the Medieval Warm Period, an era when Scandinavian Vikings colonized Greenland – growing crops, raising animals and hunting seals for meat and walruses for ivory. The Vikings are thought to have abandoned the island after temperatures dropped with the onset of the Little Ice Age. But there’s little doubt that what made it possible for the Vikings to settle in Greenland at all were a relatively hospitable climate and less ice than exists today.

To put everything in perspective, the present ice loss of 247 billion tonnes (272 billion tons) every year represents only about 0.01% of the total mass of the ice sheet. At the current rate, therefore, it would take another 10,000 years for all Greenland’s ice to melt.

Next: Ocean Warming: How the IPCC Distorts the Evidence

No Convincing Evidence That Antarctic Ice Sheet Is Melting

Of all the observations behind mass hysteria over our climate, none induces as much panic as melting of the earth’s two biggest ice sheets, covering the polar landmasses of Antarctica and Greenland. As long ago as 2006, Al Gore’s environmental documentary “An Inconvenient Truth” proclaimed that global warming would melt enough ice to cause a 6-meter (20-foot) rise in sea level “in the near future.” Today, every calving of a large iceberg from an ice shelf or glacier whips the mainstream media into a frenzy.

The huge Antarctic ice sheet alone would raise global sea levels by about 60 meters (200 feet) were it to melt completely. But there’s little evidence that the kilometers-thick ice sheet, which contains about 90% of the world’s freshwater ice, is melting at all.

Any calving of large icebergs – a natural process unrelated to warming – from an ice shelf, or even disintegration into small icebergs, barely affects sea level. This is because the ice that breaks off was already floating on the ocean. Although a retreating ice shelf can contribute to sea level rise by accelerating the downhill flow of glaciers that feed the shelf, current breakups of Antarctic ice shelves are adding no more than about 0.1 mm (about 4/1000ths of an inch) per year to global sea levels, according to NOAA (the U.S. National Oceanic and Atmospheric Administration).

Global warming has certainly affected Antarctica, though not by as much as the Arctic. East Antarctica, by far the largest region that covers two thirds of the continent, heated up by only 0.06 degrees Celsius (0.11 degrees Fahrenheit) per decade between 1958 and 2012. At the South Pole, which is located in East Antarctica, temperatures actually fell in recent decades.

For comparison, global temperatures over this period rose by 0.11 degrees Celsius (0.20 degrees Fahrenheit) per decade, and Arctic temperatures shot up at an even higher rate. Antarctic warming from 1958 to 2012 is illustrated in the figure below, based on NOAA data. East Antarctica is to the right, West Antarctica to the left of the figure.

You can see, however, that temperatures in West Antarctica and the small Antarctic Peninsula, which points toward Argentina, increased more rapidly than in East Antarctica, by 0.22 degrees Celsius (0.40 degrees Fahrenheit) and 0.33 degrees Celsius (0.59 degrees Fahrenheit) per decade, respectively – faster than the global average. Still, the Peninsula has cooled since 2000.

It’s not surprising, therefore, that all the hype about imminent collapse of the Antarctic ice sheet centers on events in West Antarctica, such as glaciers melting at rapid rates. The Fifth Assessment Report of the UN’s IPCC (Intergovernmental Panel on Climate Change) maintained with high confidence that, between 2005 and 2010, the ice sheet was shedding mass and causing sea levels to rise by 0.41 mm per year, contributing about 24% of the measured rate of 1.7 mm (1/16th of an inch) per year between 1900 and 2010.

On the other hand, a 2015 NASA study reported that the Antarctic ice sheet was actually gaining rather than losing ice in 2008, and that ice thickening was making sea levels fall by 0.23 mm per year. The study authors found that the ice loss from thinning glaciers in West Antarctica and the Antarctic Peninsula was currently outweighed by new ice formation in East Antarctica resulting from warming-enhanced snowfall. Across the continent, Antarctica averages roughly  5 cm (2 inches) of precipitation per year. The same authors say that the trend has continued until at least 2018, despite a recent research paper by an international group of polar scientists endorsing the IPCC human-caused global warming narrative of diminishing Antarctic ice.

The two studies are both based on satellite altimetry – the same method used to measure sea levels, but in this case measuring the height of the ice sheet. Both studies also depend on models to correct the raw data for factors such as snowdrift, ice compaction and motion of the underlying bedrock. It’s differences in the models that give rise to the diametrically opposite results of the studies, one finding that Antarctic ice is melting away but the other concluding that it’s really growing.

Such uncertainty, even in the satellite era, shouldn’t be surprising. Despite the insistence of many climate scientists that theirs is a mature field of research, much of today’s climate science is dependent on models to interpret the empirical observations. The models, just like computer climate models, aren’t always good representations of reality.

Al Gore’s 6-meter (20-foot) rise hasn’t happened yet, and isn’t likely to happen even by the end of this century. Global panic over the impending meltdown of Antarctica is totally unwarranted.

(This post has also been kindly reproduced in full on the Climate Depot blog.)

Next: No Convincing Evidence That Greenland Ice Sheet Is Melting Rapidly

Shrinking Sea Ice: Evaluation of the Evidence

Most of us know about the loss of sea ice in the Arctic due to global warming. The dramatic reduction in summer ice cover, which has continued for almost 40 years, is frequently hyped by the mainstream media and climate activists as an example of what we’re supposedly doing to the planet.

But the loss is nowhere near as much as predicted, and in fact was no more in the summer of 2019 than in 2007. Also, it’s little known that Arctic sea ice has melted before during the record heat of the 1930s. And the sea ice around Antarctica, at the other end of the globe, has been expanding since at least 1979.

Actual scientific observations of sea ice in the Arctic and Antarctic have only been possible since satellite measurements began in 1979. The figure below shows satellite-derived images of Arctic sea ice extent in the summer of 1979 (left image), and the summer (September) and winter (March) of 2018 (right image). Sea ice expands to its maximum extent during the winter and shrinks during summer months.   

Arctic summer ice extent decreased by approximately 33% over the interval from 1979 to 2018; while it still encases northern Greenland, it no longer reaches the Russian coast.

However, there has been no net ice loss since 2007, with the year-to-year minimum extents fluctuating around a plateau. An exception was 2012, when a powerful August storm known as the Great Arctic Cyclone tore off a large chunk of ice from the main sea ice pack. Clearly, the evidence refutes numerous prognostications by advocates of catastrophic human-caused warming that Arctic ice would be completely gone by 2016. 

Before 1979, the only data available on Arctic sea ice are scattered observations from sources such as ship reports, aircraft reconnaissance and drifting buoys – observations recorded and synthesized by the Danish Meteorological Institute and the Russian Arctic and Antarctic Research Institute. Analyses of this spotty data have resulted in numerous reconstructions of Arctic sea ice extent in the pre-satellite era.

One such recent reconstruction is shown in the next figure, depicting reconstructed Arctic summer ice area, in millions of square kilometers, from 1900 to 2013. The reconstruction was based on the strong correlation of Arctic sea ice extent with Arctic air temperatures during the satellite era, especially in the summer, a correlation assumed to be the same in earlier years as well. This assumption then enabled the researchers to reconstruct the sea ice area before 1979 from observed temperatures in that era.  

What this graph reveals is that summer ice cover in the Arctic, apart from its present decline since about 1979, contracted previously in the 1920s and 1930s. According to the researchers, the biggest single-year decrease in area, which occurred in 1936, was about 26% – not much less than the 33% drop by 2018. Although this suggests that the relatively low sea ice extents in recent years are comparable to the 1930s, the reconstruction doesn’t incorporate any actual pre-satellite observations. Other reconstructions that do incorporate the earlier data show a smaller difference between the 1930s and today.

It’s the opposite story for sea ice in the Antarctic, which is at its lowest extent during the southern summer in February, as shown in the satellite-derived image below for 2018-19.

Despite the contraction in the Arctic, the sea ice around Antarctica has been expanding during the satellite era. As can be seen from the following figure, Antarctic sea ice has gained in extent by an average of 1.8% per decade (the dashed line represents the trend), though the ice extent fluctuates greatly from year to year. Antarctic sea ice covers a larger area than Arctic ice but occupies a smaller overall volume, because it’s only about half as thick.

Another fallacious claim about disappearing sea ice in the Arctic, one that has captured the public imagination like no other, is that the polar bear population is diminishing along with the ice. But, while this may yet happen in the future, current evidence shows that the bear population has been stable for the whole period that the ice has been decreasing and may even be growing, according to the native Inuit.

In summary, Arctic sea ice shrank from about 1979 to 2007 because of global warming, but has remained at the same extent on average in the 12 years since then, while Antarctic sea ice has expanded slightly over the whole period. So there’s certainly no cause for alarm.

Next: No Convincing Evidence That Antarctic Ice Sheet is Melting

No Evidence That Climate Change Is Accelerating Sea Level Rise

Malé, Maldives Capital City

By far the most publicized phenomenon cited as evidence for human-induced climate change is rising sea levels, with the media regularly trumpeting the latest prediction of the oceans flooding or submerging cities in the decades to come. Nothing instills as much fear in low-lying coastal communities as the prospect of losing one’s dwelling to a hurricane storm surge or even slowly encroaching seawater. Island nations such as the Maldives in the Indian Ocean and Tuvalu in the Pacific are convinced their tropical paradises are about to disappear beneath the waves.

There’s no doubt that the average global sea level has been increasing ever since the world started to warm after the Little Ice Age ended around 1850. But there’s no reliable scientific evidence that the rate of rise is accelerating, or that the rise is associated with any human contribution to global warming.   

A comprehensive 2018 report on sea level and climate change by Judith Curry, a respected climate scientist and global warming skeptic, emphasizes the complexity of both measuring and trying to understand recent sea level rise. Because of the switch in 1993 from tide gauges to satellite altimetry as the principal method of measurement, the precise magnitude of sea level rise as well as projections for the future are uncertain.

According to both Curry and the UN’s IPCC (Intergovernmental Panel on Climate Change), the average global rate of sea level rise from 1901 to 2010 was 1.7 mm (about 1/16th of an inch) per year. In the latter part of that period from 1993 onward, the rate of rise was 3.2 mm per year, almost double the average rate – though this estimate is considered too high by some experts. But, while the sudden jump may seem surprising and indicative of acceleration, the fact is that the globally averaged sea level fluctuates considerably over time. This is illustrated in the IPCC’s figure below, which shows estimates from tide gauge data of the rate of rise from 1900 to 1993.

It’s clear that the rate of rise was much higher than its 20th century average during the 30 years from 1920 to 1950, and much lower than the average from 1910 to 1920 and again from 1955 to 1980. Strong regional differences exist too. Actual rates of sea level rise range from negative in Stockholm, corresponding to a falling sea level, as that region continues to rebound after melting of the last ice age’s heavy ice sheet, to positive rates three times higher than average in the western Pacific Ocean.

The regional variation is evident in the next figure, showing the average rate of sea level rise across the globe, measured by satellite, between 1993 and 2014.

You can see that during this period sea levels increased fastest in the western Pacific as just noted, and in the southern Indian and Atlantic Oceans. At the same time, the sea level fell near the west coast of North America and in the Southern Ocean near Antarctica.

The reasons for such a jumbled picture are several. Because water expands and occupies more volume as it gets warmer, higher ocean temperatures raise sea levels. Yet the seafloor is not static and can sink under the weight of the extra water in the ocean basin that comes from melting glaciers and ice caps, and can be altered by underwater volcanic eruptions. Land surfaces can also sink (as well as rebound), as a result of groundwater depletion in arid regions or landfilling in coastal wetlands. For example, about 50% of the much hyped worsening of tidal flooding in Miami Beach, Florida is due to sinking of reclaimed swampland.

Historically, sea levels have been both lower and higher in the past than at present. Since the end of the last ice age, the average level has risen about 120 meters (400 feet), as depicted in the following figure. After it reached a peak in at least some regions about 6,000 years ago, however, the sea level has changed relatively little, even when industrialization began boosting atmospheric CO₂. Over the 20th century, the worldwide average rise was about 15-18 cm (6-7 inches).

That the concerns of islanders are unwarranted despite rising seas is borne out by recent studies revealing that low-lying coral reef islands in the Pacific are actually growing in size by as much as 30% per century, and not shrinking. The growth is due to a combination of coral debris buildup, land reclamation and sedimentation. Another study found that the Maldives -- the world's lowest country -- formed when sea levels were even higher than they are today. Studies such as these belie the popular claim that islanders will become “climate refugees,” forced to leave their homes as sea levels rise.

Next: Shrinking Sea Ice: Evaluation of the Evidence

No Evidence That Heat Kills More People than Cold

The irony in the recent frenzy over heat waves is that many more humans die each year from cold than they do from heat. But you wouldn’t know that from sensational media headlines reporting “killer” heat waves and conditions “as hot as hell.” In reality, cold weather worldwide kills 17 times as many people as heat.

This conclusion was reached by a major international study in 2015, published in the prestigious medical journal The Lancet. The study analyzed more than 74 million deaths in 384 locations across 13 countries including Australia, China, Italy, Sweden, the UK and USA, over the period from 1985 to 2012. The results are illustrated in the figure below, showing the average daily rate of premature deaths from heat or cold as a percentage of all deaths, by country.

Perhaps not surprisingly, moderate cold kills people far more often than extreme cold, for a wide range of different climates. Extreme cold was defined by the study authors as temperatures falling below the 2.5th percentile at each location, a limit which varied from as low as -11 degrees Celsius (12 degrees Fahrenheit) in Toronto, Canada to as high as 25 degrees Celsius (77 degrees Fahrenheit) in Bangkok, Thailand. Moderate cold includes all temperatures from this lower limit up to the so-called optimum, the temperature at which the daily death rate at that location is a minimum.

Likewise, extreme heat was defined as temperatures above the 97.5th percentile at each location, and moderate heat as temperatures from the optimum up to the 97.5th percentile. But unlike cold, extreme and moderate heat cause approximately equal numbers of excess deaths.

The study found that on average, 7.71% of all deaths could be attributed to hot or cold – to temperatures above or below the optimum – with 7.29% being due to cold, but only 0.42% due to heat. That single result puts the lie to the popular belief that heat waves are deadlier than cold spells. Hypothermia kills a lot more of us than heat stroke. And though both high and low temperatures can increase the risk of exacerbating cardiovascular, respiratory and other conditions, it’s cold that is the big killer.

This finding is further borne out by seasonal mortality statistics. France, for instance, recorded 700 excess deaths attributed to heat in the summer of 2016, 475 in 2017 and 1,500 in 2018. Yet excess deaths from cold in the French winter from December to March average approximately 24,000. Even the devastating summer heat wave of 2003 claimed only 15,000 lives in France.

Similar statistics come from the UK, where an average of 32,000 more deaths occur during each December to March period than in any other four-month interval of the year. Flu epidemics boosted this total to 37,000 in the winter of 2016-17, and to 50,000 in 2017-18. Just as in France, these numbers for deaths from winter cold far exceed summer mortalities in the UK due to heat, which reached only 1,700 in 2018 and just 2,200 in the heat-wave year of 2003.

Even more evidence that cold kills a lot more people than heat is seen in an earlier study, published in the BMJ (formerly the British Medical Journal) in 2000. This study, restricted to approximately 3 million deaths in western Europe from 1988 to 1992, found that annual cold related deaths were much higher than heat related deaths in all seven regions studied – with the former averaging 2,000 per million people and the latter only 220 per million. Additionally, no more deaths from heat occurred in hotter regions than colder ones.

A sophisticated statistical approach was necessary in both studies. This is because of differences between regions and individuals, and the observation that, while death from heat is typically rapid and occurs within a few days, death from cold can be delayed up to three or four weeks. The larger Lancet study used more advanced statistical modeling than the BMJ study.

And despite the finding that more than 50% of published papers in biomedicine are not reproducible, the fact that two independent papers reached essentially the same result gives their conclusions some credibility.

Next: No Evidence That Climate Change Is Accelerating Sea Level Rise

No Evidence That Climate Change Causes Weather Extremes: (6) Heat Waves

This Northern Hemisphere summer has seen searing, supposedly record high temperatures in France and elsewhere in Europe. According to the mainstream media and climate alarmists, the heat waves are unprecedented and a harbinger of harsh, scorching hot times to come.

But this is absolute nonsense. In this sixth and final post in the present series, I’ll examine the delusional beliefs that the earth is burning up and may shortly be uninhabitable, and that this is all a result of human-caused climate change. Heat waves are no more linked to climate change than any of the other weather extremes we’ve looked at.

The brouhaha over two almost back-to-back heat waves in western Europe is a case in point. In the second, which occurred toward the end of July, the WMO (World Meteorological Organization) claimed that the mercury in Paris reached a new record high of 42.6 degrees Celsius (108.7 degrees Fahrenheit) on July 25, besting the previous record of 40.4 degrees Celsius (104.7 degrees Fahrenheit) set back in July, 1947. And a month earlier during the first heat wave, temperatures in southern France hit a purported record 46.0 degrees Celsius (114.8 degrees Fahrenheit) on June 28.

How convenient to ignore the past! Reported in Australian and New Zealand newspapers from August, 1930 is an account of an earlier French heatwave, in which the temperature soared to a staggering 50 degrees Celsius (122 degrees Fahrenheit) in the Loire valley, located in central France. That’s a full 4.0 degrees Celsius (7.2 degrees Fahrenheit) above the so-called record just mentioned in southern France, where the temperature in 1930 may well have equaled or exceeded the Loire valley’s towering record.

And the same newspaper articles reported a temperature in Paris that day of 38 degrees Celsius (100 degrees Fahrenheit), stating that back in 1870 the thermometer had reached an even higher, unspecified level there – quite possibly above the July 2019 “record” of 42.6 degrees Celsius (108.7 degrees Fahrenheit).    

The same duplicity can be seen in proclamations about past U.S. temperatures. Although it’s frequently claimed that heat waves are increasing in both intensity and frequency, there’s simply no scientific evidence for such a bold assertion. The following figure charts official data from NOAA (the U.S. National Oceanic and Atmospheric Administration) showing the yearly number of days, averaged over all U.S. temperature stations, from 1895 to 2018 with extreme temperatures above 38 degrees Celsius (100 degrees Fahrenheit) and 41 degrees Celsius (105 degrees Fahrenheit).

The next figure shows NOAA’s data for the year in which the record high temperature in each U.S. state occurred. Of the 50 state records, a total of 32 were set in the 1930s or earlier, but only seven since 1990.

It’s obvious from these two figures that there were more U.S. heat waves in the 1930s, and they were hotter, than in the present era of climate hysteria. Indeed, the annual number of days on which U.S. temperatures reached 100 degrees, 95 degrees or 90 degrees Fahrenheit has been steadily falling since the 1930s. The EPA (Environmental Protection Agency)’s Heat Wave Index for the 48 contiguous states also shows clearly that the 1930s were the hottest decade.

Globally, it’s exactly the same story, as depicted in the figure below.

Of the seven continents, six recorded their all-time record high temperatures before 1982, three records dating from the 1930s or before; only Asia has set a record more recently (the WMO hasn’t acknowledged the 122 degrees Fahrenheit 1930 record in the Loire region). And yet the worldwide baking of the 1930s didn’t set the stage for more and worse heat waves in the years ahead, even as CO₂ kept pouring into the atmosphere – the scenario we’re told, erroneously, that we face today. In fact, the sweltering 1930s were followed by global cooling from 1940 to 1970.

Contrary to the climate change narrative, the recent European heat waves came about not because of global warming, but rather a weather phenomenon known as jet stream blocking. Blocking results from an entirely different mechanism than the buildup of atmospheric CO₂, namely a weakening of the sun’s output that may portend a period of global cooling ahead. A less active sun generates less UV radiation, which in turn perturbs winds in the upper atmosphere, locking the jet stream in a holding or blocking pattern. In this case, blocking kept a surge of hot Sahara air in place over Europe for extended periods.

It should be clear from all the evidence presented above that mass hysteria over heat waves and climate change is completely unwarranted. Current heat waves have as little to do with global warming as floods, droughts, hurricanes, tornadoes and wildfires.

Next: No Evidence That Heat Kills More People than Cold

No Evidence That Climate Change Causes Weather Extremes: (5) Wildfires

Probably the most fearsome of the weather extremes commonly blamed on human-caused climate change are tornadoes – the previous topic in this series – and wildfires. Both can arrive with little or no warning, making it difficult or impossible to flee, are often deadly, and typically destroy hundreds of homes and other structures. But just like tornadoes, there is no scientific evidence that the frequency or severity of wildfires are on the rise in a warming world.

You wouldn’t know that, however, from the mass hysteria generated by the mainstream media and climate activists almost every time a wildfire breaks out, especially in naturally dry climates such as those in California, Australia or Spain. While it’s true that the number of acres burned annually in the U.S. has gone up over the last 20 years or so, the present burned area is still only a small fraction of what it was back in the record 1930s, as seen in the figure below, showing data compiled by the U.S. National Interagency Fire Center.

Because modern global warming was barely underway in the 1930s, climate change clearly has nothing to do with the incineration of U.S. forests. Exactly the same trend is apparent in the next figure, which depicts the estimated area worldwide burned by wildfires, by decade from 1900 to 2010. Clearly, wildfires have diminished globally as the planet has warmed.

Global Burned Area

1900-2010

In the Mediterranean, although the annual number of wildfires has more than doubled since 1980, the burned area over three decades has mimicked the global trend and declined:

Mediterranean Wildfire Occurrence & Burnt Area

1980-2010

The contrast between the Mediterranean and the U.S., where wildfires are becoming fewer but larger in area, has been attributed to different forest management policies on the two sides of the Atlantic – despite the protestations of U.S. politicians and firefighting officials in western states that climate change is responsible for the uptick in fire size. The next figure illustrates the timeline from 1600 onwards of fire occurrence at more than 800 different sites in western North America. 

Western North America Wildfire Occurrence

1600-2000

The sudden drop in wildfire occurrence around 1880 has been ascribed to the expansion of American livestock grazing in order to feed a rapidly growing population. Intensive sheep and cattle grazing after that time consumed most of the grasses that previously constituted the fuel for wildfires. This depletion of fuel, together with the firebreaks created by the constant movement of herds back and forth to water sources, and by the arrival of railroads, drastically reduced the incidence of wildfires. And once mechanical equipment for firefighting such as fire engines and aircraft became available in the 20th century, more and more emphasis was placed on wildfire prevention.

But wildfire suppression in the U.S. has led to considerable increases in forest density and the buildup of undergrowth, both of which greatly enhance the potential for bigger and sometimes hotter fires – the latter characterized by a growing number of terrifying, superhot “firenadoes” or fire whirls occasionally observed in today’s wildfires.

Intentional burning, long used by native tribes and early settlers and even advocated by some environmentalists who point out that fire is in fact a natural part of forest ecology as seen in the preceding figure, has become a thing of the past. Only now, after several devastating wildfires in California, is the idea of controlled burning being revived in the U.S. In Europe, on the other hand, prescribed burning has been supported by land managers for many years.

Combined with overgrowth, global warming does play a role by drying out vegetation and forests more rapidly than before. But there’s no evidence at all for the notion peddled by the media that climate change has amplified the impact of fires on the ecosystem, known technically as fire severity. Indeed, at least 10 published studies of forest fires in the western U.S. have found no recent trend in increasing fire severity.

You may think that the ever-rising level of CO₂ in the atmosphere would exacerbate wildfire risk, since CO₂ promotes plant growth. But at the same time, higher CO₂​ levels reduce plant transpiration, meaning that plants’ stomata or breathing pores open less, the leaves lose less water and more moisture is retained in the soil. Increased soil moisture has led to a worldwide greening of the planet.

In summary, the mistaken belief that the “new normal” of devastating wildfires around the globe is a result of climate change is not supported by the evidence. Humans, nevertheless, are the primary reason that wildfires have become larger and more destructive today. Population growth has caused more people to build in fire-prone areas, where fires are frequently sparked by an aging network of power lines and other electrical equipment. Coupled with poor forest management, this constitutes a recipe for disaster.

Next: No Evidence That Climate Change Causes Weather Extremes: (6) Heat Waves

No Evidence That Climate Change Causes Weather Extremes: (4) Tornadoes

Tornadoes are smaller and claim fewer lives than hurricanes. But the roaring twisters can be more terrifying because of their rapid formation and their ability to hurl objects such as cars, structural debris, animals and even people through the air. Nonetheless, the narrative that climate change is producing stronger and more deadly tornadoes is as fallacious as the nonexistent links between climate change and other weather extremes previously examined in this series.

Again, the UN’s IPCC (Intergovernmental Panel on Climate Change), whose assessment reports constitute the bible for the climate science community, has dismissed any connection between global warming and tornadoes. While the agency concedes that escalating temperatures and humidity may create atmospheric instability conducive to tornadoes, it also points out that other factors governing tornado formation, such as wind shear, diminish in a warming climate. In fact, declares the IPCC, the apparent increasing trend in tornadoes simply reflects their reporting by a larger number of people now living in remote areas.

A tornado is a rapidly rotating column of air, usually visible as a funnel cloud, that extends like a dagger from a parent thunderstorm to the ground. Demolishing homes and buildings in its often narrow path, it can travel many kilometers before dissipating. The most violent EF5 tornadoes attain wind speeds up to 480 km per hour (300 mph).

The U.S. endures by far the most tornadoes of any country, mostly in so-called Tornado Alley extending northward from central Texas through the Plains states. The annual incidence of all U.S. tornadoes from 1954 to 2017 is shown in the figure below. It’s obvious that no trend exists over a period that included both cooling and warming spells, with net global warming of approximately 1.1 degrees Celsius (2.0 degrees Fahrenheit) during that time.

But, as an illustration of how U.S. tornado activity can vary drastically from year to year, 13 successive days of tornado outbreaks in 2019 saw well over 400 tornadoes touch down in May, with June a close second – and this following seven quiet years ending in 2018, which was the quietest year in the entire record since 1954. The tornado surge, however, had nothing to do with climate change, but rather an unusually cold winter and spring in the West that, combined with heat from the Southeast and late rains, provided the ingredients for severe thunderstorms. 

The next figure depicts the number of strong (EF3 or greater) tornadoes observed in the U.S. each year during the same period from 1954 to 2017. Clearly, the trend is downward instead of upward; the average number of strong tornadoes annually from 1986 to 2017 was 40% less than from 1954 to 1985. Once more, global warming cannot have played a role. 

In the U.S., tornadoes cause about 80 deaths and more than 1,500 injuries per year. The deadliest episode of all time in a single day was the “tri-State” outbreak in 1925, which killed 747 people and resulted in the most damage from any tornado outbreak in U.S. history. The most ferocious tornado outbreak ever recorded, spawning a total of 30 EF4 or EF5 tornadoes, was in 1974.

Tornadoes also occur more rarely in other parts of the world such as South America and Europe. The earliest known tornado in history occurred in Ireland in 1054. The human toll from tornadoes in Bangladesh actually exceeds that in the U.S., at an estimated 179 deaths per year, partly due to the region’s high population density. It’s population growth and expansion outside urban areas that have caused the cost of property damage from tornadoes to mushroom in the last few decades, especially in the U.S.

Next: No Evidence That Climate Change Causes Weather Extremes: (5) Wildfires