No Evidence That Climate Change Causes Weather Extremes: (1) Drought

Weather extremes are a commonly cited line of evidence for human-caused climate change. Despite the UN’s IPCC (Intergovernmental Panel on Climate Change) having found little to no evidence that global warming triggers extreme weather, the mainstream media and more than a few climate scientists don’t hesitate to trumpet their beliefs to the contrary at every opportunity.

In this and subsequent blog posts, I’ll show how the quasi-religious belief linking extreme weather events to climate change is badly mistaken and at odds with the actual scientific record. We’ll start with drought.

Droughts have been a continuing feature of the earth’s climate for millennia. Although generally caused by a severe fall-off in precipitation, droughts can be aggravated by other factors such as elevated temperatures, soil erosion and overuse of available groundwater. The consequences of drought, which can be catastrophic for human and animal life, include crop failure, starvation and mass migration. A major exodus of early humans out of Africa about 135,000 years ago is thought to have been driven by drought.  

Getting a good handle on drought has only been possible since the end of the 19th century, when the instrumentation needed to measure extreme weather accurately was first developed. The most widely used gauge of dry conditions is the Palmer Drought Severity Index that measures both dryness and wetness and classifies them as “moderate”, “severe” or “extreme.” The figure below depicts the Palmer Index for the U.S. during the past century or so, for all three drought or wetness classifications combined.

What jumps out immediately is the lack of any long-term trend in either dryness or wetness in the U.S. With the exception of the 1930s Dust Bowl years, the pattern of drought (upper graph) looks boringly similar over the entire 112-year period, as does the pattern of excessive rain (lower graph).

Much the same is true for the rest of the world. The next figure illustrates two different drought indices during the period 1910-2010 for India, a country subject to parching summer heat followed by drenching monsoonal rains; negative values denote drought and positive values wetness. The two indices are a version of the Palmer Drought Severity Index (sc-PDSI, top graph), and the Standardized Precipitation Index (SPI, bottom graph). The SPI, which relies on rainfall data only, is easier to calculate than the PDSI, which depends on both rainfall and temperature. While both indices are useful, the SPI is better suited to making comparisons between different regions.

India Drought Index

1910-2010

You’ll see that the SPI in India shows no particular tendency over the 100-year period toward either dryness or wetness, though there are 20-year intervals exhibiting one of the two conditions; the apparent trend of the PDSI toward drought since 1990 is an artifact of the index. Similar records for other countries around the globe all show the same thing – no drying of the planet as a whole over more than 100 years.

Recently, the mainstream media created false alarm over drought by mindlessly broadcasting the results of a new study, purporting to demonstrate that global warming will soon result in “unprecedented drying.” By combining computer models with long-term observations, the study authors claim to have definitively connected global warming to drought.

But this claim doesn’t hold up, even in the study’s results. Although the authors were able to match warming to drought conditions during the first half of the 20th century, their efforts were a dismal failure after that. From 1950 to 1980, the “fingerprint” of human-caused global warming completely disappeared, in spite of ever-increasing CO₂ in the atmosphere. And from 1981 onward, the fingerprint was so faint that it couldn’t be distinguished from background noise. So the assertion by the authors that global warming causes drought is nothing but wishful thinking.

As further evidence that climate change isn’t exacerbating drought, the final figure below shows the Palmer Index for the U.S. since 1996. Just like the record for the period from 1900 up to 2012 illustrated in the first figure above, there is no discernible trend in either dryness or wetness. While the West and Southwest have both experienced lengthy spells of drought during this period, extreme dry conditions now appear to have abated in both Texas and California.

In summary, the scientific evidence simply doesn’t support any link between drought and climate change. The IPCC was right to express low confidence in any global-scale observed trend.

Next: No Evidence That Climate Change Causes Weather Extremes: (2) Floods

Are UFO Sightings a Threat to Science?

Credit: CoolCatGameStudio from Pixabay

Do UFO sightings threaten science? The short answer is that UFO observations don’t in themselves – as long as one separates true observations from the questionable claims of alien abduction and other supposed extraterrestrial activity on Earth.    

Unlike pseudosciences such as astrology or crystal healing, UFOs belong to the realm of science, even if we don’t know exactly what some of them are. Sightings of ethereal objects in the sky have been reported throughout recorded history, although there’s been a definite uptick since the advent of air travel in the 20th century. According to recently released records, UK wartime prime minister Winston Churchill colluded with General Dwight Eisenhower to suppress the alleged observation of a UFO by a British bomber crew toward the end of World War II, out of fear that reporting it would cause mass panic.

Since then, numerous incidents have been reported in countries across the globe, by scientists and nonscientists alike. The U.S. Air Force, which coined the term UFO, undertook a series of studies from 1947 to 1969 that included more than 12,000 claimed UFO sightings. The project concluded that the vast majority of sightings could be explained as misidentified conventional objects or natural phenomena, such as spy planes, helium balloons, clouds or meteors – or occasionally, hoaxes. Nonetheless, there was no explanation for 701 (about 6%) of the sightings investigated. 

Only in the last several months has the existence of a new U.S. program to study UFOs been disclosed, this time under the aegis of the Pentagon. Begun in 2007, the secret program apparently continues until this day, though its government funding ended in 2012. One of the few publicized incidents which was examined involved two Navy F/A-18F fighter pilots, who chased an oval object that appeared to be moving at impossibly high speeds for humans, off the coast of southern California in 2004.

Perhaps the most famous American event was the so-called Roswell incident in 1947, when an Air Force balloon designed for nuclear test monitoring crashed at a ranch near Roswell, New Mexico. The official but deceptive statement by the military that it was a high-altitude weather balloon only served to generate ever-escalating conspiracy theories about the crash. The theories postulated that the military had covered up the crash landing of an alien spacecraft, and that bodies of its extraterrestrial crew had been recovered and preserved. Over the years, details of the story became embellished to the point where more than one candidate for U.S. President promised to unlock the secret government files on Roswell.

Belief in alien activity is where UFO lore departs from science. While it’s possible that some of the small percentage of unexplained UFO sightings have been spaceships piloted by extraterrestrial beings, there’s currently no credible evidence that aliens actually exist, nor that they’ve ever visited planet Earth.

In particular, it’s belief in alien abductions that constitutes a threat to science, the hallmarks of which are empirical evidence and logic. In the U.S., the phenomenon began with the mysterious case of Betty and Barney Hill in 1961. The Hills claim to have encountered a UFO while driving home on an isolated rural road in New Hampshire, and to have been seized by humanoid figures with large eyes who took them onto their spaceship, where invasive experiments were performed on the terrified pair. Afterwards, both the Hills’ watches stopped working and they had no recollection of two hours of their bewildering drive.

Although the alien abduction narrative captured the American imagination during the next two decades, the Air Force ultimately dismissed the story and determined that the alien craft was a “natural” object. Indeed, there’s no reliable empirical evidence that any of the millions of other reported abductions have been real.  

Psychologists attribute the episodes to false memories and fantasies created by a human brain that we’re still struggling to understand. Possible physical causes of the abduction phenomenon include epilepsy, hallucinations and sleep paralysis, a condition in which a person is half-awake — conscious, though unable to move.

But while abduction stories may be entertaining, they qualify as irrational pseudoscience because they can’t be falsified. Pseudoscience is frequently based on faith in a belief, instead of scientific evidence, and makes vague and often grandiose claims that can’t be tested. One of the clear-cut ways to differentiate real science from pseudoscience is the falsifiability criterion formulated by 20th-century philosopher Sir Karl Popper: a genuine scientific theory or law must be capable in principle of being invalidated – of being disproved – by observation or experiment. That’s not possible with alien abductions, which can’t be either proved or disproved.

Next: No Evidence That Climate Change Causes Weather Extremes: (1) Drought