PJ Media

IPCC Backpedals on Extreme Weather Claims

Embarrassed by the current decade-and-a-half period without any global warming, those calling for worldwide action to halt climate change have shifted focus to worries about extreme weather events. It makes sense, of course, for alarmists to direct attention away from something that isn’t happening — global warming — towards frightening stories about something that could conceivably be occurring. Unfortunately for the alarmists — but fortunately for the rest of us — both independent scientific observations and the Intergovernmental Panel on Climate Change’s own latest report (released on Monday) make it clear that a warming of the Earth is not leading to an increase in extreme weather. In fact, the opposite seems to be the case.

As the newly released “Summary for Policymakers” of the upcoming IPCC Fifth Assessment Report indicates, the UN panel seems to be walking back many of its claims, reducing both their estimated effects of global warming and their claims of certainty regarding their predictions.

IPCC’s findings regarding extreme weather, for example, are both mundane and admittedly uncertain. For example, the summary notes:

Changes in many extreme weather and climate events have been observed since about 1950.

It would be astonishing if such changes had not occurred. The climate always changes, which no one disputes, and incidences of various types of extreme weather continually rise and fall over time. Thus the use of the ominous 1950 date — signifying the significant rise in global CO2 levels — is at best irrelevant, and in fact is quite deceptive.

The summary continues:

It is likely that the frequency of heat waves has increased in large parts of Europe, Asia and Australia. (Emphasis in original)

That’s three out of seven continents; apparently the other four are just fine. Next:

There are likely more land regions where the number of heavy precipitation events has increased than where it has decreased. The frequency or intensity of heavy precipitation events has likely increased in North America and Europe. In other continents, confidence in changes in heavy precipitation events is at most medium. (Emphasis in original)

In Table SPM.1, the summary states that the probability of further increases in warm spells/heat waves in terms of “(f)requency and/or duration increases over most land areas” in the early 21st century (the period when we will be able to observe whether the IPCC’s predictions are true) is:

Not formally assessed.

The expectation of an “(i)ncrease in the frequency, intensity, and/or amount of heavy precipitation” is declared to be “(l)ikely over many land areas.” It doesn’t specify how many such areas, indicating that they cannot claim this to be a global problem.

The summary further acknowledges “(l)ow confidence” regarding “(i)ncreases in intensity and/or duration of drought” and “(i)ncreases in intense tropical cyclone activity.”

Even this decidedly muted confidence appears to be misplaced. As Heartland Institute Senior Fellow James M. Taylor observed at Forbes.com:

Just about every type of extreme weather event is becoming less frequent and less severe in recent years as our planet continues its modest warming in the wake of the Little Ice Age.

Taylor notes that data from the National Oceanic and Atmospheric Administration showed the period of May 2012 to May 2013 had the fewest tornadoes ever recorded, and 2012 had the fewest violent tornados (EF3+) ever observed. The low incidence of violent tornadoes is particularly notable as tornadoes constitute extreme weather that does real damage. The May 2012-13 period also had the second-fewest tornado fatalities since 1875 despite a huge increase in the nation’s population since then, and the longest streak ever of days without a tornado-related death: 220 days. In July 2012, we had the fewest tornadoes since modern records began.

The same is true of hurricanes. Although the National Oceanic and Atmospheric Administration ominously predicted an “active or extremely active” hurricane season for 2013, hurricane activity has been virtually nonexistent this year, and not a single hurricane has struck the United States.

The United States is enjoying its longest-recorded streak without a major hurricane strike: almost 2,900 days. The previous record was only 2,300 days. Similarly, droughts have become shorter and less frequent, soil moisture is increasing, flooding is decreasing, and the number of wildfires is less than a third of what it was during its late-1970s/early 1980s peak. (The amount of acres burned has increased, though undoubtedly due to poor forest management by the government.)

These observations are affirmed by voluminous evidence in Climate Change Reconsidered II: Physical Science, just published by the Heartland Institute and compiled by the Nongovernmental International Panel on Climate Change. (Disclosure: I served as co-editor of the book.) Climate Change Reconsidered II acknowledges that the world is warming and that humans have certainly elevated the world’s CO2 level, especially in the past half-century, but makes two things abundantly clear in its more than 1,000 pages of peer-reviewed science:

1. The planet’s warming in recent decades is neither unprecedented nor unnatural.

2. The mild warming we have experienced has been beneficial, and any foreseeable further warming will continue to be so.

In the book’s chapter on extreme weather, chapter coauthors Madhav Khandekar and Craig Idso present more than 180 pages summarizing peer-reviewed studies from scientists all around the globe that refute the IPCC’s claims of increases in extreme weather. Khandekar and Idso state:

It is clear in almost every instance of each extreme weather event examined, there is little support for predictions that CO2-induced global warming will increase either the frequency or intensity of those events. The real-world data overwhelmingly support an opposite conclusion: Weather will more likely be less extreme in a warmer world.

The IPCC has largely ignored this evidence. Regarding flooding, the authors note:

[The IPCC] claims in its most recent report “there continues to be a lack of evidence and thus low confidence regarding the sign of trend in the magnitude and/or frequency of floods on a global scale” (p. 14 of the Technical Summary, Second Order Draft of AR5, dated October 5, 2012).

Contrary to the IPCC’s assessment of the situation, there exists a large body of scientific research on this topic. According to that research … there is much evidence to conclude CO2-induced global warming is not currently increasing the frequency and/or magnitude of floods, nor will it likely impact such phenomena in the future.

The authors then describe and cite literally dozens of studies from every corner of the globe indicating that there won’t be more flooding in a warmer world.

This is all good news, of course, and hence the IPCC’s claim of greater confidence than ever that “human influence has been the dominant cause of the observed warming since the mid-20th Century” cuts both ways. With the warmer world bringing less extreme weather, any “human influence” on the weather appears to be a net positive.

Once that fact circulates, it will be interesting to note what the next scare scenario will be.