Issue 5 Online Extra: Extreme events, global warming and reality by Patrick J. Michaels Extreme events, global warming and reality by Patrick J. Michaels

This article is a companion piece to The New Idealist Issue Five: Doomsday Edition which you can download here.

The whole aim of practical politics is to keep the populace alarmed (and hence clamorous to be led to safety) by menacing it with an endless series of hobgoblins, all of them imaginary.

H. L. Mencken, 1918

Is the notion of  an alarming increase in “extreme weather” as a result of global warming yet another of Mencken’s hobgoblins?

In the US, the  present and former Presidents, Bill Clinton and Barack Obama, regularly and glibly conflate global warming and observations of more “extreme weather”.  In doing so, they are contravening the spirit, if not the letter, of no less of an authority than the United Nations’ Intergovernmental Panel on Climate Change (IPCC).

While some debate about that authority, mainly their Republican opposition, The IPCC is often portrayed as the “consensus of scientists”.  Its most recent (2013) compendium on climate change contains an entire section on  climate extremes.  What it says isn’t what our Presidents have said.  According to the IPCC,

•The most “robust” observations on extremes are an increase in daily temperature, including “to some extent”, heat waves. The IPCC qualifies the statement because the observed increase in heat, and therefore heat waves,  caused by urbanization itself is much larger than changes in surrounding regional or global temperature.

•”There is limited evidence of changes in extremes associated with other climate variables since the mid-20th century.”

•There are “no significant observed trends” in tropical cyclone activity over the past century, as shown in Figure 1.  There is “a lack of evidence” regarding even the sign of the trend in flood magnitude and/or frequency on a global scale. Similarly, there are no obvious trends in small-scale severe weather events like severe thunderstorms or tornadoes.

The list goes on.  Consequently, our governments are doing the public a profound disservice by hawking the “extreme weather” hobgoblin in pursuit of public policy.

Figure One






Figure 1.  This the history of global tropical cyclone power, known as the “Accumulated Cyclone Energy (ACE) index.  The top (blue) dots are the global total, and the bottom is for the Northern Hemisphere.  The Southern Hemisphere total is the difference between the two (From Maue, 2011, and updates).

For major coastal cities with subtropical summer climates, there is no greater hobgoblin than the tropical cyclone.  But, as the illustration shows, there is simply no relationship between their destructive potential and global warming.  In fact,  the title of the associated reference speaks of “recent historically low” activity, quite the opposite of the long-term global trend in temperature.

If governments need to stop conflate extreme weather and global warming, then they should also be candid about that warming itself, and the failure of their own forecasts.

These forecasts are based upon mathematically cumbersome algorithms known in slang as “climate models”.  Only governments have enough money (or at least, can borrow enough of our children’s unearned money) to fund their development and use.

Highly interventionist climate policies are not based upon past weather, but rather on these climate predictions.  If these forecasts aren’t working, it is the responsibility of governments to be honest about it.

In its 2013 compendium, the UN used a suite of 107 climate model runs. They give us an average temperature for every year, back, say, to 1951 (or the “mid-20th century” that the UN speaks of).  If we go back in time, we can see what trends these models would have forecast for different periods of time.

Because we have so many models, we can generate a mean trend for each period, and the distribution about that trend. How does this compare to reality?

For trends going all the way back to those beginning in 1977, the observed warming trend is beneath the 5th percentile of the model trends, and usually beneath the 2.5th percentile.  These are prima facie criteria to reject a hypothesis.  In this case that hypothesis would have forecast what actually happened.  This sad failure  is shown graphically in Figure 2.

Figure 2
Figure 2







Figure 2.  The black dots are the observed planetary temperature trends, ending in 2013, with the first (left) year being 1951-2013 last (right) being 2002-2013. Green dots mean the obsered trends (while lower than) are between the 5th and 95th percentile of the predicted trends.   Yellow dots indicate the oberved trend falls below the 5th percentile of the models, and red, below the 2.5th percentile.   Adapted from Knappenberger and Michaels, 2013.

In a nutshell, governments aren’t really being candid with us when they glibly associate extreme weather (with the exception of heat waves) with global warming, and the UN isn’t being candid with us when it tells us that its climate models are working.

Patrick J. Michaels is Director of the Center for the Study of Science at the Cato Institute in Washington DC, and was a Research  Professor of Environmental Sciences at University of Virginia for thirty years.

Please note: This article was originally published in The New Idealist section of The Intelligent Review site in May 2014 before being transferred to this new site in July 2015.


Intergovernmental Panel on Climate Change, United Nations, 2013.  Climate Change 2013:  The Physical Science Basis.  Cambridge. pp 208-222 of 1535pp.

Knappenberger, P. C., and P.J. Michaels, 2013 (and update).  Policy Implications of Climate Models on the Verge of  Failure. Science Policy Conference, American Geophysical Union, Washington DC USA.  Presentation CC-15.

Maue, Ryan N., 2011 (and updates).  Recent Historically Low Global Tropical Cyclone Activity. Geophysical Research Letters, Vol. 38.  doi:  10.1029/2011gl047711.


Signup to receive the next issue of The New Idealist delivered straight to your inbox here.


Issue Seven: The New Future Issue (Annual Special Edition)
Issue Six: The Autism Issue
Issue Five: The Doomsday Edition (Extreme Weather Special)
Issue Four: The Issue We’re All Talking About (Guest Edited by the actress Jodhi May)
Issue Three: Has Obama been corrupted by the machine?
Issue Two: IQ VS EQ – Is Emotional Intelligence what you need to succeed in the digital age?
Issue One: Downwardly Mobile? Will the next generation find it harder to reach the next level?

Leave a Reply