Are we going to fry or drown?

Roger Pielke Jnr has degrees in mathematics, public policy and political science. For the last 20 years he has been studying extreme weather events – hurricanes, floods, tornadoes, bushfires – and has published dozens of peer-reviewed papers on the subject. Since 2001 he has been a professor of environmental studies at the University of Colorado. Quite appropriately he was called in to testify before the Senate commission “Climate Change: It’s Happening Now”. Here is the written testimony he delivered:

and some juicy excerpts from it, for those too busy to follow the links in blog posts:

Take-Home Points:

It is misleading, and just plain incorrect, to claim that disasters associated with hurricanes, tornadoes, floods or droughts have increased on climate timescales either in the United States or globally. It is further incorrect to associate the increasing costs of disasters with the emission of greenhouse gases.

Globally, weather-related losses ($) have not increased since 1990 as a proportion of GDP (they have actually decreased by about 25%) and insured catastrophe losses have not increased as a proportion of GDP since 1960.

Hurricanes have not increased in the US in frequency, intensity or normalized damage since at least 1900. The same holds for tropical cyclones globally since at least 1970 (when data allows for a global perspective).

Floods have not increased in the US in frequency or intensity since at least 1950. Flood losses as a percentage of US GDP have dropped by about 75% since 1940.

Tornadoes have not increased in frequency, intensity or normalized damage since 1950, and there is some evidence to suggest that they have actually declined.

Drought has “for the most part, become shorter, less frequent, and cover a smaller portion of the U. S. over the last century.” Globally, “there has been little change in drought over the past 60 years.”

The absolute costs of disasters will increase significantly in coming years due to greater wealth and populations in locations exposed to extremes. Consequent, disasters will continue to be an important focus of policy, irrespective of the exact future course of climate change.

Those of you forming opinions based on the media statements and PR pronouncements of NGO’s may be shocked by the above bullet points. Have we not been told again and again that the storms, heat waves, floods etc we are experiencing are a result of climate change? Are things not supposed to be getting a lot worse as the Earth is warming due to human-caused carbon emissions? Just look at the cover of the latest National Geographic magazine:


All the activists going on about “carbon criminals”, “coal trains of death”, “killing the Earth” etc cannot possibly be wrong – can they? Well, if you were to believe Roger Pielke Jnr whose CV suggests he knows what he is talking about they are at best not genuine and possibly much worse. The second paragraph from the summary of his Senate commission testimony puts the issue in perspective:

Because the climate issue is so deeply politicized, it is necessary to include several statements beyond those reported above.

Humans influence the climate system in profound ways, including through the emission of carbon dioxide via the combustion of fossil fuels.

Researchers have detected and (in some cases) attributed a human influence in other measures of climate extremes beyond those discussed in this testimony, including surface temperatures and precipitation.

The inability to detect and attribute changes in hurricanes, floods, tornadoes and drought does not mean that human-caused climate change is not real or of concern.

It does mean however that some activists, politicians, journalists, corporate and government agency representatives and even scientists who should know better have made claims that are unsupportable based on evidence and research.

Such false claims could undermine the credibility of arguments for action on climate change, and to the extent that such false claims confuse those who make decisions related to extreme events, they could lead to poor decision making.

A considerable body of research projects that various extremes may become more frequent and/or intense in the future as a direct consequence of the human emission of carbon dioxide.

Our research, and that of others, suggests that assuming that these projections are accurate, it will be many decades, perhaps longer, before the signal of human-caused climate change can be detected in the statistics of hurricanes (and to the extent that statistical properties are similar, in floods, tornadoes, drought).

The remainder of this written testimony provides data and references to support the claims made in the “take-home points” above.

So, according to Roger Pielke Jnr, the link between climate change and extreme weather events may be real but is so far undetectable using the scientific methods. In all honesty, I believe that other problems will become a challenge before we either fry or drown as a result of human carbon emissions.


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