Summary: Both sides of the public debate about climate change long ago abandoned the physical sciences. So we turn to the social scientists to understand what’s happening. This article by climate scientist Judith Curry examines how the two fields intersect in the climate wars. (1st of 2 posts today.)
The demand for certainty is one which is natural to man, but is nevertheless an intellectual vice. … To endure uncertainty is difficult, but so are most of the other virtues.
— Bertrand Russell’s “Philosophy for Laymen” (1946).
Judith Curry, posted at Climate Etc, 9 April 2015.
Reposted under her Creative Commons License.
Everybody wants to save humanity:
- The availability cascade.
- Availability entrepreneurs.
- About climate change & health?
- About the Author.
- For More Information.
(1) The availability cascade
Climate change may exacerbate environmental problems that are caused by overpopulation, poorly planned land-use and over-exploitation of natural resources. However, for the most part it is very difficult to separate out the impacts of human caused climate change from natural climate change and from other societal impacts.
Nevertheless, climate change has become a grand narrative in which human-caused climate change has become a dominant cause of societal problems. Everything that goes wrong then reinforces the conviction that that there is only one thing we can do prevent societal problems – stop burning fossil fuels. This grand narrative misleads us to think that if we solve the problem of climate change, then these other problems would also be solved.
Politicians, activists and journalists have stimulated an ‘availability cascade’ to support alarm about human-caused climate change: the more attention a danger gets, the more worried people become, leading to more news coverage and greater alarm. From the original paper by Kuran and Sunstein:
An availability cascade is a self-reinforcing process of collective belief formation by which an expressed perception triggers a chain reaction that gives the perception increasing plausibility through its rising availability in public discourse. The driving mechanism involves a combination of informational and reputational motives. Individuals endorse the perception partly by learning from the apparent beliefs of others and partly by distorting their public responses in the interest of maintaining social acceptance.
Availability entrepreneurs — activists who manipulate the content of public discourse-strive to trigger availability cascades likely to advance their agendas. Their availability campaigns may yield social benefits, but sometimes they bring harm, which suggests a need for safeguards.
Because slowly increasing temperatures don’t seem alarming, the ‘availability entrepreneurs’ push extreme weather events and public health impacts as being caused by human-caused climate change, more of which is in store if we don’t quickly act to cool the planet by reducing fossil fuel emissions. A deconstruction of this availability cascade is needed to avoid bias in our thinking and to better understand the true risks of human caused climate change:
- The basis for this cascade originates from the 1992 UNFCCC treaty, to avoid dangerous human caused climate change through stabilization of CO2 emissions. Note, it was not until 1995 that the IPCC 2nd Assess Report identified a discernible human influence on global climate.
- Then, the UNFCCC changed the definition of climate change to refer to a change of climate that is attributed directly or indirectly to human activity. This leads to the perception that all climate change is caused by humans.
- Sea level rise and extreme weather events such as hurricanes, drought and heat waves are attributed to climate change, which are de facto assumed to be caused by human-caused climate change.
- Human health impacts, national security risks, etc. that are exacerbated by extreme weather events are then inferred to be caused by human-caused climate change.
A critical link in this cascade is between human-caused climate change and extreme weather. In 2012, the IPCC published a Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX). The Report found:
- Low to medium confidence of a trend in droughts in some regions and the frequency of heavy rains in some regions, and high confidence of a trend in heat waves in Australia.
- There is no trend in hurricanes or wild fires.
- Attribution of any trend in extreme weather events to human caused climate change cannot be done with any confidence.
With regards to the perception (and damage statistics) that severe weather events seem more frequent and more severe over the past decade, there are several factors in play. The first is the increasing vulnerability and exposure associated with increasing concentration of wealth in coastal and other disaster-prone regions. The second factor is natural climate variability. Many extreme weather events have documented relationships with natural climate variability; in the U.S., extreme weather events (e.g. droughts, heat waves and hurricanes) were significantly worse in the 1930’s and 1950’s.
Has climate change affected people’s health?
As a specific example of this cascade, consider the recent announcement from the White House that it will start a new initiative to focus on the health effects of climate change, with a draft report from the USGCRP (U.S. Global Change Research Program).
Several years ago, the Cato Institute addressed this issue in their impact assessment of climate change on the U.S. The Cato Report concluded that the health effects of climate change on the U.S. are negligible today, and are likely to remain so in the future. They found that 46% of all deaths from extreme weather events in the U.S. from 1993-2006 were from excessive cold and 28% were from excessive heat, and that overall deaths from extreme weather events have declined in the U.S. They also found that diseases transmitted by food, water and insects have been reduced by orders of magnitude in the U.S. over the past century, and show no sign of resurgence.
Specifically with regards to asthma, which is an issue that influenced President Obama: the argument is that increasing heat waves will exacerbate smog, which exacerbates asthma. However, according to the EPA, smog levels have dropped 33% since 1980. Further, heat waves in the U.S. have not been increasing; the EPA’s analysis of the heat wave index for the U.S. shows that the index during the 1930’s reached levels almost an order of magnitude greater than the recent decade. While asthma rates have been climbing, the cause cannot be global warming. Nevertheless, a recent survey of the American Thoracic Society members found that 77% of the respondents observed an impact from climate change on increases in chronic disease severity from air pollution.
The availability cascade that leads to belief that climate change is exacerbating chronic respiratory diseases such as asthma misleads us away from a deeper investigation of the true causes of public health problems and from addressing these problems in a more meaningful way. And then multiply this consequence across the whole range of issues that climate change is allegedly making worse. The availability cascade of climate change as apocalypse acts to narrow the viewpoints and policy options that we are willing to consider in dealing with complex issues such as public health, weather disasters and national security. Should we be surprised when reducing CO2 emissions does not ameliorate any of these problems?
Is climate change making us stupid? I fear that the answer is ‘yes.’ This problem is exacerbated by politically correct climate change orthodoxy, enforced by politicians, advocates and the media in an availability cascade, which is destroying our ability to think rationally about how we should respond to climate change. As a result, we have created a political log-jam over this issue, with scientists caught in the cross-fire.
JC note: this is a draft of something I’m writing, I would appreciate any feedback.
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(2) About Judith Curry
Judith Curry is Professor and Chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology. She is also President and co-owner of Climate Forecast Applications Network (CFAN). Prior to joining the faculty at Georgia Tech, she served on the faculty of the University of Colorado, Penn State University and Purdue University.
She serves on the NASA Advisory Council Earth Science Subcommittee and the DOE Biological and Environmental Science Advisory Committee. She recently served on the National Academies Climate Research Committee and the Space Studies Board, and the NOAA Climate Working Group.
She is a Fellow of the American Meteorological Society, the American Association for the Advancement of Science, and the American Geophysical Union. Her views on climate change are best summarized by her recent Congressional Testimony:
- Rational Discussion of Climate Change: the Science, the Evidence, the Response, Nov 2010.
- Policy Relevant Climate Issues in Context, April 2013.
For More Information
To learn more about these things see The Rightful Place of Science: Disasters and Climate Change by Roger Pielke Jr. (Prof of Environmental Studies at U of CO-Boulder, and Director of their Center for Science and Technology Policy Research).
If you liked this post, like us on Facebook and follow us on Twitter. For more about climate see these reference pages with links to a wealth of information: The keys to global warming, Studies & reports, by subject, and My posts about climate. Especially see these posts:
- Have we prepared for normal climate change and non-extreme weather?
- Let’s prepare for past climate instead of bickering about predictions of climate change.
- Some good news about our changing climate. Enjoy it, for it might not last long.
- Prof Botkin gives us good news about our changing climate.
- More good news about the climate, giving us a priceless gift.