This morning the Senate Energy and Commerce Committee held a hearing on “Climate Change Science and Economics“. I have read through the testimonies of Panel 1 and there is little surprising or new to be found. I do have a 3 more or less random comments below.

1. Nobel laureate Mario Molina states, “Recent estimates indicate that stabilizing the amount of greenhouse gases in the atmosphere at the equivalent of twice the pre-industrial value of 280 ppm carbon dioxide provides only a 10-20 per cent chance of limiting global average temperature rise to 4 degrees Fahrenheit. Put another way, this means that the odds that average global temperatures will rise above 4 degrees is 80 to 90 percent. Unless society starts taking some aggressive actions now, we are well on our way to reaching perhaps even a tripling of pre-industrial carbon dioxide levels with far greater adverse economic and environmental consequences. The risks to human society and ecosystems grow significantly if the average global surface temperature increases 5 degrees Fahrenheit or more. Such a large temperature increase might entail, for example, substantial agricultural losses, widespread adverse health impacts and greatly increased risks of water shortages. Furthermore, a very high proportion of the world’s coral reefs would be imperiled and many terrestrial ecosystems could suffer irreversible damage. The risk of runaway or abrupt climate change also increases rapidly if the average temperature increases above about 5 degrees Fahrenheit. It is possible, for example, that the West Antarctic and Greenland ice sheets will melt, raising sea levels more than ten meters over the period of a few centuries. It is also possible that the ocean circulation will change abruptly, perhaps shutting down the Gulf Stream.”

Comments such as this suggest to me that the international climate policy community is living a lie. Specifically,


Article 2 of the Climate Convention calls for, “stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time-frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner.”

If 4 degrees is set to occur at 80-90% likelihood, then 5 degrees, which Molina clearly views as “dangerous” cannot be far behind. Prevention, simply put is not in the cards. This does not mean that we throw up our hands and do nothing, but it does mean that if we are serious about action that we should start by reopening the objective of the Climate Convention for renegotiation. This observation has been made before. In 1995, Pekka E. Kauppi wrote presciently in Science that the goal of the Framework Convention on Climate Change was either “unattainable or irrelevant If GCM projections are right, the climate will change, there will be dangerous effects and the Convention objective will be unattainable” (Science, 220:1454). It is time to stop living the lie and reconsider Article 2.

2. NCAR’s Jim Hurrell observes, “… it should be recognized that mitigation actions taken now mainly have benefits 50 years and beyond now.”

This point would seem to be generally appreciated by experts in climate science and policy but is generally lost in the more general debate. Why does this matter? The asymmetry in the timing of costs and benefits makes it incredibly hard to justify action on mitigation – my tongue-in-cheek characterization of this approach to mitigation is “Please bear these costs but you personally will never see any benefits, other than the psychological benefits of aiding future generations.” Such arguments don’t work for social security and they won’t work here. In addition, the reality of the time-lag of benefits illustrates the futility of using current climate events to justify mitigation action. Even if people take action, there can be no scientifically valid argument that such actions will lead to a better climate in their lifetime (warning tongue-in-cheek comment coming) – “Want fewer hurricanes in 2007? Drive a Prius!” Actually, not so-tongue-in-cheek, this exact strategy was tried by Scientists and Engineers for Change and Environment2004.org leading up to the 2004 elections and we all know how Florida turned out. It was a misuse of science to suggest that the 2004 election had any impact on future hurricane frequency. It is similarly a misuse to suggest that climate mitigation should be viewed as an effective policy option for issues such as malaria and disasters.

Again, the point here is not to throw up our hands and do nothing. But the asymmetry is costs and benefits suggest that we might think about different strategies, particular ones that have more of symmetry between the timing of costs and benefits. We’ve discussed such options frequently here as “no regrets” on both adaptation and mitigation – see these posts (here, here, here. I doubt that much action (i.e., actual emissions reductions, not aspirations) will happen on mitigation until action on decarbonization is framed in terms of its short term costs and benefits.

3. Sir John Houghton, former chairman of the IPCC, states the following, “Data from insurance companies show an increase in economic losses in weather related disasters of a factor of 10 in real terms between the 1950s and the 1990s. Some of this can be attributed to an increase in vulnerability to such disasters. However, a significant part of the trend has also arisen from increased storminess especially in the 1980s and 1990s.”

This is simply scientifically incorrect and politically irresponsible. No part of the trend in economic losses related to weather since the 1950s can be attributed to increased storminess (though we’d welcome learning of any research to the contrary). We discussed this in some depth here and here, and even the 2001 IPCC says as much.

If climate scientists want to be believed when they discuss science in highly politicized contexts, then a good place to start would be to be accurate when making scientific claims. It would also be a good idea for scientists to call their colleagues on statements that are unjustified by the scientific literature, even when those colleagues are advocating policies that they themselves may happen to favor. This was the message of Hans von Storch when he visited Boulder a few weeks ago (see this Der Speigel essay). In the long run both science and policy will be better served through candor and community-established norms of scientific rigor, even if there may be short-term political benefits in playing fast and loose with science.