Retired NASA scientist and climate guru James Hansen is coming out this week with another paper predicting catastrophic climate change. The paper is not yet available but has apparently been sent to some in the media, notably here and here.
As the Washington Post article says, “In the new study, Hansen and his colleagues suggest that the “doubling time” for ice loss from West Antarctica — the time period over which the amount of loss could double — could be as short as 10 years. In other words, a non-linear process could be at work, triggering major sea level rise in a time frame of 50 to 200 years. By contrast, Hansen and colleagues note, the IPCC assumed more of a linear process, suggesting only around 1 meter of sea level rise, at most, by 2100.” The Daily Beast article says Hansen predicts ‘several meters’ of sea level rise this century.
Hansen’s paper apparently also predicts possible disruptions to major ocean currents, potentially blocking the circulation “in which (in the northern hemisphere) warm water travels northward, and then colder, denser water sinks and travels back south again.”
Judith Curry has a good post up at Climate Etc. discussing this and related issues. However, as with most discussion of future impacts, she calls for close examination of the ‘worst plausible case’ to direct our response. As I think that is close to suicidal, I wrote the following as a comment there and reproduce it here.
“Sadly, I think the emphasis on ‘worst case scenarios’ does not really serve our interests, especially if the worst cases are also the least likely.
I think it would be extremely useful to have a graduated approach for a number of reasons. First, even if temperature and sea level rises prove to be high, given the stop-start nature of rises in GAT over the past century we can expect to spend a considerable period of time dealing with lower levels and whatever impacts they bring.
Preparing a response to different levels of climate impacts would allow for a measured response. Sea walls built to deal with 98cm of sea level rise could easily build in a margin of 50%, which might be adequate overall if Nic Lewis is right, but would certainly buy us enough time to see if Hansen’s catastrophic nightmares have any chance of coming to pass.
The same is true of other pre-adaptation measures. It is also true of attempts to mitigate climate change. Radically reducing coal usage in the developed world may actually be enough of a response, if sensitivity is low. But even if more will be required of us in the future, allowing the emerging countries to burn coal for the first decades of this century may be enough to generate the resilience they need to make cuts later if they are required.
Furthermore, preparing for modest impacts now would also buy time for technological innovation to spare us from huge expenses now. Using the technology of 2040 to prepare for impacts in 2075 is likely to be just as effective and far less expensive than using what is available today.
The activist side of the climate debate has consciously tried to maintain the world’s focus on outlier estimates of temperature climbs, sea level rise and sensitivity estimates. It keeps them in the news, allows them to shout denier and probably generates more funding for research.
But it does not serve our needs.”
I short, I label this ‘almost suicidal’ in terms of the politics of climate change, as it allows the climate activists to set the agenda using outlier estimates. But it is also hugely destructive for those of us advocating a more measured response over a longer period of time, as the activists who have been attacking organizations like the Breakthrough Institute, the EcoModernists and proponents of Fast Mitigation would like to take all the options these more moderate voices put forward off the table. And we need those options.
We need to remember that in terms of present impacts on our environment, climate change is an asterisk in the totals when compared to habitat loss, over hunting and over fishing, conventional pollution and introduction of alien species.
We need to remember that in terms of acting against climate change, mitigating black carbon, deforestation, HFCs and methane will reduce forcings more quickly and more cost-effectively than the measures proposed by the catastrophe activists.
In terms of solutions being put into place, we need to remember the adage ‘measure twice, cut once’. Instead of throwing windmill farms up almost at random, we need to site better and integrate with existing generation more fully. The same is true of solar.
Perhaps most importantly, we need to re-evaluate opposition to nuclear and hydro-electric, the producers of 98% of non-emissive energy in the world, and figure out how to more effectively implement these technologies that have worked for us in the past.