Perhaps the most insidious consequences of climate change will be the unequal distribution of its impacts around the globe.
The consequences of climate change are truly global in scope, but some areas of the world will be more heavily impacted than others. Small island nations are at significant risk from rising sea levels and many tropical nations face futures of increased aridity or increased frequency of extreme weather events. Countries with temperate climates are expected to weather less extreme impacts, and in some cases benefit (parts of North America and the UK may have better agricultural conditions with increased moisture and increased temperature). The sinister irony is that this effectively means that the less developed nations will face the brunt of climate change impacts while already well-off will do comparatively better.
The prediction that developing countries will be the hardest hit has further implications. These countries are the ones that will need to adapt the most to climate change adaptation but the least able to adapt technologically. How does a country like Kiribati cope with an ocean that might rise above the elevation of the island itself? How does sub-Saharan Africa, which already experiences high mortality from malaria, cope with greater malarial threat with the increase in mosquito populations projected with climate change? Surely these differential environmental, economic, and health impacts to people around the world add an additional ethical dimension to considering climate change impacts, but less obvious and more worrisome are the potential geopolitical implications of these different regional effects.
The responses to such effects could be severe. The Pentagon has released a report concocting scenarios that could result from climate change. The scenarios are extreme: shut down of the Gulf Stream, agricultural failure in China, and mass migration of people fleeing extreme events. The proposed human response to climate change is equally alarming: increased tensions over land and resources, and greater potential for international wars. Some of the scenarios explored in this report have little scientific support (shut down of the Gulf Stream) or are purely speculative (Germany becoming a nuclear power), but similar studies have come out in purely academic circles. In an article published in Proceedings of the National Academy of Science of the United States of America (a highly esteemed journal), Shuaizhang Feng and his colleagues model illegal immigration from Mexico into the United States as a consequence of climate change.
Scenarios and the Baggage They Bring
The study on Mexican climate migrants was heavily criticised for the assumptions it made as well as its focus. Roger Pielke Jr., a political scientist and commentator on science in policy, was particularly critical, stating:
To use this paper as a prediction of anything would be a mistake. It is a tentative sensitivity study of the effects of one variable on another, where the relationship between the two is itself questionable but more importantly, dependent upon many other far more important factors.As Pielke states, the paper developed a reputation for being “silly science” and could easily fuel xenophobic nationalism and racism.
This raises the interesting question of what is the value of scenario studies. The future is inherently unpredictable, and there are entire books dedicated to the failures of humanity’s best and brightest when it comes to predicting the future. The problem is further compounded by the idea that our own predictions influence how we act in the future.
But where would that leave us? If we rid ourselves of the tools that scenario analysis gives us (regardless of how poor they might be), what can we do?
The problem with dismissing scenario analysis is that any study pertinent to the future is a scenario. The IPCC results that form the foundation of so much research into climate change are themselves scenarios. Should these likewise be scuttled? Are there some scenarios that are worthy of our attention and some that are not? The answer, I think, is to understand what use different types of scenarios do have. Accurate prediction can only reasonably be argued in situations with well-understood processes and where unknowns don’t play a big part. Studies where uncertainties can be incredibly important are most useful at demonstrating the importance of individual variables with everything else constant (in a ceteris paribus sense, such as the IPCC scenarios, or as argued by Michael Oppenheimer for the value of modeling Mexican climate migrants), or at least demonstrating a worst-case scenario (fitting the old adage to “plan for the worst, hope for the best”, as demonstrated by the Pentagon report). Roger Pielke was right about the study on climate migrants: it should not be viewed as a predictive study. Can it be informative in a ceteris paribus sense?
Perhaps, but the problem with any sort of scenario analysis is that the scenarios we devise are hostage to our assumptions. We may treat the Mexican migrant study as a ceteris paribus study, or even as a worst-case scenario to be ready for, but it is entirely dependent on the assumption that migration will be the response to climate change. As Diana Liverman (pdf) points out, “environmental change and pollution [is] as much a reason for cooperation as conflict” and there is "little evidence to link environmental change to conflict and migration". The potential inadvertent repercussions of this type of scenario analysis, such as preparing for increased illegal immigration, may divert attention and resources away from issues that really need to be dealt with.
Any scenario based around societal responses will be influenced by assumptions of human nature. Even in studies of climate change the debate between Hobbes and Rousseau lives on: are humans basically noble and kind, or brutish and cruel? When faced with climate change, will nations act aggressively over ever-scarcer resource pools (the Hobbesian view) or cooperate for mutual benefit (Rousseau’s view)? Many scenarios in climate change assume a Hobbesian view, but if Liverman is right, a common threat may just lead to cooperation. The stresses that climate change will impose on many nations under may help foster international cooperation in cutting GHG emissions and adapting to climate change impacts (though we may already be too late to avoid harmful climate changes). A third option is that responses are not so general: (for instance) the response of a nation could depend on their international power. A small nation vulnerable to climate change with little political power may vie for international cooperation, but an international superpower like China may aggressively acquire land and resources if climate change affects China’s ability to feed itself. All three may also occur concurrently.
With all of the uncertainty surrounding the scenarios used to study and plan for climate change, some people may be tempted to argue that planning based on scenarios is useless and not worth the risks. The problem is that not planning itself has consequences, and will by nature favour the status quo, which is something that we hope to avoid. The trick (as I’ve suggested above) is determining how and under what conditions specific scenarios are useful.