The world will have to adapt to global warming no matter what — but higher levels of global warming will be much more difficult to adapt to.
Even if humanity could zero out its greenhouse gas emissions tomorrow, we’ve already loaded enough carbon dioxide into the atmosphere to raise global temperatures by at least 1° Celsius (1.8° Fahrenheit) over pre-industrial levels. And even a mild temperature increase will likely mean more heat waves and higher sea-level rise and so on. That means adaptation.
On the other hand, some experts think unchecked emissions could lead to a level of warming that would be difficult to adjust to. The World Bank, for instance, has argued that 4°C (or 7.2°F) of global warming could be so drastic — as heat waves and droughts and crop failures combine in unpredictable ways — that there’s no certainty that adaptation to a 4°C world is possible.
Climate-change adaptation can take a variety of forms. In the United States, Louisiana has written up a plan to restore and protect its coastline from further erosion at the hands of sea-level rise over the next 50 years. Texas is trying to improve its drought-response plans. Governors out West have begun talks on how global warming might affect water allocation in the Colorado River. New York City has to think about how to deal with fiercer storm surges in the years ahead as ice sheets melt and sea levels rise.
But so far, many countries aren’t very far along. A comprehensive survey from October 2012 found, for instance, that some states and cities around the United States are beginning to draw up plans, but they’re nowhere near adequate. “Most adaptation actions to date appear to be incremental changes,” the survey notes, “not the transformational changes that may be needed in certain cases to adapt to significant changes in climate.”
Meanwhile, poorer countries have often asked for financial aid from wealthier countries to adapt to global warming. Back in 2009, countries including the United States, Germany, Britain, and Japan promised $30 billion in aid to help developing countries adapt to the impacts of global warming and switch over to cleaner energy sources, with more on the way. (It’s not clear how much money will be coming in the future.)