It is about time to panic.
According to the NASA data, we have just experienced the hottest 12-month period in more than 100 years, which means that the past 12 months have been the hottest in at least the past 1,000 years.
What does this mean? Well, if global temperatures continue to rise at the rate that they have risen for the past generation, then the world of 2100 will see a world 4.1 degrees Fahrenheit hotter than the world of the 1970s. New York will get the climate of Washington. Los Angeles will get the climate of Tijuana.
But global warming might accelerate, especially if China, India and other industrializing powers continue to increase the amount of carbon dioxide they pour out. Perhaps the world by 2100 will be 9 degrees hotter than the world of the 1970s. That would give Washington the climate of Miami and Los Angeles the climate of Cabo San Lucas.
And we might get lucky. We might learn that the climate is in fact immensely stable on the upside. Even though past ice ages have ended quickly with very rapid warming, perhaps there are factors in the Earth's biosphere that allow it to soak up excess carbon dioxide quickly, like a sponge, and perhaps the world of 2100 will not be much warmer than the world of today. Or perhaps we will discover magical new energy technologies that are actually cheaper than our current technologies and will be rapidly adopted without the governments of the world lifting a finger to take action.
But that is not the prudent way to bet. The prudent thing to do is to plan, and to hedge: to plan for the most likely case, and to hedge by taking precautions — insurance — against the worst case. The world was supposed to plan how to deal with our global warming future at Kyoto. And then the world was supposed to plan for how to deal with our global warming future at Copenhagen. It did not do so.
So what do we do now?
Let us start with our global institutions. It is a fact that global warming is not likely to be a total human catastrophe here in California during the next 100 years. We will mourn the losses of our glaciers and our snowpack. We will lament the extinction of the polar bear, the coral reefs and the giant sequoias. We will be distressed at the transformation of California's Central Valley into the north Mojave Desert. But many San Franciscans really won't mind having the climate of Los Angeles. And many Angelenos will not be greatly distressed to have the climate of Tijuana. We will probably move a few miles north and relocate economic activity to get out of the paths of hurricanes and droughts. We will turn down our heaters and turn up our air conditioners. We will live our lives. It will be expensive for us to simply adapt, and it would be cheaper over the next century to deal with the problem. But here in California, there's little question we will be able to adapt without immediate human catastrophe for the next century.
That's not the case for Asia. China, India and their neighbors will soon have 3 billion peasants farming in the great river valleys of Asia. They depend on regular monsoon rains in the valleys and water flows down the channels of the Indus, the Ganges, the Mekong, the Yangtze and the Yellow rivers. Global climate change means that there will either be more precipitation in the valleys and feeding the rivers — or much less. If there is more, millions will die in floods, and the dwelling and working places of hundreds of millions will simply be washed away. The 3 billion are not rich enough to abandon their land and move away. They are also not rich enough to protect themselves. If there is much less water, hundreds of millions will die in famine and drought. Again, the peasant farming populations of Asia are not rich enough to abandon their land and move away. And they are also not rich enough to bring icebergs up from the Antarctic and pipe the water uphill from the sea to their farms.
The peasant farming populations are not rich enough to simply adapt. So the first thing we need to do is to beg the rulers of China and India to understand their nations' long-term interest.
But even if China and India understand and join the North Atlantic and the island nations of the Pacific in understanding the immensity of the long-run problem, that will not be enough. In the current international forum, China and India are simply two out of a 150 nations, and consensus is required. That is just too big a body with too many conflicting interests.
So the second thing we need to do is change the forum. We need a climate council made up of the seven governments that have the biggest power to influence the climate and the most at stake: the United States and the European Union, along with Japan, China, India, Indonesia and Brazil. Once the council has agreed to a treaty, it should be enorced by using aggressive and substantial trade sanctions against outsider countries that do not want to come up to the mark.
Utopian? Yes. Impractical? Probably. But what is the practical and realistic alternative that it would be better to push for?
J. Bradford DeLong is a professor of economics at U.C. Berkeley and a research associate at the National Bureau of Economic Research.