杏吧原创

鈥淐LIMATE is an angry beast, and we are poking it with sticks.鈥� The famous quip by oceanographer Wally Broecker is as true today as when he made it in 1997. More and more people are beginning to understand the dangers of climate change, but the poking still continues, and there are many more words than actions.

There could hardly be a more appropriate time, then, for two new books that survey the evolution of climate, the human role in accelerating its change, and what might be done to mitigate or adapt to the consequences. Both The Last Generation by science writer Fred Pearce and Field Notes from a Catastrophe by Elizabeth Kolbert, who writes for The New Yorker, tell the story in persuasive, non-technical and even chatty style.

Pearce stresses that his choice of title does not mean humans are about to become extinct, but that we are nonetheless the last generation that can rely on anything close to a stable global climate. It is a comprehensive and compelling work. Kolbert covers some of the same ground, but the fields from which she makes her notes are somewhat arbitrarily chosen, and her book reads a little like a series of newspaper articles.

The central difficulty in interpreting climate change has been how to distinguish natural from human-driven change. For the last 11,000 years or so, we have been in a warm interlude in a succession of ice ages. Now the human factor has kicked in, bringing deforestation linked with the growth of agriculture and cities, and a rise in carbon emissions, now at their highest level in 650,000 years. The effects, traced out in both books, can be seen in changes in the weather everywhere, gradual sea level rise, melting ice caps and glaciers, changes in ecosystems and impacts on a wide range of human activities.

One of the problems is that we suffer from a kind of sclerosis of the mind that causes us to look at each problem separately. Another major difficulty is that problems on this scale reach far beyond the remit of individual governments and require coordination of a kind rarely found in international institutions. Nonetheless, since the 1980s efforts have multiplied to put in place some institutional apparatus. Hence the United Nations Framework Convention on Climate Change of 1992 and the Kyoto protocol to curb greenhouse gases that gave effect to it in 1997. No one pretends, however, that the Kyoto protocol will solve the problems, the more so because since it was signed two important contributors to global pollution, the US and Australia, have refused to ratify it.

鈥淭he human factor has kicked in, and the effects can be seen everywhere鈥�

Both books look into what should be done. Everyone has their own priorities, but there is little doubt about the need for radical change in energy policy and for technical solutions such as carbon sequestration. Equally important is the need to reassess conventional economics, so that economic indicators account for the depreciation of natural assets and the wider cost to the environment and human health.

Pearce and Kolbert do their best to be fair and to avoid sensationalism, but their sense of alarm is evident throughout. The story of climate change may, as Pearce says, contain some heroic guesses, brilliant intuition and even occasional howlers, but taken together the conclusions are hard to contest. We risk upsetting not only human society as we know it but the stability of the biosphere as a whole.