We've wrestled with environmental problems for many decades. Those problems include, in most people's opinion and in no particular order, preservation of threatened species, green spaces and wilderness areas, clean air, reduction of landfill, keeping GM crops out of the food chain and encouragement of walking and cycling to work.
Now I don't say these things don't matter. They do. But the cost of getting them wrong is, on the scale of national finances, fairly small. Getting GM crops into the food chain won't poison anyone. The extinction of the Yangtse River Dolphin has made many people sad and no one will die because of it.
Global warming is different. Failing to deal with that will lead to millions of deaths (though not all at once) from storms, floods and starvation. Global warming does not threaten the survival of our species. The Black Death killed about a third of us but we bounced back within a century.
Yesterday I was at ?What If!'s Good Profit conference in London (an excellent event by the way). With the sainted Al Gore giving a dynamic keynote speech no-one there can have doubted the reality of the threat. Yet even there I heard people say how difficult it was to "choose between properity and the environment".
That's not the issue. The issue is choosing between a sustainable ecomony and one that will probably crash, physically or finacially, killing large numbers and undermining the right of the survivors to call themselves civilised.