Strong words from The Economist’s Democracy in America blog:

A HUNDRED years from now, looking back, the only question that will appear important about the historical moment in which we now live is the question of whether or not we did anything to arrest climate change. Everything else—the financial crisis, the life or death of the euro, authoritarianism or democracy in China and Russia, the Great Stagnation or the innovation renaissance, democratisation and/or political Islam in the Arab world, Newt or Mitt or another four years of Barack—all this will fade into insignificance beside the question of whether we managed to do anything about human industrial civilisation changing the climate of Planet Earth. It’s extremely hard to focus on this, because environmentalism goes in and out of political fashion depending on the economy, war, and so forth. But from the perspective of our great-grandchildren, the only thing that’s going to seem important is whether we burned all the fossil fuel on the planet and sent global temperatures up by at least 4 degrees Celsius in the next century, or whether we took collective action, shifted our energy sources, and held the global temperature rise to 2 degrees or less.

Joseph Romm has made a similar point before.

The blog post goes on to say:

Maybe a hundred years down the line, nobody will look back at climate change as the most important issue of the early 21st century, because the damage will have been done, and the idea that it might have been prevented will seem absurd. Maybe the idea that Mali and Burkina Faso were once inhabited countries rather than empty deserts will seem queer, and the immiseration of huge numbers of stateless refugees thronging against the borders of the rich northern countries will be taken for granted. The absence of the polar ice cap and the submersion of Venice will have been normalised; nobody will think of these as live issues, no one will spend their time reproaching their forefathers, there’ll be no moral dimension at all. We will have wrecked the planet, but our great-grandchildren won’t care much, because they’ll have been born into a planet already wrecked.

The question of how climate change will be viewed in retrospect is a tricky one. There are things about it that will be unknowable. If we do end up mitigating strongly, we will never know for sure if things would have been OK without all that action. Similarly, if we ignore the problem and things become terrible, we will never know for sure whether we could have succeeded in stopping it.