To those who say that we should just wait and see how the climate changes, without taking action to reduce our emissions, I offer the following analogy:
To assume the best possible outcome, and to make plans only on that basis, is akin to the United States assuming they would be ‘greeted as liberators’ in Iraq. Even if things had unfolded that way, it would have been irresponsible to make plans only on that basis. If they had drawn up contingency plans, and taken pre-emptive actions, on the grounds that serious opposition was possible, nobody would have thought that behaviour inappropriate, even if the outcome ended up being better than feared.
Arguing that we should wait for the science to be completely settled means waiting until climate change has actually taken place. Given the complexity of the climate system, and the fact that we only have one planet to work with, there is no way we can ever be 100% confident that our models and projections are correct. Therefore, to delay action until we have certainty is to delay action until it can no longer have any effect. It is akin to starting your contingency planning long after the war has ended.