Climate change is no longer a fringe issue; even investment bankers are worried about it. Lehman Brothers and UBS both published bumper reports on the subject on Wednesday. This sudden burst of activity illustrates a central point of the Lehman report: the progress of climate change may be slow and hard to quantify but the impact on business can be sharp and sudden. Already, some houses on low-lying land have become uninsurable and unsellable owing to the increased risk of flooding.

Even if sceptics aren’t convinced by the science, carbon dioxide is already having a big effect on the political climate. In the short term, the greatest impact on business is likely to come from more stringent regulation.