The Grniad provides this little summary in a report about a climate change meeting at the UN.

Last November, the Stern report suggested that 200 million people could
be displaced by 2050 by rising sea levels and drought. It said the
global economy could shrink by one-fifth.

Slightly misleading don’t you think? A reader would look at that and think that it will shrink 20% from current levels: which isn’t, of course, what the Stern Review said at all. Rather, that the economy will be 20% lower than it would be without the damage caused by climate change. Even with that damage, the economy would still be vastly larger than it is now.