The funds needed for local climate disasters in poor countries have quintupled since 2002.

Measuring changes in percentages is meaningful for small changes. For large changes, it is silly and misleading. I did not repeat the "800%" figure used in the article because that is a silly and misleading way of saying "an increase of a factor of 5".

Likewise, an "80% decrease" is a distorting way to report a decrease by a factor of 5.