Researchers who examined climate change’s potential effect on the global economy say data errors led them to slightly overstate an expected drop in income over the next 25 years. The researchers at Germany’s Potsdam Institute for Climate Impact Research had forecast a 19% drop in global income by 2050. Their revised analysis put the figure at 17%. The Associated Press reported on the original study when it was published in the journal Nature last year. Nature posted a retraction of it Wednesday.