Original sentence: For smaller values of warming (of up to 2°C relative to 1990 levels), the global economic effect is expect to be plus or minus a few percent of world GDP, with most people in the world negatively affected
Edited sentence: For smaller values of warming (of up to 2°C relative to 1990 levels), the global economic effect is expected to be plus or minus a few percent of world GDP, with most people in the world negatively affected