Hi, I originally chose D, but ended up switching my answer to A, mainly because of the word "hasten" in the conclusion. It seems like if you tore up all the native grass and replaced them with trees, you're only decreasing the rate at which you slow global warming (from plus 100 to plus 80).

If we view the change from 100 to 80 as a speeding up global warming, that seems to ignore the possibility of no change in the rate of global warming (maybe we have a barren field and plant neither trees nor grass?)

"Hasten global warming" seems to imply that you're doing harm, as in a negative rate (emitting CO2), which A would account for. Any help would be appreciated!

Hi all, I'm interested as well! Will send email.