Matt Damon is a known environmentalist, so when he received the ALS ice bucket challenge from Ben Affleck, he took some time to consider how best to address the situation.

California is suffering from a massive drought, and much of the world has no access to clean water, he explains in the YouTube video posted by Water.org, the non-profit he founded.

Check out what Damon came up with as an appropriate response to pal Affleck's challenge.