Added November 2020
The world is getting warmer because of increases in certain gases in the air, such as carbon dioxide, which trap and slow down heat that would otherwise escape to space.
Carbon dioxide levels are now well above 400ppm for the first time in over 800,000 years. So far, this has warmed the planet by 1ºC. On current policies, global warming is expected to reach ~3ºC above pre-industrial levels by 2100.
The Stern Review projected that climate change would cause about a 4% reduction in economic welfare in 2100. Negative consequences of climate change would include:
However, there is also a significant chance that current policies would lead to larger temperature increases. That would lead to much worse effects, but probably not to human extinction.
In the 2015 Paris Agreement, virtually every country agreed to make emissions reductions aimed at limiting global warming by 2100 to less than 2ºC. But the reductions are voluntary, current pledges would not yet reach that goal, and the U.S. has now withdrawn from the agreement.
In the U.S., attempts to address climate change through national legislation have largely failed. The 2009 Waxman-Markey cap-and-trade bill narrowly passed the House but never received a vote in the Senate, even though the Democrats controlled 59 seats at the time. In polls, Americans claim to be worried about climate change, but many say they wouldn’t be willing to pay anything to deal with it.
Founders Pledge recommends donating to the Coalition for Rainforest Nations and the Clean Air Task Force.
The impact of a $100 donation to the Coalition for Rainforest Nations, according to Founders Pledge’s estimates, would dwarf the expected carbon savings of many actions to reduce one’s carbon footprint, such as taking fewer plane trips.
Resources: Climate change (extreme risks) - 80,000 Hours