This is a linkpost for Brian Tomasik's posts on climate change.

Climate Change and Wild Animals

By Brian Tomasik

First written: 2008. Major additions: 2013. Last nontrivial update: 4 Aug 2018.

Summary

Human environmental choices have vast implications for wild animals, and one of our largest ecological impacts is climate change. Each human in the industrialized world may create or prevent in a potentially predictable way at least millions of insects and potentially more zooplankton per year by his or her greenhouse-gas emissions. Is this influence net good or net bad? This question is very complicated to answer and takes us from examinations of tropical-climate expansion, sea ice, and plant productivity to desertification, coral reefs, and oceanic-temperature dynamics. On balance, I'm extremely uncertain about the net impact of climate change on wild-animal suffering; my probabilities are basically 50% net good vs. 50% net bad when just considering animal suffering on Earth in the next few centuries (ignoring side effects on humanity's very long-term future). Since other people care a lot about preventing climate change, and since climate change might destabilize prospects for a cooperative future, I currently think it's best to err on the side of reducing our greenhouse-gas emissions where feasible, but my low level of confidence reduces my fervor about the issue in either direction. That said, I am fairly confident that biomass-based carbon offsets, such as rainforest preservation, are net harmful for wild animals.

See also:

• "Effects of Climate Change on Terrestrial Net Primary Productivity"
• "Scenarios for Very Long-Term Impacts of Climate Change on Wild-Animal Suffering"

Effects of CO₂ and Climate Change on Terrestrial Net Primary Productivity

By Brian Tomasik

First written: 2008-2016. Last nontrivial update: 28 Feb 2018.

Summary

This page compiles information on ways in which greenhouse-gas emissions and climate change will likely increase and likely decrease land-plant growth in the coming decades. The net impact is very unclear. I favor lower net primary productivity (NPP) because primary production gives rise to invertebrate suffering. Terrestrial NPP is just one dimension to consider when assessing all the impacts of climate change; effects on, e.g., marine NPP may be just as important.

Scenarios for Very Long-Term Impacts of Climate Change on Wild-Animal Suffering

By Brian Tomasik

First published: 2016 Jan 10. Last nontrivial update: 2016 Mar 07.

Summary

Climate change will significantly affect wild-animal populations, and hence wild-animal suffering, in the future. However, due to advances in technology, it seems unlikely climate change will have a major impact on wild-animal suffering beyond a few centuries from now. Still, there's a remote chance that human civilization will collapse before undoing climate change or eliminating the biosphere, and in that case, the effects of climate change could linger for thousands to millions of years. I calculate that this consideration might multiply the expected wild-animal impact of climate change by 20 to 21 times, although given model uncertainty and the difficulty of long-term predictions, these estimates should be taken with caution.

The default parameters in this piece suggest that the CO₂ emissions of the average American lead to a long-term change of -3 to 3 expected insect-years of eventual wild-animal suffering every second. My main takeaway from this piece is that "climate change could be really important even relative to other environmental issues; we should explore further whether it's likely to increase or decrease wild-animal suffering on balance".

This piece should not be interpreted to support human technological progress or development of artificial general intelligence (AGI). Although those outcomes would probably mostly eliminate the wild-animal impacts of climate change within centuries, they would also vastly multiply suffering throughout the cosmos in other ways.