Climate change is like a snowball effect, except, well, hot.
Why it matters: Like a snowball that begins small and grows larger by building upon itself, numerous feedback loops embedded in our atmosphere and society are exacerbating climate change.
Driving the news: Scientists are well acquainted with feedback loops, but the often wonky topic doesn’t break through into the mainstream despite its importance to how much the world warms and how much we respond to that warming.
- As we soak up the last of these hot summer days, and extreme weather hits parts of the country, today seems a fitting time to break this down for those of us without a Ph.D.
Here are seven feedback loops in science and beyond, and click here for the full column that goes deeper on each loop.
1. Air conditioning: Climate change is making our summers hotter, so we use more air conditioners, which emit greenhouse gases, which heats up our planet more, so we use even more AC, which heats up our planet even more. ... You get the cycle.
2. Water evaporation: Ever-warmer air in the atmosphere leads to more water evaporation, which results in water vapor, which itself is a greenhouse gas and traps heat. That increased water vapor retains ever more heat, which leads to more water evaporation, which…
3. Permafrost: It’s like a massive freezer thawing atop the world, notes Philip Duffy, climate scientist and president of the nonprofit Woodwell Climate Research Center. Nearly a quarter of Northern Hemisphere land has permafrost underneath it.
- As the warm worlds, organic matter — plants and dead animals frozen for tens of thousands of years — starts to decompose. “Those decomposition processes emit greenhouse gases,” Duffy says.
4. Albedo feedback: Lighter surfaces reflect heat more, so as ice and other cold places get warmer (i.e., the Arctic and other permafrost), their ability to reflect heat diminishes and they soak up more heat.
5. Wildfires: Trees, by definition, embody carbon. So when wildfires burn them down, carbon dioxide is emitted.
6. Policy and economic paralysis: The longer we wait to address climate change with major government action, the bigger the policy needed and the bigger economic impact that policy will have.
- Yes, but: Plausible future scenarios also exist where the impacts of a warming world grow so intense and/or clean-energy technologies become so cheap that eventually these aforementioned feedback loops are broken.
7. Geopolitics: It takes global cooperation to address climate change, given its global nature. But climate change impacts different countries differently, so they're more likely to act on their own, and in their own self-interest.