Net Zero Emissions And The Climate Crisis
Explainer: Will global warming ‘stop’ as soon as net-zero emissions are reached?
Zeke Hausfather, 29 April 2021 (Carbon Brief)
“…[W]arming is likely to more or less stop once carbon dioxide (CO2) emissions reach zero, meaning humans have the power to choose their climate future…Even in a world of zero CO2 emissions, however, there are large remaining uncertainties associated with what happens to non-CO2 greenhouse gases (GHGs), such as methane and nitrous oxide, emissions of sulphate aerosols that cool the planet and longer-term feedback processes and natural variability in the climate system…[But] temperatures are expected to remain steady rather than dropping for a few centuries after emissions reach zero, meaning that the climate change that has already occurred will be difficult to reverse in the absence of large-scale net negative emissions…
…[Combining all uncertainties,] the best estimate of the effects of zero CO2 is around 0C +/- 0.3C for the century after emissions go to zero, while the effects of zero GHGs and aerosols would be around -0.2C +/- 0.5C…Finally, while current best estimates suggest that temperatures will stabilise in a zero-emissions world, that does not mean that all climate impacts would cease to worsen…Melting glaciers and ice sheets and rising sea levels all occur slowly and lag behind surface temperature warming. A zero-emissions world would still result in rising sea levels for many centuries to come, with some estimates suggesting that at least 80cm of additional sea level rise is “locked in”…To stop these impacts may, ultimately, require reducing global temperatures through net-negative global emissions, not just stopping temperature from rising by reaching net-zero.” click here for more