We’re passing a dangerous global warming threshold — but we’re not doomed |
For the last decade, global climate politics have revolved around a single number: 1.5 degrees Celsius.
The idea was that keeping the planet below this warming threshold would hold many of the worst impacts of climate change in a manageable range. Cross it, and the risks rise sharply into uncharted territory.
This year, it became clearer than ever that we will cross it.
Key takeaways
The window of opportunity has closed on the 1.5°C climate target. Though the growth rate of greenhouse gases has started to level off, they would need to decline at an impossibly fast pace to keep the planet from warming more than 1.5°C. Overshooting this goal means more severe consequences from warming. Rising global average temperatures mean more extreme heat waves, rising sea levels, severe droughts, and floods. There may also be irreversible “tipping points” in natural systems, such as the loss of ice shelves and forests. Adaptation is more important than ever. Humanity will need to learn to live in a warmer world, but there isn’t much research into what exceeding 1.5°C of warming will mean for economics, politics, and society. Decarbonization is still underway. Wind, solar, and battery storage are growing rapidly and becoming cheaper than fossil fuels, offering an economic argument for curbing emissions beyond climate change. Every bit still matters. Missing the 1.5°C goal doesn’t mean giving up on limiting climate change. Every fraction of a degree of warming that we avoid will save lives, money, and ecosystems.Climate scientists have been warning for years that we’ve already backed ourselves into a corner where even the most optimistic forecasts of humanity’s efforts to address climate change will breach this threshold. Now this year, even some of the loudest voices calling for global action to curb emissions have begun to drop the pretense.
“Scientists tell us that a temporary overshoot above 1.5 degrees [Celsius] is now inevitable,” UN Secretary-General António Guterres said in November. “And the path to a livable future gets steeper by the day.”
Under the 2015 Paris climate agreement, countries agreed to limit the increase in global average temperatures this century to “well below” 3.6 degrees Fahrenheit (2 degrees Celsius) compared to the start of the industrial revolution. The goalpost for national commitments to cutting emissions of heat-trapping gases was 1.5 degrees C — or 2.7 degrees Fahrenheit.
In 2018, the Intergovernmental Panel on Climate Change, a team of climate change researchers convened by the United Nations, examined the differences between the two benchmarks and concluded that every bit of warming is consequential, and that in general, the hotter it gets, the worse it gets for humanity. Higher average temperatures will lead to more extreme heat........