Climate

We May Have Just Bought Ourselves An Extra Decade To Avoid Catastrophic Climate Change

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The world appears to have bought itself a little time in the fight to avoid climate catastrophe, according to a new analysis.

Virtually every major country has made pledges to limit or reduce carbon pollution in advance of the Paris climate talks this December. These pledges generally end in 2025 or 2030, and so they only matter if the world keeps ratcheting down its greenhouse gas emissions in future agreements until we get near zero by century’s end. Otherwise we will blow past the 2°C line of defense against very dangerous-to-catastrophic global warming, and hit 3.6°C warming by 2100.

That’s the key finding of a new analysis from Climate Interactive and the MIT Sloan School of Business, tallying up the global pledges to limit carbon pollution leading up to the big Paris climate talks later this year.

Those pledges, called intended nationally determined contributions (INDCs), include the European Union cutting total emissions 40 percent below 1990 levels by 2030, the U.S. cutting net greenhouse gas emissions emissions 26 to 28 percent below 2005 levels by 2025 (including land use change and forestry), and China’s peaking in CO2 by 2030.

climate pledges

Impact of national climate pledges (aka INDCs) on world’s greenhouse gas emissions measured in CO2 equivalents (CO2e).

The good news, as you can see, is that the INDCs have bought us another five to 10 years of staying close to the 2°C path. I asked Andrew Jones, one of the systems-thinking savants behind Climate Interactive, if that was correct and he said, “Yep, about seven years.” By “staying close” I mean staying close enough to the 2°C path that it remains plausibly achievable — though (obviously) politically still very, very challenging.

Of course, like all emissions models, the Climate Interactive model makes assumptions about what is a plausibly achievable 2°C path given how long we have delayed acting. And that involves deciding how fast the world could plausibly cut its greenhouse gas emissions each year — sustained for many decades. They use 3.5 to 4 percent a year. That is mostly a political-economic judgment, since there is no real way of knowing how fast humanity could act once we become truly desperate to avoid multiple simultaneous catastrophes that are irreversible on a timescale of many centuries.

The point is that a successful outcome of Paris will not “solve the climate problem” and indeed won’t give us a 2°C world, as anyone who is paying attention understands. (Sadly, a lot of folks in the media aren’t paying attention.)

The bad news, of course, is that since about 2007 leading climate experts have been explaining we only have five to 10 years to act. I debunked the myth that they’ve “always” been saying that in my May post, “The Really Awful Truth About Climate Change.”

So what Paris can accomplish is to give us another five to 10 years of … having five to 10 years to act!!! Woo-hoo.

In reality, international climate talks can never buy us more than five to 10 years at a time — until and unless countries are willing to make long-term multi-decade CO2 reduction commitments as the United States tried to do with the 2009 climate bill that was killed in the Senate. Stabilizing at 2°C requires taking global emissions down to near zero steadily by century’s end. Most Paris CO2 commitments are for 2025 or 2030.

Still, this would be an important accomplishment — and one that mirrors the incremental approach the world took to save the ozone layer. As NASA’s Gavin Schmidt told the New York Times, “By the time people get 10, 15 years of actually trying to do something, that’s going to lead to greater expertise, better technology, more experience.” Schmidt, who heads the same climate team James Hansen once did, added, “People will then say, ‘Oh, you know what? We can commit to do more.’”