We are heading toward IPCC's 1.5 C threshold of warming, but all is not lost

When the Paris Agreement was adopted by 196 countries in 2015, the goal was to limit global warming to 2 C above pre-industrial levels (1850–1900) by the end of the century. In 2018, that goal was shifted to limiting it to 1.5 C in order to avoid some of the worst global catastrophes.

But that 1.5 C threshold is slipping away.

Monday's IPCC synthesis report (referred to as AR6) notes that although we are more likely than not to reach 1.5 C in the "near term," it could drop back below that by the end of the century. 

"It has become increasingly clear that, on our current path, that we will reach that 1.5-degree limit sometime in the 2030s," UN Secretary-General Antonio Guterres said following Monday's IPCC report. 

Right now, the planet has warmed between 1.1 C and 1.3 C, and we are already seeing the repercussions, from increased deadly wildfires and flooding to droughts. 

As we edge ever closer toward that 1.5 C, it may leave one with a sense of defeat, of helplessness, that we have failed and that we might as well give up. But that shouldn't be the case.

"The conclusions from the last IPCC report were so clear. They said every bit of warming matters. And if we give up, we are doomed," said Katharine Hayhoe, Nature United's Global Chief Scientist. 

In fact, here's the good news: Before the Paris Agreement, the world was on track to reach 3.5 C of warming before the end of the century. However, since then, we are on track to reach 2.5 C. But with announced pledges from countries, it could limit warming to 1.7 C, and if we reach net zero by 2050, it could limit warming to 1.5 C.

The point? Every action policymakers and industry leaders take in reducing greenhouse gas emissions means less CO2 in the atmosphere, which will limit warming. And every degree matters. 

It was a bit surprising to see the acknowledgement in Monday's report that we are more likely than not to surpass 1.5 C, as there has been some debate as to whether scientists should even mention the fact that we are likely to miss the 1.5 C target. 

In 2020, the group Scientist Rebellion was formed by scientists from around the world demanding more action. They have taken to the streets in civil disobedience, by blocking roads, protesting and pasting climate-related articles to places such as ScottishPower, a gas and electric company.

Most recently, they penned an open letter that in part said that governments should "make clear the inevitability of missing the 1.5 C goal as laid out by the IPCC in its latest [AR5] assessment."

Climate scientist Peter Kalmus is one of the signatories. (His views on the matter are his own, and do not represent his employer, NASA).

"I just think it's time for us to be grownups. Basically, we have to look at what's really happening and respond to it. And if we're not willing to look at what's really happening, and we just try to not think about it, then we can't stop it," he said.