Scientists moderately optimist with COP26 pledges

Two groups of scientists expressed optimism Thursday about lessening the potential temperature rise, bolstered by pledges made at the COP26 climate conference in Glasgow.

The two reports, one by the International Energy Agency and the other by a team of Australian scientists, focused on optimistic scenarios where recent actions may have trimmed two-tenths or three-tenths of a degree Celsius (0.3 to 0.5 degrees Fahrenheit) from temperature increase projections made in mid-October.

Instead of 2.1 degrees Celsius (3.8 Fahrenheit) of warming since pre-industrial times, they project 1.8 (3.2 degrees Fahrenheit) or 1.9 degrees (3.4 degrees Fahrenheit).

Still both projections are far from the 1.5 degrees Celsius (2.7 degrees Fahrenheit) of warming since pre-industrial time that is the over-arching goal of the 2015 Paris climate deal.

The world has already warmed 1.1 degrees Celsius (2 degrees Fahrenheit).

"We are now in a slightly more positive outlook for the future," said University of Melbourne climate scientist Malte Meinshausen, whose flash analysis, not peer-reviewed, sees warming at 1.9 degrees, mostly because of late long-term pledges by India and China.

He did concede it was still a long way from the 1.5 degrees that was previously aimed for.

The energy agency's analysis looked at India's announcement of short-term carbon dioxide emission curbs and a net-zero pledge by 2070 on Monday and more than 100 countries pledging Tuesday to reduce the powerful greenhouse gas methane.

The agency said it was the first time projections fell below 2 degrees Celsius, a long-standing threshold for tipping points that could bring even more dangerous and potentially uncontrolled warming, according to some scientists.

Potsdam Institute for Climate Impact Research Director Johan Rockstrom touted Meinshausen's research, saying a big factor is India's long-term net zero goal for 2070.

He said these changes are key.

"So 1.5 means something really from a stability perspective on the planet," Rockstrom said.

Both teams emphasize that this is based on the most optimistic scenarios possible, using nations' mid-century, or in India's case 2070, pledge of net zero emissions that are far from codified in plans or actions.

Scenarios that look at just short-term pledges, not net-zero ones, puts warming at 2.7 degrees Celsius (4.9 degrees Fahrenheit).