What impact the promises of COP26 may have on global warming

At the equator of the COP26 Glasgow, after a week full of big announcements from countries promising to reduce their greenhouse gas emissions, what real impact can these commitments have on the global warming?

The latest emission reduction pledges – known as Nationally Determined Contributions, or NDCs – for 2030, ahead of the Glasgow conference, put the Earth on the path to an average temperature rise of + 2.7 ° Celsius this century.

Assuming all additional commitments to achieve carbon neutrality by 2050 are maintained and fully met, warming would be limited to + 2.2 ° Celsius.

In the 2015 Paris Agreement, countries pledged to limit the rise in temperature “well below” 2 ° Celsius and to work towards the target of + 1.5 ° Celsius.

This week there were new announcements, including India’s commitment to achieve carbon neutrality by 2070, promises from Brazil and Argentina to strengthen their short-term targets, and the determination of a hundred countries to reduce their carbon emissions by 30%. methane gas by 2030.

Experts believe that all this could have a significant effect on warming, but it is still difficult to calculate.

1.8 ° Celsius?

Fatih Birol, executive director of the International Energy Agency, said on Thursday that, according to an as-yet-unpublished analysis from his organization, if all COP26 commitments are met, warming would be limited to + 1.8 ° Celsius.

However, he stressed that this figure is highly dependent on countries making the rapid emissions cuts necessary to meet their carbon neutrality plans.

“What is essential is that governments turn their promises into clear and credible political actions and strategies today,” he asked.

1.9 ° Celsius?

An evaluation by the University of Melbourne this week analyzed the new pledges of net zero emissions from countries, including those of India and China – the world’s largest emitter – and concluded that they represent an “important step” towards limiting warming to + 1.5 ° centigrade.

The team applied the same climate model used in the latest report from the Intergovernmental Panel on Climate Change (IPCC) to NDCs.

And it determined that, with a “50% probability”, if the new promises made by 194 countries are added, the Earth would warm by 1.9 ° C by 2100.

Too early to specify

The UN released a preliminary assessment of the new NDCs on Thursday.

Although it has not yet converted the calculations into its temperature equivalent, it found that the latest plans would mean an increase in emissions of 13.7% in 2030 compared to 2010.

It is somewhat better than the 16% of the previous assessment made in October, but it is a long way from the 45% reduction required for the + 1.5 ° C target.

The United Nations Environment Program (UNEP) said last month that only a reduction in emissions in this decade eight times higher than expected would limit warming to +1.5 ° Celsius.

Its director, Inger Andersen, assured that she welcomes the figures circulating after the first week of COP26.

“But we do not make calculations on the back of an envelope, but a technical job,” he stressed. “Obviously, the more ads there are, the better, but these ads have to be followed by actions.”

Still insufficient

Even if Birol’s optimistic assessment were confirmed, NGOs note that it would exceed + 1.5 ° Celsius and that every tenth of a degree will cause a series of additional devastating catastrophes.

“If we reach + 1.5 ° Celsius, some countries will just disappear from the map. So what we have to get out of these figures is that we don’t just need words, we need actions ”, commented Juan Pablo Osornio, from Greenpeace.

For his part, the United States envoy for the climate, John Kerry, considered that, despite the new promises made in Glasgow, “there is work to be done.”