Will countries’ climate promises really limit warming to below 2 ° C?
Ambition is one of the keywords of the Climate Summit (COP26) that is being held these days in Glasgow. Reflected in the promises that each state has committed to fulfill in the long term, this aspiration must continue to strengthen if it is to prevent not only that the increase in temperature exceeds 2 ºC, but also 1.5 ºC.
We are much closer to reaching the 2 ° C target than six years ago, when the Paris Agreement was first signed
To do this, among the measures that were established in the Paris Agreement, approved six years ago, highlighted the nationally determined contributions (CDN), which represent objectives for the reduction of absolute greenhouse gas emissions in the entire economy of each country and which had to be updated every five years, a moment that corresponded to 2020. In this way, each state shows the world what it is willing to do to face the climate crisis.
“Each successive promise must represent a progression beyond the previous one in order to increase ambition. The commitments that have the most quantifiable impact are those that have full coverage of greenhouse gases and a clear roadmap towards net zero emissions in a given year ”, he tells SINC Allen Fawcett, head of the Climate Economics subdivision of the US Environmental Protection Agency.
By the end of September this year, more than 120 countries had already submitted their Enhanced CDNs. But although this represents an important step in the fulfillment of the climate pact, experts agree that it is still necessary to move from words to action.
A new analysis, published in the journal Science and led by Joint Global Change Research Institute in the United States, highlights that reinforced commitments by 2030 and decarbonization goals set for the year 2050 would prevent the possibility of achieving the worst climatic results with an increase of up to 4 ºC in the global average temperature by the end of the century.
“We are much closer to reaching the 2 ° C target than we were six years ago, when the Paris Agreement was first signed. The wave of strengthened climate commitments and zero-emission targets significantly increase our chances of staying below, ”announces Fawcett, one of the study’s authors.
The work thus assesses, in a rigorous way, how the increase in ambition represented in these new promises affects the possibilities of meeting the objectives of the Paris Agreement.
Yes it is possible to achieve the goal
After calculating the probabilistic results of temperature during the 21st century for five emission scenarios (from the non-contribution of new climate actions to updating commitments to achieve a 5% decarbonisation), the authors found that the updated pledges – both the NDCs and the climate neutrality commitments – provide in the short term a more solid basis for achieve the long-term goals of the Paris Agreement.
With higher ambition and increased commitments beyond 2030, the probability of staying below 2 ° C can rise to more than 60%
The researchers started from a hypothetical scenario of non-renewal of climate policies, in which no additional action would be taken on climate change, and another in which the parties would not meet their CDN targets and would continue to decarbonize beyond 2030 to pace of current policies.
The results of the research, which combined the promises of each country with the latest IPCC report, show that the NDCs presented before the Glasgow Climate Summit would be able to limit the increase in temperature to a greater extent than with the original promises from paris. With those of Glasgow we have about a third of possibilities of stopping the increase in temperature below 2 ºC.
That is, if countries meet the ambition represented in their NDCs, continue to increase ambition at a rate consistent with their current commitments, and formalize their net zero emissions (carbon neutral) targets, “then there is a 34% chance to limit the change in temperature below 2 ºC ”, emphasizes the expert.
But “with a higher ambition and an increase in commitments beyond 2030, the probability of staying below 2 ° C can increase to more than 60%. However, in order to reach 1.5 ºC, it would be necessary to further strengthen the commitments presented this year ”, points out Fawcett.
If countries do not meet their commitments, but only maintain their current policies until 2100, there is more than a 90% chance that the temperature will exceed 2 ºC
Hence the importance of COP26 in Glasgow. The summit is the first test for this reset and update mechanism of national contributions established in Paris in 2015. “If countries do not meet their commitments, but only maintain their current policies until 2100, we continue to largely rule out the worst climate outcomes of 4 ° C or more. However, there is more than a 90% chance that the temperature will exceed 2 ºC ”, concludes the researcher.
Yang Ou, et al. “Can updated climate pledges limit warming well below 2°C?” Science
Rights: Creative Commons.