The United Nations’ COP26 climate talks have pledged new net-zero emission goals that could help avoid a climate catastrophe. However, adverse outcomes are still possible if countries don’t keep their promises.
The COP26 summit in Glasgow pledged to keep alive the chance of limiting global warming to 1.5° Celsius from pre-industrial levels in a draft agreement. Scientists say this rate gives the world the best chance of avoiding the worst effects of climate change scenarios. During the past years, temperatures have risen by 1.1°C, causing more extreme weather events such as devastating floods and heat waves.
The COP26 summit follows on a climate meeting of G20 leaders that fell short of anticipations, particularly on plans to phase out coal use.
If the meeting in Glasgow delivers on everything global leaders announced, including long-term and short-term promises, the Earth will warm by 1.8°C. While still a dangerous scenario, it means a considerable improvement over the 2.1°C of warming forecasted by the International Energy Agency in advance of the summit.
The agreement also has its weak spots. Participating countries can choose their baselines and assumptions. This variability makes it hard to tell whether national commitments are enough to successfully hit the 1.5°C target.
The best possible outcome of 1.8°C reflects the fulfillment of most new net-zero pledges from some of the world’s biggest polluters.
Another possible scenario discussed during the meeting considers only net-zero goals that were formally submitted to the UN. The documents are known as Nationally Determined Contributions. Based on this scenario, global warming would rise to 2.1°C.
Uncertainties shadow all the projected temperature outcomes. As a result, scientists can’t precisely predict how much global warming could be triggered by a certain amount of greenhouse gas emissions in the atmosphere.
Based on the most optimistic scenario, warming could be as low as 1.5°C or as high as 2.4°C.
The difficulties in predicting future rates of global warming are precisely why experts advocate for deeper emissions cuts.
The biggest absolute contributions to the drop in near-term emissions came from pledges made by China, the U.S. and the European Union. Other significant polluters like Indonesia did not submit stronger targets, while countries like Brazil even lowered their ambitions. This difference in approaches risks undermining optimistic projections of the COP26 results.
Saudi Arabia and Australia, global fossil fuel giants, also pledged zero emissions by 2060 and 2050, respectively. However, Australia didn’t upgrade its ambition for the end of the decade, while Saudi Arabia’s goals lack clarity in measuring its reductions.
The discrepancy between distant net-zero goals and short-term targets is a problem that should be addressed to achieve climate goals.