Two recently published authoritative scientific reports confirm new global temperature records but insufficient mitigation actions.
It was just on November 30th, on the first day of COP28 in Dubai, that the Provisional State of the Global Climate 2023 report of the World Meteorological Organization (WMO), among the most authoritative scientific documents in the field of climate science, was released.
The key message of the Report is that 2023 is on track to set a new global average temperature record and confirms itself as the warmest year on record to date. Indeed, observations collected up to the end of October show a positive anomaly of about 1.40°C (with an uncertainty of ±0.12°C, to be precise) compared to the average of the pre-industrial period, identified by convention with the years 1850-1900. The individual months of June, July, August, September and October (and very likely, November) also proved to be the warmest since observations began 174 years ago. To date, the difference between 2023 and 2016 and 2020, the two years previously ranked as the hottest (recording anomalies of 1.29 and 1.27 °C, respectively), is such that it is absolutely unlikely that the ranking will be altered by the last two months of the year.
Besides confirming the progressive long-term anthropogenic global warming, the significant warming that occurred between 2022 and 2023 can plausibly be attributed to the development in September 2023 of El Niño, a periodic climatic phenomenon that causes strong warming of Pacific Ocean waters, scientists explain. In May, the WMO warned that El Niño would likely lead to more intense global warming, with more pronounced effects expected in 2024.
So how far are we from the warming thresholds set by the 2015 Paris Agreement?
During COP21, the international community recognized the need to limit global warming to well below 2°C and to continue to make all efforts not to go beyond 1.5°C in order to avoid serious negative and potentially catastrophic impacts on the environment and human communities. Currently, recent data provided by the Copernicus Climate Change Service (C3S) revealed that on November 17 and 18, 2023, for the first time, the Earth’s global average surface temperature exceeded the critical threshold of 2 °C relative to pre-industrial levels, albeit by only 6-7 hundredths of a degree.
“While exceeding the 2°C threshold for a number of days does not mean that we have breached the Paris Agreement targets, the more often that we exceed this threshold, the more serious the cumulative effects of these breaches will become,” said Carlo Buontempo, director of C3S, commenting on these data. Although climate change is measured over reference periods of the order of decades, this is a truly worrying sign when one also considers that, during 2023, there are already 86 days on which the “safe” threshold of 1.5°C has been exceeded.
Neglecting daily and yearly fluctuations, stable exceedance of the 1.5°C limit may be closer than it appears if swift and decisive action is not taken: experts speculate that it could occur between 2030 and 2050, but to date the most up-to-date C3S estimates, based on temperature trends over the past 30 years, predict it by 2034.
What is the gap between the mitigation action in place and the one we need?
Published ten days before the WMO report, the United Nations Environment Program (UNEP) Emissions Gap Report 2023 has a title that leaves no room for doubt: “Broken Record – Temperatures hit new highs, yet world fails to cut emissions (again)”. In fact, despite progress since the signing of the Paris Agreement, greenhouse gases emissions are still projected to rise in 2030, by 3 % compared to the 28 % reduction needed to follow a trajectory that meets the 2°C threshold and as much as 42 % for the 1.5°C target.
In light of current mitigation policies and assuming full implementation of the Nationally Determined Contributions (NDCs) by all signatory countries to the Paris Agreement, it is estimated that the level of global warming would reach values between 2.5 and 3 °C above the pre-industrial average. In the most optimistic scenario, the probability of not exceeding the 1.5 °C threshold is only 14 %. The report therefore calls on Nations to accelerate and strengthen decarbonization action, going beyond the emission reductions promised for 2030. Countries with the greatest capacity and responsibility for emissions, particularly high-income and high-emitting countries belonging to the G20, UNEP says, need to take more ambitious action while supporting developing countries technically and financially in their pursuit of low-emission growth at the same time. The next round of NDCs, scheduled for 2025 with targets to 2035, will be a key step in bringing about greater climate ambition and emission pathways consistent with the thresholds of the Paris Agreement, also considering the results of the COP28 first Global Stocktake.
Finally, the UNEP report warns that further delays in mitigating greenhouse gas emissions will result in a greater reliance on atmospheric carbon dioxide removal solutions in the future, such as nature-based solutions (e.g., reforestation and forest management) or innovative capture and storage technologies, with their associated limitations and critical issues.