During the first decade of the 21st century, scientists and policymakers emphasized a 2°C cap as the highest “safe” limit for global warming above pre-industrial levels. Recent research suggests that this threshold might still be too high. Rising sea levels pose a significant risk to low-lying islands, prompting scientists to explore the advantages of capping temperature rise at approximately 1.5°C for safeguarding vulnerable regions.
In light of this evidence, the United Nations negotiating bloc, the Alliance of Small Island States (AOSIS), advocated for a global commitment to restrict warming to 1.5°C, emphasizing that allowing a 2°C increase would have devastating effects on many small island developing nations.
James Fletcher, the former UN negotiator for the AOSIS bloc at the 2015 UN COP climate change summit in Paris, remarked on the challenges faced in convincing other nations to adopt this stricter global objective. At one summit, he recounted a low-income country’s representative confronting him, expressing their vehement opposition to the idea of even a 1.5°C increase.
After intense discussions, bolstered by support from the European Union and the tacit backing of the United States, as well as intervention from Pope Francis, the 1.5°C target was included in the impactful 2015 Paris Agreement. However, climate scientists commenced their work without a formal evaluation of the implications of this warming level.
In 2018, the Intergovernmental Panel on Climate Change report confirmed that limiting warming to 1.5°C would provide substantial benefits. The report also advocated for achieving net-zero emissions by 2050 along a 1.5°C pathway.
These dual objectives quickly became rallying points for nations and businesses worldwide, persuading countries like the UK to enhance their national climate commitments to meet these stringently set goals.
Researchers at the University of Leeds, including Piers Foster, attribute the influence of the 1.5°C target as a catalyst driving nations to adhere to significantly tougher climate goals than previously envisioned. “It fostered a sense of urgency,” he remarks.
Despite this momentum, global temperatures continue to rise, and current efforts to curb emissions are insufficient to fulfill the 1.5°C commitment. Scientific assessments predict the world may exceed this warming threshold within a mere few years.
Nevertheless, 1.5°C remains a crucial benchmark for tracking progress in global emissions reductions. Public and policymakers are more alert than ever to the implications of rising temperatures. An overshoot beyond 1.5°C is widely regarded as a perilous scenario, rendering the prior notion of 2°C as a “safe” threshold increasingly outdated.
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Source: www.newscientist.com
