A warming cap provides governments and businesses a needed signal to implement climate policies and investment strategies. After years of advocacy by AOSIS and other groups—and organizations such as WWF—1.5°C became the global benchmark, included in the Paris Agreement of 2015 and endorsed by the UN.
In 2018, the Intergovernmental Panel on Climate Change (IPCC), the UN’s climate science body, published a comprehensive assessment of a 1.5°C limit. The report clearly set out what’s at stake. In a world 2°C warmer than preindustrial levels, 2 billion people would be exposed to extreme heatwaves at least once every 20 years and over 1 billion to drought and desertification. There would also be a 170% increase in flood risk compared to today. Keeping the world under 1.5°C warmer, on the other hand, could lessen the number of people exposed to extreme heatwaves and drought by 1.3 billion and 200 million, respectively, and would mean a 70% lower risk of flooding than in the 2°C scenario.
The relative impacts are just as stark for wildlife and ecosystems. Biodiversity loss would increase from 14% in a 1.5°C world to 18% in a 2°C world. In a 1.5°C world, 70% of the world’s coral reefs would be lost by 2050, but virtually all warm water corals would be lost in a world 2°C warmer.
Recently, the IPCC published the Sixth Assessment Report—the most comprehensive assessment of the state of knowledge on climate change drivers, impacts, adaptation, and mitigation solutions in a decade. The report bolstered the findings of the 1.5°C assessment, but also gave us the dire warning that we are running out of time to achieve a cap of 1.5°C—and we must act now to keep this goal within reach. There are solutions available across all sectors that can reduce emissions by over 50% by 2030, an important milestone to limit warming to 1.5°C. But it is challenging. Countries have differing capabilities to act based on their access to money and resources. Some countries and companies are still taking a “you first” attitude, and every moment of delay makes it more unlikely the world will be able to limit warming to under 1.5°C.
Stephanie Roe, WWF’s global climate and energy lead scientist, and a lead author on the IPCC’s Sixth Assessment Report, says, “We have all the solutions and tools within our grasp. This decade is critical for ramping up implementation. We need to go bigger and faster to make real change happen in time.” In short, we need swift, dramatic, and collaborative action in the years leading up to 2030.