2024 Breached 1.5c Threshold

Last year, for the first time, the world exceeded the internationally agreed target of limiting global warming to 1.5°C above preindustrial levels. The average global temperature reached 1.6°C. While the Paris Agreement target is assessed over a 10-20 year period rather than a single year, this sobering milestone provides a stark indication of the trajectory we are currently on. The continued burning of fossil fuels is the primary cause of this warming. 

The 1.5°C threshold has become a powerful symbol in climate discussions since its adoption in the 2015 Paris Agreement. It should not be seen as a goal to aim for, but as a critical limit, representing the boundary beyond which the Earth's fundamental systems risk undergoing profound and potentially irreversible changes.

Last week UN chief António Guterres described the recent run of temperature records as "climate breakdown".

Dr Friederike Otto, at Imperial College London, said: “This record needs to be a reality check. A year of extreme weather showed just how dangerous life is at 1.5C. The Valencia floods, US hurricanes, the Philippines typhoons and Amazon drought are just four disasters last year that were worsened by climate change. There are many, many more.”

The world is on track to surpass the 1.5c target exponentially, and it is estimated that it could breach 2.7c by the end of the century. The last 10 years have been the hottest decade on record. 

A one-degree global temperature change is profoundly significant, as it requires an immense amount of heat to warm the oceans, atmosphere, and land masses collectively. Historically, even small temperature shifts have had dramatic consequences—a drop of just one to two degrees was sufficient to trigger the Little Ice Age, while a five-degree drop buried much of North America under massive ice sheets 20,000 years ago.

While this figure serves as a stark reminder of how far we still have to go and the sobering reality of our current trajectory, much will depend on future commitments. This is particularly critical in light of the inauguration of Donald Trump, who has shown limited interest in environmental regulation.