Global temperatures have exceeded 1.5°C warming for a full year, threatening global commitments made under the Paris Agreement.
According to data from the European Union’s Copernicus Climate Change Service, it is the first time that global temperatures have consistently surpassed 1.5°C of warming over the past 12 months.
This warming trend raises concerns about meeting the goals of the Paris Agreement, which aims to limit global warming to well below 2°C above pre-industrial levels.
A climate scientist from the Australian Research Council’s Centre of Excellence for Climate Extremes, Dr Kim Reid, said these temperatures do not break Paris Agreement commitments but it does bring the world much closer to the red line.
“This breach of 1.5°C for the last 12 months isn’t a death knell for the Paris Agreement, but it is a fire alarm, and we need to wake up and put out this fire,” she said.
While 1.5°C is not a binding target of the agreement, Reid explained that limiting global warming to as close to this value as possible is crucial to avoid the worst impacts of climate change.
“The risks associated with extreme weather events, sea level rise, biodiversity loss, and disruptions to ecosystems and human societies are significantly larger in a 2°C warmer world compared to a 1.5°C warmer world. Humanity’s ability to adapt to climate change will become increasingly challenging above 2°C,” Reid said.
“In the case of extreme weather events, for example, the warmer the atmosphere, the more water vapour it can hold. This, in turn, increases the potential for heavy rainfall events, tropical cyclones and severe thunderstorms.
“The probability of passing crucial tipping points also increases with every fraction of a degree of warming.”
Why did temperatures exceed 1.5°C in the past year?
Reid said the warming trend over the past decades is caused by the burning of fossil fuels. “This human-caused warming is also responsible for much of the rise in temperatures observed over the past 12 months,” she said.
“On top of that El Niño – a natural climate phenomenon associated with the increase in ocean temperatures in the central and eastern tropical Pacific Ocean – gave global surface temperatures an extra boost.”
In the period from July 2023 to June 2024, global temperatures hit record highs, peaking at 1.64°C above the pre-industrial average.
“If we continue burning fossil fuels, we’ll see more and more years above 1.5°C and we’ll move closer and closer to warming exceeding 1.5°C on average,” Reid said.
“We do need to ramp up our efforts to make sure we do not cross that line. And this can only be done by drastically reducing our emissions.
“Forget 2050, we need net zero by 2035 if we want to stay below 1.5°C.”
The ARC Centre of Excellence brings together five Australian universities and a suite of national and international partner organisations.
