Scientists sound the alarm as the world briefly breaks two-degree warming limit for the first time

The Earth’s temperature has briefly risen above a crucial threshold that scientists have been warning for decades could have catastrophic and irreversible impacts on the planet and its ecosystems.

For the first time, the global average temperature on Friday last week was more than 2 degrees Celsius hotter than levels before industrialisation.

That’s according to preliminary data shared on X (formerly Twitter) by prominent climate scientist Samantha Burgess, deputy director of the Europe-based Copernicus Climate Change Service.

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The threshold was crossed just temporarily and does not mean the world is at a permanent state of warming above 2 degrees.

But it is a symptom of a planet becoming steadily hotter and hotter, and moving towards a longer-term situation where climate crisis impacts will be difficult — in some cases impossible — to reverse.

“Our best estimate is that this was the first day when global temperature was more than 2°C above 1850-1900 (or pre-industrial) levels, at 2.06°C,” Burgess wrote.

Burgess said in her post that global temperatures on Friday averaged 1.17 degrees above 1991–2020 levels, making it the warmest November 17 on record.

But compared to pre-industrial times, before humans began burning fossil fuels on a large scale and altering the Earth’s natural climate, the temperature was 2.06 degrees warmer.

The breach of 2 degrees on Friday came two weeks before the start of the UN COP28 climate conference in Dubai.

That’s where countries will take stock of their progress towards the Paris Climate Agreement pledge to limit global warming to 2 degrees above pre-industrial levels, with an ambition of limiting it to 1.5 degrees.

One day above 2 degrees of warming “does not mean that the Paris Agreement has been breached”, Burgess told CNN.

“But (it) highlights how we are approaching those internationally agreed limits,” she said.

“We can expect to see increasing frequency of 1.5 degrees and 2 degree days over the coming months and years.”

Copernicus’ data is preliminary and will require weeks to be confirmed with real-life observations.

The world already looks on track to breach 1.5 degrees of warming on a longer-term basis in the next few years.

That’s a threshold beyond which scientists say humans and ecosystems will struggle to adapt.

A UN report published on Monday showed that even if countries carried out their current emissions-reduction pledges, the world would reach between 2.5 and 2.9 degrees of warming sometime this century.

But 1.5 is not a cliff edge for the Earth — every fraction of a degree it warms above that, the worse the impacts will be.

Warming to 2 degrees puts far more of the population at risk of deadly extreme weather and increases the likelihood of the planet reaching irreversible tipping points.

Those include the collapse of polar ice sheets and the mass death of coral reefs.

Urgency underscored

Richard Allan is professor of climate science at the University of Reading in the UK.

He called the breach a “canary in the coalmine” which “underscores the urgency of tackling greenhouse gas emissions”.

But he added that it was “entirely expected that single days will surpass 2 degrees above pre-industrial well before the actual 2 degrees Celsius target is breached over many years”.

The data comes on heels of extreme weather events, supercharged by the climate crisis — including fires in Hawaii, floods in northern Africa and storms in the Mediterranean — all of which have claimed lives.

Scientists are increasingly expressing alarm that data on temperatures are exceeding their predictions.

A string of reports checking the health of the Earth’s climate and humans’ actions to combat it in recent weeks show that the planet is careening toward a dangerous level of warming, and not doing enough to mitigate or adapt to its impacts.

A UN report last week found that according to countries’ climate plans, planet-heating pollution in 2030 will still be 9 per cent higher than it was in 2010.

According to the Intergovernmental Panel on Climate Change, the world needs to decrease emissions by 45 per cent by the end of this decade, compared to 2010, to have any hope of limiting global warming to 1.5 degrees Celsius above pre-industrial levels.