Earth exceeds critical warming threshold, officials say

For the first time since records began, the Earth has surpassed a critical temperature threshold that scientists have long warned could trigger the worst effects of climate change.

On Friday, the planet rose 2.07 degrees Celsius above pre-industrial levels, or the average from 1850 to 1900, according to the European Copernicus Climate Change Service.

Two degrees Celsius (or 3.6 degrees Fahrenheit) is the internationally agreed upon upper limit of warming set in the 2015 Paris climate agreement. The agreement seeks to keep global temperature rise well below that limit, and preferably by below 1.5 degrees Celsius, recognizing that “this would significantly reduce the risks and impacts of climate change.”

Copernicus officials shared the finding on Monday in a publish in X. Assistant Principal Samantha Burgess said preliminary data They also show that Saturday’s global temperature measured 2.06 degrees Celsius above pre-industrial levels, indicating that “there are now two days in November 2023” where the temperature exceeded the benchmark.

Scientists have long warned that sustained warming of 1.5 degrees or more will generate cascading risks to human and planetary systems, including negative impacts on ecosystems, biodiversity, water supplies and food security. According to the Intergovernmental Panel on Climate Change, warming land and ocean temperatures are already contributing to rising sea levels, melting ice sheets, and increased hazards such as heat waves, droughts, and extreme precipitation.

While significant challenges are expected for many regions and systems with 1.5 degrees warming, “the risks would be greater with 2 degrees Celsius warming and even greater effort would be needed to adapt to a temperature increase of that magnitude.” says the IPCC.

However, caution should be used when dealing with data from a single day, said Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies. He noted that the terms of the Paris climate agreement have more to do with sustained and prolonged warming to those temperatures.

Exceeding 2 degrees once or twice does not indicate a point of no return, Schmidt said. But the record-breaking weekend is worth noting in the context of broader trends.

“Is the planet warming? Yes,” Schmidt said. “Are we going to see days of temperatures above 2 degrees before we have weeks of temperatures above 2 degrees, before we get to months, before we get to years? Yes. And is the planet going through exceptional warming right now? The answer is yes, yes it is. 2023 is proving to be exceptional in both impacts and these metrics.”

In fact, Monday’s announcement came just weeks after officials warned that 2023 is on track to become Earth’s warmest year on record after record-breaking June, July, August, September and October. Most of the warming is attributed to greenhouse gas emissions from burning fossil fuels, although experts say this year’s strengthening El Niño is also playing a role, as the weather pattern is associated with warmer global temperatures.

Researchers have also postulated that last year’s eruption of the Hunga Tonga-Hunga Ha’apai volcano in the South Pacific may be contributing to extreme warming this year. The eruption spewed record amounts of heat-trapping water vapor into the atmosphere.

Additionally, a study published this month by renowned climate scientist James Hansen said a recent change in aerosol shipping regulations could be a contributing factor. Regulations reduced the amount of sulfur allowed in fuels in an effort to improve air quality, but the change may have had an unwanted planetary warming effect because the aerosols reflected sunlight away from Earth.

However, not all hope is lost. The Fifth National Climate Change Assessment, released last week by the White House, underscored that every fraction of a degree of warming added or avoided will make a difference.

The report “clearly shows that for every tenth of a degree of warming avoided, we save, we prevent risks, we prevent suffering,” Katharine Hayhoe, one of its authors, told The Times.

The news also comes ahead of COP28, an international climate conference taking place later this month in Dubai.