A streak of record-setting heat that began last summer has now persisted for an entire year across the globe, researchers announced Wednesday, pushing Earth closer to a dangerous threshold that the world’s nations have pledged not to cross.
The data released by European climate scientists showed May was the 12th consecutive month during which average global temperatures surpassed all observations since 1850, and probably any extended period for more than 100,000 years. Over the past year, according to the European Union’s Copernicus Climate Change Service, global temperatures averaged 1.6 degrees Celsius (2.9 degrees Fahrenheit) above preindustrial levels.
Under the landmark 2015 Paris agreement, the world’s leaders pledged to limit Earth’s temperature rise to 1.5 degrees C (2.7 degrees F) over preindustrial levels, to avert some of the worst effects of global warming. The fact that the planet surpassed this mark for one year does not amount to a permanent shift, but it comes as scientists are warning that it is likely to happen again - within a few years.
The World Meteorological Organization said that it is highly likely that, for at least one calendar year in the next five, temperatures will exceed 1.5 degrees C above preindustrial levels once more.
This unprecedented stretch of warmth, which has astonished scientists, prompted an urgent call by the United Nations to ban fossil fuel companies from advertising and encourage the public to stop using their products.
“For the past year, every turn of the calendar has turned up the heat,” U.N. Secretary General António Guterres said in a special address in New York. “Our planet is trying to tell us something. But we don’t seem to be listening.”
Researchers have linked the rise in temperatures to the El Niño climate pattern and decades of global heating from human emissions of greenhouse gases.
A decade ago, scientists had estimated that the chances of the planet warming 1.5 degrees C by 2020 were nearly zero. Now, the probability of that happening by 2028 is an estimated 8 in 10.