In 2015, in Paris, the nations of the world committed themselves to trying their best to prevent the planet warming by more than 1.5℃ from its pre-industrial state. Even at the time, the goal looked ambitious. In recent years, it has come to seem almost impossible.
On May 17th， 2023 the World Metcorological Organization (WMO), an arm of the United Nations, added to the gloom. It said there was a 66% chance that the world would go beyond the 1.5℃ threshold (关口) in at least one of the next five years. That is a big jump from its estimates of even a year ago, when the WMO assessed the likelihood at 48%. Even if the 1.5℃ target is not breached (突破) , the WMO thinks it is virtually certain that one of the coming five years will be the hottest in human history.
The biggest of those variations is the EI Nino Southern Oscillation (ENSO), a natural cycle of warming and cooling in the waters of the eastern Pacific Ocean hat has widespread effects on the climate. The world has just seen three"La Nina" years in a row, the name given to the cooler phase of the cycle, helping hold global temperatures down. It now seems almost certain that a warmer"EI Nino" phase will begin sometime later this year, setting up 2024 to be a very hot year.
However, there are also some encouraging signs. Global emissions of greenhouse gases from fossil fuels seem to have gone sideways for several years, leading some researchers to speak cautiously of a possible peak. Rystad Energy, a Norwegian think-tank, predicted earlier this year that global emissions of carbon dioxide from industry could peak in 2025 and then begin a slow decline.
Even so, the world's actions still fall far short of its promises. Even the upper end of the goals agreed in Paris- of limiting warming to "well below 2℃"- will be achievable only with serious action. For Europe and America to meet their commitments, for instance, would require them to switch off all their fossil-fired power plants within the next three decades.And simply stopping emissions will not be enough.
