The warmest seven years have all been since 2015, the UN's World Meteorological Organization said in a statement. And despite the fact that two consecutive La Nina events captured global attention for large portions of the year, 2021 still ranked among the seven warmest years on record, the WMO said.
Back-to-back La Nina events mean that 2021 warming was relatively less pronounced compared to recent years. Even so, 2021 was still warmer than previous years influenced by La Nina, WMO chief Petteri Taalas said in the statement.
This, he said, shows that "the overall long-term warming as a result of greenhouse gas increases is now far larger than the year-to-year variability in global average temperatures caused by naturally occurring climate drivers.
La Nina refers to the large-scale cooling of surface temperatures in the central and eastern equatorial Pacific Ocean, with widespread impacts on weather around the world.
The phenomenon, which typically has the opposite impacts as the warming El Nino phenomenon, usually occurs every two to seven years, but has now hit twice since 2020.
