Status: October 31, 2021 4:00 p.m.
The past few years have been significantly warmer than all previous years – according to the current report by the UN weather organization. 2021 was a little cooler than 2020 – but that does not change the warming trend. With all the drastic consequences.
The past seven years have been the warmest on record – the United Nations Weather Organization (WMO) announced at the start of the climate summit in Glasgow, Scotland. However, 2021 was – at least until now – on average a little cooler than the previous ones. The researchers see the reason for this primarily in the weather phenomenon “La Niña” at the beginning of the year, which had a cooling effect.
However, this does not change the long-term warming trend: Based on the measurements up to the end of September, the WMO is assuming a global average temperature of 1.09 degrees above the level from 1850 to 1900 this year. The warmest year so far was 2016, with plus 1.2 degrees. 2019 and 2020 were also in the order of magnitude. The differences between the three years were so minimal that a ranking is not possible. The WMO always calculates an average of the data from measuring stations around the world.
Sea levels rise faster
The scientists are also observing a stronger rise in sea levels, accompanied by a further increase in water temperatures. Between 1993 and 2002 the annual increase was 2.1 millimeters, between 2013 and 2021 4.4 millimeters. The rise in sea levels is due to melting ice and the expansion of salt water due to warming. In addition, the oceans acidify: The surface pH value of the open oceans is now as low as it has been for at least 26,000 years, according to the WMO. This reduces the ability of the oceans to store climate-damaging CO2.
Heat waves, floods, droughts
Extreme weather events were visible and noticeable worldwide in 2021: For the first time since records began, it rained at the highest point of the Greenland ice sheet – actually it is snowing there. In the western United States and Canada, a heat wave brought temperatures that were up to six degrees above previous records in some cases. This also resulted in massive glacier ice losses. The mass shrank from 2015 to 2019 almost twice as fast as 2000 to 2004. In the Mediterranean region, Tunisia, Sicily, Spain and Turkey reported heat records. There were also devastating forest fires. In China and Europe – for example in North Rhine-Westphalia and Rhineland-Palatinate – there were heavy rains and floods. South America experienced severe drought for the second year in a row.
The annual report “State of the Climate” brings together the findings of several UN organizations, national weather services and scientists. UN Secretary General António Guterres said the report illustrates “how the planet is changing before our eyes”. Science provides clear facts, now governments have to take just as clear measures.