Temperature: an additional 1.2 °C in 2020

The information has made little noise, so busy are our eyes and minds with the Covid-19. However, in its provisional report on the state of the climate, the World Meteorological Organization (WMO) draws up a very alarming report for 2020. The increase in temperatures is indisputable. Three measurement elements spectacularly support this observation: in 2020, the temperature has increased by an average of 1.2°C compared to the pre-industrial era. The decade 2011-2020 is the warmest decade on record. Finally, 2020 is one of the three warmest years (2016, 2019 and 2020), equaling or nearly equaling the warmest year on record: 2016. However, “record warm years have generally coincided with a strong El Niño episode, as was the case in 2016. La Niña tends to cool global temperatures, but this year’s anomaly was not enough to stop the warming. Despite this anomaly, there is already near-record warmth this year, comparable to the previous record in 2016,” said Mr Petteri Taalas, Secretary-General of WMO.

The Paris Agreement aims to limit global warming to +2 C compared to the pre-industrial era, preferably 1.5 C. Based on the latest findings, “there is at least a one-in-five chance that [the rise] will temporarily exceed 1.5°C by 2024,” Taalas said.

The effects of this rise in temperature were felt around the world in 2020, with Argentina, Paraguay and Brazil experiencing severe drought. Agricultural losses, but also fires, especially in western Brazil, followed the drought. In the United States, extreme temperatures, combined with widespread drought in the west of the country, triggered in summer and autumn the largest fires recorded over the last twenty years.

The confirmation by the World Meteorological Organisation that 2020 was one of the hottest years ever recorded is once again a brutal reminder that climate change is progressing at an implacable pace, destroying lives and means of subsistence around the world. Today, global warming has reached 1.2-degree Celsius and we are already witnessing extreme and unprecedented meteorological phenomena in every region and continent. We are heading towards a catastrophic increase in temperatures ranging from 3 to 5 degrees during the 21^st century. Making peace with nature is the great mission of our century. It must be the absolute priority of everyone, everywhere in the world”, declared the General Secretary of the United Nations, António Guterres.

The Arctic and more especially the Siberian Arctic, are among the regions most affected, with an increase of more than 5 °C in comparison to the average. In June, the temperature in Siberia even reached 38 °C, the highest temperature ever measured north of the Arctic Circle. The Arctic is warming twice as fast as anywhere else, with very considerable impacts on the weather and the climate of the rest of the planet. In September 2020, the polar pack ice covered the second smallest surface area ever recorded, with 3.74 million square kilometres. Between 1981 and 2010, the average surface area of the pack ice was 6.3 million square kilometres.

 

Melting with a double trigger

 

The melting and disappearance of the pack ice leads to a vicious circle, a phenomenon called Polar amplification: with the disappearance of the ice and snow, the white surface of the Arctic is replaced by water and vegetation, which, being darker, absorb more solar radiation. This leads to higher temperatures, leading to melting.

In Peru, another ice-melt is occurring: during the last fifty years, the country’s 2,670 glaciers have lost more than 51% of their surface area. New lakes have formed. The melting of the Andean glaciers leads to flood risks. The retreat of the Palcaraju glacier is feeding Lake Palcacocha, which now threatens the town of Huaraz and its population of 120,000.

In 2015, a Peruvian farmer, Saul Luciano Lliuya, took out a lawsuit against the German electricity company RWE. In The Guardian, a British newspaper he explained, “My father and I have long thought that those who are causing climate change should participate in solving the problems they produce. Peru is a poor and vulnerable country. The major polluters who have contributed to climate change must now participate in the solutions to our problems”. A study published in Nature Geoscience could serve as the basis for this type of action. According to Rupert Stuart-Smith, its lead author, “[our study] shows that warming caused the retreat of the Palcaraju glacier, which in turn increases the risk of flooding. It’s crucial, since it forms a direct link between the emissions and the need to implement protection measures now”.

In Venezuela, the last of the country’s five tropical glaciers is vanishing. In 1910, the Humboldt Peak glacier covered the equivalent of 300 football pitches. Today it covers only 5. The glaciers of the Alps are also suffering from the increase in temperatures. Their surfaces are shrinking before our eyes. Landslides, the formation of glacial lakes, floods, etc. and also the loss of large reserves of water. This is without counting the modification of the regimes of alpine rivers that could be caused by the disappearance of the glaciers.

 

Making radical changes

 

Due to the inertia of the climatic system, “the future is already written for the next two or three decades: warming will continue”, Jean-Michel Soubeyroux, deputy director of Metéo France, told the newspaper Le Monde.

Last January, the climatologist Jean-Pascal van Ypersele, former Vice-President of the Intergovernmental Panel on Climate Change (IPCC) also issued a warning on the pages of Le Monde) :

Work and life will become intolerable in ever larger regions and an increasingly large area of the world will become uninhabitable. […] The most vulnerable, often the poorest, will be those most affected but the others will not be totally immune. At the end of the century, in a do-nothing scenario against climate change, nearly two thirds of the European population could be affected every year by extreme climatic events”.

The urgent need to act is recalled by all. We must still accept to make the radical changes needed. For the climatologist:

We can still avoid climate change with intolerable impacts for most of the population. We hold the future in our hands. […] We’ve already achieved things that were thought impossible before, such as abolish slavery or travel to the moon. I believe in human inventiveness and it its capacity to mobilise in the face of danger.”