This is despite a cooling La Niña, whereas 2016 was a record year that began with a strong warming El Niño event
Globally, 2020 was tied with the previous warmest year 2016, making it the sixth in a series of exceptionally warm years starting in 2015, and 2011-2020 the warmest decade recorded, according to the Copernicus Climate Change Service, around 1.25°C above the 1850-1900 pre-industrial period.
In general, the Northern Hemisphere experienced above average temperatures for the year, apart from a region over the central North Atlantic. In contrast, parts of the Southern Hemisphere saw below average temperatures, most notably over the eastern equatorial Pacific, associated with the cooler La Niña conditions developing during the second half of the year.
It is notable that 2020 matches the 2016 record despite a cooling La Niña, whereas 2016 was a record year that began with a strong warming El Niño event.
Carlo Buontempo, director of the Copernicus Climate Change Service (C3S), comments: “2020 stands out for its exceptional warmth in the Arctic and a record number of tropical storms in the North Atlantic. It is no surprise that the last decade was the warmest on record, and is yet another reminder of the urgency of ambitious emissions reductions to prevent adverse climate impacts in the future.”
Continued rise of CO2
Analysis of satellite data reveals that carbon dioxide concentrations have continued to rise in 2020 reaching an unprecedented global column-averaged maximum of approximately 413.1 ppm. The estimated annual mean XCO2 growth rate for 2020 was 2.3 ± 0.4 ppm/year. This is less than the growth rate in 2019, which was 2.5 ± 0.2 ppm/year and also less than the 2.9 ppm/year increase in 2015 and 2016.
However, 2015 and 2016 experienced a strong El Niño climate event, which resulted in a larger atmospheric growth rate due to a weaker than normal uptake of atmospheric CO2 by land vegetation and large CO2 wildfire emissions, particularly in Indonesia in those years.
The wildfires in the Arctic and Australia in 2020, although of unprecedented magnitude in their regions, represent only a small fraction of global fire emissions.
Vincent-Henri Peuch, director of the Copernicus Atmosphere Monitoring Service (CAMS), comments: “While carbon dioxide concentrations have risen slightly less in 2020 than in 2019, this is no cause for complacency. Until the net global emissions reduce to zero, CO2 will continue to accumulate in the atmosphere and drive further climate change.”
In the context of the COVID-19 pandemic, it has been estimated by the Global Carbon Project that there was a reduction of around 7% of fossil CO2 emissions.
“To what extent this was a factor in the lower total increase is debatable though, as the variations in global growth rate are dominated by natural processes. We must continue efforts to decrease CO2 net emissions to reduce the risk of climate-related change”, Vincent-Henri Peuch adds.
“The extraordinary climate events of 2020 and the data from the Copernicus Climate Change Service show us that we have no time to lose. We must come together as a global community, to ensure a just transition to a net zero future. It will be difficult, but the cost of inaction is too great, which is why the commitments made under our European Green Deal are so very necessary”, highlights Matthias Petschke, director for Space, European Commission’s Directorate-General for Defence industry and Space.