World still warms in 2020 as greenhouse gases fall

Aftermath of a wildfire in Australia, January, 2020. Image: By Meganesia, via Wikimedia Commons

Greenhouse gases have fallen during 2020. But that’s no reason for congratulations, in a year of climate drama.

LONDON, 11 December, 2020 − The year of the coronavirus − the year of global lockdown − meant a record fall in emissions of the greenhouse gases that drive global warming: by December there had been 34 billion tonnes of carbon dioxide from fossil fuel combustion worldwide, a fall of 7% compared with 2019, according to a new study.

If governments followed the economic shutdown with what the UN calls a “green pandemic recovery”, then by 2030 greenhouse gas emissions could fall by up to 25%. That remains a “big if.” Right now the planet is heading towards an end-of-century average temperature rise of a calamitous 3°C, according to a second report.

And a third summary of the last 12 months finds the pandemic changed almost nothing, says the World Meteorological Organisation (WMO). The year looks to be one of the three warmest on record, in the warmest decade on record. The warmest six years ever recorded have all happened since 2015.

The news in the journal Earth System Science Data, that humankind managed not to add 2.4 bn tonnes of CO2 to the atmosphere because car journeys fell by half and airline flights dwindled at the peak of the lockdowns from Covid-19, should be encouraging.

“There is at least a one in five chance of [the world] temporarily exceeding 1.5°C by 2024. 2020 has been yet another extraordinary year for our climate”

To be on track to meet the promises made under the Paris Agreement of 2015, humankind has to reduce emissions by around 1 to 2 billion tonnes a year for the next ten years. Nobody can yet say whether the decline will continue, or whether emissions will rebound.

“All the elements are not yet in place for sustained decreases in global emissions, and emissions are slowly edging back to 2019 levels”, warned Corinne Le Quéré, of the University of East Anglia, UK. “Government actions to stimulate the economy at the end of the Covid-19 pandemic can also help lower emissions and tackle climate change.”

Here is the message of the United Nations Environment Programme’s latest Emissions Gap Report. Examining the gap between what nations promised to do in Paris, and what is actually happening, it warns that a 7% drop in emissions during 2020 translates to a reduction in global warming by 2050 of no more than 0.01°C.

If nations stepped into economic recovery with plans to advance renewable energy and save fossil fuel use, a 25% emissions cut could indeed create a chance of meeting the 2°C limit promised in the Paris Agreement. But it wouldn’t get the world to the real goal of a rise of no more than 1.5°C by 2100.

Roasting Arctic

Greenhouse gases continue to inflict a relentless burden. Right now the world is already 1.2°C warmer than at any time for almost all of human history, thanks to profligate fossil fuel use over the last century. And, says the WMO’s secretary-general Petteri Taalas, “there is at least a one in five chance of it temporarily exceeding 1.5°C by 2024.”

Ocean heat has reached record levels and 80% of the blue planet experienced at least one marine heatwave in the last year, says a summary of the year based on evidence from January to October. In the Siberian Arctic, temperatures were 5°C above normal. The Arctic summer sea ice was the second-lowest since records began 42 years ago. In California’s Death Valley in August, the thermometer hit 54.4°C, the highest anywhere in the world for at least the last 80 years.

“2020 has, unfortunately, been yet another extraordinary year for our climate. We saw new extreme temperatures on land, sea and especially in the Arctic. Wildfires consumed vast areas in Australia, Siberia, the US West Coast and South America, sending plumes of smoke circumnavigating the globe,” Professor Taalas said.

“We saw a record number of hurricanes in the Atlantic, including unprecedented back-to-back category 4 hurricanes in Central America in November. Flooding in parts of Africa and South-east Asia led to massive population displacement and undermined food security for millions.” − Climate News Network