The US space agency has revealed that the Covid-hit 2020 was also the warmest year on record, just barely exceeding the record set in 2016 by less than a tenth of a degree.
By most accounts, 2020 has been a rough year for the planet.
Massive wildfires scorched Australia, Siberia, and the US west coast—and many of the fires were still burning during the busiest Atlantic hurricane season on record.
“This year has been a very striking example of what it’s like to live under some of the most severe effects of climate change that we’ve been predicting,” said Lesley Ott, a research meteorologist at NASA’s Goddard Space Flight Center in the US.
Human-produced greenhouse gas emissions are largely responsible for warming our planet.
“The natural processes Earth has for absorbing carbon dioxide released by human activities - plants and the ocean—just aren’t enough to keep up with how much carbon dioxide we’re putting into the atmosphere,” said Gavin Schmidt, a climate scientist and Director of NASA’s Goddard Institute for Space Studies (GISS) in New York City.
According to NASA, carbon dioxide levels have increased by nearly 50 per cent since the ‘Industrial Revolution’ 250 years ago.
The amount of methane in the atmosphere has more than doubled.
As a result, during this period, Earth has warmed by just over 1 degree Celsius.
Climate modellers have predicted that as the planet warms, Earth will experience more severe heatwaves and droughts, larger and more extreme wildfires, and longer and more intense hurricane seasons on average.
“The events of 2020 are consistent with what models have predicted: extreme climate events are more likely because of greenhouse gas emissions,” NASA said in a statement late on Thursday.
Climate change has led to longer fire seasons, as vegetation dries out earlier and persistent high temperatures allow fires to burn longer.
This year, heatwaves and droughts added fuel for the fires, setting the stage for more intense fires in 2020.
This year wasn’t a record-breaker for ice loss at sea or on land.
The planet is losing about 13.1 per cent of Arctic sea ice by the area each decade, according to sea ice minimum data from NASA and the National Snow and Ice Data Center in Boulder, Colorado.
The Arctic has lost over half of its summer minimum sea ice extent in the last few decades and the trend is still declining. In 2020, Arctic sea ice covered just 3.36 million square km at its minimum.
This year brought one of the busiest and most intense Atlantic hurricane seasons on record, with 30 named storms.
Scientists said average temperatures will keep edging upwards due to the huge amount of greenhouse gases we are expelling into the atmosphere. “This isn’t the new normal,” said Gavin Schmidt, director of Nasa’s Goddard Institute for Space Studies. “This is a precursor of more to come.”
The record, or near-record, heat came despite the moderately cooling influence of La Niña, a periodic climate event. “While the current La Niña event will likely end up affecting 2021 temperature more than 2020, it definitely had a cooling effect on the last quarter of the year,” said Zeke Hausfather, a climate scientist at Berkeley Earth, which found 2020 was narrowly the second hottest year on record.
“It suggests that we’ve added an equivalent of a permanent El Niño event worth of global warming in just the last five years,” Hausfather added, in reference to the counterpart climate event that typically raises temperatures. “Records like this further reinforce the need to reduce our emissions sooner rather than later.”
The climate crisis is drastically altering environmental processes across the globe, as the scientific analyses of 2020 show.
The annual average sea ice extent in the Arctic was, at 3.93m sq miles, the joint smallest on record, tied with 2016, while oceans were “exceptionally warm”, Noaa said, with just two previous years recording hotter marine temperatures. Average annual snow cover for the northern hemisphere was the fourth lowest on record.
Rising heat in the atmosphere and water is causing glaciers to melt, rising sea levels, as well as helping fuel larger and more destructive storms. The US, buffeted by an unprecedented Atlantic hurricane season in 2020, was hit with a record number of major disasters last year, costing tens of billions of dollars and resulting in several hundred deaths.
“Global warming won’t necessarily increase overall tropical storm formation, but when we do get a storm it’s more likely to become stronger,” said Jim Kossin, an atmospheric scientist at Noaa. “And it’s the strong ones that really matter.”
Wildfires, fueled by vegetation parched by prolonged heat, ravaged huge areas of California and Australia last year, while the Arctic experienced astonishing temperatures well above average.
“This year has been a very striking example of what it’s like to live under some of the most severe effects of climate change that we’ve been predicting,” said Lesley Ott, a research meteorologist at Nasa.
The UK Met Office has already predicted that 2021 will also be among the hottest ever recorded, with the world now “one step closer to the limits stipulated by the Paris agreement”, said Colin Morice, senior scientist at the Met Office. Governments will meet later this year in Scotland for crucial UN talks aimed at building upon the Paris deal, which committed countries to avoiding a disastrous global temperature rise of 1.5C from pre-industrial levels.
“We are headed for a catastrophic temperature rise of 3-5C this century,” warned António Guterres, secretary general of the UN. “Making peace with nature is the defining task of the 21st century. It must be the top priority for everyone, everywhere.”