2020 could be on track to be another record hot year, despite global lockdowns

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People around the world took part in Global Climate Action Day on Friday, a reminder that even though we are in the midst of one of the greatest health challenges facing humanity, climate change is likely to pose an even greater threat – with increased chances of drought, forest fires, hurricanes, floods and heat waves.At the start of the COVID-19 pandemic earlier this year, businesses closed and people were stranded. As a result, greenhouse gas emissions have fallen, comprising both nitrogen dioxide and carbon dioxide (CO2), two drivers of global warming.

There was some hope that this might be the silver lining for a tragic situation, but the point is, it is unlikely to make a dent in the Earth’s rising temperature trend.

In fact, the National Centers for Environmental Information (NCEI) of the United States National Atmosphere and Ocean Administration recorded this in the world, Land and sea temperatures in August were the second highest on record. For North America, it was the hottest August on record, 1.52 ° C above average. August also marked the 428th consecutive month with temperatures above the 20th century average.

The problem is that CO2 has already accumulated in our atmosphere and the Earth is playing a catch-up game.

“Carbon dioxide can last for thousands and thousands of years in the atmosphere,” said Ahira Sanchez-Lugo, a physicist who compiles global temperature data at NCEI. “So just because with the pandemic we’ve seen a reduction in emissions, that doesn’t mean we’ll see a reduction in global temperatures anytime soon. “

This graph illustrates the increase in cumulative CO2 in the atmosphere over time. Data prior to 1958 were taken using ice cores. (Scripps Institution of Oceanography)

Climatologist Michael Mann, professor of atmospheric science at Penn State University, said there would likely be a drop in emissions but it wouldn’t make a big difference.

“This will likely lead to a reduction of around four to five percent in carbon emissions by 2020. This means a very slightly lower rate of warming,” he said.

Too many blankets

Sanchez-Lugo likes to use the analogy of CO2 acting as the Earth’s blanket: it’s needed to regulate the temperature of the planet, but additional build-up is like throwing more and more blankets on top.

“So this is currently happening in this direction: at the moment, the Earth already has several layers of covers, and it is not because we have stopped or we have reduced carbon emissions recently. that we have reduced greenhouse gas emissions, that does not mean that we are taking off those blankets. , ” she says.

Since the start of the year, the temperature has been 1.03 C warmer than average and is only behind the record heat of 2016 of 1.08 C above average.

The hottest year on record was 2016, reaching 0.94 ° C above average. It also marked the third consecutive year that a record has been set. But it was also the year of a moderate to strong El Niño, a natural phenomenon characterized by the warming of the Pacific Ocean – which in turn causes higher temperatures in some areas and more rainfall in some areas. other.

This year, however, was not an El Nino year.

Does that mean we could break the 2016 record without its warming effect?

“Right now, there is about a 55% chance [2020] being the second hottest, “said Sanchez-Lugo,” and… about a 39 percent chance that it will be the hottest year on record. ”

While 2020 might not be at the top of the list, it is likely that more and more records will be set in the years to come.

This graph illustrates temperature anomalies across the world in August 2020 (NOAA / NCEI)

A study published in May in the Bulletin of the American Meteorological Society, of which Sanchez-Lugo was a co-author, suggested that “there is more than a 99 percent chance that most of the next 10 years through 2028 will be ranked in the top 10. warmer. ”

The pandemic could be a way to illustrate that countries can reduce their emissions by changing their lifestyle, for example by not commuting to work five days a week, which would be one way to continue to see emissions decrease.

But Mann said big changes needed to be made in order to see significant improvement in the decades to come.

“If we can reduce carbon emissions a little more – around 7% per year – for each of the next 10 years, we can stay on the path that stabilizes global warming below 1.5 ° C, thus avoiding the effects the most damaging and dangerous of climate change, ”he said.

“However, simple changes in behavior will not get us there. We need systematic change, that is, policies to rapidly decarbonize our economy. “

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