Climate change: Greenhouse gas concentrations hit a new high in 2020

Accumulation of warming gases in the atmosphere rose to record levels in 2020 despite the pandemic, according to the World Meteorological Organization.

Concentrations of CO2, methane and nitrous oxide have increased by more than the annual average over the past 10 years.

The WMO says this will raise temperatures beyond the Paris Agreement targets.

They fear that our warmer world is, in turn, increasing emissions from natural sources.

Restrictions imposed around the world during the Covid pandemic saw an overall drop in CO2 emissions of 5.6%.

So why didn’t that fall echo in atmospheric concentrations?

There are a number of factors involved.

About half of the emissions from human activity are absorbed by trees, lands and oceans. But the absorbency of these sinks can vary enormously, depending on temperatures, rainfall and other factors.

Another problem is that CO2 emissions have progressively increased over the last decade.

So even though carbon production decreased last year, the increase in the level in the atmosphere was still greater than the average between 2011-2020.

According to the annual of the WMO Greenhouse gas bulletin, CO2 reached 413.2 parts per million in the atmosphere in 2020 and is now 149% of the pre-industrial level.

This is bad news for containing the rise in Earth’s temperature.

“With the current rate of increase in greenhouse gas concentrations, by the end of this century we will see a temperature increase far above the Paris Agreement targets of 1.5-2 ° C above levels. pre-industrial “, said the secretary general of the WMO, Prof. Petteri. Taala. “We are very far off track.”

“This is more than just a chemical formula and figures on a graph. It has major negative repercussions for our daily life and well-being, for the state of our planet and for the future of our children and grandchildren,” said Professor Taalas.

The authors state that the last time Earth experienced a comparable concentration of CO2 was 3-5 million years ago, when temperatures were 2-3 ° C warmer and sea level was 10-20. meters higher than today.

One of the big concerns for researchers is that the continued rise in temperatures may actually cause increased warming of gases from natural sources.

Scientists are concerned that this is already happening with methane.

Although it has a shorter lifespan than CO2, methane is much more potent as a heating chemical.

About 60% of the CH4 that ends up in the atmosphere comes from human sources such as agriculture, fossil fuels, landfills and biomass burning.

The remaining 40% comes from the activities of microbes in natural sources such as wetlands.

Last year’s increase was the biggest increase since global methane levels began to rise again in 2007.

Most came from natural sources.

‘If you increase the amount of precipitation in wetland areas and increase the temperature, these methane-producing bacteria produce more methane,’ said WMO’s Dr Oksana Tarasova.

“So this will only increase in the future because the temperature will rise. It’s a big concern,” he told BBC News.

Scientists describe these vicious cycles as feedback loops. They were also observed in the Amazon, where researchers earlier this year reported that parts of the rainforest now emitted more CO2 than they absorbed.

“The higher the temperature, the less rainfall, the greater the stress on the trees,” said Dr. Tarasova.

“So, the trees have increased mortality, they stop absorbing CO2. In addition to our emissions, we will have emissions from our forests.”

The WMO is also concerned about the increase in nitrous oxide, which comes from human activities such as the use of nitrogen fertilizers, but also from natural sources.

In addition, it has risen more than average over the past decade.

Within days of the world leaders meeting in Glasgow for COP26, the news on the level of warming of gases in the atmosphere is harsh.

“Greenhouse gas measurements are like skidding in a car accident. The disaster is getting closer and closer but you can’t stop it,” said Professor Euan Nisbet of Royal Holloway, University of London.

“You can clearly see the crash in front of you and all you can do is howl.”

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