“.. In the short term, the impact of COVID-19 lockdowns cannot be distinguished from natural variability,” said the WMO Greenhouse Gas Bulletin.
WATCH | Will COVID-19 have an impact on climate change?
The annual report published by the Geneva-based United Nations agency measures the atmospheric concentration of gases – carbon dioxide, methane and nitrous oxide – that warm our planet and trigger extreme weather events.
Levels of carbon dioxide, a product of fossil fuel combustion that contributes the most to global warming, reached a new high of 410.5 parts per million (ppm) in 2019, he said.
WMO calls for “flattening of the emissions curve”
The annual increase is greater than the previous year and exceeds the average of the last decade.
“Such a rate of increase has never been seen in the history of our records,” said WMO Secretary-General Professor Petteri Taalas, referring to a 10 ppm increase since 2015, calling for “A lasting flattening of the (emissions) curve. ”
Oksana Tarasova, head of atmospheric environment research at WMO, said the magnitude of the increase in carbon dioxide levels over the past four years was comparable to the changes observed during the passage of the period glacial to more temperate periods, but that at the time the transition took place over a good range of time.
“We humans did it with nothing, with just our shows, and we did it in four years. ”
WATCH | Impact of COVID-19 lockdowns on air pollution
Global data is not yet available for 2020, but the trend of increasing concentrations appears to be intact, WMO said, citing early readings from its stations in Tasmania and Hawaii.
Like other scientific bodies, WMO said it expects annual global carbon emissions to decline this year due to COVID measures, and attempted a preliminary estimate of 4.2 to 7.5%.
Such a drop would not lower atmospheric carbon dioxide, but would temporarily slow the rate of increase to a scale that is within normal variation, he said.
“Our whole economy and consumption patterns lead us to extremely high emissions, even though we are all stranded,” Tarasova said.
Regardless of what we do to reduce emissions today, much of the carbon dioxide already emitted decades ago stays in the atmosphere and contributes to global warming, climate scientists say.
Over the period 2018-2019, concentrations of the more potent heat-trapping methane gas increased by 8 parts per billion, according to the report – slightly lower than the previous annual change, but still above average over the past 10 years. period.
Data on methane concentrations are closely monitored by scientists as the gas is subject to unexpected leaks such as those from the fossil fuel industry. This can make its atmospheric levels more difficult to predict than carbon dioxide.
Levels of nitrous oxide, which erode the atmospheric ozone layer and expose humans to harmful ultraviolet rays, also increased in 2019, but at a slower rate than the previous year and at the same level as average growth over the past decade.