By Matt McGrath
The global response to Covid-19 has barely made a dent in the causes of climate change, according to a major new report.
While emissions of CO2 plummeted during lockdown, concentrations of the long-lasting gas have continued to rise in the atmosphere.
The period from 2016 to 2020 will likely be the warmest five years on record, the study finds.
The authors say “irreversible” climate change impacts are increasing.
The United in Science report brings together experts from a large number of international organisations, including the UN and the World Meteorological Organization (WMO), to give an updated snapshot of the state of the global climate.
The study shows that global lockdowns had a significant and immediate impact on emissions of greenhouse gases, with daily levels in April 2020 falling by 17% compared with 2019.
But this steep drop hasn’t been maintained. As the world returned to work, emissions rose and by June were within 5% of the previous year.
Over 2020, the expectation is that emissions will fall 4-7%.
While emissions can tell us what is happening on the ground, it is the concentrations of these gases in the atmosphere that makes all the difference for global temperatures.
Because CO2 can last for centuries, adding even a reduced amount to the air increases the warming potential of all the gas that has built up over decades.
This new study shows that is exactly what’s happened at a couple of key monitoring stations around the world.
At the Mauna Loa observatory in Hawaii, the amount of CO2 measured in air samples has increased from 411 parts per million (ppm) in July 2019 to 414ppm in July this year.
Similarly, at Cape Grim monitoring station in Tasmania, concentrations were also up from 407 to 410ppm in the year to July.
The study says that by 2030, the world would need to cut the combined emissions of the top six carbon-producing countries to have a reasonable chance of staying below the 1.5C “guard rail”.
While not impossible, the report says it would essentially require a pandemic-sized carbon slowdown every year from now until the end of the decade.