The increase in CO levelstwo commits the fulfillment of the Paris Agreement objectives of limiting global temperature rise in order to contain the climate crisis. The World Meteorological Organization, through its latest bulletin, sends a strong scientific message to negotiators on the subject who will participate in COP26.
The abundance of heat-trapping greenhouse gases in the atmosphere again hit a new record last year, and the annual rate of increase recorded was higher than the average for the period between 2011 and 2020. This trend continued into 2021, as noted in the Bulletin of the World Meteorological Organization (WMO) on greenhouse gases.
The concentration of carbon dioxide (COtwo), the most abundant of the greenhouse gases, reached 413.2 parts per million (ppm) in 2020 and is at 149% of pre-industrial levels. In relation to methane (CH4) and nitrous oxide (NtwoO), their concentrations were equivalent, respectively, to 262% and 123% of the levels of 1750, the year chosen to represent the moment when human activity began to alter the Earth’s natural balance.
The economic slowdown caused by COVID-19 had no obvious effect on atmospheric levels of greenhouse gases, nor on their rates of increase, although there was a temporary reduction in new emissions.
If emissions are not stopped, global temperature will continue to rise
the COtwo It is a gas characterized by its long life and therefore the currently observed temperature level will persist for several decades, although emissions are rapidly reduced until reaching the net zero level. If this is associated with global warming, the result will be the proliferation of extreme weather events, with far-reaching socioeconomic impacts.
About half the COtwo currently emitted by human activities remains in the atmosphere, while oceans and terrestrial ecosystems absorb the other half. The WMO bulletin warns of the possibility that, in the future, the oceans and terrestrial ecosystems will lose their effectiveness as sinks, which will reduce their capacity to absorb CO.two and act as regulators that prevent even greater increases in temperature.
The work shows that, between 1990 and 2020, the radiative forcing exerted by long-lasting greenhouse gases – an effect that warms our climate – increased by 47%, and about 80% of this increase was due to COtwo. These percentages were calculated thanks to the monitoring performed by the WMO Global Atmosphere Watch (GAW) Program network.
“The newsletter sends a strong scientific message to climate change negotiators attending the 26th session of the Conference of the Parties (COP26) of the United Nations Framework Convention on Climate Change. If the current rate of increase in greenhouse gas concentrations is maintained, the rise in temperature at the end of this century will far exceed the Paris Agreement target of limiting global warming to 1.5 or 2 °C above levels. pre-industrial“Said the Secretary General of the WMO, Professor Petteri Taalas. “We’re too far off the beaten path.“
Carbon dioxide remains in the atmosphere for centuries and even longer in the oceans. The last time a CO concentration was recorded on Earthtwo comparable was between three and five million years ago. “Back then the temperature was 2 to 3 °C higher and the sea level 10 to 20 meters higher than today, but then there weren’t 7.8 billion people on the planet,” explains Taalas.
“Many countries are setting targets to achieve carbon neutrality and COP26 is expected to see a dramatic increase in commitments made in this regard. But we must crystallize these ambitions into action. There is no time to lose“, concludes.