For the first time in more than 3 million years, the level of carbon dioxide present in the atmosphere will breach the symbolic 400 parts per million level for the entire year. According to a new study released by the Met Office, it looks like it is now going to sit at this level for all of our lifetimes, as even if we reach the Paris climate agreement commitments, it is unlikely to have an effect in time to cut the CO2 concentration.
The paper, published in Nature Climate Change, uses the data collected from the Mauna Loa Observatory in Hawaii, which maintains the benchmark for carbon dioxide concentrations. While the levels of the gas in the atmosphere typically fluctuate with the seasons, increasing in the winter before dropping in the summer when plant growth takes off, the Met Office predict that this will be the first year since the Pliocene when the atmospheric levels have not dipped below 400 ppm for the whole year.
“The atmospheric carbon dioxide concentration is rising year-on-year due to human emissions, but this year it is getting an extra boost due to the recent El Niño event – changes in the sea-surface temperature of the tropical Pacific Ocean,” explains Professor Richard Betts, from the Met Office and Exeter University, in a statement. “This warms and dries tropical ecosystems, reducing their uptake of carbon, and exacerbating forest fires.”
Last year's El Nino, potentially the largest one on record, has pushed CO2 levels up. NASA