Big rise in atmospheric CO2 expected in 2019

[nitpicker]

https://www.bbc.com/news/science-environment-46989789

Big rise in atmospheric CO2 expected in 2019

By Matt McGrath
Environment correspondent
8 hours ago

Met Office researchers expect to record one of the biggest rises in atmospheric concentrations of CO2 in 2019. Every year, the Earth's natural carbon sinks such as forests soak up large amounts of CO2 produced by human activities. But in years when the tropical Pacific region is warmer like this year, trees and plants grow less and absorb smaller amounts of the gas. As a result, scientists say 2019 will see a much bigger CO2 rise than 2018.

Since 1958, the research observatory at Mauna Loa in Hawaii, has been continuously monitoring and collecting data on the chemical composition of the atmosphere. In the years since they first started recording, the observatory has seen a 30% increase in the concentration of CO2 in the atmosphere caused by emissions of fossil fuels and deforestation.

Scientists argue that the increase would have been even larger without the ability of the forests, land and seas to soak up around half of the gas emitted by human activities. This ability however, varies with the seasons.

In the summer, CO2 levels in the atmosphere fall as the trees and plants soak up more of the carbon as they grow. In the winter, when they drop their leaves, they soak up less and atmospheric levels rise. But when temperatures are warmer and drier than normal, trees and plants grow less and absorb less. This natural variation is compounded in years when there's an El Niño event, which sees an upwelling of heat from the Pacific into the atmosphere.
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According to the Met Office, these limits on the ability to absorb CO2 will see a rise in concentrations this year of 2.75 parts per million, which is higher than the 2018 level. They are forecasting that average CO2 concentrations in 2019 will be 411ppm. Carbon dioxide concentration exceeded 400ppm for the first time in 2013.
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