With emissions already at a record high, the UK Met Office is predicting the build-up of carbon-dioxide in the atmosphere will be larger than last year due to a slower removal by natural carbon sinks.

During 2019 Met Office climate scientists expect to see one of the largest rises in atmospheric carbon-dioxide concentration in 62 years of measurements. This Met Office CO₂ forecast is based on a combination of factors including rising anthropogenic emissions and a relative reduction in the uptake of carbon-dioxide by ecosystems due to tropical climate variability.

The average CO₂ concentration in 2019 is forecast to be 411.3 ± 0.6 ppm, and the Met Office forecast suggests that the annual average atmospheric CO₂ concentration at Mauna Loa will be 2.75 ± 0.58 parts per million (ppm) higher in 2019 than in 2018.