Climate change denialists have yet another serious piece of evidence to  ignore.

The work was produced through a collaboration of the Global Carbon Project, University of East Anglia and British Antarctic Survey. Studies of ice cores found that levels of atmospheric carbon dioxide were rising at a rate that is about a third higher than was predicted only half a dozen years ago.

This increasing rate is not seen as due to an increase in emissions but to an apparently failing planetary capacity to soak up the excess. This is a very depressing finding, suggesting that it might soon be too late to do anything to solve the problem.

The study suggests that

….18% came from a decline in the natural ability of land and oceans to soak up CO2 from the atmosphere.
About half of emissions from human activity are absorbed by natural “sinks” but the efficiency of these sinks has fallen, the study suggests. (From the BBC report of the study)

If you can understand it, the dry pre-publication abstract is available at the Proceedings of the National Academy of Sciences website