Targeting emissions of pollutants can't protect against long-term climate change

A new study has claimed that targeting emissions of non-CO2 gases and air pollutants with climate effects might produce smaller benefits for long-term climate change than previously estimated.

The study showed that high hopes have been placed on limiting emissions of so-called short-lived climate forcers (SLCF) such as methane and soot for protecting human health, vegetation and limiting temperature increase.

New research indicates that neglecting linkages between the sources of these SLCFs and CO2 has led to an overestimation of the long-term climate benefits of controlling these pollutants in climate stabilization scenarios.

IIASA researcher Joeri Rogelj, who led the study, said that stabilizing climate at any temperature means that, at some point, global CO2 emissions have to become zero although near-term action on short-lived climate forcers can help reduce warming in the coming decades and also provides other societal benefits, such as cleaner air, it will not buy us time for delaying the reductions in carbon dioxide emissions which are required to stabilize the climate at safe levels.

John Schellnhuber, a study co-author and director of the Potsdam Institute for Climate Impact Research, said that the one and only thing that can avoid the bulk of risks that would come with unbridled climate change is rapid CO2 reduction and hopes that cutting other emissions would do a large part of the job now turn out to be misguided.

IIASA Mitigation of Air Pollution and Greenhouse Gases Program Director Markus Amann, who also contributed to the study, said that while urgent action to reduce CO2 emissions is indispensable for the protection of climate, additional SLCF measures would deliver undisputed benefits for human health and agriculture and near-term climate change, even if their contribution to long-term climate targets is less than previously estimated.

The study is published in the journal Proceedings of the National Academy of Sciences (PNAS).