AI analysed 1,500 policies to cut emissions. These ones worked

Researchers used machine learning to analyse roughly 1,500 climate policies and identify those that have dramatically reduced carbon emissions. Their study, published in Science today, found that policies that combine several tools are more effective in slashing emissions than are stand-alone measures.

The analysis identified 63 interventions in 35 countries that led to significant reductions in emissions, cutting them by 19% on average. Most reductions were linked to two or more policies. Together, the 63 policies cut emissions by between 0.6 and 1.8 gigatonnes (Gt) of CO2 equivalent.

Using the right mix of policies is more important than using a lot of policies, says Annika Stechemesser, a co-author and researcher at the Potsdam Institute for Climate Impact Research in Germany.

For example, the UK’s phasing out of coal-fired power stations worked because it was used in tandem with pricing mechanisms, such as a minimum carbon price, while in Norway, banning combustion engine cars was most effective when combined with a price incentive that made electric cars cheaper.