Nations at last month's G20 summit in China reaffirmed their 2009 commitment to phase out fossil-fuel subsidies, echoing a call from almost two decades ago to end subsidies that are “adverse in the long run to both the economy and the environment” (N. Myers Nature 392, 327–328; 1998).

Similar 'perverse' subsidies continue to encourage logging of the few remaining pockets of old-growth forest in western Canada and overfishing in the high seas. Yet the fossil-fuel industry receives the largest subsidy of all, estimated by the International Monetary Fund (IMF) last year at US$1,000 annually for every citizen in the G20 group. Most of this is provided by countries with energy taxes that are too low to cover the adverse effects of fossil-fuel consumption on human health and the environment (go.nature.com/2dbs2zf).

The IMF also estimates that eliminating fossil-fuel subsidies would cut global carbon dioxide emissions by more than 20% and raise government revenues by $2.9 trillion (or 3.6% of global gross domestic product). Such a step would save up to $93 per tonne of greenhouse-gas emissions removed (see go.nature.com/2dowcw).

These sums alone would fund climate adaptation and the protection of imperilled global biodiversity for the next 30 years (D. P. McCarthy et al. Science 338, 946–949; 2012). The money would also boost development of renewable energy sources and domestic support for a low-carbon economy.