Compensating affected parties necessary for rapid coal phase-out but expensive if extended to major emitters.

Coal power phase-out is critical for climate mitigation, yet it harms workers, companies, and coal-dependent regions. We find that more than half of countries that pledge coal phase-out have  "just transition" policies which compensate these actors. Compensation is larger in countries with more ambitious coal phase-out pledges and most commonly directed to national and regional governments or companies, with a small share going directly to workers. Globally, compensation amounts to over $200 billion (uncertainty 163-258), about half of which is funded through  international schemes, mostly through Just Energy Transition Partnerships and the European Union Just Transition Fund. If similar transfers are extended to China and India to phase out coal in line with the Paris temperature targets, compensation flows could become larger than current international climate financing. Our findings highlight that the socio-political acceptance of coal phase-out has a tangible economic component which should be factored into assessing the feasibility of achieving climate targets.

Limited emission reductions from fuel subsidy removal except in energy-exporting regions.

Hopes are high that removing fossil fuel subsidies could help to mitigate climate change by discouraging inefficient energy consumption and levelling the playing field for renewable energy. In September 2016, the G20 countries re-affirmed their 2009 commitment (at the G20 Leaders' Summit) to phase out fossil fuel subsidies and many national governments are using today's low oil prices as an opportunity to do so. In practical terms, this means abandoning policies that decrease the price of fossil fuels and electricity generated from fossil fuels to below normal market prices. However, whether the removal of subsidies, even if implemented worldwide, would have a large impact on climate change mitigation has not been systematically explored. Here we show that removing fossil fuel subsidies would have an unexpectedly small impact on global energy demand and carbon dioxide emissions and would not increase renewable energy use by 2030. Subsidy removal would reduce the carbon price necessary to stabilize greenhouse gas concentration at 550 parts per million by only 2-12 per cent under low oil prices. Removing subsidies in most regions would deliver smaller emission reductions than the Paris Agreement (2015) climate pledges and in some regions global subsidy removal may actually lead to an increase in emissions, owing to either coal replacing subsidized oil and natural gas or natural-gas use shifting from subsidizing, energy-exporting regions to non-subsidizing, importing regions. Our results show that subsidy removal would result in the largest CO2 emission reductions in high-income oil- and gas-exporting regions, where the reductions would exceed the climate pledges of these regions and where subsidy removal would affect fewer people living below the poverty line than in lower-income regions.