The world could transition to 100% renewable energy by 2050 at about a quarter of the cost of current subsidies for fossil fuels, according to a new climate study funded by the Leonardo DiCaprio Foundation.

Investment in onshore and offshore wind, PV, concentrating solar power (CSP) and green hydrogen must be scaled up rapidly, alongside the electrification of transport and heat, while natural-gas networks must eventually be converted to run on green hydrogen in order to keep global warming to well below 2C, according to the authors of the report, entitled Achieving the Paris Climate Agreement Goals.

The researchers — from the German Aerospace Center, the University of Technology Sydney and the University of Melbourne — explain that the annual PV market must increase from close to 100GW in 2017 to 454GW by 2030; the onshore wind market must expand threefold to 172GW by 2025; while offshore wind installations must reach 32GW a year by 2050. CSP plants with storage, must play a far greater role than they do now due to their ability to provide 24-hour energy — increasing from an expected 3GW annual market in 2020 to 78GW by 2030.

The report envisages that by 2050, 64-65% of all power will come from variable renewables, with 27-29% from dispatchable renewables — namely, CSP, bioenergy, hydropower and geothermal. The remaining power will come from hydrogen.

Nuclear power, carbon capture and storage and “geoengineering” were not considered for the report due to their “major uncertainties in terms of social, economic or environmental consequences”. It also took a subtle dig at previous similar studies that “have relied upon technologies that are expensive and not proven at scale”.

Investment in power generation until 2050 will total about $50trn — $30trn more than a reference scenario — which includes meeting the increased demand for electricity from transport, heat and the production of hydrogen and other synthetic fuels. This figure does not include the cost of grid expansion, storage and other flexibility measures such as demand response. A recent study published in the journal World Development said global fossil fuel subsidies reached $5.3trn in 2015 alone.

Power markets will have to be redesigned to give priority dispatch to renewables and encourage storage and other flexibility measures, the study points out.

Other measures highlighted in the report include phasing out 618GW of coal-fired power plants by 2025; creating legally binding national targets for 100% renewables pathways; establishing minimum price on carbon; offering incentives to increase the take-up of electric vehicles (EVs) (including EV-only car parks and driving lanes); transforming cities to discourage passenger cars through pedestrianisation, cycle lanes and improved public transport; as well as massive deforestation. Governments must put their hands in their pockets to offer incentives for greener options, as well as to pay for research and development, the authors say.

The study also envisages that 90% of road vehicles will powered by electricity or hydrogen by 2050, with about 60% of buses and heavy-goods vehicles powered by batteries, a further 20% using fuel cells (powered by hydrogen or other synthetic fuels), and the remainder using synthetic fuel or biofuel. Synthetic fuels will also be needed for the shipping and aviation industries, it adds.

A transition to 100% renewable energy would also massively boost employment, the report adds. Under its 1.5C and 2C scenarios, the number of energy-sector jobs in 2050 will reach 46.3 million or 48.7 million, respectively, compared to about 30 million in a 5C scenario — roughly the same as today’s levels.