BRUSSELS — Renewable sources could provide a majority of the world’s energy supplies by 2050, but only if governments dramatically increase financial and political support for technologies like wind and solar power, experts from a United Nations panel said Monday.
The Intergovernmental Panel on Climate Change said in a report that the availability of renewable sources like the wind and sun was virtually unlimited, and could provide up to 77 percent of the world’s energy needs by mid-century, but governments needed to adopt policies to take advantage of them.
“The report shows that it is not the availability of the resource, but the public policies that will either expand or constrain renewable energy development over the coming decades,” said Ramón Pichs Madruga, a member of the I.P.C.C. and the director of an economics research center in Cuba.
The report said renewable sources — bioenergy, wind, solar, geothermal, hydropower and ocean energy — currently accounted for about 13 percent of global energy supply.
To reach the goal of generating nearly 80 percent of the world’s energy from those same sources would require investments by governments and the private sector amounting to $5.1 trillion through 2020, and nearly $7.2 trillion between 2021 and 2030, according to the report.
The benefits would include better public health from cleaner air, as well as fewer greenhouse gas emissions, which would help hold an increase in global temperature to below 2 degrees Celsius.
Even so, a “substantial increase of renewables is technically and politically very challenging,” said Ottmar Edenhofer, a member of the I.P.C.C. and the chief economist at the Potsdam Institute for Climate Impact Research in Germany.
Among the most challenging factors is using a wider variety of technically and geographically diverse sources of energy in the future, according to the report.
Under the I.P.C.C. process, 120 experts and researchers prepared a Special Report on Renewable Energy Sources and Climate Change Mitigation of about 1,000 pages comparing more than 160 scenarios on renewable energy.
In the second part of the process, government representatives of U.N. member states took until the early hours of Monday to agree on an outline of that report, called a Summary for Policy Makers. That summary is hugely important to clean energy companies and activists to press government leaders and international lenders to adjust energy policies and pay for new investment and infrastructure.
The New York Times