A UN report has concluded that up to $15 trillion needs to be invested in renewable energy over the next two decades to keep global greenhouse gas emissions in check.
Close to 80 per cent of the world’s energy supply could be met by renewables by the middle of the century – up from 13 per cent in 2008 – according to the UN’s Intergovernmental Panel on Climate Change (IPCC), reports the Financial Times. However, that is likely to require sustained investment at a time when some of the world’s wealthiest countries may still be struggling with sovereign debt difficulties, a challenge acknowledged by the panel.
“The substantial increase of renewables is technically and politically very challenging,” said Professor Ottmar Edenhofer, co-chair of the IPCC working group that unveiled the report in Abu Dhabi on 9 May.
Ramon Pichs, another co-chair, said the report, which has taken more than 120 researchers over three years to produce, underlined the need for public policy support to tackle greenhouse gas emissions. “The report shows it is not the availability of the resource, but the public policies that will either expand or constrain renewable energy development over coming decades,” he said.
Even so, the IPCC found that despite the recent global downturn, renewable energy capacity grew in 2009 – by more than 30 per cent in the case of wind power. The report analyses more than 164 scenarios for the longer-term potential of renewables to replace fossil fuels, and four in detail.
According to these four, global investments in the renewable power sector range from $1300bn to $5100bn to 2020, and $1400bn to $7100bn for the next decade to 2030.
Many analysts argue that low-carbon nuclear power stations will turn out to be a cheaper way of cutting greenhouse gas emissions for some time to come. But the IPCC said most of the scenarios it reviewed “estimate that renewables will contribute more to a low-carbon energy supply by 2050 than nuclear power or fossil fuels using carbon capture and storage”.
The report, which runs to about 1000 pages and has been approved by governments in 194 nations, assessed the potential of six renewable technologies: wind, solar, ocean, hydropower, bioenergy and geothermal.
It found some had more potential than others. Direct solar energy, for example, now contributes only a fraction of 1 per cent of total global energy supply, but could become a significant source by 2050, depending on “continued innovations, cost reductions and supportive public policies”.
Wind power, which now meets almost 2 per cent of global electricity demand, could grow to more than 20 per cent by 2050. However, the share of hydropower projects, such as dams, in global electricity supply was likely to fall over the longer term. And the proportion of geothermal energy, which can be used for electricity or heating, was expected to remain relatively low.