THE WORLD could use renewable sources for more than three-quarters of its energy by 2050 if backed by the right policies, the UN’s Intergovernmental Panel on Climate Change (IPCC) says.
A major report compiled by more than 120 experts worldwide says this would cut greenhouse gas emissions by up to a third from “business as usual” projections, and could contribute towards holding the rise in global temperature below 2 degrees.
The findings, published after being approved by 194 member countries of the IPCC in Abu Dhabi, are contained in a summary for policymakers of the expert group's Special Report on Renewable Energy Sources and Climate Change Mitigation, which runs to 1,000 pages.
“Renewable energy sources can contribute substantially to human wellbeing by sustainably supplying energy and stabilising the climate,” Prof Ottmar Edenhofer, co-chair of the IPCC working group, said. This would be “politically very challenging”, he added.
UN climate chief Christiana Figueres said that, if governments were to achieve the 2-degree limit, “they must reach their goal by making use of renewable energy sources on a very large scale” through national policies and international co-operation.
IPCC chairman Dr Rajendra Pachauri said the report brought together “the most relevant and best available information to provide the world with this scientific assessment of the potential of renewable energy” and provided a “sound knowledge basis for policymakers”.
The renewable energy sources examined include hydropower, direct solar energy, onshore and offshore wind power, bioenergy (including “second generation” biofuels), geothermal and ocean energy (including harnessing temperature differences in the seas).
Costs have declined for most of them, and the authors expect significant technical advancements and further cost reductions in the future compared to the price of fossil fuels – resulting in a greater potential for climate change mitigation.
The report notes that renewables accounted for 140 gigawatts of around 300 gigawatts of new electricity generating capacity globally between 2008 and 2009 – much of it in developing countries like China – with wind power growing by 30 per cent, and solar power by 50 per cent. Over 160 existing scientific scenarios on the possible penetration of renewables by 2050 were examined by the experts, who narrowed these down to four for in-depth analysis, taking account of alternative pathways of development and technological change.
“Under the scenarios analysed in depth, less than 2.5 per cent of the globally available technical potential for renewables is used – in other words, over 97 per cent is untapped, underlining that availability of renewable sources will not be a limiting factor”, the report continues.
The most optimistic of the four scenarios sees renewable energy accounting for as much as 77 per cent of the world’s energy demand by 2050, amounting to about 314 exajoules per year – equivalent to roughly three times the annual energy consumption in the US.
The latest report will feed into the broader work of the IPCC as it prepares its Fifth Assessment Report on Climate Change, which is due to be finalised for publication in September 2014.
