The study is one of few reports to look in detail at how energy use would have to be overhauled to meet the toughest scenarios for curbing greenhouse gases outlined by the Intergovernmental Panel on Climate Change. "Renewable energy could provide all global energy needs by 2090," according to the study, entitled "Energy (R)evolution."
A more radical scenario could eliminate coal use by 2050 if new power generation plants shifted quickly to renewables. Solar power, biomass such as biofuels or wood, geothermal energy and wind could be the leading energies by 2090 in a shift from fossil fuels blamed by the IPCC for stoking global warming.
The total energy investments until 2030, the main period studied, would come to 14.7 trillion dollars, according to the study.
By contrast, the International Energy Agency (IEA), which advises rich nations, foresees energy investments of just 11.3 trillion dollars to 2030, with a bigger stress on fossil fuels and nuclear power.
Rajendra Pachauri, head of the IPCC, which shared the 2007 Nobel Peace Prize with ex-US Vice President Al Gore, called the study 'comprehensive and rigorous.'
"Even those who may not agree with the analysis presented would, perhaps, benefit from a deep study of the underlying assumptions," Pachauri wrote in a foreword to the report.
EREC and Greenpeace said that a big energy shift was needed to avoid 'dangerous' climate change, defined by the European Union and many environmental groups as a temperature rise of 2 degrees Celsius since before the Industrial Revolution.
The report urged measures such as a phase-out of subsidies for fossil fuels and nuclear energy, 'cap and trade' systems for greenhouse gas emissions, legally binging targets for renewable energies and tough efficiency standards for buildings and vehicles.