Could Greenpeace's latest report once again prove more accurate than those of some mainstream analysts.
What was once seen as "fanciful or unrealistic" is now very much in vogue. The vision for a fully decarbonised, and perhaps even 100 per cent renewable powered global economy, has in the past year moved from being an environmentalist pipe dream to official policy in a growing number of countries. The G7 nations earlier this year backed calls for the full "decarbonisation of the global economy over the course of this century", providing a major boost to efforts to get a clause requiring the development of a net zero emission economy post 2050 into the planned Paris climate change agreement.
Only last week, Sweden joined a growing band of countries pledging to become fossil fuel-free, and the week before the South Australian government set a goal for Adelaide to become the first carbon neutral city in the world.
All of which makes the publication today of the fifth edition of Greenpeace's bi-annual Energy (R)evolution report, detailing how to deliver a global energy system that is 100 per cent renewable by 2050, particularly timely. The report, which is developed in partnership with the Global Wind Energy Council and SolarPower Europe, shows how it remains technically and economically feasible to power the global economy using renewable energy. But only if a series of green policy measures are embraced and clean technologies continue their rapid improvement.
It would be all too easy to reject Greenpeace's conclusions with a 'they would say that, wouldn't they' shrug, but for two important considerations. First, the scenario set out by the campaign group is no longer a million miles from the scenario being pursued by many of the world's largest economies, namely the full decarbonisation of the energy industry by 2050. Greenpeace's on-going opposition to nuclear power and scepticism about the role of carbon capture and storage may be rejected by some governments, but the attempt to predict how clean technologies could one day decarbonise the global economy is highly relevant to policies currently being pursued from Washington to Beijing.
Moreover, Greenpeace's attempt to sketch out how the global energy industry could decarbonise provides a useful counterpoint to similar long term projections from the International Energy Agency (IEA) or BP, which demonstrate how the industry will fail to meet long term emissions goals. As the (R)evolution report argues, its scenario results in total carbon emissions between 2012 and 2050 that add up to 667 gigatonnes, which is "well within the IPCC's "safe" limit of 1,000 gigatonnes". "Switching to 100 per cent renewable energy is therefore a matter of humankind's survival," it adds.
Secondly, over the 10 years the (R)evolution report has been running it has proven to be remarkably prescient. As the report notes, "while our predictions on the potential and market growth of renewable energy may have seemed fanciful or unrealistic, they have proved to be accurate".
This trumpet blowing is not unfounded. For example, in 2000, the IEA predicted global installed capacity for wind turbines would reach 32.5GW in 2010. This goal had been reached by early 2003, only two-and-a-half years later.
By 2014, the annual global wind market had reached 39GW, increasing the total cumulative capacity to around 370GW; around 10 times more than the IEA's assumption a decade earlier.
It is a similar story when mainstream predictions for the solar sector over the past 15 years are considered. In contrast, Greenpeace's projections for renewables deployment have been broadly accurate.
"We have looked at our projections for solar and wind since 2000 and we are pretty much spot on with wind and actually a little bit too conservative with solar," reflects the report's lead author, Dr Sven Teske. "We have checked our own prognosis and for renewables we have been right on track, plus or minus five per cent. Where we have been less accurate is for energy demand, which has been higher than we expected because of the growth in China."
Teske argues mainstream predictions for the role of renewables in the energy industry suffer from an innate conservatism that fails to account for the rapid technological improvements and market growth the clean tech industry has delivered. "The IEA predictions keep assuming the sector will grow over the next 10 years the amount they grew in the past year," he tells BusinessGreen. "They predicted that in 2006 for the wind industry and then what happened was the market grew at double digit growth rates for the next decade."
Teske acknowledges the renewables industry will not continue to grow indefinitely, but the report argues a combination of market forces and progressive policies means there is huge room for continued expansion. "Renewable energy technologies have become mainstream in most countries as a result of dramatically falling prices," the report argues. "A global renewable energy supply is no longer science-fiction, but work in progress. Renewables contributed 60 per cent of new power generation worldwide in 2014, and in some countries the share was higher. The three main power generation technologies (solar photovoltaics, wind and hydro) together added 127GW of new power generation capacity worldwide in 2014... All this has happened in an environment where subsidies are weighted heavily in favour of fossil fuels, which receive a global annual subsidy of $550bn, more than double the subsidy for renewables."
The report predicts the continued acceleration of these trends would allow renewables to meet 42 per cent of global energy demand in 2030, 72 per cent in 2040 and 100 per cent in 2050, through continued energy efficiency improvements and renewables and electrified transport becoming the default technology choice in both industrialised and developing economies.
Teske argues many of these changes will be driven by simple market forces. "For industrialised countries the power plant suite is old and is going to need replacing regardless," he argues. "If you compare new build with new build it is increasingly clear wind and solar are cheaper than coal, even before you account for the environmental costs of coal."
The situation is different for developing countries, which still require a huge increase in energy capacity to drive development. But again Teske argues renewables offer some inherent advantages. "You can add capacity through renewables cheaper and faster than you can large fossil fuel plants," he argues. "And because the technologies are modular and quick to deploy you can avoid the problem Europe had in the 1970s and China is having now where you build overcapacity."
It is an optimistic vision that Greenpeace would be the first to accept faces a host of significant barriers. First, there are the technical challenges that will need to be overcome if we are to deliver a 100 per cent renewable powered system, challenges that are particularly acute for aviation and industry. Then there are the political and policy challenges associated with the inevitable decline of polluting fossil fuel industries. And finally there is the daunting reality that soaring global energy use means renewables' share of the global mix has, to date, only inched upwards.