As a kid compiling her Christmas list, Greenbang would always take great delight in putting some ridiculous items among the more plebian board games, books and My Little Ponies. You know, a car, a pony, a time machine, a penguin butler. Greenbang knew there was no chance Santa could produce the goods, but requested them anyway, just on the off chance the bearded one might pull it out of the bag.

Greenbang wonders if the same strategy is being used by the International Energy Agency – they’re after $45 trillion (yes, that’s no typo) to get the world to ditch oil.

The IEA, much like an environmental Bagpuss, has put its thinking cap on to work out how the world can cut its carbon levels to 50 percent below what they are today.

It’s all achievable, the IEA, says in a new report – but it will cost $45 trillion.

Here’s why, from the horse’s mouth:

“Emissions halving implies that all options up to a cost of USD 200/t CO2 will be needed. This is based on a set of optimistic assumptions for technology development. Under less optimistic assumptions, options that would cost up to USD 500/t CO2 may be needed. Total additional investment needs in technology and deployment between now and 2050 would amount to USD 45 trillion, or 1.1% of average annual global GDP over the period”, Nobuo Tanaka, Executive Director of the International Energy Agency, stressed.

We would need a virtual decarbonisation of the power sector. Given the growing demand for electricity, this would mean that on average per year 35 coal and 20 gas-fired power plants would have to be fitted with CO2 capture and storage (CCS) technology, between 2010 and 2050 at a cost of USD 1.5 billion each. Furthermore, we would have to build an additional 32 new nuclear plants each year and wind capacity would have to increase by approximately 17.500 turbines each year. This also implies numerous issues that would need to be overcome, such as the NIMBY-attitude (not in my backyard), the need to boost the numbers of engineering and technical graduates, and to resolve the questions on the availability of sufficient geological formations for captured CO2 or geologically stable sites for nuclear reactors or waste storage. In addition to all this, we would also have to make an eightfold reduction of the carbon intensity of the transport sector. This represents the most difficult and costly step due to the ongoing rapid demand growth and limited potential based on existing technology.

“There should be no doubt – meeting the target of a 50% cut in emissions represents a formidable challenge. We would require immediate policy action and technological transition on an unprecedented scale. It will essentially require a new global energy revolution which would completely transform the way we produce and use energy”, Mr. Tanaka stressed. “The energy security benefits of such a development, however, would be tremendous. Oil demand by 2050 would be 27% below the level of 2005. Yet massive investments in remaining reserves will be needed to make up for the shortfall as low-reserve provinces are exhausted.”

CO2 capture and storage, renewables, nuclear energy and energy efficiency – all must play a much more important role. New insights from this study include recognition of the important role for CO2 capture in industry, the potential for electrification of end-use sectors in combination with CO2-free electricity, the need for further development of solar electricity, and the importance of second generation biodiesel.

“We need to act now. We need roadmaps that accelerate international technology development and implementation, but that leave room for flexible responses on a country level”, Mr. Tanaka said. This implies additional funds in the order of USD 100-200 billion per year in the coming decade, rising to USD 1-2 trillion in the coming decades. “The IEA and its technology collaboration network are ready to support this change.”

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