Harvesting forests to reduce fossil fuels the next big boondoggle
by: Bjorn Lomborg From: The Australian May 20, 2013 12:00AM
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WE are all brought up to recycle paper to save trees. Indeed, environmentalism was born with a call to preserve the forests.
But now, in the name of saving the planet from climate change, environmentalists are proposing a global campaign to cut down and burn trees to reduce fossil-fuel use. This could be dismissed as a weird irony if it weren't for its phenomenal costs, which include likely destruction of biodiversity, increased water use and reduced global food production. And it may increase global CO2 emissions to boot.
When most people think of renewables, they imagine solar panels and wind turbines. Globally, however, solar and wind were less than 7 per cent of renewables in 2010. Hydropower is a much bigger player, at 17 per cent.
But most important is biomass, humanity's oldest fuel that makes up 76 per cent of renewable energy and 10 per cent of all energy. About 60 per cent of this is wood, twigs and dung, used by almost three billion people who lack modern fuels, resulting in terrible air pollution and millions of deaths.
But the West uses the other 40 per cent of biomass to produce heat, and it will increasingly use it to generate electricity. This makes sense; because solar and wind power are inherently unreliable we still need electricity on cloudy days or when the wind dies down. Biomass (along with hydropower) can be used to smooth the fluctuations inherent to wind and solar.
Biomass is experiencing a revival, because it is considered CO2-neutral. The conventional wisdom is that burning wood only releases the carbon sucked up while the tree was growing, and hence the net climate effect is zero.
But a growing number of voices challenge this view. The European Environment Agency's Scientific Committee has called it a "mistaken assumption" based on "a serious accounting error" because if a forest is cut down to burn wood it will take a long time for new growth to absorb the CO2 emissions. The effect could be a net increase in emissions if forests are cleared to plant energy crops.
According to the committee's members, "the potential consequences of this bioenergy accounting error are immense". Environmentalists' plan to obtain 20-50 per cent of all energy from biomass could mean a tripling of biomass consumption, placing its production in direct competition with that of food for a growing global population while depleting water supplies, cutting down forests and reducing biodiversity.
An academic paper published last year makes the point clear in its title: "Large-scale bioenergy from additional harvest of forest biomass is neither sustainable nor greenhouse gas neutral". Its authors point out that, while the industrial revolution caused climate change, reliance on coal was actually good for forests because our forebears stopped raiding them for wood. This is one of the major reasons why forests in Europe and the US have recovered, and why many forests in developing countries are threatened.
The developed world's re-enchantment with biomass could take it down a similar road.
But the biggest problem is that biomass production pushes other agricultural production elsewhere. In Denmark, researchers estimated how much various crops would reduce CO2 emissions. For example, burning a hectare of harvested willow on a field previously used for barley (the typical marginal crop in Denmark) prevents 30 tonnes of CO2 annually when replacing coal. This is the amount proud green-energy producers will showcase when switching to biomass.
But burning the willow releases 22 tonnes of CO2. All of that CO2 was soaked up from the atmosphere the year before; had we just left the barley where it was, it too would have soaked up quite a bit, lowering the reduction relative to coal to 20 tonnes. And, in a market system, almost all of the barley production simply moves to a previously unfarmed area. Clearing the existing biomass there emits an extra 16 tonnes of CO2 a year on average (and this is likely an underestimate).
So, instead of saving 30 tonnes, we save four tonnes at most. And this is the best-case scenario. Of the 12 production modes analysed, two would reduce annual CO2 emissions by only two tonnes, while the other 10 actually increase total emissions up to 14 tonnes a year.
At the same time, we are paying a king's ransom for biomass. Germany spends more than $3 billion annually or $167 per tonne of avoided CO2 emissions, which is more than 37 times the cost of carbon reductions in the European Union emissions trading system.
And the estimate of avoided emissions ignores indirect land use changes, making the likely real cost at least eight times higher.
Ten years ago, the EU and the US embraced biofuels to combat global warming. Today, the US turns 40 per cent of its maize into ethanol to fuel cars. This has driven up food prices, caused tens of millions to starve, costs more than $17bn a year in subsidies and causes agricultural deforestation elsewhere in the world, with more total CO2 emissions than the entire savings from the ethanol. Biofuels are an almost unstoppable, unmitigated disaster.
We need to confront the potentially much bigger biomass boondoggle. Yes, we should turn waste into energy and be smart about agricultural leftovers.
But we are about to diminish biodiversity, over-extract water, make food more expensive, and waste hundreds of billions all while cutting down trees to burn them and potentially increasing CO2 emissions. We have been brought up to know and do better.
Bjorn Lomborg is adjunct professor at the Copenhagen Business School.
