Prospect has published my essay on bioenergy, in which my
research left me astonished at the environmental and economic harm
that is being perpetrated. Biomass and biofuels are not carbon
neutral, can't displace much fossil fuel, require huge subsidies,
increase hunger and directly or indirectly cause rain forest
destruction. Apart from that, they're fine... Here's the
text:
From a satellite, the border between Haiti and the Dominican
Republic looks like the edge of a carpet. While the Dominican
Republic is green with forest, Haiti is brown: 98 per cent
deforested. One of the chief reasons is that Haiti depends on
bioenergy. Wood-mostly in the form of charcoal-is used not just for
cooking but for industry as well, providing 70 per cent of Haiti's
energy. In contrast, in the Dominican Republic, the government
imports oil and subsidises propane gas for cooking, which takes the
pressure off forests.
Haiti's plight is a reminder there is nothing new about bioenergy.
A few centuries ago, Britain got most of its energy from firewood
and hay. Over the years the iron industry moved from Sussex to the
Welsh borders to Cumberland and then Sweden in an increasingly
desperate search for wood to fire its furnaces. Cheap coal and oil
then effectively allowed the gradual reforestation of the country.
Britain's forest cover-12 per cent-is three times what it was in
1919 and will soon rival the levels recorded in the Doomsday Book
of 1086.
Yet if the government has its way, we will instead emulate Haiti.
In 2007, Tony Blair signed up to a European Union commitment that
Britain would get 20 per cent of its energy from renewable sources
by 2020. Apparently neither he nor his officials noticed this
target was for "energy" not "electricity." Since much energy is
used for heating, which wind, solar, hydro and the like cannot
supply, this effectively committed Britain to using lots of wood
and crops for both heat and electricity to hit that target. David
Cameron and Chris Huhne, anxious to seem the "greenest of them
all," dare not weaken the target, despite its unattainability.
Biomass consumption in power stations was up 27 per cent in 2010
and "co-firing" (burning biomass alongside coal) was up 39 per
cent. To replace coal, the government projects that by 2020 Britain
will be generating electricity from burning up to 60m tonnes of
biomass, mainly wood, about five times the timber harvest that
Britain could conceivably produce. To replace oil, the European
Union has set a target of making 10 per cent of our transport fuel
renewable by 2020, which will mean mainly biodiesel made from rape,
soybean and imported palm oil. To replace gas, a gold rush of
developers is trying to build anaerobic digesters on farms, where
they will turn whole crops into methane.
All this is driven by subsidies that are mouth-wateringly generous
to energy producers and eye-wateringly costly to consumers and
drivers. According to the pressure group Biofuelwatch, the biomass
power stations proposed for Britain would attract over £3bn a year
through "renewable obligation certificates." Drax power station
alone gets £43m a year to "co-fire" biomass alongside coal, much of
it imported-for example in the form of olive pits, sunflower husks
and peanut shells.
For all the furore that wind farms attract, bioenergy is a much
bigger drain on the public purse than wind. Bioenergy currently
supplies 83 per cent of all renewable energy used in Britain, while
wind, solar, hydro, tide, wave, geothermal and heat pumps manage
just 17 per cent, or 1 per cent of total energy. About half of that
bioenergy is from waste incineration, sewage and landfill gas. The
rest comes from timber or crops. The uncomfortable truth is that
more than four-fifths of all "renewable" energy involves burning
something.
If you mention biomass crops to an environmentalist, he or she
will usually agree they are a bad thing-for reasons I will come
to-but claim that they have little to do with the green movement,
being driven instead by American electoral politics. (Iowa, a key
state for presidential candidates to win early support, benefits
from subsidies when the maize grown there is turned into ethanol.)
Inconveniently for this thesis, the amount of Britain's primary
energy supply from biomass (3 per cent) is about the same as
America's (4 per cent).
It was not US politics that caused a subsidised wheat ethanol
plant to open on Teesside in 2009 (and then close in May because
the smell was a nuisance and the wheat price had become too high).
As Robert Palgrave of Biofuelwatch says: "In America, bioenergy's
supporters stress energy security; here the big driver has been
climate change and in particular the European Union's Renewable
Energy Directive."
Whether they admit it or not, the green movement caused this
policy, the sole justification being to address climate change. Yet
bioenergy is not just doing nothing to help cut carbon emissions-
like wind; it is actually making the problem worse.
Here is why. A carbon atom is a carbon atom, wherever it comes
from. Oxidise (burn) it and you get carbon dioxide. That is true
whether it is in a hydrocarbon (like coal, oil or gas), a
carbohydrate (like sugar in sugar cane or starch in maize), or a
lipid (like oil from palm oil). Roughly one-third of the atoms we
oxidise to liberate energy are carbon and two-thirds hydrogen.
(Oxidised hydrogen is better known as water.)
As Jesse Ausubel of Rockefeller University has calculated, wood
has a higher ratio of carbon to hydrogen (10) than coal (1), oil
(0.5) and gas (0.25). Burn wood and you make 40 times more carbon
dioxide for each unit of energy than if you burn gas. It's the
worst thing you can do in carbon terms.
However, a carbon atom in wood was absorbed from the air a few
years before when the tree grew, whereas a carbon atom in coal or
gas was absorbed from the air hundreds of millions of years before.
Since a felled tree can be fairly quickly replaced by a new one,
wood is said by its supporters to be "carbon neutral" whereas gas
is not.
The trouble with this argument is that it fails to take into
account the fact that burning the timber oxidises carbon atoms
decades before they would be released naturally. According to a
report from Joanneum Research, this up-front carbon debt could take
two or three centuries to be paid back in the case of timber.
Harvesting also denies the carbon atoms to other species, such as
beetles and woodpeckers (whereas almost nothing eats coal or
gas).
In the case of crops grown for liquid fuel, a bigger problem
emerges: the carbon oxidised in planting, harvesting, transporting
and drying the grain turns out to be about as much as the carbon
content of the plant itself. That is to say, almost as many carbon
atoms (and almost as much energy) are burned in making the fuel as
are in it. This is the case for maize grown for ethanol in the US,
for example. By contrast drilling for, transporting and refining
petrol has a 600 per cent energy gain.
Some biofuels are better. Brazilian sugar cane, which supplies a
third of all fuel used by cars in that country, contains more
carbon atoms than were burned in growing it. But don't celebrate
too soon. The reason is that Brazilian sugar cane is mostly cut by
poor labourers on piece rates, some of them children, rather than
by machinery.
It gets worse. When a forest is felled to make way for a biofuel
crop, the carbon stored in the trees and soil leaks into the
atmosphere through decay. The crop is then grown with nitrogen
fertiliser, some of which turns to nitrous oxide, a greenhouse gas
300 times more potent than carbon dioxide.
In Borneo vast areas of forest have been cleared to grow palm oil
to make into biodiesel to sell to Europeans striving to meet their
renewable targets. Much of this forest grew on waterlogged peat
with high carbon content. When this is drained, the peat oxidises.
Researchers at the University of Leicester have calculated that the
carbon emissions from the drained peat are double the previous
estimates of carbon emitted in the clearing of forests, so the
policy of clearing forest for palm oil can "actually increase
emissions relative to petroleum fuels." It would take 423 years to
pay back the up-front carbon debt.
This is to say nothing of the orangutans whose habitat is eroded
and fragmented. The European Environment Agency (EEA) says that
"accelerated destruction of rainforest due to increasing biofuel
production can already be witnessed."
Even if you do not clear rainforest to grow biofuels, you usually
displace a food crop. This pushes up food prices, as a total of 17
independent reports have concluded. In August the UN Committee on
World Food Security said biofuels had been a bigger cause of recent
food price increases than the growth of the Asian middle class. The
independent scholar Indur Goklany has estimated that biofuels
killed 192,000 people in 2010 by increasing hunger.
Higher prices encourage farmers to cultivate more virgin land, so
biofuels encourage the destruction of rainforest to grow food, even
if they did not directly replace forest. Such "indirect land use
change" is impossible to measure. The European Commission promised
to come up with an estimate, but in September Reuters obtained a
leaked report in which the commission admitted it could not put a
number on the problem. A few days later the EEA issued a statement
that because biofuels displace food crops, the assumption that they
are carbon neutral is "not correct."
An American study published in Science in 2008 concluded that
because maize made into ethanol could not be exported as food, some
virgin land would be cleared and ploughed elsewhere in the world
for every acre of ethanol maize grown, which meant that ethanol had
effectively double the carbon footprint of petroleum.
Britain gets most of its biofuel from Argentinian soybeans. A
recent report commissioned by the Department of Energy and Climate
Change concluded that if bioenergy grows to 20 per cent of primary
energy by 2020 as envisaged, we will be importing 67 per cent of
it. So not only is the impact on hunger and rainforest destruction
directly on our conscience; there is also no prospect of energy
security from bioenergy. This import dependence is causing second
thoughts about how "sustainable" Britain's rush to biomass really
is, and that is frightening off the banks that would need to lend
to such projects.
At this point, biofuel's supporters argue that the second
generation of biofuels, consisting of "cellulosic" miscanthus grass
and jatropha plants, will be grown on marginal land not used for
farming and not covered in rainforest. When asked where this land
is, and how it can be made fertile enough to grow biofuels, they
point to degraded and abandoned farmland. The trouble is, they
forgot to tell the people who live there. Göran Berndes of Chalmers
University of Technology in Sweden co-authored a report that
studied 17 bioenergy feasibility studies. Its conclusion was that
"land reported to be degraded is often the base of subsistence for
the rural population."
In Andhra Pradesh, Berndes did find that jatropha planting helped
retain water and didn't prevent land being grazed, so its impact
was "generally positive, creating a complementary source of income
to the farmers." But elsewhere things are not so rosy. Fatou Mbaye,
food rights co-ordinator for Action Aid Senegal, told the New
Internationalist recently: "At first, we were told that [jatropha]
would be grown on marginal land. But it's being grown on the best
arable land with the highest rainfall, or where good irrigation is
possible, to make it economically profitable."
While the impact of bioenergy on food prices has been severe, the
reduction in oil use has been minuscule. In 2010, America turned 40
per cent of its maize crop into fuel, displacing just 3 per cent of
its oil consumption. Worldwide, 5 per cent of grain was turned into
fuel, displacing just 0.6 per cent of oil. To cut say 20 per cent
of world oil use would require such a gigantic land grab that
starvation would be widespread and rainforest a distant memory.
The land grab is huge because of bioenergy's low power density.
According to Jesse Ausubel, an American ethanol farm generates
about 0.047 watts per square metre, once the energy inputs are
deducted; a New England forest can provide wood at the rate of
about 0.1 watts per square metre; and a Brazilian sugar cane field,
ignoring human toil, manages about 3.7.
The energy expert Vaclav Smil of the University of Manitoba says a
realistic estimate of the energy density of bioenergy worldwide is
less than 0.5 watts per square metre. The world economy uses energy
at the rate of 15,000 gigawatts (474 exajoules per year). To supply
that from bioenergy would require 30 million square km, a territory
the size of China, Brazil, India and Australia put together. Or
"Renewistan" as engineer Saul Griffith calls this fabled land.
The champions of biofuels are left with one card to play: algae.
In theory, by growing algae in closed bioreactors in salty water in
sunny places, you can achieve much higher power densities. In
practice, many engineering hurdles remain before first-generation
algal farms go commercial.
The conclusion is stark. There is no way to run even a fraction of
the world economy on bioenergy without severely damaging the
planet. For the environment's sake we must use a much denser form
of energy, such as fossil fuel or nuclear, whose footprints I
estimate to be about 100 and 10,000 times smaller than biofuel's
respectively. The same applies to other forms of renewable energy,
with the possible exception of solar power, whose density could one
day be better than the rest (except in cloudy Britain). So by all
means install a wood-burning stove or use biodiesel in your car.
But don't pretend you are doing the planet a favour.
A declaration of interest. As a landowner I benefit from the
recent increases in prices of wheat and wood caused by bioenergy.
Recently I turned down a proposal to establish an anaerobic
digester on my farm, even though it would have guaranteed a good
income. So the views expressed here are against my financial
interest.
