Day 8
You should spend about 20 minutes on
Questions 14-26,
which are based on Reading
Passage 2 below.
Russia’s boreal forests and wild grasses could combat climate
change
A
Scientists believe Russia’s ancient forests are the country’s best natural weapon
against climate change, even though the stockpile of carbon beneath the ground
also makes these areas vulnerable to carbon release. A recent study found that half
the world’s carbon is stored within land in the permafrost region,
about two-thirds
of which lies in Russia. Overlying former glaciers, they are a coniferous mix called
the boreal forest. There’s a lot of carbon there and it’s very vulnerable,’ says Josep
Canadell co-author of the study. ‘If the permafrost thaws, we could be releasing ten
percent more carbon a year for several centuries more than our previous models
predicted. It’s going to cost a lot to reduce our emissions by that much - but it will cost
more in damage if we don’t.’
В
The study was published in Global Biogeochemical Cycles, Researchers found
that the region contains 1,672
billion tons of organic carbon, much of it several feet
underground, that would account for approximately 50 percent of the estimated
global below-ground organic carbon’. Another paper published in Nature found that
old forests, which make up perhaps half of the boreal forest, “continue to accumulate
carbon, contrary to the long-standing view that they are carbon-neutral’. Even though
fires and insect infestations destroy entire swaths of forest and release into the
atmosphere the carbon they contain, old-growth forests still take in more than these
natural disturbances release, says lead
author Sebastiaan Luyssaert, a biologist at
the University of Antwerp in Belgium. T h is is all the more reason to protect Russia’s
boreal forests, which take in 500 million tons of carbon a year, or about one-fifth of
the carbon absorbed by the world’s landmass, says Mr Canadell, who is executive
director of the Global Carbon Project, based in Canberra.
С
Jing Ming Chen, a University of Toronto geography professor who specialises in
climate modelling for the
boreal region, says: ‘Cutting boreal trees increases the
amount of carbon in the atmosphere and it takes 50 to 100 years to put that carbon
back in the ground.’ Luysaaert and Chen argue there’s a strong case for conserving
the old-growth forests. It’s better to keep as much carbon in the forest as possible
right now, Mr Luyssaert explains. ‘If we want to avoid irreversible processes like
melting permafrost or changing ocean currents, we absolutely have to control our
emissions in the next two or three decades. It’s a case where you need to be short
sighted to be far-sighted. The threats to the boreal forests don’t seem significant right
now,’ explains Nigel Roulet, a carbon cycle specialist at McGill University in Montreal,
Reading Passage 2
‘but I’m convinced pressure will increase as the region gets warmer and
it gets easier
to operate there. Also, I expect these resources to become more valuable as others
are exhausted.’
D
Scientists say Russia and Kazakhstan could make a unique contribution to the fight
against global warming by harvesting wild grasses that have overgrown 100,000
square miles of agricultural lands abandoned in the nineties, and using them to
make ethanol - or, better yet, burn them in coal-fuelled power plants. According to
Nicolas Vuichard, principal author of a paper published in Environmental Science and
Technology of Washington, DC, using the grasses to make ethanol would sequester
in the ground, over 60 years, about 10 million tons of carbon a year-one-quarter
as dead root matter in the soil and the rest in producing ethanol as a substitute for
petroleumbased fuels. That’s
not huge on a world scale, but it’s substantial,’ he says.
Fossil fuels emit about eight billion tons of carbon a year, of which about two billion
tons are absorbed by plants and soil.
E
Renton Righelato, visiting research fellow at the University of Reading and former
chairman of the World Land Trust, agrees. “Given that it would take the world’s
entire supply of arable land to replace just two-thirds of our transport fuel needs,’ he
says, ‘biofuels are not a practicable long-term solution for transportation emissions.
What we need is carbonfree fuel. But in the case of abandoned croplands, using
grasses as biofuels could
make a contribution, he adds. Study co-author Adam
Wolf, of the Carnegie Institution for Science at Stanford University, cites a study by
Elliott Campbell in Science magazine that showed that burning grasses in a coal-
fuelled plant doubles the savings in carbon emissions compared to using the same
grasses to make ethanol. ‘If biofuels are going to reduce emissions, using abandoned
croplands to make electricity and offset coal use is our best bet,’ he says. Both of
these countries
have coalfuelled power plants, so the process could start soon.’
Thus, Russia and Kazakhstan are now in a position to become leaders in green
energy, and could use the grasses to export clean electricity in addition to oil and
gas, according to Mr Wolf.
Which paragraph contains the following information?
Write the correct letter, A -E , in boxes 14-18 on your answer sheet.
NB You may use any letter more than once.
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