2020-02-01_New_Scientist

(C. Jardin) #1
1 February 2020 | New Scientist | 15

Analysis Climate change

OIL companies and airlines should
pay for a huge tree-planting drive
to fight climate change as soon
as next year, the UK government’s
climate advisers have urged.
The proposal is one of the
eye-catching ideas presented
by the Committee on Climate
Change (CCC) in a report on the
big changes in farming and land
use necessary for the UK to hit its
2050 net-zero emissions target.
The report calls for a fifth of
farmland to be used to store
carbon instead of producing food,
a rapid expansion of crops grown
for energy, and measures to try to
get the public to consume 20 per
cent less beef, lamb and dairy.
To meet the UK’s net-zero
target, emissions from land
use will have to fall 64 per
cent by 2050, equivalent to
37 megatonnes of carbon
dioxide. The rest of the emissions
associated with land use will be
offset elsewhere. Trees and
forestry, which absorb carbon,
could deliver around half the
reduction. Land use, including

agriculture, forestry and peatland,
accounts for 12 per cent of the
UK’s greenhouse gas emissions.
One of the committee’s key
proposals is turning 22 per cent of
farmland over to other uses such
as tree planting. The UK currently
produces half its own food, so
other changes would be needed
to maintain this. The CCC thinks
the answer is a big increase in
agricultural productivity, which
it argues is feasible as the UK

already lags other countries on
this, plus a shift in diets and an
end to food waste.
The way farmers work will
need to change, too. That includes
relatively simple ideas such as
avoiding compacting soil, which
can damage it, to more innovative
ones, such as breeding cows to
belch less methane. Many of the
ideas are like those suggested
by farmers. “It really is time we
ended this adversarial discussion
between climate and farming,”
says Chris Stark at the CCC.

Getting people to eat less meat
and dairy may sound hard, but
consumption of both is already
falling in the UK. “This isn’t a
revolutionary proposal,” says John
Gummer, chair of the CCC. The
public sector can lead by offering
a daily vegan choice on menus,
but by 2025, the government
should consider stronger options
to shape dietary choices, such
as pricing, the group says.
That could be a meat tax,
something other researchers have
said would save lives and money.
For now, the CCC’s message is to
eat less meat and choose local
produce, as emissions from UK
beef production are lower than
in many other countries.
However, the biggest push is in
tree planting, something political
parties tried to outbid each other
on during the December general
election. The CCC thinks that
by 2024 there needs to be a
minimum of 30,000 hectares of
trees planted a year, equivalent to
around 100 million trees a year.
The area covered by trees
would rise from 13 per cent of
the UK now to 17 to 19 per cent
by 2050. The cost is estimated at
£500 million a year, to be paid for
by a levy on polluters, with fossil
fuel producers and the aviation
industry named in the report.
Dave Reay at the University
of Edinburgh in the UK says the
report is very well-researched and
blunt in its message. “UK land use
must change, and fast,” he says.
The CCC says land-use change
takes time, so action is needed
urgently and the group wants
many of its ideas adopted this
year. Gummer says: “These are
major changes and cannot be
delivered just in the normal course
of business. It really does require
government action and that needs
to be immediate. We are in a race
WA against time.” ❚

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More of the UK must be
forested to help meet
climate change targets

64%
The fall in emissions from UK
land use needed to hit net zero

Make polluters pay for new trees A report from the UK’s
climate advisers urges big changes to get us to net zero - but
they should be possible, says Adam Vaughan

Air quality


Michael Marshall


SPIKES in air pollution in New York
City have been traced to smoke
from wildfires burning thousands
of kilometres away. The finding
suggests city residents will face
many similar pollution episodes
in the coming decades.
“When people are making
predictions about climate change,
they’re predicting increases in
wildfires, so this sort of pollution
is likely to become more common,”
lead author Haley Rogers at Yale
University said in a statement.
Rogers and her colleagues
studied two spells of unusually
severe air pollution in Connecticut
and New York City on 16-17 and
27-29 August 2018. There were
high levels of three pollutants:
carbon monoxide, a class of tiny
particulate matter called PM2.
and black carbon – otherwise
known as soot.
The researchers studied satellite
images to gauge how far the clouds
of pollution spread. They then used
a weather model to simulate wind
patterns at the time and estimate
where the pollution came from.
The first cloud of pollution
arrived from western Canada, where
wildfires were burning several
days earlier. The second came
from wildfires in the south-eastern
US (Atmospheric Chemistry and
Physics, doi. org/ dkdb).
Air pollution from wildfires “is not
a typical problem one would think
about for New York City and the
region”, says Drew Gentner, who
worked with Rogers on the study.
Air pollution can cause various
health problems. But it isn’t yet
possible to estimate the public
health impact of the pollution that
drifted to New York, says Gentner.
Similarly, it is unclear what
constitutes a minimum safe level of
exposure for health. “The resulting
health impacts from particulate
matter exposure is a very active
area of research,” he says. ❚


New York City air


pollution came from


fires 4000 km away

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