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CHAPTER 2
ENERGY: THE BURNING QUESTIONS
others have global implications. In
some cases our awareness of these
impacts is relatively recent.
Other including agriculture 6%
Residential 8%
The pressing need for alternatives
Fossil fuels and the
changing climate
Climate change is the most powerful
driver for movement away from
fossil fuels. It has been estimated
that average global temperatures
have risen by 0.8°C since the end
of the 19th century, with the fastest
rises during the last 25 years. Most
scientists now agree that this rise is
due to an increase in the amount of
greenhouse gases (especially carbon
dioxide (CO2), methane and nitrous
oxide) in the atmosphere and that this
is linked to anthropogenic (human)
causes, namely our increasing use of
fossil fuels.
Electricity generation is the
largest emitter of CO2. The Drax
power station, the largest in the UK,
burns 30,000 tonnes of coal a day. It
generates 7% of the UK’s electricity
but in the process emits 22 million
tonnes of CO2 per year. Although it
is a more efficient thermal power
station (power station where coal,
oil or gas is used to generate steam
to create electricity) than most and
captures 90% of its sulphur dioxide
emissions, CO2 emissions continue
to be a major issue. Plans to reduce
its CO2 footprint by burning willow
Electricity and heat
generation 40%
Transport 20%
Manufacturing 20%
Figure 2.9 Percentage contribution by sector to global carbon dioxide emissions.
Source: EIA, 2009.
biomass alongside the coal were
shelved in early 2010 for financial
reasons. There are now plans to buy
up carbon credits so that Drax can
continue to emit the CO2.
People concerned about climate
change and our impact on the
climate fall into three main groups.
First, there are those who want
a speedy end to the use of fossil
fuels. They support an expansion
of nuclear power, because of its
minimal greenhouse gas emissions.
A second group comprises
people who want a rapid move to
renewable sources, including large
wind turbine farms. They oppose
any expansion of nuclear power
with its problems of radioactive
waste and potential for military
12,000
Million tons CO2
10,000
8000
6000
4000
2000
0
Coal/peat
Oil
Gas
Other
Figure 2.10 Contribution to global carbon dioxide emissions by fuel type (2007).
Source: IEA.
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Other energy 6%
use. A third group acknowledges
that we must face the problems
of greenhouse gas emissions, but
favours a compromise. They think
we should employ the cleaner
fossil fuel technologies and nuclear
power in the medium term, while
moving as fast as possible, and with
maximum government financial
investment, towards renewable
energy sources.
Even as we begin to put in place
strategies that will stabilise the
climate and mitigate the effects of
greenhouse gas emissions, the time
lag means the climate will continue
to change. An important first step
towards recognising our impact
on the climate and attempting
to mitigate it was the 1997 Kyoto
Protocol.
The aim of the Kyoto Protocol
was to secure international
agreement to reduce greenhouse
gas emissions. Most developed
nations signed up to reducing their
emissions by a minimum of 5%
from their 1990 levels, but the USA
was concerned about the damage
this would cause to the US economy
and pulled out of the agreement.
In 2007 the Bali Roadmap set
new targets to guide countries
towards reducing fossil fuel use
and greenhouse gas emissions.
Although not all developed countries
signed up, each time there is an
international meeting – such as the
2009 Copenhagen United Nations
Climate Change Conference – the
issue of our fossil fuel use and
climate change returns to public
and government attention and
pressure grows for meaningful
action. By March 2010, not only
had the USA agreed to reduce its
emissions, but China and India had
also signed up to the Copenhagen
Accord, although they will need
financial and/or technological help
if they are to be able to meet the
reduction targets. At each round
of climate talks we edge closer
to a global strategy for reducing
emissions and combating
climate change.
Acid rain
This is sometimes referred to as
‘yesterday’s problem’ as in Europe,
where it appeared first, solutions
are now in place to drastically
reduce its effects. However, acid
rain is now a problem in the newly
emerging superpowers of China
and India.
Normal rainfall contains
dissolved gases, mainly CO2, which
make it naturally slightly acidic,
with a pH of about 5.6. Burning
fossil fuels – for transport, power
generation and industry – releases
into the atmosphere additional
CO2, plus sulphur dioxide (SO2) and
nitrogen dioxide (NO2). When these
gases are dissolved in rain they
cause the pH level to fall, i.e. the
rainfall becomes more acidic. (A
more accurate term for the process
is acid deposition, as particulates
of sulphur and nitrogen oxides can
reach the ground without being
dissolved in rain.) The pH scale is
logarithmic: one pH unit represents
a ten-fold increase in acidity. Acid
rain often has a pH of 4 or less.
These are some of its impacts:
• acid rain/deposition can increase
soil acidity, causing nutrients
to be more easily leached away
from plant root level, stunting
growth
• acidity can release heavy metals
present in the soil, causing
dieback, poor growth and even
plant death
• in standing bodies of water, acid
rain can kill plants and their
dependent organisms, leaving
lakes beautifully clear but lifeless
• the increase in the atmosphere
of the gases that cause acid
rain can also aggravate lung
problems in humans
• acid deposition can corrode
metals and stone buildings.
Acid rain can travel from the area/
country where it was produced to
fall and cause problems hundreds
of miles away in another region
or country. It is a transboundary
pollutant carried on rain bearing
winds. The fossil fuel-burning
power stations and industries of
the UK produce SO2 and NO2 which
are carried in the prevailing south
westerly winds towards Sweden
where it falls as acid rain causing
devastation to about 20% of that
country’s lakes. The problem was
at its greatest during the 1980s but
since then the UK has reduced its
emissions of the gases involved by
the use of flue gas desulphurisation
(FGD) units.
Figure 2.11 NASA satellite image of eastern Asia shows a dense blanket of polluted air over central eastern China – dense
enough that the coastline around Shanghai virtually disappears. The 'Asian Brown Cloud' is a toxic mix of ash, acids and
airborne particles from car and factory emissions, as well as from low-tech polluters like wood-burning stoves.
Photo: NASA/Goddard Space Flight Center, The SeaWiFS Project and GeoEye, Scientific Visualization Studio.
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