The Truth About Global Warming reading answer

The Truth About Global Warming IELTS reading answer

Eleven of the Forrest years since 1850 occurred between 1995 and 2006, Last year in
Nations Intergovernmental Panel on Climate Change (IPCC) reported that the earth was a
0,75°C warmer than it was in 1850. While this doesn't sound like a lot, a small difference in
can make a big difference in the climate. During the last ice age, for example,
the planet was only about 5°C colder than now.
The JPCC has.concluded that human activity is very likely responsible, by increasing the
concentrations of greenhouse gases and thus the greenhouse effect. More than 25 scientific
societies, including the national science academies of the G8 nations, have endorsed the
conclusion, Some scientists, however, siui Disagree, arguing that human contribution is a minim
The effect, explains Robert Charlson, a proféssor at the University of Washington, 'has been
on the scientific books for over a century. t has been tested very thoroughly.' Certain gases
cause the atmosphere to trap great energy at the earth's su.rface. Without the gree: house ever
he earth's average global tom, armature would be - 0, rather than the present comfortable
14.6°C. The concern is with thc enhanced greenhouse effect that humans cause - arecfica
that it will heat the planet too mu.ch.
The main greenhouse gases (GIHGS) are carbon dioxide (CO), methane, nitrous oxide,
chlórofluorocárbons (CFCs) and water vapour. Except for CFCs, which are foi commercial
purposes, these gases are found in nature. Euming fossil fuels, trees and agricultural waste
adds o the CO,, methane and nitrous oxide, as do landfills, oil refineries and coal mines. Anu
we affect water vapour indirectly, too. As the earth warms because other GHG levels increased
evaporation ramps up, creating more water vapour.

The Truth About Global Warming IELTS reading answer

Co2, has increased 35 per cent since the beginning of the industrial era,' says Gavin Schmidt
climatologist with NASA's Goddard Institute for Space Studies in New York. 'Meghan has ma
than doubled. Nitrous oxide has gone up 17 per cent.

Scientists are particularly concerned about CO because it is the most abundant of the gases that
ue affect directly. While we have stabilised our CFC and methane emissions, we have not done the
same with CO, so far. The carbon dioxide in the atmosphere continues to rise by about 0.4 per cent
a year - because the fossil fuels that produce it fill 85 per cent of our energy requirements.
According to NASA's Schmidt, 'CO, stays around for centuries.' Worldwide, we produce some
23.5 gigatonnes of CO, annually. (A gigatonne is a trillion kilograms.) Fortunately, only half of this
amount stays in the atmosphere; natural systems absorb the rest. For instance, oceans, our
largest repository of carbon dioxide, take in more than a quarter of our CO, emissions every year.
They already hold about 50 times the amount in the atmosphere and ten times that in the land,
the biosphere. But just how much more they can safely store is still not clear. In addition, forests and
plants soak up less than a quarter of CO, emissions. Through photosynthesis, plants separate
CO, into oxygen, which they emit, and carbon, which becomes part of their cells.
Climate change may also result from regular shifts in the orbit of the earth and the tilt of its axis
changing how sunlight is distributed around the globe and may explain why the ice ages came
and went. These shifts take place slowly over hundreds of thousands of years.
Tiny particles pumped into tre atmosphere by erupting volcanoes and industrial pollution reflect
some solar energy back 10 space, with the effect of making things cooler. In 1991, Mount
Pinatubo in the Philippines blew so much dust into the stratosphere that the temperature
dropped by half a degree for two years.
Water in the form of vapour and clouds plays a role, but their impact is hard to predict/ Water
évapolating from warner oceans creates clouds that can both trap heat and reflect it into
space. Low clouds tend to cool the planet,' Professor Charlson says. 'High clouds warm it.'
EPS ARCADE
Many researchers have concluded that natural forces alone do not explain the temperature
increases over the past 30 or 40 years Bruce Bauer who studies ancient weather systemş at
the World Data Centre for Paleoclimatology in the US, says, 'When you try :o do the maths, the
the only way you can calculate what's happening is to Include the effects of artificial CO
The theory of heat-trapping gases projects that as CO, emissions go up, temperatures will rise
in the lower atmosphere and at the surface nf the earth. Thomas Kari, director of the National