climate / ˈklaɪmət / || / ˈklaɪmɪt/
warm 1 /wɔːrm / || /wɔːm/
≠ worm 1 /wɜːrm / || /wɜːm/
drought /draʊt/
poor 1 /pɔːr / ||/pɔːr/ , /pʊə(r)/
food /fuːd/
flood 1 /flʌd/
unpredictable / ˈʌnprɪˈdɪktəbəl/
shortage / ˈʃɔːrtɪdʒ / || / ˈʃɔːtɪdʒ/
cyclone / ˈsaɪkləʊn/
intense /ɪnˈtens/
malnutrition / ˈmælnuːˈtrɪʃən/
soil 1 /sɔɪl/
erosion /ɪˈrəʊʒən/
vulnerable / ˈvʌlnərəbəl/
desalination plant
ozone layer
carbon dioxide
running water
lime
debate 1 /dɪˈbeɪt/
frequent 1 / ˈfriːkwənt/
glacier / ˈɡleɪʃər / ||/ ˈɡlæsɪə(r)/ , /
ˈɡleɪsɪə(r)/
reliable /rɪˈlaɪəbəl/
wreak /riːk/
havoc / ˈhævək/
Crop [countable]
1 a plant such as wheat, rice, or fruit that is grown by farmers and used
as food [↪ GM]:
The main crops were oats and
barley.
Crop production
Crops grown for market
2 the amount of wheat, rice, fruit etc that is produced in a season[= harvest]
temperature / ˈtemprətʃər / || / ˈtemprətʃə(r)/
hurricane / ˈhɜːrəkeɪn / ||/ ˈhʌrɪkən/ , /-keɪn/
intense /ɪnˈtens/
emergency /ɪˈmɜːrdʒənsi / || /ɪˈmɜːdʒənsi/
production /prəˈdʌkʃən/
devastate / ˈdevəsteɪt/
Lack [singular, uncountable]
When there is not enough of something, or none of it [= shortage]
scar‧ci‧ty [singular]
A situation in which there is not enough of something
Scarcity of
The scarcity of employment
opportunities
Global Warming
Types of radiation from the electromagnetic spectrum make life on Earth
possible, but some have hazards associated with them. These hazards need to be
carefully considered, and the evidence weighed up in order to reach a
scientific explanation.
Greenhouse gases
Some gases in the Earth’s atmosphere absorb infrared radiation. One of
these is carbon dioxide. Even though carbon dioxide is only about 0.04 per cent
of the atmosphere, it is a very important greenhouse gas because it absorbs
infrared well.
Greenhouse effect
The Sun’s rays enter the Earth’s atmosphere.
Heat is emitted back from the Earth’s surface.
Some heat passes back out into space.
But some heat is absorbed by carbon dioxide, a greenhouse gas, and
becomes trapped within the Earth’s atmosphere. The Earth becomes hotter as a
result.
Water vapour and methane - higher only
Other greenhouse gases are water vapour, and also methane. Even though
methane is present in trace amounts only, it is a very efficient absorber of
infrared.
The carbon
cycle
The amount of
carbon dioxide in the atmosphere is controlled by the carbon cycle.
- Processes that
remove carbon dioxide from the air:
Photosynthesis by
plants
Dissolving in the
oceans
- Processes that
return carbon dioxide from the air:
Respiration by
plants, animals and microbes
Combustion ie
burning wood and fossil fuels such as coal, oil and gas
Thermal
decomposition of limestone, for example, in the manufacture of iron, steel and
cement
Cellulose
All cells contain
carbon, because they all contain proteins, fats and carbohydrates. For example,
plant cell walls are made of cellulose, a carbohydrate.
Decomposers
Decomposers, such
as microbes and fungi, play an important role in the carbon cycle. They break
down the remains of dead plants and animals and, in doing so, release carbon
dioxide through respiration.
For thousands of
years, the processes in the carbon cycle were constant, so the percentage of
carbon dioxide in the atmosphere did not change. Over the past 200 years, the
percentage of carbon dioxide in the atmosphere has increased steadily.
Burning more and
more fossil fuels as energy sources
Burning large
areas of forests to clear land, which means that there is less photosynthesis
removing carbon dioxide from the air.
Global warming
Although the changes have been gradual, most, but not all, scientists
agree that the climate is getting gradually warmer. This is called global
warming.
Again, most, but not all, scientists lay the blame for this on human
activities increasing the amount of carbon dioxide in the atmosphere.
Global
warming could cause:
- climate change
- extreme
weather conditions in some areas
Climate change may make it impossible to grow certain food crops in some
regions. Melting polar ice, and the thermal expansion of sea water, could cause
rising sea levels and the flooding of low-lying land.
Computer climate models - higher only
One piece of evidence which supports the view of scientists who blame
human activities for global warming has been provided by supercomputers. Computer
climate models, based on different amounts of carbon dioxide in the atmosphere,
produce the same changes as have been observed in the real world.
Ideas about science
– correlation and cause
The ideas of
correlation and cause are illustrated with the evidence for global warming.
Any process can be
thought of in terms of factors that may affect an outcome.
In global warming,
one factor is the amount of carbon dioxide in the atmosphere. The outcome is
the mean temperature of the atmosphere.
Establishing a
correlation
To establish a
correlation between a factor and an outcome, convincing evidence is needed.
This usually means that enough data must be collected, and that different
samples should match.
Compare these two
graphs and consider these questions:
Are the changes
reported significantly large?
Are they properly
matched in terms of the times over which they are reported?
Do these two
graphs match well enough?
Other factors
A correlation
between a factor and an outcome does not mean that the factor causes the
outcome. They could both be caused by some other factor.
Example
Children with
bigger feet (factor) are, on average, better readers (outcome).
There is another
factor which, in fact, causes both of these. It is age, because older children
usually have bigger feet, and older children are usually better readers!
To investigate the
relationship between a factor and an outcome, it is important to control all
other factors that may affect the outcome.
Other factors
affecting global warming
Another factor
that may affect the mean temperature of the atmosphere is the amount of energy
given out by the Sun. Most scientists agree that this has not changed in the
past 200 years.
There are some
scientists who agree that global warming is taking place, but do not agree that
carbon dioxide levels are to blame.
Scientific
explanation - higher only
Once experiments
have shown that there is a definite correlation between a factor and an outcome,
it is still not enough to prove that the factor causes the outcome.
For this to be
proven, there must be some scientific explanation of how the relationship can
happen.
For carbon dioxide
and global warming, the explanation is that carbon dioxide is a greenhouse gas.
It absorbs infrared given off by the warm Earth, and this infrared cannot then
escape into space. This keeps the Earth warmer than it would be if the carbon
dioxide did not absorb so much infrared.
Este es
el correo de la persona que puso la feria del libro en la EOI: englishbooksinspain@hotmail.com
