ni2 25/4/12

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

➔ cash crop

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