Climate

For the last hundred years the climate has been growing much warmer. This has had a number of different effects. Since the beginning of the twentieth century, glaciers have been melting very rapidly. For example, the Muir Glacier in Alaska has retreated two miles in ten years. Secondly, rising temperatures have been causing the snowline to retreat on mountains all over the world. In Peru, for example, it has risen as much as 2700 feet in 60 years.

As a result of this, vegetation has been changing. In Canada, the agricultural cropline has shifted 50 to 100 miles northward. In the same way cool-climate trees like birches and spruce have been dying over large areas of Eastern Canada. In Sweden the treeline has moved up the mountains by as much as 65 feet since 1930.

The distribution of wildlife has also been affected, many European animals moving northwards into Scandinavia. Since 1918, 25 new species of birds have been seen in Greenland, and in the United States birds have moved their nests to the north.

Finally, the sea has been rising at a rapidly increasing rate, largely due, as was mentioned above, to the melting of glaciers. In the last 18 years it has risen by about six inches, which is about four times the average rate of rise over the last 9000 years.

► Questions:

1. How have glaciers been melting?

a) slowly b) quickly c) annually

2. What does retreat mean?

a) to move rapidly b) to move slowly c) to move away from a position

3. Does vegetation refer to:

a) flora? b) fauna? c) water?

4. Where do wild animals in Europe move to?

a) east b) west c) north

5. Is Greenland washed by

a) the North Sea? b) the Baltic Sea? c) the Norwegian Sea?

6. What has been rising at a rapidly high rate?

a) water level b) temperature level c) sea level

7. What do climate changes affect?

a) glaciers melting b) trees moving up c) sea level rising

8. Which of the following best describes the main point of the text?

a) Everything around us is constantly changing.

b) The climate in different regions changes according to the season.

c) Natural climatic changes lead to dramatic effects.

9. Correspond the facts with the following numbers:

60 years / 100 miles / 65 feet / 25 species of birds / 6 inches / 9000 years

3.25. Read the following four texts and match them with the headings:

● Changes in Living Things ● Changes in Climate

● The Changing Landscape ● Threats of Climatic Changes

1) Natural climatic changes take place gradually over thousands of years and so are no great threat to us at present. Of far greater importance is the danger that our large-scale industrial activity is changing the earth’s climate. These changes will happen much more quickly and could well be much more dramatic. The greenhouse effect, smoke and dust clouds blocking out sunlight, and the destruction of the ozone layer are all real threats.

2) The climate in different regions of the world changes throughout the year, according to the season. This is because the earth’s axis is tilted whilst it travels around the sun. In tropical areas, with temperatures constant all year round, the amount of rainfall determines the season – dry or rainy. Further north and south, the climatic changes are much greater (especially in temperature), and there are four main seasons – winter, spring, summer and autumn.

3) The seasonal differences in climates result in many changes in living things. Many animals adapt their life cycles to the changes in temperature and availability of food. Some migrate to other areas, often hundreds of miles away, where conditions are more suitable for feeding or breeding, or both.

The Arctic seagull breeds in the summer on the shores of the Arctic Ocean, then flies 20,000 km to the Antarctic to feed during its summer. It travels over 40,000 km each year.

4) The changes made by man to the earth’s natural conditions can be seen all around us. In many places, farming, industry and urban developments have changed natural landscapes into man-made environments such as fields, towns and cities. Much of this has taken place over centuries, but increasing populations and industrialization in recent times have caused a dramatic increase in both the scale and intensity of these changes.

3.26. Are these statements true (T) or false (F)?

1. Industrial activity changes the earth’s climate.

2. Natural forces slowly change the face of the earth.

3. Animals can’t adapt to the changes in temperature.

4. Natural climatic changes refer to four main seasons.

5. Natural landscapes are changed by man into towns and cities.

3.27. Answer the following questions.

1. Why do animals migrate?

2. Why do birds migrate?

3. What are the real threats of the earth’s climate?

4. What seasons do you know? Are there all the seasons in your region? What is your favourite season and why?

5. What causes the intensity of the landscape changes?

6. Give one example of a changing landscape in your area.

3.28. Match the two parts of the sentences.

1. For billions of years great natural forces like the earth’s movement, volcanic activity and erosion	a) cause climatic variations.
2. The climate and the earth’s landscape interact	b) and are expected in the West Pacific.
3. The interaction of winds and ocean currents	c) to create the life-supporting soil.
4. The weathering effects of temperature, wind and water	d) have been reshaping the face of the earth.
5. Drought conditions now exist in Indonesia and Australia	e) and their distribution over our planet.
6. The major atmospheric elements are: latitude, land and water relationships, ocean currents,	f) climatic regions situated at the greatest distance from the equator.
7. The polar climates are the last of Köppen’s climatic subdivisions and they characterize	g) altitude, mountains and human activities.
8. Climatology is the study of the varieties of climates	h) break down the rocks on the earth’s surface.

3.29. Read the text below and find the words in the text which mean the following:

1. average	6. rays from the sun
2. dry	7. make less extreme
3. height above sea level	8. situated very far from the sea
4. distance from the equator	9. differing weather conditions at
5. rain and snow	different times of the year

Schemes for dividing the Earth into climatic regions are based on a combination of indices of mean annual temperature, mean monthly temperature, annual precipitation totals and seasonality. The climate of a place is affected by several factors. Latitude affects the amount of solar radiation received, with the greatest in equatorial regions and the least in polar regions. Elevation affects both temperature and precipitation; mountainous areas are generally cooler and wetter. Location close to the sea or to large bodies of water moderates temperature; continental areas are generally more arid and more affected by extremes of temperature.

3.30. Choose the correct word.