geography

The highest point of the troposphere is known as the tropopause. This is least at the shafts, where it is around 7 - 10 km over the World's surface. It is most elevated (around 17 - 18 km) close to the equator.

The Stratosphere

This stretches out upwards from the tropopause to around 50 km. It contains a significant part of the ozone in the atmosphere. The expansion in temperature with height happens as a result of retention of bright (UV) radiation from the sun by this ozone. Temperatures in the stratosphere are most elevated over the mid -year shaft, and least ridiculous post.

By engrossing perilous UV radiation, the ozone in the stratosphere shields us from skin malignancy and other wellbeing harm. Anyway synthetic substances (called CFCs or Freon’s, and halons) which were once utilized in fridges, splash jars and fire dousers have decreased the measure of ozone in the stratosphere, especially at polar scopes, prompting the purported "Antarctic ozone opening".

The Mesosphere

The region above the stratosphere is called the mesosphere. Here the temperature again decreases with height, reaching a minimum of about -90°C at the "mesopause".

The Thermosphere and Ionosphere

The thermosphere lies over the mesopause, and is an area wherein temperatures again increment with stature. This temperature increment is brought about by the ingestion of lively bright and X-Beam radiation from the sun.

The locale of the air above around 80 km is likewise caused the "ionosphere", since the vivacious sun powered radiation thumps electrons off particles and molecules, transforming them into "particles" with a positive charge. The temperature of the thermosphere shifts among night and day and between the seasons, as do the quantities of particles and electrons which are available. The ionosphere reflects and ingests radio waves, permitting us to get shortwave radio stations in New Zealand from different pieces of the world.

The atmosphere is important to the study of the atmosphere in the sense that we experience climate generally at the surface of the earth. This is the intersection of a number of different and distinct parts of the climate system. Understanding the different components of the climate system is critical for being able to simulate the system.

QUESTION TWO

Examine the effects of climate change on agriculture in the developing nations

(12 Marks) Most developing countries depend heavily on agriculture; the effects of global warming on productive croplands are likely to threaten both the welfare of the population and the economic development of the countries. Tropical regions in the developing world are particularly vulnerable to potential damage from environmental changes because the poor soils that cover large areas of these regions already have made much of the land unusable for agriculture. Although agronomic simulation models predict that higher temperatures will reduce grain yields as the cool wheat-growing areas get warmer, they have not examined the possibility that farmers will adapt by making production decisions that are in their own best interests. A recent set of models examines cross-sectional evidence from India and Brazil and finds that even though the agricultural sector is sensitive to climate, individual farmers do take local climates into account, and their ability to do so will help mitigate the impacts of global warming.

Changes in climate may also impact the water availability and water needs for farming. If temperature increases and more sporadic rainfall events result from global warming, it is possible that irrigation needs could increase in the future. In anticipation of these changes, plant breeders are currently working to develop new varieties of crops that are considered to be drought tolerant, and more adaptable to varying levels of temperature and moisture.

The accelerating pace of climate change, combined with global population and income growth, threatens food security everywhere. Agriculture is extremely vulnerable to climate change. Higher temperatures eventually reduce yields of desirable crops while encouraging weed and pest proliferation. Pests management become less effective, meaning that higher rates of pesticides will be necessary to achieve the same levels of control. Heat waves can cause extreme heat stress in crops, which can limit yields if they occur during certain times of the plants' life-cycle (pollination, pod or fruit set). Also, heat waves can result in wilted plants (due to elevated transpiration rates) which can cause yield loss if not counteracted by irrigation. Heavy rains that often result in flooding can also be detrimental to crops and to soil structure. Most plants cannot survive in prolonged waterlogged conditions because the roots need to breathe. The overall impacts of climate change on farming are expected to be negative, threatening global food security.

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