Geography Quiz

Climate Change Revision:

Greenhouse effect is entirely natural:
-Greenhouse gases, esp. water vapour, form part of Earth’s atmosphere
-Gases allow sun’s energy to enter atmosphere
-Energy radiated back, some trapped, some radiates into space

Enhanced greenhouse effect, result of human activities:
1. Solar heat, incoming solar radiation passes through atmosphere, warming land and sea
2. Heat trap, with more co2, more heat is trapped
-CFC’s, cause thinning of ozone layer
-Deforestation, produces co2
-Fossil fuels, releases large amounts of carbon
-Nitrous Oxide, from nitrogen-based fertilizers and fuel
-Vehicles, exhaust is source of heat-trapping gases
-Methane, from people and animals
-Oceans, unable to absorb as much co2 as is produced, increased temperature reduces this ability

Enhanced greenhouse effect
-->increased average global temperature and sea surface temperature
-->sea levels rise, changed ocean circulation, changed atmospheric circulation
-->Leads to climate change
-->Affects coastal areas, weather, agriculture, human health, ecosystems/habitat

Factors causing climate change:
-The increase of fossil fuels; coal, oil and natural gases contain carbon which is released when burnt. 20billion tonnes of co2 produced annually, 10billion reach the atmosphere, the rest absorbed by plants and oceans
-Deforestation; Clearing, burning and decay of vegetation release co2 that is stored in trees into the atmosphere. Also, reduction in vegetation means there are fewer plants to absorb/store co2
-Increase in methane production; Agricultural production where herbivorous animals such as cattle and sheep release methane, as well as rice paddies and other forms of irrigated agriculture. Land fill, forest fires and extraction of coal or gas also contribute.
-Increase in nitrous oxides; fossil fuel burning, motor vehicles and nitrogen-based fertilizers in agriculture are all responsible.
-Chlorofluorocarbons; once used in devices such as fridges, aircon, plastic foam and aerosol cans, they have been phased out since 1989 but once released, last for up to 100 years in the atmosphere.
-Increase in water vapour; indirectly, atmosphere warms through increase of other gases, and so temperature rises, evaporation increased and thus water vapour levels increase

INCREASE IN HUMAN POPULATION, NEED TO FEED PEOPLE, INCREASING MODERNISATION OF SOCIETY

Global warming: increased will be distributed unevenly across the world, differences between land and sea temperatures, changes in physical process affecting climate
Thermohaline circulation: Aka the great conveyer belt, it is the movement of ocean water powered by differences in salinity and temperatures. Air in the atmosphere is constantly moving as different parts of the globe receive different amounts of heat from the sun.

Global warming alters ocean circulation and heating, thus air above also moves differently resulting in shifts of the existing climatic belt
Sea level rise:
1. When water warms it expands, causing sea level rise
2. Warmer temperatures melt polar ice caps and mountain glaciers, adding to sea level

Impacts on weather:
Weather is driven by heat from the sun, causing circulation in the atmosphere and hydrologic cycle. Additional heat speeds up the system, increasing movement of air and water
1. Rainfall; Atmosphere is able to hold more water vapour, thus some places will be drier and others will be wetter. In general, dry places will become drier, wet places wetter. Flooding, landslides, and drought will increase.
2. Storms; tropical cyclones need warm water to form, thus temperature increase will increase distribution and intensity of these storms.
3. Heat waves; more extreme temperatures occurring due to climate change, affecting people crops, livestock, fish and wildlife. Wildfire risks also increase.

Impacts on coastal areas:
-islands submerged, increased flooding damage to crops and buildings meaning food production is decreased and money spent on protection, fresh water contaminated by saltwater

Impact on ecosystems and habitats:
-species forced to migrate, others that cannot adapt will become extinct, some habitats such as coral reefs destroyed by warmer conditions, water temperatures rise killing organisms and affecting food chains and ecosystems, migrating/distant species incur flow-on impacts

Impacts on agriculture:
-some plants unable to grow in increased temperatures, weeds, insects and plant diseases will expand, soil moisture changes may increase/decrease which kill plants that are unable to adapt, and increased co2 should increase photosynthesis and stimulate plant growth

Impacts on human health:
-freshwater shortage due to contamination, increasing drought, water quality affected so diseases such as cholera spread, range of diseases carried by vectors increase, more extreme natural disasters cause death more air contaminants from expanding deserts affect those with respiratory conditions.

Combating global warming:
-global policies such as Montreal protocol of 1987 and Kyoto Protocol of 1997 reducing emissions
-carbon taxes, energy-efficient technology, incentives for business to reduce, education, public awareness, renewable energy, reforestation, incentives to individuals, setting targets
-have energy-efficient homes, plant trees, reduce consumption (plastics, cans), use public transport locally grown food, bikes and walking car that suits needs, encourage government