Climate change

Question 1

Enhanced Greenhouse effect

Answer 1

The current climate crisis is largely being caused by human activities leading to pollution in the atmosphere which is causing an enhanced greenhouse effect

Question 2

Greenhouse effect

Answer 2

Incoming radiant energy from the sun travels through the atmosphere as short waves (e.g. visible and ultraviolet radiation). Some of this incoming energy is reflected by the atmosphere as well as the earths surface and travels back out into space. Most radiant energy is absorbed by the earth and is converted into thermal energy (it heats up the earth). Warm objects radiate long-wave infrared radiation, i.e. the earths surface re-radiates infrared rays. Some of the infrared radiation moves through the atmosphere and escape into space. Infrared radiation is also trapped by greenhouse gases as thermal energy, heating up the gases in the atmosphere. The more greenhouse gases in the atmosphere, the more thermal energy is trapped. The greenhouse effect is what keeps the earth habitable by trapping enough thermal energy (warmth) to prevent the earth from freezing over.

Question 3

Greenhouse gases

Answer 3

Earth’s greenhouse gases trap heat in the atmosphere and warm the planet. The main gases responsible for the greenhouse effect include carbon dioxide, methane, nitrous oxide, and water vapour.

Question 4

Main greenhouse gases

Answer 4

Earth’s greenhouse gases trap heat in the atmosphere and warm the planet. The main gases responsible for the greenhouse effect include carbon dioxide, methane, nitrous oxide, and water vapour.

Question 5

Methane

Answer 5

Gram for gram, Methane has a greater effect as a greenhouse gas. It comes from natural anaerobic decomposition. Causes of increased methane emissions include leakage from industry (e.g. dealing with natural gas and crude oil), agriculture (e.g. manure sources and rice plantations) and human waste (e.g. land-fill sources and sewerage treatment plants). Climate change itself is also a cause of increased methane emissions as melting permafrost in the tundra significantly increases decomposition in these soils.

Question 5

Carbon dioxide

Answer 5

Carbon dioxide is a product of combustion and respiration. Causes of increased carbon dioxide emissions include combusted fossil fuels (transport, electricity generation and industries) and fires. Decreased carbon sequestration (capture) includes deforestation (forests are carbon sinks as well as increased forest fires) and desertification (soils release stored carbon).

Question 5

Ways to reduce carbon dioxide

Answer 5

Ways to reduce carbon dioxide in the atmosphere include alternatives (e.g. solar, geothermal or wind power), efficiency (e.g. save electricity), control (e.g. stricter laws on emissions), awareness (e.g. educate people of the effects), incentives (e.g. rewards for ‘going green’).

Question 6

Ways to reduce methane emissions

Answer 6

educing and finding alternatives to fossil fuels, reduce waste production and using methane as a fuel source itself

Question 7

Rising average temperatures

Answer 7

The enhanced greenhouse effect causes rising global average temperatures. This has a dramatic effect on climates, i.e. climate change.

Question 8

Melting ice caps and glaciers

Answer 8

caused by increased temperatures

changes ocean circulation and sea level

changes ocean salinity

polar habitats are changing and species are going extinct

Water availability is affected e.g. Himalayan glacial melts

Question 9

Rising sea levels

Answer 9

due to melting ice caps and glaciers as well as the expansion effect of warmer sea water

sea level has risen by 15 cm during the 20th Century

Question 10

Rising sea temperatures

Answer 10

Warmer sea water, especially in shallows

Warm water absorbs less carbon dioxide

algae in corals killed causing coral bleaching and death

Warm water also expands increasing the sea level

Question 11

Ocean acidification

Answer 11

sea water becomes more acidic as more carbon dioxide dissolves in sea water.

Carbonic acid is formed which lowers the pH.

this impacts organisms e.g. corals lose calcium carbonate due to the acidic conditions.

Question 12

Increased extreme weather

Answer 12

More frequent and stronger storms such as hurricanes and tornadoes

rising temperature of water leads to more evaporation and stronger winds
Increased droughts and heatwaves

higher evaporation may lead to more droughts where water is scarce

rainfall may be lower in particular areas

may lead to desertification

areas may be more vulnerable to large fires

Floods and flooding events more frequent

Rising sea levels flooding coastal areas

Higher evaporation least to more extreme rainfall in places

Question 13

Loss of biodiversity

Answer 13

habitats are lost due to shifting biomes

species shift to cooler habitats or become extinct

Cooler biomes or biomes with nowhere to shift to are most vulnerable e.g. polar, alpine, coral reefs and fynbos

mutually dependent species may no longer correspond in their life cycles e.g. flowers and pollinators

Question 14

Global food and water shortages

Answer 14

Warmer climates result in certain diseases or their vectors becoming more widespread where previously they did not exist

Question 15

Broad solutions include:

Answer 15

International cooperation, legislation and incentives

reduced greenhouse gas emissions

carbon capture and enhancing carbon sinks

Question 16

Individual solutions include:

Answer 16

Reducing your carbon footprint

Activism - urge government to take bold, ambitious climate action now

Question 17

Reduced greenhouse gas emissions

Answer 17

The most effective way to reduce carbon dioxide emissions is to reduce fossil fuel consumption. In addition, oil and gas production is often the largest human source of methane.

Industries need to reduce their emissions by supporting developing innovative low-carbon technologies:

alternatives (e.g. solar, geothermal or wind power)

efficiency (e.g. save electricity)

control (e.g. stricter laws on emissions)

awareness (e.g. educate people of the effects)

incentives (e.g. rewards for ‘going green’)

Question 18

Carbon footprint

Answer 18

A carbon footprint is the amount of carbon dioxide released into the atmosphere as a result of the activities of a particular individual, organisation, or community.