Climate Change - global issues 2

Question 1

Physical changes

Answer 1

• changes in solar radiation (sunspot activity)
• changes in oceanic circulation
• volcanic eruptions
• the movement of the earth ( Milankovich cycles)
• movement of crustal plates

Question 2

Change is solar radiation:

Answer 2

• the amount of energy we receive from the sun changes due to sunspot activity
• areas of intense heat of the sun
• the greater number of sunspots the more heat we receive from the sun

Question 3

The movement of the earth

Answer 3

• Milankovich theory suggests that cyclic variations in the earth’s tilt, wobble and stretch results in climate change
• THE EARTH’S CHANGING TILT: changes in cycles that average 40000 years, axis varies between 22.1 and 24.5 degrees, currently is 23.5; causes exaggeration to seasons ( more tilt means warmer summers and colder winters; less tilt means colder summers and warmer winters)
• THE EARTH’S CHANGING STRETCH: changes in 98000 year cycles, from a thin ellipse (oval) to a circle
• THE EARTH’S CHANGING WOBBLE: changes in its rotational axis alter the dates of when the earth is closest to the sun and when the earth is furthest away

Question 4

Volcanic eruptions

Answer 4

• ash and gases are sent to the atmosphere, absorbing some energy from the sun, preventing it from reaching the Earth’s surface

Question 5

Oceanic circulations

Answer 5

• help to redistribute energy across the earth
• receives 67% of the sun’s energy
• holds heat for longer than land does
• ocean currents transfer about 25% of the global heat budget
• overtime, currents change direction and become stronger or weaker, changing the climate of the places they flow past

Question 6

Plate movement

Answer 6

• continental plates have moved overtime

- when there are many continents near the poles, ice sheets will quickly form and the world cools down

Question 7

Human changes

Answer 7

• increased carbon dioxide
• increased methane
• increased Nitrous Oxide
• Increased Chloroflurocarbons

Question 8

Increased carbon dioxide

Answer 8

• burning of fossil fuels, coal, oil and gas
• Deforestation: cutting down and burning of the trees (“lungs of the planet”) increases CO2 in the atmosphere
• More Vehicles: use petrol, releases CO2 (over 1 billion cars alone in 2011)

Question 9

Increased Methane

Answer 9

• remains in the air for 12.4 years, 86x more powerful than CO2
• Landfill: as waste decomposes, it produces methane
• Animal Dung and belching cows: one cow releases 100kg of methane each year
• Podi Fields: rice absorbs carbon from the atmosphere. If the planet is unable to use the carbon it is dispersed into the soil and converted into methane

Question 10

Increased Nitrous Oxide

Answer 10

• remains in the atmosphere for 121 years, 268x more powerful than CO2
• Fertilisers: soils release over half of the nitrous oxide in the atmosphere
• Vehicles: nitrous oxide is released when petrol and diesel is burned
• 200-300 more effective in trapping heat*

Question 11

Increases Chloroflurocarbons

Answer 11

• stays in atmosphere for 45 years, 7000x more dangerous than CO2
• used in Aerosols, polystyrene packaging, air conditioning system
• banned in developed countries
• linked to the reduction of the ozone layer and the compounds are also greenhouse gases.

Question 12

Effort to manage global warming:

Answer 12

• passed laws to reduce the levels of emissions of harmful gases: The UK introduced green taxes to reduce emissions from road traffic, industries that emit gases (e.g CO2, sulphates, nitrates), reduce gases from rubbish tips and emissions from aircrafts
• signed international agreements to reduce greenhouse gases, notably the Kyoto Protocol (USA refused to sign during the second Bush administration)
• Legal measures in Brazil, where rain forests are being destroyed to make way for cattle ranching
• persuade people to reduce their use of fossil fuels, notably oil, coal and gas, and replace them with less harmful alternative fuels

Question 13

Global effects of climate change

Answer 13

• SEA LEVELS: higher temperatures result in ice melting in places like Greenland and Antarctica, flow into the sea and begin to rise; flooding may become an issue for million in countries like Bangladesh and India as low lying coastal areas are at increased risk of rising sea levels, lose homes, destroy farm land
• WEATHER: some places becoming drier/wetter, warmer/colder, likely to see an increase in storms, floods and drought, Areas around the Mediterranean sea could become deserts, whilst areas like Jersey could suffer flooding; people, plants and animals may find it difficult to survive.
• WATER: places in Africa already lack enough water for people living there, some areas (e,g Scotland) are likely to experience drier conditions but others will experience more rain
• PLANTS AND ANIMALS: could be affected by temperature change and rainfall. ( e.g: temps rising and polar ice melting, affect habitats and hunting grounds for polar bears, may become at risk of extinction)