Climate Change - Key Facts

Question 1

The evidence for climate change (ice)

Answer 1

1. Arctic sea ice - between 1980 and 2015, 13.3% decrease of sea ice per decade (1980 - 7.9 million km2/ 2012 - 3.7 million km2) NB short term data only (rising sea levels - 1901 to 2010 rose by 0.91 metres)
2. Ice core evaluations testing cleanliness and levels of CO2, O2 and methane, volcanic eruptions (from ash) - calculate temperature from atmospheric gas concentrations (past 400,000 years) rapid increase in last decades.

Question 2

Evidence for climate change (surface)

Answer 2

1. Increased surface temperature - 1880 to 2015, 0.87°C increase.
2. Little Ice Age - 1600 to 1814 northern hemisphere froze for long periods eg Thames froze to enable markets to be held on it. Last fair/market was in 1814.

Question 3

what is the greenhouse effect ?

How does it work ?

Answer 3

A function of the Earth’s atmosphere is to keep in some of the heat lost from the Earth (the greenhouse effect).

Atmosphere allows heat from sun (short wave radiation) to pas through and heat the Earth’s surface.
The Earth’s surface reflects some heat (and absorbs some)(long wave radiation)
Some of the reflected heat is trapped by greenhouses gases and radiated back towards Earth

Question 4

Which Gases are greenhouse gases ?

Answer 4

Carbon dioxide
Methane
Nitrous oxide

Question 5

What human factors increase greenhouse gases

Answer 5

Agriculture - Methane from cows, nitrous oxide from pesticides
Deforestation - trees aren’t photosynthesising so there is more carbon dioxide.
Burning fossil fuel - coal, gas, oil all release when burned.
Dumping waste in landfill - releases methane when decomposing.

Question 6

What natural factors increase global warming

Answer 6

Orbital cycle - Earth has natural cooling/warming patterns (milankovitch cycles)
Volcanic activity- eruptions release CO2
Solar output - fluctuations in the amount of radiation from the Sun (sunspots caused by magnetic storms, Earth can receive more energy every 11yrs) (increased radiation = increased temperature)

Question 7

Name and explain the three milankovitch cycles

Answer 7

Eccentricity - The earth has a circular and oval orbit. This is the process of moving from one to another. Circle = warmer, Oval = colder in general but larger differences in seasons. (Per 100,000)
Obliquity - Earth’s tilt changes from 22.5° (colder) to 24.5° (warmer). (Per 40,000)
Precession - The Earth wobbles while it spins on its axis caused by gravity of the Sun and Moon. North Star = colder, Vega = warmer. (Per 23,000)

Question 8

impacts of climate change in the uk (positive)

Answer 8

• new crops (e.g. grapes and peaches)
• reduced heating costs in winter
• less winter accidents/ illness (saves money for the NHS)
• tourism

Question 9

Impacts of climate change in the uk (negative)

Answer 9

• increased sea levels leading to flooding and coastal erosion
• extreme of precipitation (droughts and floods)
• heatwaves: increased health care service demand and more demand for water putting pressure on water supplies.
• loss of tourism for Scottish ski resorts.
• severe storms lead to land and infrastructure damage.

Question 10

Impacts of climate change worldwide (positive)

Answer 10

Longer growing season for agriculture
Less energy consumption due to warmer climates
Frozen regions such as canada may be able to grow crops

Question 11

Impacts of climate change worldwide (negative)

Answer 11

• increased risk and potency of drought, fire, floods and tropical storms
• increased desertification (Sahara spreading north)
• retreating glaciers impacts fresh water supply
• sea levels rise (floods eg Maldives or high populated areas like the Ganges delta)
• species affected/extinct in arctic or coral reefs.
• increase in diseases such as malaria
• change in crop yields e.g. wheat yield is decreasing but demand is rising.
• negative industry impact e.g. coral reef tourism or skiing in the alps.

Question 12

Maldives 2080 - how will they be affected by climate change ?

Answer 12

Sea levels rise 1 metre
Half of the Maldives is submerged
Floods and tsunamis - loss of tourism, deaths and residents moving away
Freshwater becomes scarce
Hotter
All of this reduces GDP (reliant on tourism)

Question 13

Potency of greenhouse gases

Answer 13

CO2
Methane is 25% more effective a trapping heat than CO2
CFCs - 15000x more effective
Nitrous oxide - 250x more effective

Question 14

%contribution to EGE (4 types of gases)

Answer 14

CO2 - 60%
CH4 - 15%
CFCs - 15%
N2O - 6%
Other - 4%