Climate Change

Question 1

What is the Quaternary Period

Answer 1

Divided into 2 epochs:
1. The Pleistocene (2.558 million years ago - 11,700 years ago)
2. The Holocene (11,700 years ago - present)

Question 2

Milankovitch Cycles (Orbit)

Answer 2

Earth’s orbit is normally slightly elliptical
Orbit it stretched out more sideways
Overall impact is that temperature is colder due to less solar energy
Occurs every 80-120,000 years

Question 3

Milankovitch Cycles (Tilt)

Answer 3

Usually earth’s tilt is around 5 degrees off 90 degrees
Axis can move a few degrees either way
Tilt can cause sunlight to reflect off of ice in the poles - sends solar radiation back to the sun
Tilt the other way can cause sunlight to hit land and the oceans (60% absorbed and 40% reflected)
The sea moderates temperature as it takes a long time to heat up and a long time to cool down
Land takes a short time to heat up and a short time to cool down
Changes between reflection and absorbing
Occurs every 40-50,000 years

Question 4

Milankovitch Cycles (Wobble)

Answer 4

Same process as tilt but more obvious
Reflection is higher and absorption of light
Occurs every 20-25,000 years

Question 5

Milankovitch Cycles (What happens when they all line up?)

Answer 5

Every 600,000 years (approx.) all 3 line up
This results in either an ice age or a heatwave
This can be changed by the other - way to get out of an ice age is through a heatwave

Question 6

Sun Spots

Answer 6

Magnetic storms create sun spots of high energy (heat). They can be seen as dark spots on the sun’s surface. Sun spots appear in an 11 year cycle. The Little Ice Age and Mediaeval Warm Periods are linked to the sunspot cycle.

Question 7

Volcanic Activity

Answer 7

Volcanoes produce lots of greenhouse gases which can warm the planet.But, they pump out millions of tonnes of dust and aerosols which block and reflect the sunlight and can cause global temperatures to drop, cooling the planet.

Question 8

Proxy data - Ice Cores

Answer 8

An ice core is a tube pressed into the ground and you get a tube of ice which can analyse how much CO2 was in the atmosphere a certain amount of time ago.

Ice cores are very reliable because they have pockets of air which scientists can analyse and discover what was in the ice 800,000 years ago.

Ice cores only measure back 800,000 years ago, so there is a little bit of a limitation.

Question 9

Proxy Data - Sea Ice Positions

Question 10

Proxy Data - Global Temperature Data

Question 11

Proxy Data - Paintings + Diaries

Answer 11

Historical documents are the weakest form of proxy data. It can vary from diaries and paintings to grape harvests. It is highly subjective because there is no record that it actually happened. This data is used for confirmation of other proxy data.

Question 12

Greenhouse Effect

Answer 12

Solar radiation emitted from the sun hits the atmosphere - most light gets through greenhouse gases, some is absorbed by greenhouse gases and some is sent back towards the Sun (around 80% gets through the atmosphere)
Most solar radiation is absorbed and readmitted meaning that it changes wavelength (shortwave radiation on the way in to longwave radiation on the way out)
A lot more of the readmitted solar radiation is absorbed by the greenhouse gases but some is sent back to earth
Solar radiation continues to go back and forth between the earth and the atmosphere

Question 13

Enhanced Greenhouse Effect

Answer 13

Greenhouse effect occurring more than it should so upsetting the natural balance

Question 14

Human activities contributing to greenhouse effect

Answer 14

Farming - lots of methane emitted
Burning fossil fuels - lots of CO2 released into atmosphere
Cement production - lots of CO2 released into atmosphere
Deforestation - Plants remove CO2 from atmosphere so more CO2 released into atmosphere

Question 15

Global environmental impacts of climate change

Answer 15

Temps expected to rise by 0.3-4.8°C between 2005 and 2100
Warmer temps causing glaciers to shrink and ice sheets to melt (causing sea level rise)
Sea ice shrinking - loss of habitat
Some species are declining due to warming (e.g. bleaching coral reefs)
Precipitation patterns are changing
Distribution + quantity of some species can change and biodiversity can decrease

Question 16

Global economic impacts of climate change

Answer 16

More money needs to be spent on predicting extreme weather events
Permafrost can lead to collapse of buildings / pipelines
Farming being affected - some crops suffer due to higher temps
Water shortages affect our ability to generate hydroelectric and thermal power

Question 17

Global social impacts of climate change

Answer 17

Increased threat of wildfires in some areas - risk peoples lives + homes
Low-lying coastal areas can flood / be lost to sea to they are uninhabitable, other areas can become uninhabitable due to lack of rain + high heat - these both can lead to migration + overpopulation in other areas
Political tensions to do with water as changing rainfall patterns affects how much water some areas receive
Lower crop yields can increase malnutrition, ill health and death from starvation

Question 18

Environmental impacts of climate change on UK

Answer 18

Climate - winter rainfall expected to increase by 16%, summer rainfall expected to decrease by 23%, summer temp expected to increase by 3.9°C by 2080
Sea Level Rise - expected to rise by 12-76cm by 2095 leading to habitat loss
Extreme Events - droughts expected to become more frequent and intense + flooding expected to become more common due to increase rainfall and sea level rise
Wildlife - some species have already left habitats to move to cooler places which upsets balance of natural ecosystems

Question 19

Economic impacts of climate change on UK

Answer 19

Tourism - industry could be boosted but could also lead to decline in snowy areas (e.g. Cairngorms)
Fishing - industry could be affected - more extreme weather puts fishing infrastructure at risk, livelihoods of fisherman affected by changing fish population and species
Agriculture - can be benefited as productivity of some crops can be increased, crops adapted to warmer climates could grow in S.England but reduced rainfall would mean that irrigation would need to be used (expensive)

Question 20

Social impacts of climate change on UK

Answer 20

Health - deaths from cold-related illnesses can decrease but heat-related illnesses could become more common
Floods - can damage homes + businesses especially ones near rivers and the coast
Water Shortages - drier summers will affect availability especially where population density is high