Climate Change

Question 1

Is Climate change the result of natural or human factors?

Answer 1

Climate change is the result of both natural and human factors, and has a range of effects.

Question 2

Climate change

Answer 2

Any significant change in the Earth’s climate over a long period.

Question 3

The Quaternary period

Answer 3

The most recent geological time period, spanning from about 2.6 million years ago to the present day.

Question 4

Describe the changes in global temperature during the Quaternary period.

Answer 4

Global temperature has fluctuated between cold glacial periods (lasting around 100, 000 years) and warmer interglacial periods (lasting around 10, 000 years).

Question 5

What was the Earth’s climate like before the Quaternary period?

Answer 5

-warmer
-quite stable

Question 6

When did the last glacial period end?

Answer 6

Around 15 000 years ago. Since then, the climate has been warming.

Question 7

Global warming

Answer 7

The sharp rise in global temperatures over the last century.

(It’s a type of climate change).

Question 8

Where can scientists find evidence for climate change?

Answer 8

Ice and Sediment cores
Temperature records
Tree rings

Question 9

Ice and Sediment cores

Answer 9

Ice sheets are made of layers - one layer is formed each year.

Scientists can drill into ice sheets and draw out long ‘cores’ of ice.

They then analyse the gases trapped in the layers of ice to work out what the temperature was each year (this is indicated by the level of CO₂).

They can also analyse the composition of the water to calculate the temperature of the atmosphere as that water fell as snow.

Question 10

How long ago does the ice core found in Antarctica date?

Answer 10

400 000 years

Question 11

Temperature records

Answer 11

Since the 1850s, global temperatures have been accurately measured using thermometers. This gives a reliable record of past temperatures, however only from the 1850s onwards.

Question 12

How much have average global temperatures increased by since 1950?

Answer 12

More than 0.6°C. This warming is projected to continue throughout the century.

Question 13

Ice sheets and glaciers melting

Answer 13

-Arctic sea ice has declined by 10% in 30 years

-Average global sea levels have risen by 10-20 cms in the past 100yrs due to additional water from sea ice and thermal expansion (a phenomenon where water expands as it heats up so its volume increases).

Question 14

Other ways are needed to indirectly…

Answer 14

…calculate global temperatures in the past.

Question 15

Changes in ecological patterns

Answer 15

Seasonal patterns of wildlife are changing. For example, birds are migrating further north in the summer months. This is an indicator that climate must be affecting the seasons.

Question 16

Tree rings

Answer 16

Studying tree rings is a reliable method to find out what climate was like during the past 10,000 years.

A tree forms a new ring each year as it grows. The larger the tree ring, the warmer and wetter the conditions.

Question 17

Name the natural factors that are possible causes of climate change.

Answer 17

Orbital changes
Volcanic activity
Solar Output

Question 18

Orbital changes theory

Answer 18

The way in which the Earth orbits the sun changes over thousands of years.

This affects how much solar radiation the Earth receives: more energy means more warming.

These orbital changes follow a very similar pattern to the glacial and interglacial cycles of the Quaternary period (so may have caused them).

Question 19

What is the influence of the Earth’s orbit on climate known as?

Answer 19

Orbital forcing

Question 20

Name the three orbital changes/variations

Answer 20

Eccentricity
Tilt
Precession

Question 21

Eccentricity

Answer 21

The Earth’s orbit around the sun varies from circular to elliptical. This affects the intensity of the sun’s rays on Earth.

Question 22

Tilt

Answer 22

The Earth’s axis is tilted at an angle (which changes over 41,000 years) as it orbits the sun. This affects the contrast between the summer and winter seasons.

Question 23

Precession

Answer 23

The earth’s axis wobbles like a spinning top. This affects the lengths of the days.

Question 24

Solar output

Answer 24

There is an identifiable relationship between the Earth’s climate and the amount of sunspot activity present on the sun.

The activity changes in a cycle of about 11 years.

Where there is reduced solar output, this means that the Earth’s climate may become cooler in some areas.

Question 25

Is solar output thought to have a major effect on Global climate change?

Answer 25

No, however incidences of temperature changes have occurred such as the ‘Little Ice age’ in the medieval period (1450 to 1534) and there have been frost fairs on the Thames during the ‘maunder minimum’ (when sunspots are rare).

Question 26

What indicates enhanced solar output in images of the sun?

Answer 26

Darker sunspots

Question 27

Volcanic activity

Answer 27

Major volcanic eruptions eject large quantities of material into the atmosphere.

Some particles stay in the atmosphere and block out the sun (e.g. volcanic ash).

Some reflect the sun’s rays back out to space (e.g. sulfurous gases react to form aerosols which reflect solar insolation).

So the Earth’s surface cools (but only for a short period of time).

Question 28

Volcanic activity example

Answer 28

Volcanic activity may cause short-term changes in climate. For example, global temperatures fell by about 0.5°C after the 1815 eruption of Mount Tambora, Indonesia.

This lead 1816 to be commonly referred to as ‘the year without a summer’. The cooling led to crop failures and famine, with an estimated 200,000 deaths.

Question 29

Name the human factors that are possible causes of climate change.

Answer 29

-use of fossil fuels
-agriculture
-deforestation

(these increase the concentration greenhouse gases in the atmosphere).

Question 30

There us a scientific consensus that human activity is causing global warming through…

Answer 30

…the (enhanced) greenhouse effect.

Question 31

What is the greenhouse effect?

Answer 31

A natural process where greenhouse gases such as carbon dioxide and methane trap energy from the sun (which else would go back to space as long-wave radiation) inside Earth’s atmosphere, heating the Earth.

Question 32

Steps to the greenhouse effect:

Answer 32

1 - Short wave solar radiation travels to Earth and heats the ground surface

2- Earth gives off heat (long-wave radiation) as it cools

3-Some of this leaves the atmosphere and goes into space, whilst some is trapped by greenhouse gases keeping the Earth warm.

Question 33

What has led to the enhanced greenhouse effect?

Answer 33

Human activities release greenhouse gases into the atmosphere at a higher rate than natural processes.

This means that there is more gas in the atmosphere than usual, trapping more of the sun’s energy.

This heat is reradiated around the earth, which means there is more warming in the air.

This process has led to increased warming in recent years known as the ‘enhanced greenhouse effect’.

Question 34

(Burning) Fossil Fuels

Answer 34

Humans burn fossil fuels (like coal, oil, and natural gas) for energy e.g. to fuel cars.

As fossil fuels are made from the remains of organic material, this means that carbon dioxide is released into the atmosphere when they are burned.

Which means that the concentration of greenhouse gases in the atmosphere increases hence the amount of solar radiation trapped will increase also.

Question 35

Agriculture

Answer 35

Meat and animal products are in high demand around the globe. This means that many farm livestock which contributes additional greenhouse gases to the atmosphere as livestock produce a lot of methane (from digestion).

Question 36

What percentage of global warming is thought to be because of methane emissions?

Answer 36

25%

Question 37

How do rice paddies contribute to global warming?

Answer 37

Flooded fields emit methane

Rice is heavily cultivated around the globe (huge contributor)

Question 38

Agricultural fertilisers release Nitrous Oxide into the atmosphere, which is…

Answer 38

3x more efficient at trapping heat than CO₂.

Question 39

Deforestation

Answer 39

Large numbers of trees act as a carbon sink, absorbing and storing carbon dioxide (to be converted into organic matter for photosynthesis).

This means that when trees are cut down (for example to make space for agriculture, or for fuelwood) this carbon sink is removed, which means that less carbon dioxide will be absorbed from the atmosphere.

Furthermore, CO₂ is released into the atmosphere when trees are burnt (as fuel or just to make space for agriculture).

Question 40

What is increasing in a similar pattern to the levels of CO₂ in the atmosphere?

Answer 40

Global temperatures, hence emissions of greenhouse gases due to human activity is thought to have a bigger influence on current global warming than natural causes of climate change.

Question 41

With temperatures spiking, they are projected to increase by _______ between 2021 and 2100.

Answer 41

1.0 to 5.7 °C

Question 42

Health - effects of cc on people

Answer 42

Warmer temperatures can lead to increased health issues, such as heat stress or skin cancer.

This could lead to an increase in the number of deaths due to heat.

Question 43

Uninhabitable areas - effects of cc on people

Answer 43

Some areas could become so hot and dry that they’re very difficult or impossible to live in.

For example, low-lying areas like the Maldives could be lost to the sea or flood so often that they become uninhabitable.

This means that populations could be displaced and the people would have to migrate to other areas, which could lead to overcrowding.

Question 44

Farming - effects of cc on people

Answer 44

Climate change effects farming in different ways around the world.

Rising temperatures have led crops to suffer in continents such as Africa and Asia.

This means that people there may suffer from food shortages, which means that there is an increased risk of malnourishment and hence death by starvation in these areas.

However, farmers in high - latitude countries are benefiting from the warmer conditions, being able to grow new types of crop.

Question 45

Water supply - effects of cc on people

Answer 45

Some areas are struggling to supply enough water for their residents due to problems with water availability caused by changing rainfall patterns.

This can lead to political tensions, especially where rivers cross borders.

Question 46

Extreme weather - effects of cc on people

Answer 46

Climate change means the weather is getting more extreme.

This means that more money has to be spent on predicting extreme weather events, reducing their impacts, and rebuilding after they take place, which can effect the economy of a country.

Question 47

Sea ice is shrinking, leading to…

Answer 47

..the loss of polar habitats which could lead to the extinction of species like polar bears.

Question 48

Flooding - effects of cc on the environment

Answer 48

Rising sea levels mean low-lying and coastal areas, (like Miami, USA) will flood more regularly.

This means that coastal erosion will increase and some areas may be submerged, which means that habitats will be lost.

Question 49

Coral Bleaching

Answer 49

Rising sea temperatures make coral expel the algae that lives in them, causing the coral to starve and die. This means that species could decline e.g. coral in the Great Barrier Reef, Australia.

Question 50

Precipitation patterns are…

Answer 50

changing as global warming is affecting how much rain an area receives.

Question 51

Decrease to biodiversity - effects of cc on the environment.

Answer 51

Some species have migrated to higher latitudes due to warming temperatures at the equator (it’s too hot!!)

Some habitats are being damaged or destroyed due to climate change e.g. it limits bamboo growth leading to a decline in giant panda numbers because they rely solely on bamboo as their food source.

Question 52

Mitigation

Answer 52

Reducing the risk/causes

Question 53

Adaptation

Answer 53

Responding to changes/ adjusting to extreme events

Question 54

How can we mitigate climate change?

Answer 54

-alternative energy production
-carbon capture
-planting trees
-international agreements

Question 55

How does mitigation aim to reduce the causes of climate change

Answer 55

By reducing the concentration of greenhouse gases in the atmosphere.

Question 56

Planting trees

Answer 56

This increases the amount of CO₂ that is absorbed from the atmosphere (to be converted to organic matter during photosynthesis).

Question 57

Carbon capture

Answer 57

Carbon Capture and Storage (CCS) involves capturing CO₂ emitted (from power stations burning fossil fuels) and storing it safely e.g. deep underground.

This means that the emissions from the power stations are reduced.

Question 58

Alternative energy production

Answer 58

Fossil fuels can be replaced with nuclear or renewable energy. This means that greenhouse gas emissions can be reduced.

For example, in the UK, more offshore wind farms are being built e.g. in East Anglia alongside several wave, tidal, and nuclear power projects that have been planned.

Question 59

The Paris Agreement

Answer 59

-aims to reduce greenhouse gas emissions and reduce global warming

-encourages developed countries to help developing countries put mitigation strategies into place

-each country has submitted a pledge which indicates how much they will try to reduce their greenhouse emissions by

Question 60

Date that The Paris Agreement came into force?

Answer 60

4th November 2016

Question 61

How many parties has the Paris agreement been signed by?

Answer 61

195, including the European Union (EU).

Question 62

How much did the UK pledge to reduce their greenhouse emissions by?

Answer 62

At least 68% from their 1990 levels by 2030.

Question 63

Why might it be necessary to change agricultural systems?

Answer 63

The productivity of existing systems may decrease because of higher temperatures and changing rainfall patterns.

Question 64

How can we change agricultural systems?

Answer 64

-Plant new crop types that are more suited to the new climate conditions in an area e.g. soya and peaches may be grown in southern England.

-Biotechnology can be used to create new strands of crop, which are more resistant to extreme weather events, e.g. drought-resistant millet is being grown in Kenya.

Question 65

Why do we need to manage water supplies?

Answer 65

Dry areas are predicted to get drier. This means that there will likely be more water shortages, which means that people will need to use water resources more efficiently.

Question 66

How can we manage water supply?

Answer 66

-Water meters can be installed in homes to discourage excessive water use.

-Rainwater and waste water can be collected and recycled.

Question 67

Why must we reduce the risk of rising sea levels?

Answer 67

They are predicted to rise between 0.28m and 1.01 m by 2100. This would flood many islands and coastal or low-lying areas.

Question 68

How can we cope with rising sea levels? (reduce risk, adaptation)

Answer 68

-Better flood warning systems can be put in place

-Physical defences such as flood barriers can be built to prevent flooding e.g. the Thames Barrier in London can be closed to prevent sea water flooding the city

-In areas that can’t afford expensive flood defences (like Bangladesh) people are building raised flood shelters and building houses on embankments. This protects them from floodwater (reducing the cost of damage).