AQA GCSE Geography: Climate Change

Climate Change

Any significant change in the Earth's climate over a long period of time

Quaternary period

The present period of geologic time spanning from 2.6 million years ago to now

Glacial periods

Cool periods- more ice volume. Leads to lower sea levels

Interglacial periods

Warm periods- less ice volume. Leads to higher sea levels

Global warming

The term used to describe the sharp rise in global temperatures in the last century

Evidence for climate change

➡️ice cones ➡️sediment core ➡️tree rings ➡️pollen analysis ➡️temperature records

Ice and sediment cores

A proof of climate change. Gas trapped in ice and sediment layers can show what the temperature was like in a year, with one sample from Antarctica going back 400,000 years

Tree rings

A proof of climate change. As rings in a tree are thicker in warm, wet climates we can see the temperatures over a long period of time

Pollen Analysis

A proof of climate change. As pollen gets preserved in sediment, scientists can identify when it was from and thus what species were alive then. This can show the climate

Temperature Records

A proof of climate change. Since the 1850's, global temperatures have been recorded giving us a reliable but short term record of climate change

Natural causes of climate change

➡️orbital changes ➡️volcanic eruptions ➡️solar output

Orbital Changes

A natural cause of climate change. Every 96,000 years the earth's orbit around the sun changes from a circle to an ellipse then back to a circle. When the earth is closer to the sun, the temperatures increase and vice versa. These are known as Milankovitch Cycles

Volcanic Activity

A natural cause of climate change. Major volcanic eruptions scatter material into the atmosphere that reflect the suns rays and cool the earth (although it is short term)

Solar Output

A natural cause of climate change. Because the suns output is not constant, the earth's climate may increase or decrease following periods of high or low solar activity. This has a minor impact on climate change

Human causes of climate change

➡️fossil fuels ➡️cement production ➡️farming ➡️Deforestation

Burning fossil fuels

A human cause of climate change. When fossil fuels are burned, they release CO2 (a greenhouse gas)

Farming

A human cause of climate change. High levels of farming lead to high levels of methane (a greenhouse gas)

Cement production

A human cause of climate change. Cement is made from limestone which contains CO2 (a greenhouse gas), which is released in the process of making cement

Deforestation

A human cause of climate change. Plants remove CO2 from the atmosphere and when they are burned, it is released

Effects of climate change

Environmental and human

Environmental effects of climate change

️⃣Glacial melt, ️⃣sea level rise, ️⃣loss of habitat, ️⃣flooding, ️⃣coral bleaching, ️⃣changed rain patterns, ️⃣decreased biodiversity, ️⃣more extreme weather

Human effects of climate change

️⃣Death from overheating, ️⃣areas become inhabitable ➡️low lying coastal areas lost, ️⃣decreased drinkable water supply, ️⃣changes in farming, more extreme weather

Management strategies

Mitigation and adaptation

Mitigation

Reduce the causes of climate change

Carbon capture

A mitigation strategy. Storing CO2 deep underground so it doesn't go into the earth's atmosphere

Planting trees

A mitigation strategy. By planting more trees, CO2 will be absorbed from the atmosphere

Alternative energy production

A mitigation strategy. By replacing fossil fuels with clean, renewable energy like solar or nuclear we can reduce greenhouse gas emissions

International agreements

A mitigation strategy. Countries can agree to monitor and reduce their greenhouse gas emissions to a target

Adaptation

Responding to the changes caused by climate change

Changing agricultural systems

An adaptation strategy. We can change our crop types to suit the changing climate

Managing water supply

An adaptation strategy. By installing water meters and collecting rainwater, dry areas will not be so short of water

Coping with rising sea levels

An adaptation strategy. As sea levels rise, we will need physical defenses such as flood barriers and flood warning systems or different building styles such as stilt houses