Global climate change

Weather

This refers to the day-to-day changes in the atmosphere

Climate

This refers to the average weather conditions over a long period of time

Climate change

This refers to the long-term shifts in temperatures and weather patterns

What is the most notable change in the Earth’s climate?

Rising global temperatures

Global temperature anomaly

This is how much warmer or cooler it is than the long-term average, between 0-4°C

What are the six greenhouse gases?

• Carbon dioxide

• Chlorofluorocarbon

• Methane

• Nitrous oxide

• Ozone

• Water vapour

Why are greenhouse gases vital for life on Earth?

They trap enough heat to ensure life on Earth can be sustained, without them the average global temperature would be 18°C

The greenhouse effect

This is a natural process in which greenhouse gases in the atmosphere trap heat from the sun

The greenhouse effect

What are the eight human causes of climate change?

• Cement

• Chemicals

• Deforestation

• Energy use in buildings

• Landfills

• Livestock

• Rice cultivation

• Transport

Cement

Limestone is converted to lime, which releases CO2 that otherwise would have been left in the rock

Chemicals

Chemicals such as ammonia are use in cleaning supplies, which releases CO2 and N2O as a byproduct

Deforestation

This means that there is less vegetation to take in CO2, which reduces how CO2 is stored

Energy use in buildings

Buildings use electricity as a source of power, which uses fossil fuels like CO2 to heat

Landfills

Waste products are sent to landfills, decaying in low oxygen environments, which emits methane

Livestock

Animals kept as livestock produce methane when microbes in their digestive systems breaks down grass, which is released in the atmosphere

Rice cultivation

As the global population increases, the demand for rice increases, which emits methane when the crop dies

Transport

Most transport uses fuels deprived from oil, which releases CO2 and N20 as the engine burns

What are the five physical causes of climate change?

• Melting icecaps

• Milankovitch cycles

• Ocean circulations

• Solar variations

• Volcanic eruptions

Melting/retreating icecaps

This exposes the land underneath, which reduces the albedo effect and when the permafrost melts methane is released

What are the three Milankovitch cycles?

• Axial precessions (axis wobble)

• Changes in eccentricity (orbit shape)

• Changes in obliquity (axis tilt)

What are the two ocean circulation episodes?

El Niño and la Niña

Solar variations

Sunspots are storms on the sun’s surface that releases intense amounts of magnetic energy, this leads to sun flares that are violent eruptions that can reach temperatures up to 20 million degrees

Volcanic eruptions

Huge amounts of ash, dust, and gases like SO2 are released into the atmosphere which reflects the sun’s energy, this causes the temperature to drop as the sun’s energy is not reaching the Earth’s surface

Solar maximum (solar variations)

This is when the sun is most active, resulting in global warming

Solar minimum (solar variations)

This is when the sun is least active, resulting in global cooling

Axial precessions (axis wobble)

The Earth wobbles on its axis, which can change the timings of seasons and affect how big the range in temperatures is

Changes in eccentricity (orbit shape)

The Earth’s orbit stretches, causing changes in how close or far away Earth is to the sun

Changes in obliquity (axis tilt)

A greater tilt means more sunlight in the polar regions, which reduces the likelihood of ice building up

Positive feedback loop

When ice melts, the land and oceans absorb the suns energy instead of reflecting it

El Niño

This occurs when there are above-average sea-surface temperatures over equatorial pacific, bringing warmer and wetter weather

What are the eight impacts of climate change?

• Air pollution

• Conflict and tension

• Drought

• Falling crop yields and livestock deaths

• Flooding of coastal communities

• Heat waves

• More frequent tropical storms

• Reducing fish stocks

Air pollution

Local industry factories are outputting gases, which affects low-middle income countries as they cannot afford to move away

Conflict and tension

Countries that are dependant on other countries imports will loose out on resources, which affects a countries resources as they can no longer make an income from trading

Falling crop yields and livestock deaths

Droughts and/or heatwaves can cause crops to die, which affects a country as they will need to rely on outside help to not starve

Flooding of coastal communities

The surrounding water rises and floods are becoming more likely, which affects smaller countries that live on islands as households become lost due to damage

Heat waves

Rising temperatures can affect already hot countries as the temperatures continue to rise, which affects people who cannot afford air-conditioning or water storages as they become prone to health concerns like heat stroke

Reducing fish stocks

As waters become warmer fish will migrate to cooler waters, which affects communities that rely on fish as a food course as people will go hungry and loose an income

More frequent tropical storms

Rising sea temperatures contribute to an increased risk of tropical storms, which affects countries that live in tropical areas as some communities cannot rebuild as easily as others

Drought

Warming temperatures can cause places to dry, which affects countries that rely on agriculture as they are no longer able to rely on their country to produce food

What two things are required to manage climate change?

Adaptation and mitigation

Adaptation

The response to the impacts that are already occurring because of climate change

Mitigation

The reduce the rising levels of greenhouse gases in our atmosphere

What are the eight mitigation strategies?

• Afforestation schemes

• Carbon trading

• Eating less meat and shopping local

• Home energy efficiency grants

• Improvements in public transport

• Low emission zones

• Recycling

• Renewable energy

Afforestation schemes and its effectiveness

The Great Green Wall is a mass tree planting scheme spanning from Senegal to Djibouti that aims to reduce desertification and offers sustainable firewood, this is ineffective due to as of 2020 only 4% of the great green wall has been planted

Carbon trading and its effectiveness

Trading systems within countries helps meet the global reduction of the world’s greenhouse gas emissions, this is effective as businesses have been forced to become more efficient and pollute less

Eating less meat and shopping local and its effectiveness

Some people include more plant based foods in their diet, resulting in less methane being emitted, this is effective as between 2019-2020 there has been an increase of 46% people buying vegan meals

Home energy efficiency grants and its effectiveness

Councils provide money to upgrade council housings as to not let energy escape, this is effective as it reduces council housing prices while still heating homes

Improvements in public transport and its effectiveness

Edinburgh city council has come up with a ‘city mobility plan’ which aims to reduce the number of km travelled by cars, this is effective as it has reduced the volume of cars travelling in and out of Edinburgh’s city centre

Low emission zones and its effectiveness

These are designed to reduce emissions by restricting the most polluting vehicles, this is effective because between 2017-2022 CO2 emissions decreased by 46%

Recycling and its effectiveness

This reduces the amount of items going into low oxygen level environments in order to reduce methane levels, this is effective as it helps to control the disposal of large items such as fridges to ensure CFC’S do not go into the atmosphere

Renewable energy and its effectiveness

Investing in wind farms, solar panels, and hydro/geothermal power aims to reduce greenhouse gas emissions by 80% before 2030, this is effective as emissions fell by 57% in 2017

La Niña

This occurs when there are below-average sea-surface temperatures over the Pacific, brining cooler and drier weather