Physical Geography- Climate Change

In the period before the Quaternary, the Earth was warmer and quite stable. 

During the Quaternary, global temperature has shifted between cold glacial periods that last for around 100,00 years and warmer interglacial periods that last for around 10,000 years. 

The last glacial period ended 15,000 years ago and since the climate has been warming. 

Evidence used to determine climate change 

Ice Sheets- Scientists drill into them and see what gases are trapped in the layers of ice which determines the temperature it was each year. 

Temperature Records- Thermometers have given a reliable but short-term record of temperature change. 

Historical Records e.g. newspaper weather reports can extend the temp records further.  

Natural Causes 

Orbital Changes- The Earth's path of circular orbit and elliptical orbit change every 96,000 years. 

This affects the amount of solar radiation we receive. (more energy means it gets warmer)

Volcanic Activity- Particles from major volcanic eruptions reflect the Sun's rays back out to space which means the Earth's surface cools. 

Solar Output-Periods when solar output is reduced may cause the Earth's climate to become cooler in some areas. 

Human Causes

Fossil Fuels- Carbon dioxide is released into the atmosphere when fossil fuels are burnt. 

Deforestation- When plants and trees are chopped down they release carbon dioxide. 

Agriculture- Farming cows produce a lot of methane /ice paddies as flooded fields emit methane 

Environmental Effects 

• Rising sea levels mean low lying and coastal areas like the Maldives will be flooded more regularly. 
• Other species are declining due to warming e.g some coral reefs are suffering from bleaching due to warm sea level temperatures. 
• Precipitation patterns are changing- warming is affecting how much rain areas get. 

Effects on People 

• Deaths due to heat have increased but deaths due to cold have decreased. 
• Lower crop yields could increase malnutrition, ill health and death from starvation. 
• Low, lying coastal areas could be lost to flooding which would lead to migration and overcrowding in other areas.  

Alternative Energy Production

Replacing fossil fuels with nuclear power and renewable energy can help reduce climate change by reducing greenhouse gas emissions from power stations. 

In the UK more nuclear plants are being planned and wave and several tidal projects are planned. 

Planting Trees 

Increases the amount of carbon dioxide absorbed from the atmosphere through photosynthesis. 

Carbon Capture 

Reduces climate change by reducing emissions from fossil fuel burning power stations. It involves capturing carbon dioxide and transporting it to be safely stored underground. 

International Agreements 

From 1997, most countries agreed to monitor and cut greenhouse gas emissions by signing the Kyoto Protocol. The UK exceeded their target by reducing emissions by 22%

Changing Agricultural Systems 

Necessary to plant new crop types that are more suitable to the new climate conditions in an area  e.g.Soya, peaches and grapes may be grown in Southern England. 

Managing Water Supply 

Water meters can be installed in homes to discourage people from wasting water. 

Rainwater can be collected and wastewater can be recycled. 

Coping with Rising Sea Levels 

Flood barriers are being built and flood warning systems are being put in place.e.g. the Thames barrier. 

In LICs people are building their houses on earth embankments and building raised flood shelters for emergencies.