1B.3 Changing Climate Flashcards
Define global warming.
The increased heating of the atmosphere, probably caused by human activities.
Describe the greenhouse effect.
- Incoming solar radiation passes directly through the natural greenhouse gases in the atmosphere.
- The Earth’s surface is warmed.
- Outgoing radiation passes through the greenhouse gases except infrared radiation which is either absorbed by greenhouse gases, trapped beneath them or reflected back to the Earth’s surface.
- Some heat escapes back into space, normally creating a balance:
- CO₂ from creatures = CO₂ taken into trees
- O₂ given out by trees = O₂ used by creatures
- There is an increase in greenhouse gases due to human activity (burning fossil fuels, deforestation, methane release and CFCs)
- Less heat escapes into space.
- More heat is trapped, causing global warming.
List the main greenhouse gases and how much they contribute.
Carbon dioxide - 64%
Methane - 20%
CFCs (chlorofluorocarbon) - 12%
Nitrous oxides - 4%
Define greenhouse effect.
The process whereby gases such as CO₂ in the Earth’s atmosphere trap heat escaping from the Earth and radiate it back to the surface.
Explain 2 natural causes of climate causes.
- Natural climatic cycles:
• Every 100,000 years, the Earth’s orbit around the sun changes very slightly from a circular path to a more elongated path. In the past this has led to climatic changes, most evident in the periods of glacial cycles and warmer cycles which follow.
• Sunspots can also affect the temperature on Earth. The period between 1645 and 1715 was a time when there were very few sunspots and this coincides with a very cold period in Europe known as the little Ice Age. - Volcanic activity:
• When a volcano erupts, gases and dust particles are ejected into the atmosphere, which partially block the sun’s incoming radiation, leading to cooling on Earth.
• The sulphur dioxide produced forms small droplets of sulphuric acid in the upper atmosphere which reflect sunlight, reducing the amount of heat reaching the Earth’s surface.
List how the main greenhouse gases are emitted.
CO₂ - road vehicles, burning fossil fuels and deforestation
Methane - decaying organic matter
CFCs - aerosols and refrigerators
Nitrous oxides - car exhausts, power stations and fertilizers
Explain 2 human causes of climate change.
- Burning fossil fuels:
For 200 years, most of our energy has come from burning fossil fuels such as coal, oil and gas in power stations to generate electricity. Industrial development and population growth is causing more and more fossil fuels to be burned worldwide. In 2010, power stations and the industry in the UK accounted for 60% of CO₂ emissions into the atmosphere from our country, which increase the amount of greenhouse gases, trapping heat in our atmosphere. - Motor vehicle pollutants:
More and more vehicles are using the roads in the 21st Century. In the UK, over the past 20 years road traffic has grown by 70%. In 2010, vehicles accounted for 22% of CO₂ emissions in the UK. The exhausts of cars also emit polluting gases such as nitrous oxide which add to the amount of greenhouse gases in the atmosphere and lead to global temperature increases.
What are fossil fuels?
Natural resources such as coal, oil and natural gas, formed from dead plants and animals over millions of years.
Define actual effects.
Effects that have already happened.
Define potential effects.
Effects that might happen in the future.
Describe 2 ACTUAL effects of climate change on the ENVIRONMENT.
- Increasing rainfall - wet places are getting wetter and dry areas are getting drier. However, seasons are starting to change with summer rainfall in the British Isles decreasing while in winter it is increasing. December 2015 was the wettest month on record in the UK.
- Glacier and ice cap melt - warming global temperatures are causing polar ice caps and glaciers to melt rapidly. Sea ice at the Arctic has retreated by 20% in 2 decades while the Greenland and Antarctic ice sheets are shrinking. Glaciers in mountains like the Alps are melting while 85% of Kilimanjaro’s glacier volume has been lost.
Describe 2 POTENTIAL effects of climate change on the ENVIRONMENT.
- Plants and animals - climate change means that some species will be unable to adapt. There is some evidence that polar bears in the Arctic are now more at risk as they have to swim further between flows of ice to hunt for food in summer. As they have to use up more energy, they are losing body weight and fat, and so may starve.
- Sea level rise - some estimate that the release of water from ice and snow could raise the sea levels around the world by up to 5m. Even a rise of 1m could flood 25% of Bangladesh and other low lying areas.
Describe 2 ACTUAL effects of climate change on SOCIETY.
- Death rates in LEDCs - The Global Humanitarian Report has stated that already 300,000 people per year are seriously affected or are dying due to the impact of climate change and being unable to adapt.
- Food shortages - climate change can cause droughts or extreme flood events and both have had major impacts on global food stocks. It is estimated that 800,000 people in LEDCs, like Ethiopia, have suffered food shortages due to such events.
Describe 2 POTENTIAL effects of climate change on SOCIETY.
- Disease - a warmer climate will make more of the world’s population at risk from insect-borne diseases such as malaria and Dengue fever and water bourne diseases like cholera. These diseases could spread noth into Europe with increasing temperatures.
- Environmental refugees - climate change and rising sea levels will threaten the existence of low lying islands in the Pacific and Indian Oceans such as Kiribati and the Maldives. This will force hundreds of thousands of people to become refugees seeking a permanent home elsewhere in countries like Australia.
Describe 2 ACTUAL effects of climate change on the ECONOMY.
- Farming - the traditional patterns of farming are being disrupted. It is becoming more and more difficult for farmers in marginal areas (across Africa and South America) to continue to farm the land as soil erosion increasingly affects the fields.
- Travel - airlines have started to introduce optional and sometimes compulsory taxes on travellers to help reduce the carbon footprint of their travel plans. As awareness rises about the impact of climate change, people have to pay more to compensate for any pollution that may be generated.
