1-A Climate Change Flashcards
Is there evidence for climate change from the beginning of the Quaternary period to the present day?
- the Earth’s average surface air temperature has increased by 1*C over the last 100 years
- Sea levels has risen by 19 cm since 1900 - due to thermal expansion and ice sheets melting
- Ocean temperatures are the warmest since 1850
- World’s glaciers and ice sheets are decreasing in size
What are the 3 main natural factors of climate change and could any of them be the cause of it?
Solar Output, Orbital Changes, Volcanic Activity
None of them could have been the cause
What is Solar Output?
the intensity of solar energy output from the sun has increased
What is Orbital Change?
Earth’s orbit is an eclipse, every 100,000 years ellipse shape changes. The angle of the tilt increases, which exaggerates climate
Earth not perfect sphere - Earth spins and wobbles on axis
What is Volcanic Activity?
the greenhouse gases released from volcanoes trap the Sun’s heat in the Earth’s atmosphere
What are the 3 main human factors of climate change?
Fossil fuels, Agriculture, Deforestation
How does fossil fuels impact climate change?
Fossil fuels account for majority of global greenhouse gas emissions (over 50%)
Fossil fuels are used in transportation, building, heating homes and manufacturing industry
Burnt in power stations to generate electricity
How does agriculture impact climate change?
Agriculture accounts for 20% of global greenhouse gas emissions
Produces large volumes of methane (cattle + microbes)
Demand for food increases = food production increases (more meat + crops)
How does deforestation impact climate change?
Trees photosynthesis, which takes away CO2 from the atmosphere, but trees being cut down mean that the word photosynthesis rate decreases
Why do we cut down trees?:
- Clearing land for agriculture
- Logging for wood and paper
- Building roads to access remote areas
- Making room for expansion of urban areas
How does climate change impact the world (in a general sense)?
Climate change increases + decreases temperature. Which,:
> Causes flooding / drought -> bad agriculture + places ruined - animals and humans both impacted
> Wildlife dying - marine and on land (due to change in quality of food for animals + lack of food supply for wildlife + loss of habitat (like ice caps melting))
> Health risks for humans - heat waves increased + waterborne diseases + skin cancer risk increased
What 2 approaches do we have to tackle climate change and what are they?
1) Mitigation: about strategies that deal with the cause of the problem - reduce or prevent greenhouse gases
2) Adaptation: responds to impacts of climate change and tries to make populations less vulnerable. Adaptation are local and not global
What techniques of mitigation can limit the amount of greenhouse gases?
Alternative Energy Production
Carbon Capture
Planting Trees
International Agreements
How does alternative energy production help prevent climate change?
Alternative energy production:
- Renewable energy sources provide a solution to reduce the volume of greenhouse gases contributing to climate change
- Renewable energy is more expensive than fossil fuels, but are becoming cheaper and more competitive, as they don’t produce CO2
- 14.9% of UK’s electricity generate by renewable energy sources (2013)
How does carbon capture help prevent climate change?
Carbon Capture:
- Capture carbon dioxide and safely store it in underground rock formations and the oceans
Done by turning CO2 into liquid (supercritical CO2) and injecting into sedimentary rock - impermeable ‘cap rock’ prevents it from escaping
How does planting trees help prevent climate change?
Planting Trees:
- Deforestation is one of major driver of climate change
- According to UN Environment Programme, deforestation and forest degradation occurs at 13 million hectares per year
- US invested $40 billion in reforestation
