Water and carbon cycle 6 - Water, carbon and climate Flashcards
What is at the base of most food chains
Plants
What happens when photosynthesis occurs
They use energy from the sun to convert CO2 and H2O into biomass that gets passed up the food chain
What inputs are both required for photosynthesis
Water and carbon
How is water present in the atmosphere
Water vapour
How is carbon present in the atmosphere
CO2 and methane
What kind of gases are these
Greenhouse gases
Why are they greenhouse gases
They cause a natural greenhouse effect that prevents energy escaping into space and reflects it back to earth
What does this cause
Temperature on earth to be higher than they otherwise would be
What would happen without the natural greenhouse effect
The earth would be frozen and inhabitable
What else is increasing the concentration of greenhouse gases in the atmosphere
Human activities
What do most scientists agree this is causing
An enhanced greenhouse effect
What’s the enhanced greenhouse effect
This is where the additional greenhouse gases reflect more energy back to the earth in the natural greenhouse effect, so temperature increases further
What is this said to be causing
Global warming and other changes to the climate
What are the effects of a change to a system
Maybe affected by positive or negative feedback
How does positive feedback work in the water cycle
1) Temperature rises
2) Evaporation increases
3) Amount of water vapour in atmosphere increases
4) Greenhouse effect increases
How does negative feedback work in the water cycle
1) Temperature rises
2) Evaporation increases
3) Amount of water vapour in atmosphere increases, causing more clouds to form
4) Increased cloud cover reflects more of the sun’s energy back to space
5) Temperature fall
How does positive feedback work in the carbon cycle
1) Temperature rises
2) plant respiration rate increases
3) Amount of CO2 in atmosphere increases
4) Greenhouse effect increases
How does negative feedback work in the carbon cycle
1) CO2 in atmosphere increases
2) Extra CO2 causes plants to increase growth
3) Plants remove and store more CO2 from atmosphere
4) Amount of CO2 in atmosphere reduces
What is happening in these positive feedback examples
Increasing global warming / climate change because of the amplifying temperature rise
What is happening in these negative feedback examples
Cancel out the temperature increase, so global warming wouldn’t increase
What 3 ways do the carbon and water cycle depend on each other
1) Carbon combines with water in the atmosphere. Allowing for chemical weathering, removing carbon from the atmosphere
2) Water is needed for photosynthesis, which removes carbon from the atmosphere
3) The amount of CO2 in the atmosphere effects global temperatures, which affect the amount of evaporation that takes place, which affects the amount of precipitation
What is climate change predicted to do
Have major impacts on plants, animals and people
How will climate change affect precipitation
Wet areas are expected to get wetter and dry areas are expected to get drier. Thus can cause water shortages in some areas, leading to conflicts in the future
How will climate change affect extreme weather events
They’ll be more frequent. Less developed countries will probably be worst affected as they’re less able to deal with these issues
How will climate change affect agriculture
Agricultural productivity will decrease in some areas, leading to food shortage
How will climate change affect sea levels
They’re expected to rise further . This will cause flooding in coastal and low - lying areas
How will climate change affect the geographical range of some species
The arrival of new species in an area may damage eco systems and some species may become extinct
How will climate change affect plankton
Their numbers may decline if temperature increase, this will have a knock on effect on marine food chains.
How have humans influenced the carbon cycle
Extracting and burning fossil fuels
How much more CO2 is in the atmosphere now compared to 1750
40% more
How are the UN tackling these issues
They set up the Intergovernmental Panel on Climate Change (IPCC) - an international organisation
what does the IPCC do
States that countries need to reduce CO2 emitted by human activities in order ti prevent larger temperature rises
How are people trying to mitigate the impacts of climate change
On an individual, regional and national and global scale
What 2 things can be done on an individual scale
- People choose to use their cars less and buy fuel efficient cars
- They make their homes energy efficient like having double glazing windows
What 4 things can be done on a regional and national scale
- Governments reduce reliance on fossil fuels for heating and powering homes by increasing the availability and reducing the cost of renewable sources
- Afforestation and restoring degraded forests can increase carbon uptake by the biosphere
- Planners can increase the sustainability of developments by improving public transport and creating more green space
- Governments invest in carbon capture and storage. CO2 emitted from burning fossil fuels is captured and stored underground such as depleted oil
What 2 things can be done on a global scale
- Countries work together to reduce emissions. For example the Paris agreement in 2015 and COP26 in Glasgow in 2021
- There’s international carbon trading schemes. Countries and businesses are given a limit on the emissions they can produce - if they produce less, they can sell the extra credits, if they produce more they need to buy more credits
