Water, Carbon, Climate And Life On Earth

Question 1

What is climate change mitigation

Question 2

How effective are the different strategies to mitigate climate change?

Answer 2

1. Carbon capture and sequestration technologies
   - captures 90% of co2 emissions, preventing co2 entering the atmosphere
   - three parts capturing, transporting and storing
   -eg 100-megawatt coal and CCS plant in Canada called Boundary
   - however challenges: unproven technology - delays shift away from fossil fuel economy
2. Changing rural land use
   - grassland offers a mitigation potential of 810 million tonnes of co2 (in the period up to 2030)
   - forests able to reduce co2 emissions by storing large stocks of carbon both above and below ground
   - eg, protection and reforesting
   - however, landowners have huge power. Farmers demand subsidies. And many are opposed to wind and solar farms.
3. Improved aviation practices
   - design and technology. Eg, increased engine efficiency, increased use of biofuel
   - movement management. Eg, towing while on the ground, avoid circling / queueing, adopt fuel efficient routes
   - flight management. Eg, 100% occupancy of seats, cruising at lower speeds.
   - Eg - the Airbus A380 use less than 3litres of fuel per 100 passengers per km
   - however, challenges: people love cheap fights and many of the ideas are still in theoretical stages.

Question 3

What is the importance of water and carbon for life on earth?

Answer 3

Carbon - it bonds with other elements such as oxygen and hydrogen and nitrogen to form complex molecules. Carbon forms the key components for all known life on earth.

Water - every drop of water cycles continuously through air, land and sea to be used by something else in the cycle.

Impact on climate: as co2 in the atmosphere increases, temps increase, warmer oceans can absorb less carbon. Positive feedback - enhances enhanced greenhouse effect

Question 4

Outline the relationship between the water cycle and the carbon cycle in the atmosphere?

Answer 4

• co2 mixes with water vapour to form carbonic acid
• photosynthesis uptakes co2 from the atmosphere and requires h20 from precipitation
• decomposition also requires precipitation from the atmosphere and releases co2 back into the atmosphere
• increasing co2 has a warming effect on the atmosphere, encouraging more evaporation + higher humidity (co2 causes about 20% of the greenhouse effect)