Tundra & Permafrost:
- This is positive feedback as Arctic warms: The Arctic is going to increase in temperature by 7.
- GHG increase concentration leading to more global warming
- Warming air temperatures and more melting snow
- Soil warms up from warmer air and absorbing sunlight
- Soil thaws as ice melts
- More methane is released
- More decomposition occurs of dead organic matter releases CO2.
Biological Carbon Cycle:
- Marine ecosystems e.g. phytoplankton (algae), coral reefs and terrestrial ecosystems e.g. forests, wetlands, grassland, tundra
- Humans place huge pressures on these ecosystems through pollution, over-abstraction, climate change, and land-use change e.g. deforestation and conversion of natural habitats into farmland
- Growing demand for food increases pressures on natural environments e.g. land-use change
- More demand for fuels such as biofuels in Brazil increase pressures as well
- This ‘degrades’ the carbon cycle as there are less carbon stores, and more CO2 is emitted, e.g. from forests, DOM from soils, and the ocean
- Some areas however are improving and act as CO2 sinks e.g. afforestation programmes – which in turn improves the carbon and water cycle functioning, and also ecosystem resilience
Problems for the Amazon:
- Deforestation: 20% of the rainforest has already gone – which is the biggest issue
- Main cause is cattle farming. 70% for beef. Other grasslands increasingly used for biofuels so cattle farmers are forced to clear the rainforest even more.
- Future climate change methods such as droughts.
Coral Reefs & Ocean
Acidification:
- Act as a home for 25% of all marine life.
- Carbon dioxide concentration is increasing in the oceans sink due to more diffusion from the atmosphere.
- Water is slightly more acidic. Small reductions in pH, destroying coral reefs ecosystem.
- Corals are calcium carbonate so positive feedback could affect the carbon cycle.
The Tipping Point:
- A point might be reached when there is no going back. Climate change has accelerated and becomes uncontrollable.
- Positive feedback becomes so strong and keeps growing and so GHC becomes strong. And CO2 spirals out of control causing huge climatic forces and global warming at a huge scale.
Energy Consumption
Increasing:
- Energy is increasing up until 2020.
- Consumption is also increasing.
Climate Belt Shifting:
- Rainforest could shrink due to more droughts and forest fires, releasing carbon and storing less
- Deserts will spread as temperatures evaporation and droughts increase e.g Sahel grasslands will shrink as Sahara grows
- Alpine areas will shrink as mountains warm up and glaciers mean snow melts earlier.
- Tundra areas (frozen soil in the Artic) will shrink as coniferous forests move north.
Climate Change Affecting
Forests:
- Rising air temperatures means more climate variability, less snow along with faster and early snowmelts. Floods may be more impacted to the ability to store water.
- Warmer water bodies mean altered forest habitats – drier vegetation, increased pathogens and fire.
Changes to Conventional
Rainfall:
- 60% of the Amazon rainfall is from evapotranspiration water from forests.
- Biomass carbon in plants and trees will decrease.
- Dead organic matter will decompose and decrease also release more CO2
- Water cycle disruption will include less precipitation, interception, lower soil moisture, less storage and maybe more flooding.