The carbon cycle Flashcards
(51 cards)
What is carbon?
An element found in both biotic and abiotic factors of an ecosystem. Stored in sedimentary rock as well as the ocean and the air, and moved between stores by animals.
What are sedimentary carbonate rocks?
Sedimentary rocks that store carbon e.g limestone in the form of calcium carbonate, mostly from the shells and bones of marine creatures, and phytoplankton that absorb carbon through photosynthesis.
How is carbon released geologically?
Through weathering (especially chemically). Also through tectonic processes where sedimentary rock is heated to extreme temperatures at plate boundaries, and during volcanic eruptions.
How is carbon stored in the ocean?
Phytoplankton turn carbon into organic matter during photosynthesis. This is called the biological carbonate pump. Carbon moves from atmosphere to shallow ocean to deep ocean when they die and fall to the seabed.
What is thermohaline circulation?
Cold dense water sinks and warmer water rises. This moves oxygen, nutrients, and heat to the surface (as well as carbon dioxide). This is happening on a global process over a very long time period - hundreds or thousands of years.
How do land based ecosystems store carbon?
Plants absorb CO2 during photosynthesis and it is released during their decomposition after death, or stored in the soil if there is a higher biomass.
What is the natural greenhouse effect?
Sun’s energy reaches earth - half is reflected back by clouds. Some of the heat is then absorbed due to the dense atmospheric gases like CO2 and methane.
What are the implications of fossil fuel consumption?
Pre-ind-rev carbon cycle was fairly balanced, now increasing levels of carbon has led to recent warming that is unexplainable by natural processes e.g Milankovitch cycles, ENSO etc.
How will temperature increase impact the climate?
Weakening of thermohaline circulation. Melting ice shelves. stronger storm activity on tropical zones. More extreme precipitation or lack thereof.
How will temperature increase impact ecosystems?
10% of species will die out as the climate changes, biodiversity will be impacted especially in birds as their habitats are destroyed. Plants will lag behind fauna as they cannot move so will die out faster.
How will a 2% temperature increase impact the hydrological cycle?
Rivers will dry up and some small glaciers will disappear. 20-30% decrease in water availability in the mediterranean. Heavy precipitation events and high humidity will become more common.
What is the energy mix of a country?
The mix of different energy sources they use. This used to be mainly coal and oil but these are starting to decline. This energy diversification will be slow as new technologies need to develop, and trade links are often based on political ties that can’t be easily broken.
What factors impact a country’s access to energy sources?
Availability and accessibility of primary resources. Energy needs and consumption patterns of a country’s population. National policies, country history and culture and finances.
What are the priorities of energy players?
Energy players have 3 priorities - security, equity, and sustainability.
How have fossil fuels impacted the energy scene?
They are only found where historical geological conditions have been favourable, determining the location of manufacturing on a regional and global scale.
What are energy pathways and what impacts them?
The way energy is transported between countries. This includes oil pipelines, shipping containers etc. This can be impacted by physical obstacles such as hurricanes, and human ones such as pipeline leaks, piracy, and geopolitical conflicts.
What are some unconventional fossil fuel resources?
The search for these has increased as oil reserves are used up bby developing economies. New technologies include:
- Deep water oil
- Tar sands
- Oil shale
- Shale gas
What is deep water oil?
Found by deep sea drilling in the Gulf of Mexico.
What are tar sands?
Mixture of regular sediments and bitumen (a viscous oil). Can be extracted using lots of energy, which contributes more to global warming and leaves scars across the landscape.
What is oil shale?
Can be mined and heated to a high temperature to release oil. This is expensive, releases GHG, disturbs the environment and produces lots of waste rock.
What is shale gas?
Natural gas trapped inside rocks that cant be released through drilling so must be extracted through fracking. This is very invasive and can cause earthquakes underground, as well as methane leaks and potential groundwater contamination.
What is happening with renewables?
IPCC says drastic increase needs to happen by 2050. HEP, solar and wind power are all steadily increasing. Nuclear is increasing in some areas but decreasing in others and hydroelectric is suffering from climate uncertainties.
Are biofuels a good alternative?
IPCC says they are crucial but is more suitable on a smaller scale than for large scale operations due to land use changes and necessity of farmland for crops for consumption in many countries.
What new technologies are there for energy?
- Hydrogen fuel cells
- Electric vehicles
- Carbon capture and storage
- Nuclear fusion
- Nanotechnology
