carbon paper 1 Flashcards
6.2a phytoplankton sequester atmospheric carbon during photosynthesis in surface ocean waters; carbonate shells/tests move into the deep ocean water through the carbon pump and through thermohaline circulation.
The oceans are the Earth’s second largest carbon store. The oceanic store of carbon is 50 times greater than that of the atmosphere. Most of the oceanic crust is stored in marine algae, plants and coral. The rest occurs in dissolved form.
types of oceanic carbon pump: (circulates and stores carbon)
Biological pumps - move carbon dioxide from the ocean surface to marine plants called phytoplankton through photosynthesis. Phytoplankton are microscopic plants and plant-like organisms drifting or floating in the sea/freshwater. This effectively converts carbon dioxide into food for microscopic animals and their predators. Most of the carbon dioxide taken up by phytoplankton is recycled near the surface. About 30% sinks into deeper waters and converted back into CO2 by marine bacteria. phytoplankton sequester 2bn CO2 annually!
Physical pumps - ocean circulation. move carbon compounds to different parts of the ocean in downwelling and upwelling currents
Downwelling occurs in parts of the ocean where cold, denser water sinks. These currents bring dissolved carbon dioxide down to the deep ocean. Once there, it moves in slow-moving deep ocean currents, staying there for hundreds of years. Eventually, these deep ocean currents, part of the thermohaline circulation, return to the surface by upwelling.
The cold deep ocean water warms as it rises towards the ocean surface and some of the dissolved carbon dioxide is released back into the atmosphere.
Carbonate pumps - carbon sedimentation. marine organisms use CaCO3 to make hard shells and skeletons (plankton, oysters, crabs, corals). when they die and sink to ocean floor, shell dissolves and carbon stored becomes part of deep ocean store.
The thermohaline circulation = global system of surface and deep ocean currents driven by temperature and salinity differences between different parts of ocean. Its like a giant conveyor belt that plays a vital part in the carbon cycle.
6.3b ocean & terrestrial photosynthesis regulates composition of atmosphere. soil health is influenced by stored carbon which is important for ecosystem productivity.
photosynthesis by terrestrial & oceanic organisms keeps co2 levels constant and regulates earths temp.
arctic ice melt is increasing, means greater areas of oceans are exposed to sunlight for longer, causing algal bloom. algae sequesters CO2 but alters marine ecosystems.
soil health:
the amount of carbon stored in the soil depends on: size of the store in different biomes, total input (the amount of plant litter & animal waste), total output (the amount of decomposition, erosion and uptake by plant growth).
stored carbon is important for soil health. helps moisture and fertility. healthy soil will be dark, has worms and organisms and have good infiltration rates. small amount of surface erosion can impact soil fertility and health.
6.4a consumption (per capita and in terms of units of GDP) and energy mix (domestic and foreign, primary and secondary, renewable versus non-renewable)
Energy security: when there is an uninterrupted availability of energy at a national level and at an affordable price. All countries seek to achieve this; the most secure energy situation is where the national demand for energy can be completely satisfied by domestic sources. The more a country demands on imported energy, the more it is exposed to risks of an economic and geopolitical kind.
aspects of energy security are: availability accessibility affordability - competitively priced energy supply reliability - uninterrupted
energy is vital for country to function. it powers transport, lights, commercial agriculture; warms/cools homes and domestic appliances, modern communications, manufacturing.
consumption of energy is measured in two ways:
in per capita terms (as kilogrammes of oil equivalent or megawatt hours per person. In general, this measure rises with economic development)
by energy intensity (calculating the units of energy used per unit GDP.) The fewer the units of energy, the more efficiently a country is using its energy supply. energy intensity values decrease with economic development
primary energy sources: consumed in their raw form (fossil fuels, renewable and nuclear sources)
secondary energy sources: made from transformation of conversion of primary sources e.g electricity that is used by homes & businesses
6.4b Access to and consumption of energy resources depends upon physical availability, cost, technology, public perception, level of economic development and economic priorities (national comparisons: USA vs France)
Factors affecting per capita energy consumption:
physical availability
cost
standard of living
environmental priorities (of governments) -for some, energy policy will be taking the cheapest route to meeting the nation’s energy needs, regardless of the environmental costs. Others will seek to increase their reliance on renewable sources of energy; wile still other will have in place policies that raise energy efficiency and energy saving
climate - very high consumption in North America, Middle East and Australia reflect the extra energy needed to make the extremes of heat and cold more comfortable (at home, at work and in public places)
public perception - for some consumers, energy is perceived almost as a human right and therefore to be used with little or no regard for the environmental consequences. Others give priority to minimising the wastage of energy and maximising security
economic development
technology
The USA and France rank second and tenth in the league table of energy consumers respectively, but total energy consumption in France is only one-tenth that of the USA. The difference is largely explained by differences in population - 318.9 million in the USA compared with 64.6 million in France. In per capita terms, the USA tops the rankings whilst France is placed sixth.
USA, over three quarters of energy comes from fossil fuels and 10% renewable.
French energy mix is different, with half its energy coming from fossil fuels and around 40% coming from nuclear energy & 10% renewable.
France is much less energy secure than the USA, because nearly half of its primary energy is imported. The USA is much more self-sufficient importing only 15%.
6.4c Energy players (role of TNCs, The Organisation of the Petroleum Exporting Countries (OPEC), consumers, governments) have different roles in securing pathways and energy supplies.
energy pathway = route taken by any form of energy from its source to its point of consumption. involve different transport like tanker ships, pipelines and electricity transmission grids.
At the supply end of the pathway, there are energy companies and the governments of energy-producing countries. There are governments at the demand end and consumers from industrial to domestic. Along the pathways, there are companies responsible for the movement and processing of energy
TNCs - the big names in the oil and gas business (Gazprom, ExxonMobil, PetroChina and Royal Dutch Shell) Nearly half of the top 20 companies are state-owned (all or in part) so very much under government control. Because of this they are not TNCs. Most are involved in a range of operations: exploring, extracting, transporting, refining and producing petrochemicals.
Organisation of the Petroleum Exporting Companies
OPEC has 14 member countries, between them own about two-thirds of the world’s oil reserves. it is in a position to control the amount of oil and gas entering the global market, as well as the prices of both commodities. OPEC has been accused of holding back production in order to drive up oil and gas prices. it protect the interests of member countries, stabilises oil prices and limit price fluctuations, ensures efficient, economic and regular supply of oil to consuming nations
Energy Companies - companies that convert primary energy (oil, gas, water, nuclear) into electricity and distribute it. They have considerable influence when it comes to setting consumer prices and tariffs.
Consumers - the most influential consumers are transport, industry and domestic users. largely passive players when it comes to fixing energy prices.
Governments - have different roles; guardians of national energy security and can influence the sourcing of energy for geopolitical reasons.
6.6a renewable & recyclable energy (nuclear power, wind power and solar power) could help decouple fossil fuel from economic growth; these energy sources have costs and benefits economically, socially, and environmentally, and in terms of their contribution to energy security. (changing UK energy mix)
reducing co2 emissions involves increasing reliance on alternative sources so decoupling economic growth from dependence on fossil fuels. this means widening energy mix including renewable and recyclable energy sources.
renewable energy sources are hydro, wind, solar, geothermal and tidal.
Not all countries have renewable energy to exploit for geographic reasons:
not all countries have coasts, flowing rivers or climates with either long sunshine hours or persistently strong winds
Partly because of this, there are very few countries where renewables might completely replace all the fossil fuel energy.
Other factors reinforcing this include:
the economic costs- fossil fuel gas prices are low, renewables become a more expensive option.
environmental costs - river valleys have to be drowned to create HEP reservoirs, and large areas of land/the offshore zone are covered by solar or wind farms.
while majority of people believe that we should use renewable sources, most suddenly go off the idea when constructing a wind or solar farm near them is made
Recyclable Energy (Nuclear) countries with high energy consumption will have no option but to look to nuclear energy to generate their electricity supply in a reasonably carbon-free manner. An advantage is that nuclear waste can be reprocessed and reused = recyclable energy
downsides of nuclear energy:
risks to do with safety and security (accidents and terrorism)
disposal of radioactive waste with an incredibly long decay life
technology involved is complex and its use is only an option for developed countries
although the operational costs are low, the costs of constructing and decommissioning power stations are high
The UK’s Changing Energy Mix - when it comes to primary energy consumption in the UK, there has been a complete shift away from coal.
reliance of oil and gas is 80%. used to generate electricity. unlikely to change in future.
UK consumes less energy than we did in 1970 even though pop. increased by 6.5million. more efficient use in producing and using energy. industry uses 60% less energy and households use 12% less. UK will be using same amount of energy in 2030 like today
How the energy mix has changed: UK
1820 - mainly biofuels (amount of biofuels remains constant until it rises slightly in the latter half of the 20th century). Very small amount of coal.
1900 - 50 exajoules - 30 coal, 20 biofuel .
1920 - 60 exajoules. Now some oil and tiny amounts of hydropower.
A rapid increase takes place from 1940.
1960 - 120 exajoules. about 40 of which is oil. Small amounts of natural gas now being used.
1980 - 330 exajoules, increase in hydropower (about 10) and natural gas now at about 50 exajoules. Introduction of nuclear power. mainly oil
2010 - 540 exajoules. About 40 biofuels, 150 coal, 190 oil, 110 natural gas, 20 hydro and 20 nuclear.
