The carbon cycle and energy security (DONE) Flashcards
What forms can carbon exist as and how does it move between its forms?
- Carbon is a common element in the composition of the planet Earth.
- It exists in gas, liquid and solid forms, and in biotic (living) and abiotic (non-living) forms.
- carbon moves between these forms (the carbon pathway) through natural biogeochemical processes over a very long geological timescale.
How does the balance of atmospheric gas change over time?
- The balance of atmospheric gases has changed over geological time because of changes in the Earth’s systems and processes.
What happened to the balance of atmospheric gases during the Precambrian geological period?
- During the Precambrian geological period, volcanic activity added carbon dioxide (CO2), water (H2 0) and sulphur dioxide (S02) to the atmosphere at an exponential rate, forming the basic composition of the atmosphere today.
What did primitive bacteria do to the atmosphere 3 billion years ago?
- When primitive bacteria such as cyanobacteria started photosynthesising 3 billion years ago, they added oxygen to the atmosphere and absorbed CO2 from it.
- The higher oxygen levels that resulted allowed more complex organisms to develop about 2 billion years ago
How was CO2 in the early atmosphere stored?
- CO2 was dissolved in the
early oceans and then stored in sedimentary rocks. - This process accelerated when land-based (terrestrial) ecosystems developed about 400 million years ago (mya).
When did the earth establish its present carbon cycle balance?
- The Earth established its present carbon cycle balance about 290 mya, at the time of the Carboniferous tropical rainforests.
Why has the present carbon cycle been altered since the 1800s?
- The balance has been altered since about 1800 by human activities such as deforestation and the burning of fossil fuels, which release the stored carbon.
How much carbon do crustal rocks contain in comparison with other elements?
- Overall, crustal rocks have a small amount of carbon (320 ppm) compared to other elements, especially oxygen (466,000 ppm) and silicon (277,000 ppm). I’m
Which rocks have the highest concentrations of carbon?
- Sedimentary rocks, however, have much higher concentrations:
- limestone, for example, is about 42 per cent calcium carbonate by weight.
- while sandstone is 5 per cent
- shale (mudstone) is 3 per cent.
What happened during the carboniferous period that reduced carbon concentrations in the atmosphere?
- During the Carboniferous period the formation of coal stored carbon underground and reduced concentrations in the atmosphere for 300 million years.
What elements does the oceans mass consist of in %s?
- In oceans, carbon is only 0.003 per cent of the mass.
- while chlorine and sodium are 1.9 and 1.06 per cent respectively.
- with water making up 96.7 per cent.
What types of carbon stores are there?
- There are small carbon stores, such as the organic part of marine ecosystems, and large carbon stores such as in the ocean.
What are carbon stores also referred to as?
- The stores are sometimes referred to as ‘sinks’ or ‘reservoirs’.
What are the exchanges of carbon between stores?
- There is an exchange of carbon between stores over a yearly timescale, called annual fluxes.
- but exchanges also take place over a longer timescale.
What are the benefits of crude oil exploitation?
- Can be sold to bring wealth to a country and people - Can support industry, even in an economic recession • Easy to transport (e.g. pipeline or tanker)
- Large worldwide demand and thus a very tradable
commodity - Makes people’s lives easier, especially allowing fast air and land transport
- Has brought a culture based on freedom of movement
- Money from oil can be invested in nding the next flexible energy resource
What are the problems of crude oil exploitation?
- Burning releases CO2, which contributes to global warming
- Burning releases NOx, which contributes to acid rain
- Wars have been fought over oil
- Cultures have become dependent on oil
- Fluctuations in the cost of the resource have caused recession and inflation.
- Oil spills may damage the natural environment (e.g. Exxon Valdez, Deepwater Horizon)
- Oil is a finite resource and will run out in the 21st century (estimated 2061)
What is regarded as one of the main causes of anthropogenic greenhouse emissions and why?
- Population growth is regarded as one of the main causes of anthropogenic greenhouse emissions, because more people mean a higher demand for energy by households and businesses, and transport, deforestation and commercial farming all increase.
- The UN predicts that the world population will reach 9 billion by 2030 and 10 billion by 2050.
- Even though the growth rate is slowing, billions of people are being added, all of whom would like an improved quality of life which often leads to increased energy use.
What are the 3 main objectives of energy players that The World Energy Council suggest?
- The World Energy Council has suggested that energy players have three objectives, but recognises that these may conflict and so will not be easy to achieve:
• Energy security: ensuring that energy supply meets current and future demand.
• Energy equity: ensuring accessible and a ordable energy for all countries.
• Environmental sustainability: ensuring efficient use of energy and use of renewable sources, so reducing pollution and moving towards lower greenhouse gas emissions.
How has energy security been threatened during the ‘oil age’?
- During the ‘oil age’, energy security has been threatened by geopolitical tension, mainly in the Middle East since the 1973 Arab-Israeli war.
- More recent wars in Iraq, tensions between the USA and Iran, and the Arab uprising in North Africa and the Middle East have created political factions and terrorism.
- This attracted the involvement of the big energy players such as the USA and Russia, who wish to protect the energy pathways and supplies.
Why do conflicts and tensions over energy security attract the involvement of the big energy players?
- TNCs that supply energy wish to keep trade flowing through the established pathways and to control prices.
- Governments gain the revenues from state-owned energy TNCs such as Gazprom (Russia), Petronas (Malaysia) and Saudi Aramco (Saudi Arabia), and in most countries governments impose high taxes on energy use, and use the revenues to help develop the country.
Why is there conflict between environmental groups and large energy TNCs?
- There is a conflict with environmental groups concerned about damage to natural ecosystems and the slow progress that large energy TNCs are making towards ‘green energy’.
- While the number of major oil spills from tankers has decreased since double hulls were introduced in the 1990s, there are still risks of spills from pipelines in fragile environments and from extraction activities in deeper waters, including the Arctic Ocean.
- Governments are sometimes torn between ensuring a constant supply of energy and environmental considerations.
Which countries in Europe have changed their energy mixes towards renewables?
- Many governments in Europe have been changing their energy mixes towards renewables, partly to meet ambitious CO2 reduction targets.
- The UK government has supported solar and wind energy, albeit inconsistently.
- Germany has invested greatly in renewables since a policy change in 1990
and then again since the Fukushima nuclear disaster of 2011.
How has China’s energy mix influenced energy prices?
- When China decided
to develop its industries along more ‘western’ economic lines, China’s need for energy jumped
and the government sought resources in Africa. - This increased global energy prices, because they were competing to buy the available supplies.
- When China’s growth slowed significantly in 2015, energy prices fell, demonstrating their volatility.
Who are a key group of energy players who can influence future energy mixes?
- A key group of energy players is the scientists and engineers, whose research and development into alternative energy resources and more efficient technologies can change future energy mixes and security.
How has production of oil, coal and natural gas varied from the mid 20th century?
- From the mid-20th century, countries with oil reserves beneffited from the wealth resulting from this valuable resource.
- During the last quarter of the 20th century and into the 21st century, production of oil, coal and natural gas steadily increased, with a dip in coal production in 2014.
- Emerging economies such as India and China have been responsible for increased global energy consumption since 2000, while in 2014 EU energy consumption fell to its lowest level since 1985.
How did oil consumption vary in 2014?
- Oil accounted for 32.6 per cent of global energy consumption, but was in slow decline (refining was at 80 per cent capacity), although production and refining remained high in the USA and the Middle East.
- The oil trade grew mainly because of China, which in 2013 had overtaken the USA as the world’s largest importer of oil.
How did natural gas consumption vary in 2014?
- Natural gas accounted for 23.7 per cent of primary energy consumption, with the USA having the world’s largest increase, but with declines in Russia, Netherlands and the EU as a whole.
- Trade fell in 2014, including pipeline shipments, which fell by 6. 2 per cent - the largest decline ever recorded.
How did coal consumption vary in 2014?
- Coal’s share of global primary energy consumption declined to 30 per cent, mainly through slower Chinese economic growth.
- The Ukraine and the UK had significant decreases in consumption, while India posted the largest increase.
How are energy resources transported from source areas to areas of demand?
- Energy resources inevitably need to be transported from their source areas to areas of demand; this takes place by pipeline (oil and gas) over land, by bulk carrier ship (coal, uranium), tanker
ship (oil and LNG) by sea, or via underground electricity cables. - All of these routes are called energy pathways.
What natural obstacles can cause energy pathways to become complex?
- Pathways between producers and consumers may be complex, because they must move through different natural and human environments.
- Natural obstacles include vast distances and difficult terrain such as the tundra in Alaska (Trans-Alaskan pipeline) and Siberia (Trans-Siberian pipeline).
- Extracting oil from the tar sands of Alberta in Canada or from deep water in the Gulf of Mexico - especially in hurricane season - also brings challenges.
How can technical problems cause energy pathways to become complex?
- Human obstacles, including technical problems such as pipeline leaks, could temporarily disrupt pathways.
- Supplies might run out, for example North Sea gas.
- Or supplies might be diverted for greater profit, such as to China.
What are choke points in energy pathways and how can they lead to pathways being blocked?
- Political tensions and disagreements may lead to pathways being blocked (at ‘choke points’).
- These choke points are subject to change, but many fossil fuel resources are in unstable locations such
as the Middle East and Russia, the South China Sea and the Red Sea. - Examples include the Iraq wars (1990s), Somalian pirate activity, and Russian/Ukraine disputes (from 2004).
How can embargoes cause disruption in energy pathways?
- Embargoes and sanctions also disrupt production and supplies, such as from Iran and Russia.
- Pathway disruption can have socio-economic and political consequences, such as recession and job losses as well as energy shortages affecting lifestyles, and even armed conflicts to secure pathways and resource locations.
Why should energy pathways become less important in the future?
- These pathways should become less important as energy mixes change, because many renewable resources are ubiquitous.
Why will the search for other sources of energy intensify in the future?
- As fossil fuel reserves, notably oil, will soon be used up, especially as developed and emerging economies increase consumption, the search for other sources has intensified.
- This includes exploring deeper ocean areas such as the Gulf of Mexico, offshore Brazil and the Arctic Ocean, tar sands in Canada, and shale gas in the USA.
Where is deep water oil found?
- Deep-water oil is found in the Gulf of Mexico, where one of the largest and deepest oil elds is Atlantis (sea depth = 2,150 m).
How have the number of oil/gas platforms in the gulf of Mexico changed?
- Although the number of new oil/gas platforms in the Gulf of Mexico has decreased, they are getting larger and being located in deeper water.
- In 2010 only 14 rigs were in deep water, but by 2014 there were 63.
What was the USA’s 2012-17 leasing plan for deep water oil?
- Drilling in deep water is not easy and there are hurricanes as well as long distances to shore for undersea pipelines.
- Despite this the USA’s 2012-17 leasing plan extended the Gulf of Mexico area and also opened up the Alaskan Arctic, with the aim of reducing imports.
What does BP’s Atlantis platform produce from deep-water oil?
- BP’s Atlantis platform (2007-22) produces 200,000 barrels of oil and 5.1 million m3 of gas a day.
How has the deepwater horizon incident improved technology for deepwater oil extraction?
- Since the Deepwater Horizon incident (2010) highlighted the risks involved with deep-sea drilling, new regulations and technological improvements have been made.
- such as remotely operated underwater robots that can seal a leak within 45 seconds.
- However, environmental groups believe that cost cutting (due to recession and low oil prices), along with complacency and untested technologies, could lead to future large oil spills.
What are tar sands?
- Tar sands are a mixture of clay, sand, water and bitumen (very viscous oil).
How is oil from tar sands extracted?
- The oil is too thick to be pumped from the ground.
- Instead, it must be taken from an open pit, or strip-mined.
- To recover the oil it must be separated from the sands using very hot water diluted with lighter hydrocarbons.
Why may people start to extract oil from tar sands?
- When oil prices are high - at least US$120 a barrel - it becomes economical to extract oil from the sands.
What countries are the largest extractors of oil from tar sands?
- The largest reserves and production are in Alberta, Canada and in Venezuela (Orinoco Belt).
- Venezuela has more oil reserves than Saudi Arabia, which in 2012 raised its average GDP per capita (PPP) to US$12,772 and allowed the government to keep petrol prices very low
What are the issues with extraction of oil from tar sands?
- Issues with tar sands include the large amounts of energy needed (heating and pumping) even before the oil is used; this results in an estimated contribution to global warming three times higher than conventional oil.
- The mining process leaves scars on the landscape - which are refilled with the sands once the oil has been extracted.
- There are also impacts on local wildlife and people, leaks into water supplies from tailings ponds, and infringements of indigenous peoples’ treaty rights over shing and hunting grounds.
How is oil shale formed?
- Oil shale contains solid bituminous material (kerogen) that formed when silt and organic matter were heated and pressurised under water, but not enough to turn it into oil.
How is oil shale extracted?
- Oil shale can be mined, but must be heated to a high temperature to release the oil; this is expensive and releases greenhouse gases.
Which countries have reserves of oil shale?
- The USA has large reserves in the Green River Formation of rocks in Colorado, Utah and Wyoming (perhaps 800 billion barrels).
- but currently there is little commercial development anywhere in the world.
- although in April 2016 it was reported that an Australian company would be expanding its oil shale exploration in Alaska.
What are the environmental impacts of the extraction of oil shale?
- Environmental impacts include:
- disturbance of land and vegetation cover.
- Disposal of the waste after processing (over 1 tonne of waste rock for every barrel of oil).
- Over-use of water resources (two barrels of water for every barrel of oil produced).
- Air and water pollution.
- However, the Royal Dutch Shell Company has developed a plan to heat shale underground while surrounded by a ‘freeze wall’, so that the kerogen seeps out into drilled holes for collection.
What is shale gas?
- Shale gas is natural gas (mostly methane) trapped inside impermeable shale rocks, so it cannot be extracted by normal drilling.
How is fracking used to extract shale gas?
- impermeable shale rocks cannot be drilled, instead the rock must be broken to free the gas, which is done
by hydraulic fracturing, more commonly called ‘fracking’. - This involves forcing water mixed with chemicals into the shale rock so that the rock splits apart and any gas flows into a prepared well where it is concentrated enough to recover.
What are the negative impacts of fracking for shale gas?
- Fracking can involve horizontal as well as vertical drilling, which reduces the impact on the ground surface, but many drill sites are needed because the gas is dispersed.
- Other negatives include:
- lowered local groundwater levels.
- possible chemical contamination of groundwater and surface water.
- methane gas leaks (not all the gas can be captured) adding to the greenhouse effect.
- risk of minor earth tremors and ground subsidence from altering the rock underground.
- Shale gas is still a fossil fuel, releasing carbon dioxide when combusted.
What are the positives of fracking for shale gas?
- Positives include:
- increasing the energy reserves of a country and reducing the need for imports.
- It is a flexible energy source; for example in 2015 in the USA natural gas overtook coal as the main generator of electricity.
- In addition, the carbon footprint of shale gas is about half that of coal and lower than liquefied natural gas (LNG), which is transported around the world.
What does the IPCC advise in order to drastically reduce climate change?
- In 2014 the IPCC concluded that, in order to drastically reduce enhanced climate change, the share of energy production that is accounted for by renewable energy sources needs to be trebled, and must dominate world energy supplies by 2050.
How much do renewables account for in global energy production?
- Renewables accounted for 3 per cent of global energy production in 2014, and continue to increase their share as action is taken to reduce dependence on fossil fuels and to mitigate climate change through reduced CO2 emissions.
How much do renewables account for in electricity production?
- Renewables represent 6 per cent of electricity production, especially in China, which accounted for all of the global increase in HEP production in 2014.
- Wind energy continues slowly to expand, but solar energy increased by 38.2 per cent in 2014.
How is the development of renewable and recyclable energy uncertain?
- The development of renewable and recyclable energy is uncertain:
- for example nuclear energy is an increasing source of energy in South Korea, China and France, but decreasing in Japan, Belgium, Germany and the UK.
- Hydroelectric energy is suffering from climate uncertainties; it had an increasing share of world energy production (6.8 per cent) in 2014, but drought conditions reduced outputs in Brazil and Turkey.
Where is there the greatest potential for solar energy?
- The greatest solar energy potential is in equatorial areas where sunlight and heat are most focused and intense.
- Also in desert areas where skies are clear, for example the Saharan and Great American deserts.
- Areas with potential include inland temperate regions that are not as affected by cloud cover, such as Germany.
- high-altitude areas where sunlight is more intense, such as the Tibetan plateau.
What can solar energy from the sun be used to do?
- Heat from the Sun can be used to heat water, or photoelectric cells can generate electricity directly.
Which country has invested most in solar energy?
- Germany has invested the most in solar energy, producing nearly 25,000 gigawatts of electricity.
- It can do this because it is a wealthy country able to invest in research and development and has a strong Green Party.
- It is aiming to cut CO2 emissions, and the 2011 Fukushima nuclear disaster in Japan (caused by a tsunami) encouraged them to develop alternatives.
What are the benefits of developing solar energy?
• Safe, clean and non-polluting once made
and installed.
• Renewable, so a sustainable source of energy.
• Can be used by poorer countries.
• Links well with other sources of energy.
• Flexible and modular, so can be used on
roofs of buildings or developed into a solar
power station.
What are the problems of developing solar energy?
• Not enough research and development, especially into storage methods.
• Electricity produced is initially more expensive than from conventional power
stations.
• Not very effective in cloudy climates or polar latitudes.
• Energy still needs to be stored for later use.
What did the IPCC identify as having a crucial role in mitigating climate change?
- In 2014 the IPCC identi ed bioenergy as having a crucial role in the mitigation of climate change through efficient biomass-to-bioenergy systems.
Why may bioenergy not be crucial in mitigating climate change?
- Biofuel is more suitable for small-scale rather than large scale operations and the resulting land use changes will have an impact on:
- carbon fluxes between soil, vegetation and atmosphere.
- food security where food crops are replaced by biomass crops.
- water resources (by changing the water cycle).
- conservation of the environment.
- the livelihoods of local people.
In which countries is the use of biofuels growing?
- The use of biofuels continues to grow slowly, mainly in the USA, Brazil, Indonesia and Argentina.
- In the UK, bioenergy accounted for 6.8 per cent of electricity production in 2014.
What are the challenges facing Africa when trying to increase the use of biofuels?
- Extensive areas in Africa are suitable for bio-ethanol (starch-based) or bio-diesel (oilseed) crops, but there are concerns about using land that is needed for food crops and water for people.
What are the negative impacts of the growing use of biofuels?
- Pressures from governments and companies could lead to changes in land ownership (tenure), reduce
the livelihoods of women, and take grasslands away from pastoralists or migrant farmers who need open access. - Biofuel crops grown in marginal farming areas could also stress the natural environment and increase forest loss as people are forced to find new land.
- Deforestation would offset any carbon reduction benefits gained from switching to biofuels, so it would not be carbon-neutral.
Why is more research needed on biofuels?
- For example the Jatropha plant has been suggested as an oilseed crop for Africa, but oil yields are variable and unconfirmed, with little information on impacts.
- Also, in tropical South and Central America, palm oil is a significant biofuel crop, but is strongly linked to deforestation, especially in Colombia and Ecuador.
what are the negative impacts of using palm oil as a biofuels?
- In Peru, 72 per cent of new palm oil plantations were in forested areas, accounting for 1.3 per cent of the country’s deforestation between 2000 and 2010.
How are biofuels able to impact Africa’s carbon emissions?
- Biofuels can help Africa decrease carbon emissions:
- 24 per cent of non-electrical energy in 2012 was from biofuels and waste, compared with 16 per cent for the world as a whole.
- But biodiversity may be lost, food prices may increase and water resources may be stretched.
- Biofuels are climate-dependent, and future temperature and rainfall changes are not yet known with any certainty.
What could hydrogen fuel cells be used for?
- This alternative energy source could replace petrol for transport or natural gas for heating.
What does the term ‘hydrogen economy’ mean?
The term ‘hydrogen economy’ describes the possible widespread use of hydrogen as an energy source.
Why does hydrogen have an instant appeal as a fuel for radical technology?
- Hydrogen has an instant appeal because, whether it is combusted to produce heat or used in a fuel cell to produce electricity, the only waste product is water.
- One of its best potential uses is in electric cars or public vehicles that use fuel cells converting hydrogen as it can be obtained from a variety of sources.
- Fuel cells are also more efficient than a petrol or diesel engine.
What is an example of where a hydrogen fuel cell has been used commercially?
- Toyota developed a car
with a fuel cell stack (the Mirai) and a range of 270 miles, which went on sale in California in 2015.
What are the disadvantages of using hydrogen as a fuel for radical technologies?
- Hydrogen is not found in a pure form and has to be separated from other compounds such as water, biomass, ethanol or natural gas (methane).
- Processes to separate it require large amounts of energy and may emit large quantities of greenhouse gases.
- Hydrogen is an energy carrier or a way of storing energy, rather than a primary energy source, and hydrogen tanks need to be strong enough to withstand impacts.
Why is further development needed for electric vehicles?
- The distances a purely electric vehicle can travel are relatively short before lengthy recharging
is needed, so further technological development is required. - Range varies from 62 to 340 miles, depending on battery capacity and linked technologies.
How are charging points for electric vehicles distributed across urban and rural areas?
- Some communities, such as BedZED in the London borough of Sutton, have public charging points, but these are often scattered.
- According to Zap-Map (April 2016) there were 3,919 public charging locations in the U K to serve over 60,000 registered electric vehicles.
- London had 19.7 per cent of the charging points, and other cities have large concentrations.
- the fewest charging points are in rural regions of Wales (3 per cent) and the east of England (3.5 per cent).
- Therefore electric vehicles may be best suited to urban environments, helping cities reduce air pollution levels.
How do hybrid vehicles reduce carbon emissions?
- Hybrid vehicles, using a petrol or diesel engine in conjunction with an electric engine, have engine management systems that decide which is the most economical to use during a journey.
Which company uses radical technology and creates electric vehicles
- Tesla has manufactured electric vehicles since 2008.
- in 2016 it announced its third model and within three days had received 276,000 orders, with first deliveries planned for the end of 2017.
- However, it is not known if the small company can meet expectations.
What are the benefits of electric vehicles?
- The benefits of electric vehicles include zero carbon emissions and virtually no noise pollution, as well as being cheap to run.
What are the negatives of electric vehicles?
- They can be more expensive to buy than normal cars.
- They are so quiet that some people are concerned about collisions with pedestrians.
- Their biggest disadvantage is how the electricity is created for charging the batteries, because the carbon emissions of an electric vehicle depend on the energy profile of the country in which it is being used, so electric cars are more eco-friendly in Paraguay (hydroelectric) and Iceland (geothermal) than in India or Australia
(both coal).
What does a carbon capture and storage system do?
- A complete carbon capture and storage system (CCS) collects CO2 emissions from fixed points such as industrial and power plants, then transports the gas and injects it (in compressed form) into a suitable geological structure (over 800 m below ground).
- The storage is then monitored to ensure safety and no releases into the atmosphere.
Which country was the first to utilise CCS and what impact will it have on emissions?
- In 2014 Canada opened the first coal - fired power plant with CCS at Boundary Dam, at a cost of US$1.3 billion.
- It will reduce emissions by 90 per cent by pumping CO2 underground and selling it to an oil company (Cenovus) for ‘priming’ nearby oil fields; this helped make the scheme economical.
How can CCS be combined with bioenergy to remove co2 from the atmosphere?
- CCS can be combined with bioenergy (BECCS) to capture CO2 produced during bioenergy production such as ethanol.
- This ensures that there is a net removal of CO2 from the atmosphere, as all CO2 produced during farming is stored as well.
How did the IPCC rate CCS in mitigating climate change and how do they expect it to develop in the future?
- The 2014 IPCC report recognised the uncertain availability and deployment of this geo-engineering technology - in 2013 there were only 2 small BECCS operations.
- But the IPCC regarded it as an essential mitigation action to limit temperature increase to under 2°c by the end of the century.
- The IPCC believes that power generation without CCS must be phased out by 2100, and expects great progress after 2050.
What are the benefits of CCS?
- Lower pollution and climate benefits.
- CCS could also extend the use of fossil fuels and encourage greater efficiency.
What are the negative impacts of CCS?
- Concerns include CO2 leakage affecting human health.
- Underground pressure causing small earthquakes.
- Increased water usage affecting natural environments.
What is nuclear fusion?
- Another radical technology is nuclear fusion, where two or more atomic nuclei join together
to make a new larger nucleus, releasing energy in the process.
What are the advantages of using nuclear fusion?
- The advantages of this energy source are that:
- it is clean, with no greenhouse gas emissions or radioactivity.
- and it requires common elements
How are countries working together to make nuclear fusion a reality?
- Nuclear fusion is still a long way from becoming a reality.
- But 35 countries are working together at the 500 MW International Thermonuclear Experimental Reactor (ITER) being constructed at Aix-en-Provence in France.
How did the Chinese take a step forward in research for nuclear fusion?
- In February 2016 a Chinese research team reported that it had managed to sustain a superheated plasma gas for over one-and-a-half minutes in a ring-shaped reactor using high-powered magnets.
- While this did not create usable energy, many regard it as a critical technical step forward.
How have the German government tried to encourage development of nuclear fusion?
- The German government has allocated over US$1.46 billion for research.
How can nanotechnologies make solar fuels?
- Another avanced approach uses nanotechnology to make solar fuels, which could replace fossil fuels.
- Solar fuels could be made using the action of sunlight on simple substances.
- This creates a photochemical reaction or artificial photosynthesis
- for example splitting water to make hydrogen.
- or using microorganisms or enzymes to ‘harvest’ light energy.
What did the annual report of the global footprint network show of the demand for resources?
- The 2015 annual report of the Global Footprint Network showed that it is beyond the capacity of the planet to satisfy current human demand for ecosystem services.
What did the global footprint networks ecological footprint show on carbon sequestration?
- Collecting accurate data on all variables is almost impossible, but the Network’s Ecological Footprint showed that the average forest carbon sequestration per year is 0.73 tonnes of carbon per hectare.
What calculation is used to calculate impact of growing demand for resources?
I = P x A x C x T
- Where I is impact.
- P is population size.
- A is affluence of the population.
- C is consumer behaviour (C1 = food supply in calories and C2 = crop production volume)
- T is technology.
What does the equation for impacts of growing demand for resources show when applied to a situation?
- When applied to food production, it shows that population and affluence increase impacts as more food is grown.
- technology lowers impacts as it makes farming more efficient.
- Consumer behaviour may increase or decrease impacts through more or less consumption or through changing the ratio of food to non-food crops.
How has the population increase impacted the world energy use and is this the reason for increased demand?
- Between 1990 and 2015 world energy use increased by 54 per cent, while the population increased by 36 per cent.
- This shows that while population growth may increase energy use, it is economic development and prosperity that account for most of the increased demand.
Which countries use the most and least amount of energy?
- Developed countries use half of the world’s energy.
- North America has the highest use per capita - more than ten times that of sub-Saharan Africa or South Asia.
- Many developing countries rely on wood or other biomass (such as charcoal or animal dung), which creates pressures on forests and impacts on human health.
How is the world population expected to grow by 2050?
- the world’s population is expected to increase to 9.2 billion by 2050 (UN estimate), especially in South, East and South-East Asia.
- more food and resources will be required and more energy will be used.
Why is there a need to increase food production in some world regions?
- In 2015 an estimated 1.4 billion people su ered from hunger or malnutrition even though absolute poverty fell, so there is a need to increase food production in some world regions.
Why is there a need to cater for the tastes of a wealthier global population?
- There is also a need to cater for the tastes of a wealthier population:
- the Food and Agricultural Organisation (FAO) expects world meat consumption (37.4 kg/person in 2000) to increase to 52 kg/person per year by 2050.
How does the rising consumption of meat put strain on resources?
- Meat production is land and water intensive and requires more land for fodder crops, diverting farmland from staple crop production and degrading water and soil.
How has global food consumption increased over time and how will it increase in the future?
- World per capita food consumption (kcal/person/day) increased by 8.9 per cent between 1990 and 2015.
- But the FAO predicts that it will increase by only 3.5 per cent between 2015 and 2030.
How have increases in food consumption varied across the world?
- There are contrasting trends around the world with the largest increases in food consumption between 1990 and 2015 in East Asia (+20.1 per cent), sub-Saharan Africa (+14.1 per cent) and Latin America and the Caribbean (+11.9 per cent).
- But the FAO predicts a slowing of food consumption in all world regions except sub-Saharan Africa (+7.2 per cent) and South Asia (+7.0 per cent).
Which regions have had the greatest increase/decrease in CO2 emissions between 1996 - 2011?
- East Asia and pacific with 175.6% increase.
- North America with 21.1% decrease.
Which regions have the greatest/lowest freshwater withdrawals as a % of internal water resources?
- The Middle East and North Africa with 133.6% in 2014.
- Sub saharan Africa with 3.0% in 2014.
What % of greenhouse gas emissions did the IPCC estimate to be from agriculture?
- In 2013 the IPCC estimated that 24 per cent of greenhouse gas emissions came from agriculture and land-use change.
- such as biomass burning.
- deforestation
- methane emissions from livestock farming and wet rice cultivation.
How have global forest areas and arable areas varied between 1995 and 2005?
- Between 1995 and 2005 the global forest area decreased by 80 million ha, while arable land area increased by 24 million ha.
What does the UNEP expect to happen to natural grounds between 2005 and 2050?
- At current rates the United Nations Environment Programme (UNEP) expects that between 320 and 850 million ha of natural grasslands, savannah or forest could be lost to crops between 2005 and 2050.
- In order to prevent this it
needs to be stopped by 2020.
How is the amount of farmland changing across developed and emerging countries?
- Emissions are decreasing in developed countries as the amount of farmland decreases; farming area is stable in the poorest and emerging countries, but is increasing in developing countries.
What do the FAO think will happen as a result of changes to agriculture and increasing meat production?
- The FAO believe that changes to agriculture in sub-Saharan Africa could increase deforestation and carbon emissions, even with efficient changes.
- Increasing meat production could increase methane emissions in India and China.
What do the IPCC recommend to reduce greenhouse gas emissions?
- The IPCC recommends a switch to low-emission food crops.
- Changing croplands to forests or bioenergy crops.
- reducing food waste (30 to 40 per cent is lost from ‘farm to fork’).
- Changing diets (plants not meat) and reducing food consumption.
Why are degraded soils unable to store much carbon?
- Degraded soils, particularly organic soils that have lost organic matter and moisture, are not capable of storing much carbon.
- When soils dry out through lack of vegetation cover, drainage or evaporation from increased temperatures, they emit rather than store greenhouse gases.
How does soil as a carbon store compare to vegetation?
- It is estimated that soils can store three times more carbon than vegetation
What impacts the amount of carbon which soil can store?
- The amount of carbon in soil is decided by inputs of dead plant material and outputs from decomposition and mineralisation.
Why is land management important for the carbon in soil?
- Land management is important, especially in areas of moist, peat - rich soil:
- undisturbed waterlogged peat soils, which cover 3 per cent of the world’s land area, store up to 25 per cent of the global soil carbon store.
- However, drainage has increased decomposition, respiration, fire risk and emissions of CO2 and N2O, especially in Asia and Europe.
How can degraded soils be restored?
- Degraded soils can be restored through managing fertility and water conservation.
- along with afforestation and longer fallow periods (conservation tillage).
- all of which help retain soil moisture and organic matter.
How is ocean acidification changing over time?
- Acidification of the oceans is increasing as the sea absorbs more CO2 from the atmosphere.
How has ocean acidity changed since the industrial revolution?
- Since the Industrial Revolution, pH has fallen by 0.1 (to 8.1), which on the log scale is a 26 per cent increase in acidity.
Why are oceans an important store of carbon?
- Oceans are able to store 50 times more inorganic carbon than the atmosphere.
- The carbon and the ocean create a weak H2CO3 acid by releasing hydrogen ions.
- The ocean is an important carbon sink for anthropogenic CO2 emissions.
How much of anthropogenic CO2 emissions do the oceans absorb but why does this vary?
- In 2014 the IPCC reported that the oceans had absorbed about 30 per cent of anthropogenic CO2 emissions.
- Absorption rates vary because of ocean oscillations, such as El Nino, and sea temperatures.
Where has the largest and smallest pH reduction in oceans been?
- The largest pH reduction has been in the North Atlantic.
- The smallest in the subtropical waters of the southern Pacific.
Why can it be difficult to determine the effects of ocean acidification?
- It is not easy to separate the effects of acidification from those of sea-level rise and seawater temperature increase.
How much have sea levels risen since the 1900’s?
- Sea levels have risen at an accelerating rate:
- by 1.7 mm/yr between 1901 and 2010.
- by 3.2 mm/yr between 1993 and 2010.
What are the main reasons for the sea level rises?
- This increase is due to thermal expansion.
- glacier mass loss.
- ice sheet loss
- increased water storage on land.
