Water + Carbon - Case studies (DONE)

Question 1

Human disruption to the water cycle in Amazonia:

Answer 1

• In tropical rainforests as in South America, the multiple canopies of vegetation cause high rates of interception and evapotranspiration.
• This causes high humidity and heavy local convectional rainfall.
• The tropical rainforest is a self-sustaining cycle where water is recycled within the system.
• Evaporation is important to sustain regional rainfall in areas around the periphery of the tropical rainforest, which is important to agricultural regions of Brazil and other countries.
• Research in the Amazon basin suggests that deforestation is significantly reducing evapotranspiration and precipitation, while also increasing runoff and river
  discharge.
• For example, the Tocantins River showed a 25% increase in river discharge between 1960 and 1997, coincident with increased deforestation.

Question 2

Drought in the Sahel, Africa:

Answer 2

• The Sahel is a vast semi-arid region at the southern edge of the Sahara desert, covering parts of 11 countries.
• Occasionally severe droughts occur, making it difficult for the population to adapt and survive.
• Since the late 1960s there has been a decline in annual rainfall.
• The most recent severe drought occurred in 2011-12.
  Human causes:
  -Studies showed Sahel droughts were caused by air pollution (sulphur-based aerosols) generated in Europe and North America. These pollutants interrupted atmospheric circulation so ITCZ rains did not arrive.
  -Other studies show the Sahel droughts were the result of higher sea-surface temperatures caused by anthropogenic climate warming. This caused rain-bearing winds to fail.
  Physical causes:
• 2015/16 El Nino event was predicted to increase water stress in the western Sahel, as temps were 2°C higher than average and rainfall was lower.
• Easterly winds in the Pacific effected other regions, and cooler North Atlantic sea added to the drying conditions with reduced evaporation.
• Sahel has one of the world’s highest poverty rates and lowest development levels.
• Highest population growth rates in the world (annual growth rates 2.5 – 4%).
• Demand for food and fuel wood is accelerating, and natural dryland ecosystems are being converted into farmland, which is being overcultivated and overgrazed, causing desertification.
• Where reduced rainfall and human pressures are combined, there is reduced vegetation cover and soil moisture, which may create self-perpetuating severe droughts.

Question 3

The Millennium Drought in south-eastern Australia, 1997-2009:

Answer 3

• The Millennium Drought was a series of years between 1997 and 2009 where rainfall was 12.4 per cent below the 20th-century mean.
• The drought was the result of multiple physical and human causes:
• El Nino events in 2002-3 and 2006-7 explained two-thirds of the rainfall deficit in eastern Australia.
• Strengthening of the subtropical ridge (STR), accounted for 80 per cent of the rainfall decline.
• The STR blocked depressions, forcing them towards higher latitudes and reducing frontal rainfall.
• Changes to the Hadley Cell and the STR are associated with anthropogenic global warming; the STR has intensified as global surface temperatures increase.
• Scientists have conducted simulations of global climate over recent decades.
• In these simulations, the climate model was only able to reproduce STR strengthening when human emissions of greenhouse gases were included.
• Anthropogenic warming is reducing the temperature gradient (rate of temperature change over a unit length) between the Equator and the Pole, reducing the energy available for mid-latitude storm systems and the polar front jet stream.

Question 4

State-controlled energy companies:

Answer 4

• Government may take over a company to control production or to gain maximum revenues.
• One example is Coal India Ltd, which is the world’s largest coal producer.
• India’s coal mining industry was nationalised in 1972/73.
• It is responsible for 5.9% of the world’s coal production and 80% of India’s coal production.
• Increased efficiency has seen a decline in workers, but an increase in production over the same period from 260.69 million tonnes to 494.24 mil tonnes.
• India is the third-largest consumer of coal behind China and the USA, using it in the steel industry and thermal power stations.
• The government gained $12.9 billion in revenues during 2013/14.
• Russia’s Gazprom was put under state control in 2000.
• One of the largest producers of natural gas in the world.
• Has reserves in Siberia and the Ural and Volga regions of Russia.
• Gas is a major Russian export, it helps the trade balance and earns revenue for the government.
• Pipelines move the gas to its domestic and international customers.
• Germany is an important customer as they imported 40 billion m3 of natural gas in 2013.
• The Ukraine also used 44.8 billion m3 in 2011.
• However, political conflict and terrorism in the Ukraine and Turkey have made the pipelines vulnerable.
• Russia and Ukraine’s dispute over gas in 2005 increased tensions.
• In 2014 Gazprom’s profits declined due to EU and US sanctions after Russias intervention in Crimea, sales of natural gas to the Ukraine fell by 65 per cent.

Question 5

Canadian tar sands:

Answer 5

Tar sands in Canada:

• In Alberta, Canada, there are reserves of 166 billion barrels of oil.
• By 2013, 895 km2 of land had been disturbed through mining, including tailings ponds.
• Production has increased and is predicted to reach 4 million barrels a day by 2030.
• Investment in tar sands, is expected to create $4 trillion in revenues to the government through taxes and 151,000 jobs being created.
• Tar sands operations are highly regulated, Specified Gas Emitters Regulations set a target of a 20% reduction in greenhouse gas emissions in Alberta by 2017.
• Environmental monitoring also checks air, water and human health - and Regional Plans protects air and water quality and sets land aside for conservation.
• In 2013 8.5 per cent of Canada’s greenhouse gas emissions came from tar sands with a 14 per cent increase predicted by 2030.
• There are plans to use CCS in the future.
• The tailings ponds contain toxic chemicals and there are concerns about leakages into groundwater and rivers.
• An Oil Sands Community Alliance has been set up to provide services and facilities for local people.

Question 6

The changing UK energy mix:

Answer 6

• The UK energy mix shows there has been a decline in coal.
• Oil has remained constant.
• Natural gas grew until 2005 and then declined.
• And nuclear grew until the late 1990s and then declined.
• Renewables have grown the most, but still account for only a small proportion.
• Use of fossil fuels reached its lowest level in 2014 for about 50 years.
• There are several reasons for the decline of coal, mostly linked to carbon emissions targets but also to the loss of UK steel industries and increased biomass power stations.
• Despite the 6% decline in total energy use in 2014, the UK economy grew by 2.8 per cent, proving that economic growth does not depend on greater energy use.
  In 2014:
  • it was a warm year, reducing UK CO2 emissions by 10%; this could cause negative feedback for even lower energy use in the future
  • 7% of energy was from renewables, which shows that the UK target of 15 percent by 2020 may be achievable
  • onshore and offshore wind energy had the largest renewables share of 9.5%, with solar providing only 1.2 per cent - less than hydroelectric power.
• However, fossil fuels still accounted for 85% of total energy and 60% of electricity production.
• The consumption of energy by transport accounts for 38% of UK energy and is an obstacle to changing the energy mix further.

Question 7

Biofuels in Brazil:

Answer 7

• Sugar cane was originally grown in Brazil to produce sugar, but today Brazil is the world’s biggest producer of ethanol from sugar cane.
• Most cars in Brazil use ethanol and petrol, with bio­ refineries producing $50 billion worth a year.
• This provides 1.34 million direct jobs and 16 per cent of the domestic energy supply.
• When crude oil prices increased dramatically in the 1970s, the government encouraged the production of ethanol.
• In the 1990s sugar cane subsidies were removed, but government ensured strong links between sugar cane producers, ethanol producers and ethanol distributors.
• Hydrous ethanol was developed, and in the 2000s cars were built with flex-fuel engines.
• Ethanol production expanded due to greater efficiency and productivity.
• Growth not linked to deforestation of tropical rainforest - and sugar cane grows best in other climates.
• Electricity is also produced from bagasse, the waste plant remains.
• There are 370 cogeneration (electricity + heat produced) energy systems in sugar and ethanol mills, providing 7.2 per cent of the electricity in Brazil 2012.
• The ethanol industry provides 11 jobs for every tonne of oil produced.
• Workers are better paid than agricultural workers.
• Ethanol struggled to compete when the government reduced taxes on fossil fuels to control inflation - biofuel plants were bankrupted, and fields returned to growing food crops.
• However, in 2015 the government raised the minimum amount of ethanol in the fuel mix to 27 per cent and removed petrol subsidies.
• In Brazil, 6 million flex vehicles and 3 million others can run on hydrous ethanol.
• Sugar cane provides 8-10 times more energy than the inputs to grow it, and reduces greenhouse gases by 90 per cent.
• In 2015 the price of a litre of ethanol in Brasilia, the capital, was 2.594 reals ($0.72 or 50 pence).
• Domestic consumption of ethanol in 2016 was about 30 billion litres, with about 1.35 million litres exported, mainly to the USA and South Korea.

Question 8

Droughts in Amazonia, South America:

Answer 8

• Drought events are a feature of the Amazonian climate, along with extreme flood events after exceptional rainfall.
• Since 1911-12, droughts have occurred about once every ten years, but the 2005 mega-drought was followed five years later by another mega­ drought.
• Between 1995 and 2005 less water had been available for rainforest plants, which introduced stress into the ecosystem and made the 2005 drought worse.
• In 2005 about 70 million hectares of pristine mature forest in south-west Amazonia was damaged, amounting to 30 per cent of the total area, with 5 per cent severely affected.
• Visible changes could be seen in the forest canopy layer, with tree fall and dieback of branches, and NASA satellite data showed reduced moisture volumes and biomass.
• Half the area affected had problems for several years after 2005, despite higher rainfall, and so by the 2010 drought, trees had not recovered and were even more vulnerable.
• In 2010 nearly half of Amazonia was affected, 20 per cent severely, covering a large part of the 2005 affected area.
• Research by UNEP and the Global Ecosystems Monitoring (GEM) network showed that during these severe droughts the trees absorbed less CO2, with photosynthesis slowing by about 10 per cent over a six-month period, despite growth continuing at the same rates as unaffected trees.
• It appears that drought-affected plants may prioritise growth rates - the race to sunlight over health.
• During the droughts, emissions of CO2 increased as a result of more frequent wildfires and decomposing dead wood as more trees died.
• Using infrared gas analyses, it was estimated that the 2005 drought emitted 5 billion tonnes of CO2 and the 2010 drought 8 billion tonnes - which was more than the CO2 absorbed.
• This is worrying, as it suggests that the Amazonian tropical rainforest may in the future cease to operate as a carbon sink and instead become a carbon source, accelerating global warming, climate change and further change to the biome (an example of positive feedback).
• Climate models predict more Amazonian mega-droughts, based on sea surface warming in the tropical Atlantic Ocean, which disrupts the atmosphere and weather patterns in the region.
• But the El Nino/La Nina cycles in the Pacific, the usual climate and seasonal variability, and anthropogenic­ enhanced climate change also have an input.
• For example, the 2014/15 drought in south-east Brazil was due to a blocking anticyclone (high­ pressure area), and it is not known whether this was a result of climate change.

Question 9

Changes in the Arctic water cycle:

Answer 9

• The 2014 IPCC report identified changes to the Arctic water cycle:
  • The largest global increase in temperature is in the Arctic.
  • Higher temps and evaporation rates are drying up Arctic ponds.
  • The greatest humidity increases are in northern high latitudes.
  • Higher air temperatures will reduce the duration and extent of ice and snow cover and increase snow and ice ablation.
  • Ablation (removal) of glacial ice, such as in Greenland, will alter runoff (‘freshwater flux’) and create more local river-ice floods.
  • Permafrost thawing will increase causing increased river discharges in winter.
  • Decline in Arctic sea-ice area will increase.
  • The Arctic Ocean could be ice free by 2037.
  • Arctic lakes will freeze later, with earlier ice break-up and thinner ice in winter.
  • Between 1977 and 2007, 19 polar Arctic rivers had a 9.8 percent discharge increase, with increasing spring snowmelt producing earlier peak discharges.
  • Earlier annual peak river discharges will occur in the Russian Arctic because of higher temperatures and an earlier spring thaw.
  • Eurasian Arctic river discharges will increase as a result of a pole ward shift of moisture transport.
• People in the Arctic may experience building and structure collapse as a result of permafrost thawing, and stresses on wildlife may lead to food insecurity as ecosystems change and hunting areas move.
• Alaskan people may be forced to by extreme weather and hazards such as avalanches or river floods.
• Damaged infrastructure, drought or changing hydrology - for example sediments and pollutants in rivers - may limit freshwater supplies.
• There is uncertain confidence in many predictions as climate models lack valid data to predict effects in Arctic systems.

Question 10

Coral reefs:

Answer 10

• Warmer seas, stronger storms and acidification are damaging coral reefs.
• Bleaching is predicted to severely affect 50% of coral reefs by 2050, with a transition to net erosion because of reduced calcification (build up of calcium) and coral mortality.
• Corals will be less effective at protecting coasts from storms.
• Marine productivity is decreasing, with fewer fish larvae, which is damaging fish stocks: in the Caribbean it is expected that fisheries will soon have a revenue loss, and in Pacific Island states a 20 per cent decline in reef fisheries by 2050 is predicted.
• Over 100 countries benefit from the tourism and recreational value of coral reefs, which is worth $9.6 billion according to the IPCC (2014).
• Damage to the reefs harms local economies in small island states and developing countries.
• In Viti Levu, Fiji, coral reef degradation will cause losses of $5-14 million a year by 2050, due to reduced fisheries, habitats and tourism.
• Also in Viti Levu, human health is being affected as warmer seawater leads to fish eating ciguatoxic algae, which poisons people when they eat the fish; numbers affected are expected to increase to 700 times current levels.

Question 11

Germany’s Energiewende:

Answer 11

• Even before the Japanese Fukushima nuclear disaster, Germany had been reducing the amount of electricity it produced from nuclear power, partly because of pressure from a strong Green Party.
• The final nuclear power station closure is scheduled for 2022, and it is planned that solar, wind and biomass energy will produce 80 per cent of Germany’s electricity by 2050.
• However, this policy is not without its challenges:
• There are fixed high consumer energy prices and subsidies ($18 billion in 2013) to help establish renewable energies (for example in Bavaria).
• Higher energy costs make businesses and industries less competitive in a globalised world and so the government has subsidised these, but this may conflict with EU laws on unfair competition.
• The policy has created a state-planned (top-down) energy industry and economy.
• Solar and wind energy are dependent on weather conditions, and this unreliability needs back up technology such as battery storage, which is still under development.
• Energy security in the short term comes from conventional power stations burning lignite (brown coal), which produces the highest emissions of any energy source. Since many jobs rely on lignite mining, political difficulties may arise when production is cut (for example in North-Rhine Westphalia).

Question 12

The Paris Agreement, 2015:

Answer 12

• The 1997 Kyoto Protocol set CO2 emission targets.
• It was not a truly global agreement, as it omitted emerging and developing countries.
• However high emissions from emerging countries such as China and India, it was soon necessary to involve emerging countries.
• In 2015 at a conference in Paris, 195 countries promised to reduce greenhouse gas emissions to almost zero by 2065; countries will monitor themselves and report progress every five years.
• The richer nations pledged around $100 billion a year by 2020 to help poorer countries switch away from fossil fuels.
• The overall aim is to limit temperature increase to 1.5°C above pre-industrial levels, as many believe that 2°C would create damaging change.
• However, there is little to force countries to meet the targets, and progress reporting may not be accurate.
• Perhaps only pressures from within countries (a bottom-up approach), arising from severe air pollution and a high risk of coastal flooding, such as in China, will force governments to take action.
• However, science suggests that the target is unrealistic, with 1°C of warming being reported at the start of 2016.
• In addition to the huge reduction in fossil-fuel use it will also be necessary to remove carbon from the atmosphere, which is expensive- the International Energy Agency estimates it will cost about $16.5 trillion by 2030.

Question 13

Brazilian deep-water oil:

Answer 13

Deep-water oil in Brazil:

• With help from China, Brazilian state company Petrobras developed a deep-water oilfield with reserves of 50 to 80 billion barrels.
• In 2015 production reached 885,000 barrels a day.
• The oilfield is 200-300 km offshore, where the seabed is at a depth of 2,000 m.
• Drilling conditions are therefore difficult, with the addition of flammable gases and rock salt layers that flex.
• Costs are high with storage and offloading ships, investments between 2014 and 2018 will reach $221 billion.
• Only 13% of Brazil’s electricity is from fossil fuels, the oil would help diversify its energy mix providing energy security in case drought reduces hydroelectric capacity.
• It also creates jobs and income from exports.
• However, by 2016 Petrobras was $100 billion in debt due to lower global oil prices.
• High costs of developing the oilfield caused political corruption resulted in the arrest of politicians.
• New construction activities, such as a refinery at Comperj, were delayed.
• There are concerns about oil-related activities spoiling the environment (Guanabara Bay) and causing oil spills.