Carbon - EQ3 - Flashcards
How are the carbon & water cycles threatened by human activity
- water pollution
- increased drought
- ocean acidification
- conversion of grassland to farming
Growing demand for food, fuel & other resources have led to…
- contrasting regional trends from land conversion
What is land conversion
- any change from natural ecosystems to an alternative use, it usallu reduces carbon & water stores & soil health
There is a growing demand for food, fuel and other resources globally due to…
- increased population growth
- increased economic growth in NICs/NEEs/MICs (people start to favour meat over rice, etc.)
- improved living standards
Which areas of the world are more affected by changes to land use from resource extraction
- Deforestation and conversion of grasslands to farming is mainly occurring in NICs, LICs and MINT countries
- Afforestation in mainly HICs
What are the implications of land use change
- Changes in forest cover is leading to a decrease in rainfall;
- & the digging up of grasslands reduces the terrestial carbon store,
- having wider implications for the water cycle and soil health..
Give a statistic to say people in developed countries are eating more
By 2030, only 1 in 7 people are expected to be consuming less than 2,500 calories per day
What are the implications for the planet of changing diets
- Grains make up 45% of the world’s diet
- Meat production intensely uses land and water
In 2013 the IPCC estimated that ….% of greenhouse gas emissions came from agriculture and land-use change
24%
Between 1995 and 2005 the global forest area decreased by … million ha, while arable land area increased by .. million ha
- 80 million
- 24 million
Changes in demand leads to changes in land use such as (name 3)
- deforestation
- afforestation
- grassland conversion
What is 1/2 of all deforestation caused by
- soy
- palm oil
- beef
- paper production
Which 5 countries show the highest rates of deforestation globally
- Nigeria
- Indonesia
- North Korea
- Bolivia
- Papau New Guinea
Forests cover …% of the planet although only …% is natural (primary forest)
- 30
- 15
What role do trees play in the water ccyle
- interception, transpiration, rainfall generation & stemflow/ leap drip encourage inflitration & therefore groundwater recharge
What role do trees take in the carbon cycle
- terrestrial store (biomass & leaf litter)
- & CO^2 absoroption during photosynthesis
What are the impacts of deforestation on the water cycle
- Runoff and erosion increase
- Flood peaks are higher and lag time is shorter
- Annual rainfall is reduced
What are the impacts of deforestation on the soil health
- Rapid soil erosion leads to a loss of nutrients
- Raindrop impact washes finer particles away
- Biomass is lost due to reduced plant growth
What is the impact of deforestation on the atmosphere
- Oxygen content is reduced
- Reduced shade means more direct sunlight hitting the floor
- Reduced evapotranspiration which leads to dry air
What is the impact of deforestation on the biosphere
- Reduced carbon store
- Species diversity is reduced
- Ecosystem services are reduced which leads to a decrease in habitats
Why has deforestation occurred in Madagascar and why is it encouraged by the government
- A growing international demand for tropical hardwood, an expanding population and debt repayments
- meant that Madagascan government began to encourage farmers to clear more land to earn money
How are carbon fluxes and stores changed when tropical rainforests are disturbed by deforestation
- Deforestation has a major impact on the size of the terrestrial carbon store
- & also increases the amount of carbon being carried by fluxes such as photosynthesis and respiration
What is afforestation
- refers to planting trees on patches of land which were not previously covered in the forest
What are 2 pros of afforestation
- afforestation is beneficial when trees have been previously removed
- can be advantageous when tackling global warming
What are the cons of afforestation
- These new trees will never create exactly the same ecosystem as the original forest
- The original trees, thousands of years old, —> years for the new trees to catch up
- rare species, may not be replaced, meaning extinction & a reduction of biodiversity could be inevitable
Explain afforestation’s impact on Savanna or tropical grassy biomes
- Land which may appear degraded may actually house its own ecosystem, as tropical grassy biomes are often misunderstood and neglected
- These ecosystems can provide important ecological services & rare species, which could be outcompeted by the introduction of new trees
- Therefore, although carbon sequestration will increase, many ecosystems will be negatively affected or lost
How can the negative possibilities of deforestation & afforestation be limited
- deforestation should be kept to a minimum and afforestation only occurs on truly degraded land
- Without research into land before being afforested & global considerations, irreversible damage can occur unknowingly
What are the 2 types of grasslands
- temperate
- savannah/tropical
What took place concerning biofuel from 2007-15
- Between 2007 and 2015, a biofuel ‘rush’ swept across the American Midwest
- Farmers were encouraged to grow……………………………………………..as part of the US Environmental Protection Agency’s Renewable Fuel Standard policy
- corn, soya, canola (a cype of rapeseed) and sugar cane
What are the aims of the US Environmental Protection Agency’s Renewable Fuel Standard policy
- increase the amount of ethanol being used in petrol
- boost the economies of rural US states
- reduce US dependence on overseas oil imports
- reduce CO, emissions from transport
Give a stat suggesting the demand for biofuel has economic consequence
- By 2013 the price of corn had trebled
- Grasslands, traditionally used for cattle ranching, were ploughed up,
- & in some states the area of corn being cultivated doubled
Give a stat displaying how biofuel demand led to land exploitation in the Americna Midwest
Over 5.5 million hectares of natural grassland disappeared across the American Midwest, which matches the rate of rainforest deforestation across Brazil, Malaysia and Indonesia
What are the benefits of natural grasslands
- maintain natural habitats
- cultivated soils
- act as a carbon sink - absorbing CO,
What are the disadvantages of converting grasslands to grow biofuel crops
- The initial removal of grasslands releases CO
- Annual ploughing enables soil bacteria to release CO
- Biofuel crops need carbon-based nitrogen fertiliser and chemical pesticides, so they produce a net increase in CO, emissions
- biofuel crops are heavy consumers of water
Ocean Acidification
Our oceans have absorbed approximately ….. our CO^2
half
Ocean Acidification
As the oceans warm what can it no longer do
- take up as much CO^2
Ocean Acidification
What happens to some sea creatures such as clams, oysters & coral
- their shells & skeletons are getting weaker
Ocean Acidification
Why is shells and skeletons of marine life becoming weaker an issue
- 1 in 7 people get there protein from seafood, & if shellfish cant grow as big, the food chain will be massivley affected having a knock on effect
Ocean Acidification
How much more acidic has the ocean become since we started pumping out CO^2
- 30%
Ocean Acidification
How many ocean species live in coral reef ecosystems
1/4
Ultimately, why is ocean acidification such a major concern
- we might make the ocean more acidic than it has been in the last 20 years, so species will not be able to evolve quick enough
How is ocean acidification impacting in the biological carbon store
- food webs
- phytoplankton
- deep ocean sediments
- shellfish & corals
How is ocean acidification impacting in the geological carbon store
- carbon sequestration from biological organisms reduces
- this affects the amount of carbon in the food chain
- the dead creatures have less carbon which reduces marine snow
- reduced carbon in the calcareous ooze
- less stored in the geology
Coral around the world turning white & dying has triggered…
- the fourth global mass coral bleaching event
Across the ……km of the Great Barrier Reef, it houses vast structures that house …% of all marine species
- 2,000
- 25%
Give an example of how fish biodiveristy would decline
- once coral dies, creatures like fish that navigate using coral noise can struggle to find their way home
Coral can recover from …. stress, but it needs time - ideally several …..
When weakened, it is susceptible to ….. & can easily die
- heat
- years
- disease
what is the calcareous ooze
- a calcium carbonate mud formed from the hard part of bodies of free-floating organisms
- once this mud has been deposited it can be conerted into stone by processes of compaction, cementation & recrystallisation
define ph
- ph - a measurement of acideity or alkalinity within the oceans