Carbon must know Flashcards
What is the size of the Lithosphere?
99.985%
What is the size of the Hydrosphere?
0.0076%
What is the size of the Pedopshere?
0.0031%
What is the size of the Cryosphere?
0.0018%
What is the size of the Atmosphere?
0.0015%
What is the size of the Biosphere?
0.0012%
What is the global distribution of the major stores?
Cryosphere
polar regions and highland areas of Himalayas and Patagonia
What is the global distribution of the major stores?
Atmosphere
Mainly over North America, Europe and Asia - the major sources. These are highest in autumn and winter when trees lose their leaves and photosynthesis slows down - in the spring and summer the opposite happens.
South Africa, Java, China and South America are high, especially over summer due to burning of forests
What is the global distribution of the major stores?
Hydrosphere
- highest concentrations in the Atlantic and Bay of Bengal. These can be seen to be mirroring the warm ocean currents e.g. the Gulf Stream, which keeps carbon at the surface whilst cold water takes carbon to the bottom of the ocean.
What is the global distribution of the major stores?
Lithosphere
hydrocarbons are mainly found concentrated in North America, Former USSR, and the Middle East.
What is the global distribution of the major stores?
Biosphere
- higher content in TRF due to lush vegetation. Also high in other forests due to high amount of biomass. Grasslands and deserts have less biomass.
What is the global distribution of the major stores?
pedosphere
- highest concentration in northern latitudes e.g. Boreal forest due to slower decomposition in soils.
How do stores vary over time?
These stores e.g. plants, coral, sedimentary rocks, vary due to changes in the fluxes e.g. diffusion, ventilation etc. Some of these fluxes are part of the fast carbon cycle (rapid, years, decades, centuries) e.g. diffusion, photosynthesis. Whilst others are part of the slow cycle (millions of years) e.g. compaction and weathering.
Why is there a variance in the stores?
There is variance of these stores due to whether something is a sink (absorbs more CO2) e.g. plants, oceans, rocks, permafrost, shells/coral, soil, hydrocarbons, rainforest or whether it is a source (produces more CO2) e.g. decomposition, agriculture, humans, fires, volcanoes.
What is Carbon sequestration?
when CO2 is removed and held in solid or liquid long-term store/sinks.
What are the levels of the carbon cycle?
The carbon cycle operates at 3 levels, plant e.g. a tree, sere e.g. an ecosystem, continental e.g. global.
What is the boreal forest an example of?
The Boreal Forest an example of a sere (a community of plants in a particular environment). High carbon content due to slower decomposition due to climatic conditions, waxy nature and smaller surface area of pine needles, and presence of peat which contains 30% of all carbon stored on land. Peat is formed from decaying plant matter in waterlogged conditions, sequestering carbon for thousands of years.
What is happening to the siberian tundra?
Siberian Tundra regions (continental scale) - as permafrost melts carbon stored as methane and CO2 is released. This carbon has accumulated over 2.5m years as 8+ ice advances have broken down material and then released or trapped it in tens of metres of soil. There is also negative feedback as higher temperatures have stimulated plant growth which at present absorbs more CO2 so it is currently a sink.
How does the atmosphere vary through time?
The atmosphere - varied through time - 500m 7000ppm, 2m 180ppm, today c.400ppm. Due to changes in temperature e.g. plant growth, colder oceans absorb more.
How does the carbon cycle change over time due to natural variation?
Cold weather
Low co2 every 100,000 years Less transfer pedosphere Less flow into hydrosphere Less decomposition Less forest cover More weathering
How does the carbon cycle change over time due to natural variation?
Hot temperature
More co2 every 100,000 years
Melting of permafrost (Siberia) release of CO2 and methane
How does the carbon cycle change over time due to natural variation?
Volcanic eruptions
542-251 million years more active
130-380 million tonnes/year
How does the carbon cycle change over time due to natural variation?
Wildfires
Indonesia (97/13)
Noticeable spike
Sink to source
How does human impact change the carbon cycle over time?
-Hydrocarbons for energy and power
Increased since Industrial Revolution, dramatic increase since 1950s (ninefold increase), 2013 - 61% higher than 1990
Top 3 emitters (China, USA, India) all growing
Burning fossil fuels and industry responsible for 78% of increase in last 40 years.
What is the relative importance?
-Hydrocarbons for energy and power
Very important in terms of long term stores - 70-100 million years old
87% of CO2 emissions
How does human impact change the carbon cycle over time?
Land use change
Important stores (vegetation and soils) replaced Urban pop to reach 60% by 2030, growing 1.3 million people a week
What is the relative importance?
Land use change
Can have big impact on small-scale carbon cycles
Urban - 2% land use but 97% of CO2
Cement - 2.4%-5% of global emissions
How does human impact change the carbon cycle over time?
Deforestation
releases CO2 quickly with no time for new vegetation to grow
Replaced with grassland therefore absorption reduced
13 million ha cut down every year
What is the relative importance?
Deforestation
20%-30% of all CO2 emissions
Changes forests from sink to source
How does human impact change the carbon cycle over time?
Agriculture
fertilisers based on fossil fuels, machinery emissions, livestock e.g. cows releasing methane,rice paddies produce methane, ploughing breaks down organic matter quicker releasing carbon
Movement to meat diets - emissions from animals up 11% (2001-11)
Rice yields up 25% due to more CO2, but methane up 40%
44% from Asia for last 10 years
What is the relative importance?
Agriculture
Rice 10-20% - staple for 50% of the world
Cattle in USA responsible for 20% of USA methane
Is any sphere in balance in the other?
no
What are the main sinks?
The hydrosphere, pedosphere and biosphere are the main sinks.
What is the main store?
lithosphere
Where is greatest exchange of carbon?
The greatest exchange of carbon is between the atmosphere and both the hydrosphere and the biosphere
What stores absorb the most amount of carbon
most-> least
The atmosphere absorbs the most amount of carbon followed by the biosphere and then hydrosphere
What is happening to the natural cycle due to humans?
The natural sources of carbon are far greater than human sources, however human sources are causing an increasing imbalance.
What is Carbon fertilisation?
more CO2 means more photosynthesis and more plant growth.
What is the impact of the carbon cycle on the land?
-positive
If CO2 is doubled plant growth might increase from 12-76%
70% of greening (1982-2015) thought to be due to rising CO2
Negative feedback - more CO2 = more plants = less CO2
What is the impact of the carbon cycle on the land?
-negative
Plant growth limited by other factors e.g. availability of water, nutrients especially nitrogen, sunlight
If plants grow faster can become more susceptible to diseases
Water stressed plants become more susceptible to fire and insects
Evidence that plants in Northern Hemisphere have slowed their growth in summer and seen an increase in burning.
Little agreement on which regions will benefit the most due to differences in climate and vegetation.
What will increasing temperature lead too?
Increase in temperatures will lead to increase in decomposition in the soil therefore leading to increase in CO2 - 55 trillion kg by 2050.
What is the impact of the carbon cycle on the atmosphere?
The greenhouse effect
Incoming shortwave (UV) radiation heats the earth’s surface (although some is reflected back out by clouds etc) The earth’s surface radiates this heat out as longwave (infrared) radiation which heats the air above it Some of this longwave radiation escapes back out into space whilst some is trapped by the greenhouse gases e.g. CO2, methane, water vapour...making the earth warmer The average temperature of our planet is 15℃, without the greenhouse effect it would be -18℃
What is the enhanced greenhouse effect
An increase in these gases results in more longwave radiation becoming trapped, further increasing the temperature of the planet.
The balance between the incoming and outgoing radiation is called the radiative forcing
What is the impact of the carbon cycle on the atmosphere?
What is the evidence?
16 of the top 17 hottest years on record have occurred since 2000
Overall there has been an increase in global average temperature, since 1880 by around 1 degree
Every month of the year is seeing an increase.
Comparison of CO2 levels and Antarctic temperatures for the last 800,000 years show a strong correlation
What will happen to the atmosphere in the future?
RCP (representative concentration pathways) predict between 450 and 1300ppm and 2 and 6 degrees by 2100
How does the carbon and water stores and cycles support life on earth?
-carbon
essential for respiration and photosynthesis.
Creation of shells and coral in the oceans.
50% of biomass is made of carbon.
Provides energy e.g. hydrocarbons.
Is a greenhouse gas keeping the atmosphere at habitable levels
How does the carbon and water stores and cycles support life on earth?
-water
Needed by all living organisms
Vital source of power and energy production.
What is the relationship between the water cycle and the carbon cycle in the atmosphere?
-Hydrosphere
exchange of CO2 from the atmosphere into the hydrosphere
What is the relationship between the water cycle and the carbon cycle in the atmosphere?
-Atmosphere
carbon and H2O combine to form carbonic acid
What is the relationship between the water cycle and the carbon cycle in the atmosphere?
-Weathering
water in form of carbonic acid dissolves carbon rich rocks and rivers take these carbon ions to the sea where they are turned into calcium carbonate by shells and coral.
What role do feedbacks make within and between cycles?
-Ocean salinity
increase in CO2 leading to warming ocean and melting of ice which leads to less saline water and possible collapse of thermohaline conveyor.
What role do feedbacks make within and between cycles?
-Albedo
increase in CO2 leading to warming ocean, therefore less ice and less albedo therefore more warming.
What role do feedbacks make within and between cycles?
-Permafrost
higher temperatures leads to melting therefore more CO2 and more warming.
What role do feedbacks make within and between cycles?
-Global warming
increase in temperature leads to more evaporation, therefore more water vapour (GHG) therefore more warming.
what do warmer oceans lead to?
Warmer oceans leads to reduction in absorption of CO2.
How do humans intervene in the carbon cycle to influence transfers and mitigate the impacts?
-Mitigation
attempts to slow down the process of global climate change, usually by lowering the level of greenhouse gases in the atmosphere.
How do humans intervene in the carbon cycle to influence transfers and mitigate the impacts?
-Carbon Capture Storage (CCS)
converting CO2 into liquid under high pressure and transporting by ship or pipeline, storing it (sequestration) in depleted oil and gas fields several km below.
Good - capture 90%, forces out more oil and gas which would partly offset costs, traps the CO2, could also be stored in ocean.
Bad - forcing out more oil and gas just adds to problem, storing in ocean leads to acidification, very expensive - $800m Boundary Dam
How do humans intervene in the carbon cycle to influence transfers and mitigate the impacts?
-Changing rural land use
ensuring carbon inputs are greater than losses
Grasslands - adding manure and fertiliser increases soil organic carbon (SOC) and plant productivity. Avoiding overstocking of grazing animals.
Croplands - mulching to add organic matter and stop release of carbon, less ploughing, use of animal manure to increase plant productivity, rotation of crops and improved varieties.
Forested land - protection of forests, reforesting/afforestation, agroforestry.
How do humans intervene in the carbon cycle to influence transfers and mitigate the impacts?
-Aviation industry
2013 produced 700m tonnes of CO2 and by 2020 will be 70% higher and could be 300-700% higher by 2050.
Movement management - towing aircraft whilst still on ground, avoiding stacking, adopting fuel efficient routes.
Flight management - 100% occupancy, cruising at lower speeds, matching aircraft to route.
Design and tech - increased efficiency, use of biofuels, improved aerodynamics, reduced weight, carbon capture with engines, maximising number of seats
What is the annual rainfall and temperature in the TRF?
Annual rainfall around 2000mm and temperatures 27℃,
What happens as deforestation takes place?
as deforestation takes place atmosphere becomes less humid as evapotranspiration is reduced.
With few trees, most rainfall reaches the ground immediately, compacting it and encouraging overland flow. Exposed to the sun, the soil becomes very dry and vulnerable to erosion.
Few trees remain, so little interception or evapotranspiration.
Rates of runoff will increase, with an increased risk of flooding.
It is estimated that deforestation will affect places downwind, perhaps reducing rainfall by up to 20%.
Half of the world’s rainforests have already been wiped out for commercial farming, mining, logging, settlements - often resulting in fires.
Photosynthesis ceases and respiration drops.
Rain washes ash into ground (increasing carbon content) and rivers.
Decomposers largely absent.
Replacing rainforest with crops etc reduces effectiveness of carbon cycle.
What relationships are there between the water, carbon cycle and the environment in the TRF?
Absorb huge amounts of CO2 and 28% of world’s oxygen.
Rainforests allow a considerable amount of water to be returned to the atmosphere through evapotranspiration.
The canopy intercepts up to 75% of the rainfall, the other 25% is evaporated. Of this 75%, half is used by the plants and the other half either infiltrates into the ground or runs-off to the river.
Warm and wet climate ideal for plant growth, promoting photosynthesis and respiration.
Wood is 50% carbon so a huge carbon store and sink.
Decomposition is active due to climatic conditions
