3.1.1.3 The Carbon Cycle

Lithosphere store features

Includes fossil fuels and soils, 80% of global carbon emissions, slow carbon sink

Hydrosphere store features

Oceans absorb 25-30% of anthropogenic co2, 2nd largest active store

Cyrosphere store features

Permafrost and glaciers, create positive feedback loops

Biosphere store features

Vegetation, soil organic material, food webs, terrestrial plants

Atmosphere store features

Small but dynamic store, includes methane and co2

Transfers

Weathering, Photosynthesis, Respiration, Decomposition, Combustion, Burial, Carbon sequestration

Photosynthesis

Co2 + Water — Glucose + Oxygen (Light energy power). Role in carbon sequestration and transfer of carbon

Respiration

Glucose converted into energy, co2 returned to the atmosphere as by product

Physical causes of change in the carbon cycle

Glacial/inter glacial, Wildfires, Volcanic activityG

Glacial

Reduces biological activity and lowers atmospheric co2

Interglacial

Warming releases stored co2 and enhances greenhouse effect

Impact of cold weather on transfers/stores

Weathering more active as cold water holds more co2, Soil frozen so transfers stop, decomposers less effective, Forest volume and distribution dramatically changes

Advantage of wildfires

Regenerate ecosystems for future sequestration

Human causes of change to the carbon cycle

Combustion of fossil fuels, Land use change, Farming practices, DeforestationCo

Combustion of fossil fuels features

90% of anthropogenic co2 release, transfers from lithosphere to atmosphere

Land use change features

10% of global release, urbanisation reduces sequestration, cement production 2.4% of global emissions, peatland drainage releases ancient carbon

Farming practices features

Soil disturbances release Co2, Cultivation of rice 20% of methane emissions, livestock emit methane, Machinery/fertilisers use fossil fuels

Deforestataion

Reduces carbon sinks (20% of global emissions), carbon neutral in a natural system, burning causes immediate release and reduces future absorption

Carbon budget

Data describing inputs, outputs and stores of carbon in a cycle

What had disrupted the modern carbon budget

Emissions and insuffecient abosrbtion by sinks

What does the carbon cycle impact

Land, ocean, atmosphere, regional

Positive influence of carbon cycle on land

Stored in vegetation/soil for biomass growth, formation/developing soils, soil fertility

Negative influence of carbon cycle on land

loss of carbon lowers agricultural productivity and rising temperatures accelerate decomposition

Positive influence of carbon cycle to oceans

Calcium carbonate builds organism shells, acts as biological pump through phytoplankton uptake

Negative influence of carbon cycles to oceans

Ocean acidification, threat to coral reefs

Positive influence of carbon cycles on atmosphere

Greenhouse effect supports life

Negative influence of carbon cycles on atmosphere

Rising temperatures, precipitation patterns, extreme weather

What are regionally impacted

Vegetation, deforestation, Increased phytoplankton, Volcanic erruptions

How does vegetation regionally impact the carbon cycle

Dense vegetation Photosynthesise/respire more which increases humidity and cloud cover

How does increased phytoplankton regionally impact the carbon cycle

Formation of clouds through creation of chemical DMS

How do volcanic eruptions regionally impact the carbon cycle

Release CO2 which absorbs radiation and cause volcanic winters