Carbon cycle EQ3 Flashcards
human population growth and an increase in economic development have changed the ways people use land
- greater demand for resources eg food
- economic needs change - improving living standards
positives of land use change
- absorbs carbon into its biomass and soils
- sustain habitat quality and biodiversity
- regulates water cycle locally and globally
negatives of land use change
- deforestation emits carbon into atmosphere
- deforestation can lead to droughts and desertification
- deforestation can lead to more intense flooding
the amazon
- 11000 sq km of rainforest destroyed from 2019-2022
- 3 million species and 1 million indigenous people
- brazils president encouraged agriculture and mining activities there
deforestation impact on water cycle
- infiltration decreased
- runoff and erosion increased
- flood peaks higher and lag time shorter
- flooding
deforestation impact on soil health
- CO2 released from decaying woody material
- biomass is lost
deforestation impact on the atmosphere
- oxygen content reduced and transpiration rates lower
- reduced shading leads to more direct sunlight reaching the ground
deforestation impact on the biosphere
- less absorbtion of CO2 means reduced carbon store
- biomass is lost from reduced photosynthesis
benefits of natural grasslands
- acts as a carbon sink - absorbing CO2 and releasing O2 all year round (a ‘lung effect’)
- acts as a terrestral carbon store
disadvantages of converting grasslands to grow biofuel crops
- initial removal of grass releases CO2 from soils
- anual ploughing releases CO2 from soil bacteria
- biofuel crops need carbon-based nitrogen fertiliser and chemical pesticides, so they produce a net increase in CO2 emissions
- the ‘lung effect’ is reduced
BBC news: Carbon capture projects will support 2000 jobs
£22bn funding for ‘carbon capture clusters’ on Teesside and Merseyside over nect 25 years
ecosystem
a biological community of interacting organisms and their physical environment eg a forest or a desert
ecosystem services
a holistic term to describe the services that ecosystems provide such as soil formation, food provision, climate regulation and recreation facilities
provisioning services definition, examples, coral reefs
d:products obtained from ecosystems
e:food, fuel, drugs, transportation, national defence
c:millions of people depends on reefs for the fishing industry
regulating services definition, examples, coral reefs
d:benefits obtained from the regulation of ecosystem processes
e:regulating air quality, pollination, flood prevention, control of pests, climate regulation
c: reduce waver energy by 95%, protecting coastlines from erosion
cultural services definition, examples, coral reefs
d: non-material benefits obtained from ecosystems
e: spiritual well-being, science, educational, recreation, heritage
c: provide evidence and education of where life began
supporting services definition, examples, coral reefs
d: services necessary for the production of all other ecosystem services
e: soil formation, photosynthesis, water cycling, biological diversity, primary productivity
c: shelter 25% of marine species
ocean acidification
the decrease in the pH of the earths oceans caused by the uptake of carbon dioxide from the atmosphere
ecosystem resilience
the level of disturbance that ecosystems can cope with while keeping their origional state
Deforestation Trends (2000-2012)
Global forest loss of 2.3 million km², particularly in tropical regions (e.g., Bolivia, Indonesia, Angola). Boreal forests also lost due to fires and forestry.
Carbon Storage & Climate Impact:
Tropical rainforests store 32% of global forest carbon. Deforestation disrupts the carbon cycle, reducing carbon sequestration and increasing atmospheric CO₂.
Water Cycle Links to forest loss
Trees regulate water through interception, evapotranspiration, and absorption. Deforestation reduces these processes, affecting water supplies.
Key Concerns:
Human Drivers & Impacts
Forest loss has been a major issue since the 1970s. Despite slowing in some areas (e.g., Brazil), deforestation continues, driven by agriculture (soya, palm oil), plantations, and hydroelectric projects.
Fires & Feedback Loops
Human Drivers & Impacts
Deforestation dries out soils, increasing susceptibility to fires, which release aerosols, degrade air quality, and worsen respiratory issues (e.g., Amazonia drought, 2005).
Soil Degradation
Human Drivers & Impacts
Loss of vegetation leads to soil erosion, threatening food security.
Kuznets Curve Theory
Economic & Policy Influences
Environmental degradation initially rises with economic development but later improves as policies and technology advance. Brazil’s forest policies show potential for a ‘turning point.’
Global Trends
Economic & Policy Influences
Indonesia had the highest forest loss (2000-2012). Developed nations show afforestation efforts (e.g., boreal forest expansion post-wildfires). Russia saw the largest net forest loss (365,015 km²).
Rising Temperatures & Ice Loss
changes in the Arctic water cycle
- The Arctic is experiencing the fastest global temperature increase, especially in winter.
- Higher temperatures lead to more evaporation, humidity, and permafrost thawing (with increased river discharges).
- Arctic sea ice is shrinking rapidly and could be ice-free by 2037
Hydrological Changes & River Systems
changes in the Arctic water cycle
- Increased snow and glacial melt (e.g., Greenland) affect river runoff, leading to more floods.
- Arctic lakes freeze later, and river discharges peak earlier due to earlier spring thaws.
- Eurasian river discharges are increasing due to moisture shifts toward the pole
Environmental & Human Impacts
changes in the Arctic water cycle
- Permafrost thaw causes infrastructure collapse, threatening Arctic communities.
- Wildlife and ecosystems shift, leading to food insecurity for Indigenous peoples.
- Extreme weather, floods, and droughts impact water quality and availability
Uncertainty in Future Projections
changes in the Arctic water cycle
- Climate models lack complete data for long-term Arctic feedback effects.
- More monitoring sites are needed to improve predictions of Arctic changes
uncertain futures - natural factors
- oceans take decades to respond to greenhouse gasses
- global total of forests is falling eg tropics
- oceans and forests act as carbon sinks and store heat
uncertain futures - economic growth
- after 2008 financial crisis, was predicted that CO2 emissions would rise
- but emmission rates fell to 0.5% in 2014
uncertain futures - energy sources
- energy consumption grew by 2% between 2008-2014
- renewable sources made up of 2/3 of increase in electricity production
uncertain futures - population change
- increasing affluence means extra billion consumers by 2050
- changing diets, increased mobility
permafrost
when melted releases carbon into atmosphere - greenhouse gas effect
peatlands
accumulation of partly decayed vegetation, low rate of carbon breakdown in cold waterlogged soils, warming of 4c causes 40% loss of soil organic carbon in shallow peat
Paris 2015 agreement
- 195 countries promised to reduce greenhouse gas emmisions by almost 0 by 2065
- aimed to limit temperature increase to 1.5 degrees celcius
1988
UNEP formed, WMO provide science advice on climate change
1992
Earth Summit meeting in Brazil
1997
Kyoto protocol
2007
Nobel peace prize went to IPCC and ALGore for climate change
2014
IPCC reports made all countries reduce emmissions
