Carbon EQ3 Flashcards
Define sequesters
The process by which carbon dioxide is removed from the atmosphere and stored in a solid or liquid form, typically by physical or biological means such as vegetation, oceans, or geological formations.
What is happening to the Biospheres capacity to sequester CO2?
However, the biosphere’s capacity to sequester carbon dioxide is being reduced due to land conversion.
Land conversion is being driven by an increasing demand for food, fuel and other resources.
Summarise deforestation?
Forests cover 30% of the Earth’s land area and absorb rainfall and increase groundwater storage.
- Deforestation occurs for either the timber or the space they occupy and is driven by the increasing demand for commodity production.
An estimated 10 million hectares are deforested every year
Impacts of deforestation on the water cycle?
- Reduced interception by vegetation so infiltration to soil and groundwater changes
- Increased erosion and surface run-off, increasing sediment eroded and transported into rivers
- Less transpiration
Impacts of deforestation on the carbon cycle?
- Reduced storage in soil and biomass
- Reduced carbon dioxide intake during photosynthesis
- Increased carbon influx to atmosphere by burning and decomposing vegetation
What is afforestation and reforestation?
Afforestation is the planting of trees in land that has NEVER had coverage before.
Reforestation is replanting trees where they used to exist but might have been deystroyed.
Pro and Con of afforestation / reforestation?
Afforestation and reforestation are beneficial for carbon dioxide sequestration but can be controversial in its impacts:
- Commercial trees such as palm oil often store less carbon, use more water and are prone to disease
What are the two types of grassland?
There are two main types of grassland which cover 26% of the Earth’s land area
- Temperate grassland - no trees and a seasonal growth pattern linked to a large annual temperature range e.g. North America
- Tropical grassland or Savannah- scattered trees with a wet and dry season e.g. Africa’s serengeti
How does land conversion affect global warming (6)?
1️⃣ Point: Deforestation reduces carbon sequestration
- Evidence: Trees absorb CO₂ through photosynthesis and store it in biomass.
- Explain: Removing vegetation reduces the amount of carbon being drawn out of the atmosphere.
- Link: This increases net atmospheric CO₂, enhancing the greenhouse effect.
2️⃣ Point: Replacing natural land with agriculture or urban surfaces increases albedo and reduces soil health
- Evidence: Converting forests or grasslands to cropland or concrete changes surface reflectivity and disturbs soil structure.
- Explain: This reduces soil’s ability to store carbon and increases emissions through fertiliser use or machinery.
- Link: Indirectly leads to higher carbon emissions and disrupts natural carbon cycling.
3️⃣ Point: Soil disturbance from land conversion releases stored carbon
* Evidence: Agricultural ploughing or land clearance exposes soil organic matter to oxygen.
- Explain: This triggers microbial activity, causing carbon to oxidise into CO₂.
- Link: Increases the volume of carbon transferred from the lithosphere to the atmosphere.
What is ocean acidification?
Oceans are important carbon sinks but due to their increasing uptake of carbon dioxide from the atmosphere, their overall pH is decreasing leading to ocean acidification
- The acidity of the ocean today is estimated to be on average about 25% greater than it was during pre-industrial times
Risk and counter of ocean acidification?
Ocean acidification increases the risk of marine ecosystems reaching a critical threshold of permanent damage
- HOWEVER, Ecosystem resilience is important - if the rate of acidification is slow enough, the organisms may be able to adapt to the changes and be more resilient
Describe the impact of ocean acidification on coral reefs (chain of reasoning).
- More CO₂ enters the ocean from the atmosphere due to rising emissions.
- This causes ocean acidification (the water becomes more acidic).
- Acidic water leads to fewer carbonate ions in the water (because the acid reacts with them reducing the free ions).
- Corals need carbonate ions to build their calcium carbonate (CaCO₃) skeletons — just like shellfish do.
- With fewer carbonate ions available, corals struggle to grow and maintain their skeletons.
- Their skeletons become weaker, grow more slowly, or even dissolve in extreme cases.
- If corals weaken or die, coral reefs can collapse, disrupting entire marine ecosystems.
How does the Amazon act as a global regulator?
The Amazon acts as a global and regional regulator, pumping 20 billion metric tonnes of water into the atmosphere every day
Climate zones?
There are around 30 different climate zones which can be simplified as:
- Equatorial
- Tropical
- Temperate
- Polar
These climate zones are not static and the increasing of earth’s temperatures could lead to 5% of the Earth’s land area shifting to a new climate zone.
There is already evidence of the expansion of subtropical deserts and poleward movement of stormy wet weather in mid-latitudes.
What is the ITCZ?
The ITCZ is a belt of low pressure around the equator, where warm air from both hemispheres converges, causing heavy rainfall and thunderstorms.
How many people depend on forests?
An estimated 1.6 billion people depend on forests and more than 90% of these are in developing countries.
- Forests are essential for human well-being through their services as well as being the source of 80% of global biodiveristy
What are the supporting functions of a forest?
- Nutrient cycling
- Soil formation
- Primary production
Explain how Forests regulate Earth’s systems?
Green lungs - Absorb CO2 and release oxygen while filtering and cooling the enviroment through shade and evapotranspiration.
Radical point regarding forests importance?
Cultural Value:
- Aesthetic
- Spiritual
- Educational
- Recreational (inc. tourism)
What does global warming generally effect in the hydrological cycle?
- Precipitation patterns
- River Regimes
- Water Stores (cryosphere and drainage basin)
What can you compare the arctic to in terms of enviromental impacts?
The Arctic acts as an early warning system for the environmental impacts resulting from the burning of fossil fuels
Impacts of increased temps on the cyrosphere?
- Antarctica and Greenland ice sheets have lost mass and glaciers are shrinking
- Arctic temperatures have risen twice as fast as the global average in the past few decades
- Significant loss of sea ice e.g., the North-west Passage can now be navigated in the summer
What is albedo?
A measure of how sunlight is reflected off the Earths surface.
Impacts of increasing temprature on Arctic?
- Significant loss of sea ice e.g., the North-west Passage can now be navigated in the summer
- Permafrost is melting
- Carbon uptake by plants is increasing because of the lengthening of their growing season
- A loss of albedo as the ice that once covered the land is replaced by tundra and tundra is replaced by taiga (further encouraging global warming - positive feedback loop.)
