Water, carbon climate and life on earth Flashcards
(10 cards)
Key role of the water cycle
-Essential for all life forms- hydration, nutrient transport, climate regulation
-Distributes energy via latent heat transfer
-maintains weather patterns, precipitation, plant growth and ecosystem
Key role of the carbon cycle
-Carbon is a building block to life- forms organic molecules (proteins, DNA)
-Regulates global temperature through CO2 and CH4 concentrations
-Photosynthesis & respiration are key processes for ecosystem functioning
Relationship between the water cycle and the carbon cycle
The two cycles are closely interlinked, especially in the atmosphere and biosphere
-Photosynthesis: plants absorb CO2 (carbon cycle) and water (water cycle) to create glucose and oxygen
-Respiration: Plants and animals release CO2 and H2O back into the atmosphere
-Combustion: Burning biomass/ fossil fuels releases both CO2 and H2O vapour.
-Evapotranspiration: Affects cloud formation and precipitation, influenced by vegetation (carbon store)
-Ocean-atmosphere exchange: CO2 dissolves in oceans, water tempertire affects solubility (warmer water = less CO2 uptake)
Positive feedback loops within and between the carbon and water cycle
-Warming - ice melt- lower albedo - more warming (water cycle & climate)
-Warming- permafrost thaw- more CO2 & CH4- more warming (carbon cycle)
Negative feedback loops within and between the carbon and water cycles
-CO2 rise - more plant growth- more Co2 absorbed (bioshpere regulates CO2)
- More evaporation - more clouds - increased reflection of sunlight (cooling effect)
Link to climate change
-Disruption to carbon and water cycles through deforestation, fossil fuel use, and urbanisation is leading to increased greenhouse gases and changing rainfall patterns
-oceans absorb more CO2 - acidifcation, harming marine ecosystems
-increased temperatures change precipitation- droughts, floods, threatening agriculture and biodiversity
Implications for life on Earth
-Climate instability: Altered weather patterns, droughts, floods
-Sea level rise: from ice melt and thermal expansion
-Ecosystem loss: Coral bleaching, desertification, biodiversity loss
-Water stress: insecure freshwater supply in some regions
-Food insecurity: crop failures due to erratic rainfall or heat
Why intervene in the carbon cycle?
Human activities (e.g. burning fossil fuels, deforestation) have unbalanced the carbon cycle, increasing atmospheric CO2 and accelerating climate change.
Intervention aims to:
-reduce carbon emissions
- Enhance carbon sequestration
-Restore balance between carbon stores and flows
Key human interventions
- Afforestation/reforestation:
-Planting trees to absorb CO2 via photosynthesis
-creates a biological carbon sink
+ low-cost, enhanced biodiversity
- takes time, vulnerable to fire/disease - Carbon capture and storage
-Captures CO2 emmission source
-CO2 is compressed and stored underground in geological formations
+ Cuts emissions at source
-Expensive, long-term safety unknown
3.
Changing land use practices
-Conservation tillage, crop rotation, and cover cropping help increase soil carbon storage
-Peatland restoration prevents carbon loss
+ improves soil health & yield
-Needs farmer support, varies by region - Renewable energy transition
-replacing fossil fules with solar, wind, hydroelectric to reduce CO2 output
+ clan energy source
- Requires infrastructure, initial cost
5.
Bioenergy with carbon capture and storage
-burning biomass for energy, then capturing and storing the CO2
-Considered carbon-negative if sustainably managed
+ Removes CO2 while generating power
- land competition with food crops
6.
International Agreements & carbon trading
- Agreements like the Paris Agreement commit countries to cut emissions
-Carbon credits allow companies to offset emissions
+ Global cooperayion
- Enforcement and equity issues
Mitigating climate change
-Slows global temperature rise
-protects ecosystems & water cycle stability
- Reduces climate-related hazards (drought, flood, sea level rise)
-Help achieve net-zero carbon goals
