Water-Carbon Interactions

The water and carbon cycles do not operate in isolation — they are deeply interconnected through a web of physical, chemical, and biological processes. Changes in one cycle inevitably affect the other, often through feedback mechanisms that can amplify or dampen the original change. Understanding these interactions is a key requirement of the AQA A-Level specification and provides the foundation for evaluating the potential consequences of climate change.

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How the Cycles Are Linked

graph TD
    subgraph "Water-Carbon Interactions"
        WC1["WATER CYCLE"] ---|"Weathering: water dissolves
CO₂ to form carbonic acid"| CC1["CARBON CYCLE"]
        WC1 ---|"Photosynthesis requires
water as a raw material"| CC1
        WC1 ---|"Soil moisture controls
decomposition rate"| CC1
        WC1 ---|"Ocean circulation transports
dissolved carbon"| CC1
        WC1 ---|"Precipitation controls
vegetation distribution & NPP"| CC1
        CC1 ---|"CO₂ concentration drives
greenhouse warming → more
evaporation"| WC1
        CC1 ---|"Vegetation (carbon store)
modifies interception,
transpiration, infiltration"| WC1
        CC1 ---|"Peatlands store carbon
only when waterlogged"| WC1
    end

Key Linkages