2.1.9 Links between the water and carbon cycles

What is meant by land use change

The alteration of natural land cover by human activities such as deforestation agriculture and urbanisation

How does deforestation affect the water cycle

It reduces interception and evapotranspiration increasing runoff erosion and flood risk

How does deforestation affect the carbon cycle

It releases stored carbon and reduces future carbon sequestration

How does urbanisation alter the water cycle

Impermeable surfaces reduce infiltration increase surface runoff and raise flood risk

How does urbanisation indirectly affect the carbon cycle

Increased energy use transport and construction raise carbon emissions

How can sustainable farming reduce water cycle disruption

By improving infiltration reducing runoff and limiting soil erosion

How can sustainable farming reduce carbon loss

By maintaining soil structure and increasing soil carbon storage

How does peatland restoration affect the water cycle

It increases water storage and regulates river flow

How does peatland restoration affect the carbon cycle

It restores peatlands as long term carbon sinks

Why are peatlands described as natural regulators

They store water and carbon and release them slowly over time

How does agriculture in the River Exe catchment affect water flow

It increases runoff sediment load and reduces water quality

How does agriculture in the River Exe catchment affect carbon stores

Soil disturbance releases carbon and reduces sequestration

How does afforestation affect the water cycle

It increases interception and evapotranspiration reducing runoff

How does afforestation affect the carbon cycle

Trees absorb CO2 and store carbon in biomass

Why can land use change have both positive and negative impacts

Effects depend on management scale and land type

What is the link between rising atmospheric carbon and rainfall patterns

Increased warming alters global circulation and precipitation patterns

How does climate change affect evaporation rates

Higher temperatures increase evaporation from land and oceans

How does increased evaporation affect precipitation

It intensifies rainfall in some areas and increases drought risk in others

How has UK winter rainfall changed due to climate change

Winter rainfall has become more frequent and intense

Why are UK summers projected to become drier

Reduced frontal rainfall and shifting pressure systems

How does increased winter rainfall affect river discharge

It increases river flooding frequency and duration

Why may summer river flows decrease in southern England

Less rainfall and higher evaporation reduce recharge

What is infiltration excess overland flow

Runoff that occurs when rainfall intensity exceeds infiltration capacity

Why does intense summer rainfall not always recharge groundwater

Water runs off quickly before infiltration occurs

How does climate change affect flood risk

More intense rainfall increases the likelihood of flash flooding

How does melting ice link the water and carbon cycles

Ice loss raises sea levels and reflects warming driven by greenhouse gases

How does ocean warming affect sea level rise

Thermal expansion increases ocean volume

How fast is global sea level currently rising

About 3 millimetres per year

How does atmospheric CO2 contribute to ocean acidification

CO2 dissolves in seawater forming carbonic acid

What proportion of human CO2 emissions are absorbed by oceans

Nearly one third

Why is ocean acidification harmful to marine life

It reduces carbonate availability for shell formation

How does warming oceans affect CO2 absorption

Warm water holds less CO2 reducing ocean uptake

How does increased water vapour amplify climate change

Water vapour is a greenhouse gas that enhances warming

Why is water vapour considered a positive feedback

Warming increases evaporation which increases further warming

How does drought affect carbon uptake in forests

Water stress reduces photosynthesis and carbon sequestration

How do wildfires link the water and carbon cycles

Dry conditions increase fires which release stored carbon

What role does El Niño play in carbon and water cycles

Warmer oceans cause droughts fires and carbon release

How does reduced evapotranspiration affect rainfall

Less moisture recycling leads to lower regional rainfall

What is savannisation in the Amazon

The shift from rainforest to savannah like vegetation

How does savannisation affect carbon storage

Savannas store significantly less carbon than rainforests

What is a climate feedback loop

A process where an initial change triggers further reinforcing changes

Why is the Amazon vulnerable to feedback loops

Reduced rainfall fire and deforestation reinforce carbon loss

How could Amazon deforestation affect global climate

Large scale carbon release accelerates global warming

Why are water and carbon cycles described as interdependent

Changes in one directly affect processes in the other

What is the overall impact of rising carbon on Earth’s energy budget

More energy is trapped increasing global temperatures

Why is understanding these links important

It helps predict climate change impacts and guide sustainable management