Water and carbon cycles

Importance of water

S:Drinking, leisure activities, cooking, cleaning

Ec: Industry, tourism, agriculture

Env: Rich source of wildlife, aquatic ecosystems, ensures health of rivers and wetlands

Importance of carbon

Absorbed by plants, consumed by animals, holds synthetic items together, found in everything, a building block for all living things

Positive feedback in the carbon cycle

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Negative feedback in the carbon cycle

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The water cycle

Major stores of earths water

Oceanic - 97% of earths water, only 5% explored

Cryosphere - water in solid form e.g. sea ice, ice sheets, ice caps, alpine glaciers, permafrost

Terrestrial - 4 classes: surface, groundwater, soil and biological

Atmospheric - exists in all 3 states but most commonly water vapour, relfelcts sunlight so maintains earths temperature, redistrubtes water around the globe and cleans air by precipitation

What % of water on earth is freshwater

3%, only 1% of this is easily accessible

Overland flow

Fast flow of water down slopes to the nearest channel

Infiltration

Water soaking into the ground, rate depends on soil porosity

Throughflow

Lateral movement of soil water downslope, eventually reaching the nearest channel

Perculation

Water moving vertically down the soil and saturated rock

Groundwater flow

Once water percolates, it is held in the pores of rocks as groundwater, passes slowly into rocks and can feed rivers in times of drought

Evaoporation

Energy from solar radiation hitting water causing it to change shape from a liquid to a gas - water vapour

Condensation

As air cools it holds less water vapour to access water converts to liquid, visible as clouds

Precipitation

Clouds become too heavy to hold the water so it releases it as rain, snow, hail or sleet

Transpiration

Loss of water from vegetation through stomata or surfaces

Interception

Temporary storage of precipitation on a natural or man made canopy

Stem flow

The portion of precipitation intercepted by the canopy that reaches the ground via stems or stalks

Drainage baisin

Area of land that is drained by the river

River source

Where the river starts, in upland areas

River mouth

Where the river ends and meets the sea

Watershed

Highest lying land that separates drainage baisins

Tributary

Small river leading to the main river

Distributary

Where the river splits into two separate channels

Confluence

Where two rivers meet

River channel

Area of land where river water flows

river discharge

volume of water which flows through the river at any given time

water balance

the balance between the inputs and outputs of a drainage basin

water balance equation

precipitation=discharge+evaporation+/-changes in storage

what does water balance vary depending on?

river regimes and soil moisture budget

river regimes

discharge levels in rivers rise and fall, often showing an annual pattern

soil moisture budget

how much water soil can absorb

soil moisture utilisation

water in soil being used up by plants and animals due to potential evapotranspiration exceeding precipitation, occurs in early summer

soil moisture recharge

water stores filling back up as precipitation increases, occurs in autumn

soil moisture surplus

water stores are full, soil is saturated due to precipitation exceeding potential evapotranspiration, leads to overland flow, occurs in winter

soil moisture deficit

lack of precipitation and high evapotranspiration means that water stores have dried out, plants wilt or have adaptations, occurs in late summer

Physical and human factors affecting discharge levels

Soil type, geology, climate, vegetation coverage, drainage density, basin area

Deforestation, urbanisation, farming, irrigation schemes, river management schemes, water abstraction schemes

Flood hydrograph

A graph that shows how a rivers discharge changes over a period of rainfall

Where and what is the Eden basin case study

Located in north west of England in Cumbria, very vulnerable to flooding due to steep topography and low lying confluences.

Physical and human factors that effect the Eden Basin

Higher rainfall than UK average, long and narrow shape, igneous rocks on west side all also contribute to flood risk.

Farming in the area reduces infiltration and vegetation, construction reduces infiltration and creates UHI effect, deforestation and climate change enhances risk

Flood event in the Eden Basin

December 2015, 203mm of rain in 48 hours, over 2000 properties were flooded

Why does carbon make the basis of all living matter?

It’s simple atomic structure enables it to to form bonds easily

What type of radiation enters the earths atmosphere?

Short wave radiation (UV)

Key stores of carbon in the lithosphere

Sedimentary rocks and fossil fuels

2 categories in the biosphere

Plants and soils

What is the slow carbon cycle

Millions of years of laying down of sedimentary rocks and ocean sediment, carbon gets slowly released from weathering, transportation and volcanic activity

What is the fast carbon cycle

Movement of carbon through food chains within a lifetime - photosynthesis can take minuets

difference between inorganic and organic carbon

inorganic is non-living, found it sedimentary rocks, gas and coal. organic is living and found in all forms of life

is the carbon cycle an open or closed system?

Closed

Lithosphere as a carbon store

99.9% of worlds carbon, found in sedimentary rocks and as fossil fuels, both organic and inorganic forms

Hydrosphere as a carbon store

Second largest store, 0.04% of worlds carbon, found in the surface layer of water and deep in the oceans

Cryosphere as a carbon store

Less than 0.001% of worlds carbon, mainly in permafrost (frozen soil)

Atmosphere as a carbon store

0.001% of worlds carbon, CO2 has vital role in regulating earths temperature, also found as methane and carbon monoxide

What is the natural and current amount of CO2 in the atmosphere?

Natural- 280ppm 2021- 400ppm

Biosphere as a carbon store

0.0004% of worlds carbon, stored in living organisms and vegetation, plant litter, soil humus and peat

Fluxes in the carbon cycle

Photosynthesis, respiration, decomposition, combustion, ocean uptake, ocean outgassing, ocean pumps, sequestrian, wildfires, volcanic activity

combustion of carbon

burning it in the presence of oxygen to release energy

decomposition

The break down of matter, often by a decomposer which releases carbon dioxide through their own respiration

outgassing

The release of dissolved carbon dioxide e.g. at plate boundaries or warming the oceans

photosynthesis

The process of converting carbon dioxide and water into glucose and oxygen

respiration

The process of converting glucose and oxygen into carbon dioxide and energy

sequestratian

The transfer of carbon from the atmosphere to other stores e.g. living biosphere, formation of inorganic rocks, etc.

Ocean outgassing

Water dissolves CO2, warm surface water is carried to polar regions making it dense enough to sink, when it returns to the surface and warms it looses CO2 to the atmosphere (vertical circulation)

3 natural changes in the carbon cycle

Wildfires release CO2 through combustion

Volcanic activity realises carbon during eruptions

Climate change melts the cryosphere and increases ocean out gassing and wildfires

Milankovitch cycles

Earths orbit around the sun

Earths tilt towards the sun

Earths wobble relitive to the sun

What is the eccentricity cycle?

96,000-100,000 year cycle of the distance between the earth and the sun changing

What is the precession cycle?

21,000 year cycle of Earth sometimes tilting towards/away from the sun

What is the obliquity cycle?

42,000 year cycle of changes in the spinning effect of the Earths daily rotation

what is anthropogenic forcing?

human influences to changes in the carbon cycle

what are the 4 anthropogenic forces?

burning fossil fuels, agriculture, deforestation, cement manufacturing

what impact does warmer temperatures have on the climate?

more photosynthesis → more CO2 absorbed → temp decrease

more decomposition/combustion/permafrost melting → more CO2 released → temp increase

what impact does colder temperatures have on the carbon cycle?

reduces transfer of carbon between stores because carbon is frozen in water stores as ice ad respiration/photosynthesis is reduced

explain how fossil fuel combustion has an impact of the carbon cycle

makes up 75% of human forcing, burning coal, oil and gas for energy required for domestic lives, workplaces, leisure and transport

Explain how cement manufacturing has an impact on the carbon cycle

5% of human emissions, released from warming calcium carbonate and burning fossil fuels to power process, for every 1000kg produced, 900kg of carbon is released

Explain how farming practises have an impact on the carbon cycle

When soil is ploughed, air mixes in increasing microbial activity (increasing decomposition), methane is produced from livestock during digestion (enteric fermentation)

Explain how deforestation has an impact on the carbon cycle

Logging to clear land for infrastructure or agriculture, some is natural, 13 million ha. of worlds forests cut down every year, reforestation reduces net loss of forests, biomass often burned and exposed land accelerates decomposition, soils get degraded leading to possible desertification and a negative impact on water cycle

Explain how urban growth has an impact on the carbon cycle

Over 50% live in urban areas, continuous growth, CO2 emitted from energy consumption and cement manufacture, vegetation cleared, reducing storage in biomass

What is carbon sequestration?

Capturing CO2 from the atmosphere and putting it into long-term storage, the two main types are geological and terrestrial/biological sequestration

What is geological sequestration?

Capturing CO2 at its source and injecting it in liquid form into underground stores such as salt formations and deep in the ocean where it can remain for thousands of years

What is terrestrial/biological Sequestration ?

Using plants to capture CO2 by using land management strategies to maximise carbon store in soil and plants e.g. by enriching ecosystems. However there is a risk of forest fires which instantly releases all carbon back into atmosphere

Impact of the changing carbon budget on the land

Warming tundra increases rate of decay, some farmland is replaced by trees which stores much more carbon, wildfires are extinguished, storing more CO2 in woody material

Impact of ocean acidification

pH of oceans surface has decreased by 30% since 1750, less carbonate ions for corals and plankton to make shells making them thinner and more fragile, acidification is linked to millions of oyster larvae dying, acidic water dissolves rocks releasing carbonate ions increasing oceans capacity to absorb CO2

What is the carbon budget?

Difference between the inputs and outputs of carbon in a sink

What is radiative forcing?

Forced temperature increase / enhanced greenhouse effect

Implications of permafrost melting

Permafrost in the northern hemisphere holds 1672 Gtc, if just 10% of this thaws it is predicted it will lead to a 0.7% temperature increase by 2100

examples of how climate change is affecting life on earth

global precipitation patterns are changing

more heatwaves and forest fires

more extreme weather events

agricultural productivity is compromised

sea levels are rising leading to flooding

more species are becoming extinct  

what is the climate like in rainforests?

equatorial so warm and wet

rates of what are high in rainforests (6)

precipitation

evapotranspiration

nitrogen leeching and recycling

humidity

decomposition 

biodiversity 

importance of rainforests

provides 20% of worlds oxygen

used in cancer-fighting drugs

holds 50% of Earths plant and animal species 

valuable food resources

major carbon sink that regulates the climate 

how big is the amazon rainforest?

550sq/km

how does the amazon rainforest impact the water cycle?

high precipitation, evaporation, interception, transpiration

50% of rain is recycled

only 30% of rain reaches forest floor

how does the amazon rainforest impact the carbon cycle?

high photosynthesis, CO2 uptake, productivity, sequestration and decomposition

holds 80-110bn tonnes of carbon

local carbon mitigation strategies

reducing technology use, heating/air con, energy efficient lightbulbs, appliances, buildings, diet changes and reduced car usage

national carbon mitigation strategies

increased use of renewable energy, improved urban design, carbon capture and storage, improved aviation policies and biological sequestration 

how has deforestation impacted the water cycle?

evapotranspiration and precipitation reduced

flood risk increased due to more surface runoff 

river discharge reduced due to less precipitation 

freshwater ecosystems are destroyed due to flash floods

soils loose bacteria and fungi to decay matter, become dry and baked as they are more exposed to the sun

pre-combustion capture

removing CO2 from fuels before it is burnt

post-combustion capture

removes CO2 from flue gas after the fuel has been burned

oxy-fuel combustion

burning fuel in pure oxygen instead of air, producing a flue gas that’s mainly COs and H2O which is easier to separate 

what is the Paris agreement?

a legally binding global treaty on climate change, adopted in 2015, to limit global warming to well below 2°C, ideally 1.5°C, above pre-industrial levels

Approaches to mitigate deforestation in the Amazon rainforest

Environmental laws to ban excessive logging and control land use

Protection policies such as national parks

Selective logging

Re-planting the same species of tree lost