Human Factors Changing Carbon Cycle

Question 1

Name 4 ways humans change carbon cycle.

Answer 1

Burning / extracting fossils fuels.
Farming practices.
Deforestation.
Urban growth.

Question 2

Where does the most human caused carbon release come from ?

Answer 2

According to IPCC 90% comes from combustion of coal, oil and natural gas.

Question 3

What helps to mitigate against this big surge of co2 from combustion?

Answer 3

Vegetation and oceans which reabsorb 50% of this.

Rest absorbed by atmosphere.

Question 4

How much have co2 levels risen by in last 50 years ?

Answer 4

80ppm

Question 5

Process of burning ?

Answer 5

Most of worlds has/oil comes from rocks that are 70-100 million years old.
Carbon remains locked up in these deposits for all that time.
When burnt to generate energy the stored carbon is released into atmosphere mainly as co2.

Question 6

What does combustion of hydrocarbon release ?

Answer 6

Carbon dioxide and water vapour into atmosphere.

Question 7

How much co2 does the cement industry produce.

Answer 7

5% of all human induced global co2 emissions.

50% of which comes from heating of calcium carbon and 40% from burning of fuel to power the process

Question 8

How much cement produced for how much co2 released?

Answer 8

For every 1000kg of cement produced.

900kg of co2 released into atmosphere

Question 9

Which fossil fuel generates most co2 emissions?

Answer 9

In 2013
43% coal
33% oil

Question 10

Is global co2 emissions from fossil fuel use and cement increasing or decreasing ?

Answer 10

Increasing.

In 2013 it topped 36 GtC which is 61% higher than in 1990

Question 11

Which countries release most co2?

Answer 11

2013
Dominated by 
China - 28%
USA - 14%
India -7%
All NEEs

Question 12

What is the greatest source of carbon emissions in agriculture?

Answer 12

Enteric fermentation - methane belched by livestock during digestion.

Question 13

How much does enteric fermentation release ?

Answer 13

In 2011 it made up 39% of all agriculture carbon emissions.

Increased by 11% since 2001 - 2011

Question 14

What happens when soil is ploughed?

Answer 14

Soil layers invert with each other allowing air to mix in.
As a result soil microbial activity increases resulting in more soil organic matter being decomposed.
As a result more co2 lost to atmosphere along with co2 produced by farm trackers doing ploughing in first place.

Question 15

What happens in rice paddies?

Answer 15

Biological processes in rice paddies generate methane which makes up 10% of all agriculture carbon emissions

Question 16

What % does burning of tropical grasslands make up ?

Answer 16

5%

Question 17

How much carbon dioxide is released from land use change

Answer 17

30% for deforestation for all human induced emissions.

Question 18

What is logging ?

Answer 18

They remove forests.

Some act illegally building roads to access remove forests.

Question 19

Why else does deforestation occur?

Answer 19

Result of urban sprawl.
Wildfires / overgrazing prevent reestablishment of younger trees.
Conversion to pasture : agriculture.

Question 20

When forests are cleared for conversion to agriculture what happenes?

Answer 20

Large proportion of above ground biomass May be burned leading to huge release of co2

Question 21

What does forest clearing also accelerate ?

Answer 21

The decay of dead wood, little and below ground organic carbon

Question 22

What long term negative impacts does deforestation have on carbon cycle ?

Answer 22

Forest souls are moist but without shade from trees they soon dry out.
Trees maintain water cycle by returning vapour back to atmosphere through transpiration.
Former forest land quickly turn into barren deserts.

Question 23

What has planting of trees resulted in?

Answer 23

A reduced net loss of total forest area.

Question 24

How much forest has been lost ?

Answer 24

3% of forests were lost between 1990 and 2005 at a rate of 200km2 per day meaning forests could vanish completely within 100 years.

Question 25

Over 50% of worlds population , lives where ?

Answer 25

Urban areas Z

Question 26

Urban areas decrease or increase ??

Answer 26

Expected to reach 60% by 2030.

Growing 1.3 million people per week

Question 27

What happens when cities grow ?

Answer 27

Land use changes from natural vegetation to a one being built on.

Question 28

Where are most carbon emissions concentrated highly around ?

Answer 28

Polluting cities. The worst 21 polluting cities contribute 10% of all energy related carbon emissions.

Question 29

How will polluting cities become worse?

Answer 29

By 2030 the worst 10 polluting cities will contribute to the same 10% of all energy related carbon

Question 30

Animal store

Answer 30

Fossil fuels are intercepted and stored in plants.

Animals will then eat plants and will have a larger store of carbon.

When animals die they decay and the amount of carbon is realised will be a high amount.

Question 31

Ocean species

Answer 31

when organisms die they sink to bottom of ocean floor and over time become cemented together creating sedimentary rocks which means they store carbon as stone.

(Biological pump)

Question 32

Pollution and fish

Answer 32

Fish becoming more threatened as more plastic enter ocean by humans.

Fish eat this or become trapped in it and die.

This will then release co2 and reduce the biological pump

Question 33

Positive feedback.

Climate

Answer 33

An increase in burning fossil fuels means the climate becomes warmer as there is more carbon emissions suspended in atmosphere.

This will then increase surface temp of oceans.

Which will increase evaporation from oceans.

More water vapour in atmosphere.

This enhances the greenhouse effect causing more warming

Question 34

Negative feedback climate.

Answer 34

An increase in burning fossil fuels means the climate becomes warmer as there is more carbon emissions suspended in atmosphere.

Meaning more trees growth and more photosynthesis occurs.

This increases the biosphere carbon store as trees act as natural carbon store taking in co2 from atmosphere.

Potentially nullifying affects of extra carbon.

(However, Warmer temps can lead to desertification of landscapes, reaching number of trees taking in carbon. Less biosphere store and more co2 In atmosphere)

Question 35

Transport -cars

Answer 35

More cars = more wealth = more materialism meaning more road networks/ congestion and in then co2 emissions increase.

However, in modern society more electric cars are being made which helps decrease carbon emissions but to power cars the powers is generated using carbon so in turn shifts the problem.

Question 36

Transport - airports

Answer 36

More airports = more wealth = advanced technology.

Means more area cleared and less trees.
This not only reduces natural store of carbon in biosphere but more aeroplanes means large source of carbon emissions given off

Question 37

Agriculture - trees 2 plants

Answer 37

Brazil where slash and burn / clearing methods remove forest for land use whether that’s for infrastructure/ livestock / agriculture.

It means less carbon is able to store in biosphere as trees absorb the most co2 from atmosphere then smaller plants.

More co2 in atmosphere as less photosynthesis- more cc

Question 38

Agriculture - grass 2 crops

Answer 38

In cases were natural grasslands have been now used for crops or afforestation this in turn implements a carbon store as they take in more co2 into their leaves when growing.

Question 39

Residential

Answer 39

Increase in population = increase demand in housing.

Meaning vegetation/ trees are removed and replaced by impermeable surfaces. Reduction in biosphere store. Less photosynthesis.

More housing = more power = more carbon transferred from lithosphere to atmosphere due to combustion of fossil fuels.

(More trees planted as decoration - reduce noise/ protection so absorb lots of co2 when growing)

Question 40

Commercial

Answer 40

More factories = more co2 emissions from combustion of fossil fuels = more co2 transferred from lithosphere into atmosphere - cc

More workers = more waste into ocean = co2 would then diffuse into hydrosphere = contaminate water / poison sea life = death of sea life releases co2 back into atmosphere

Question 41

what is Carbon sequestration ?

Answer 41

Capturing co2 and storing in long term storage.

Question 42

What is geological sequestration?

Answer 42

Carbon captured at source such as power plants and then injected into liquid form underground storage.

Depleted at oil / gas reservoirs / deep ocean

Experimental

Question 43

What is biological sequestration

Answer 43

Capturing carbon long term from atmosphere within plants.

Stores it in stems and roots as well as soil

Reduces co2 in atmosphere and would mean ecosystems would be positive leading to enrichment of wildlife - negative feedback effect

However plants and trees can be lost to fires

Question 44

Ocean sequestration

Answer 44

Carbon stored in oceans due to large surface area

Sinks within weeks and months and it’s long term

Question 45

Strategies

Answer 45

Renewable energy - wind/ solar.

Public transport

Walking / cycling

Flying less - employees don’t travel to other place to discuss work they just FaceTime

Question 46

Disadvantages of land based plantations?

Answer 46

Slow growing
Active monitoring
Management for lifetime of plantation