Carbon 2.3

Question 1

What is the order of biomes is terms of net primary productivity and where is most the carbon stored in this biome?

Answer 1

1. tropical rainforests - above ground biomass
2. savannah and tropical grasslands- soil
3. temperate forests- biomass and underground in roots
4. temperate grasslands - soil
5. boreal forests (taiga) - soil
6. deserts and dry shrub land -soil
7. tundra - permafrost

Question 2

What are the positive role of greenhouse gases?

Answer 2

They absorb and reflect back some of the radiated heat from earth’s surface. By retaining this heat, they keep the earth’s surface at 16 degrees Celsius which is warmer than it would be otherwise - warm enough to sustain life on earth

Question 3

What are the characteristics of CO2?

Answer 3

It’s the most common greenhouse gas making 89%.
Makes up only 0.04% of earth’s atmosphere and 20% will stay in the atmosphere for 800 years.
It’s main source is burning fossil fuels and deforestation and since 1850, it has increased by 30%

Question 4

What are the characteristics of CH4?

Answer 4

-stays in the atmosphere for 10 years
-makes up 7% of all greenhouse gases
-Its main source is gas pipeline leaks and rice and cattle farming
-It’s 21 times more powerful than CO2 in warming power
-It’s increased by 250% since 1850

Question 5

What are the characteristics of Nitrous oxide (N20)?

Answer 5

-Stays in the atmosphere for 100 years
-contributes to the destruction of the ozone layer
-makes up 3% of all greenhouse gases
-its main sources are jet aircrafts, cars, fertilisers and sewage farms
-It’s 250 times more powerful in warming power than CO2 and has increased by 16% since 1850

Question 6

What are the characteristic of halocarbons?

Answer 6

-make up 1% of all greenhouse gases
-the sources are from industry, solvents and cooking equipment
-they are 3000 times more powerful in warming power compared to CO2

Question 7

How has the greenhouse effect been enhanced?

Answer 7

The concentration of greenhouse gases has increased by 25% since 1750. Since the 1980s, 75% of CO2 emissions have come from burning fossil fuels.
This is leading to increased temperatures, as well increased evaporation, condensation and cloud cover, trapping more heat in the atmosphere
When carbon is released, it combines with oxygen to form CO2 and nitrogen combines with oxygen to form nitrous oxide

Question 8

What controls temperature worldwide in varying locations?

Answer 8

The amount of solar energy reaching the earth’s surface varies at different locations; the angle of the sun’s rays makes solar insolation intense at the equator, but dispersed over a wide area at the poles
The albedo also affects how much affect how much heat is absorbed or reflected - snow reflects heat while dark forests absorb it.
Heat is also redistributed by air movement, caused by both pressure differences and ocean currents

Question 9

How does temperature impact precipitation?

Answer 9

Warm air rises and cools, leading water vapour to condense and clouds to form causing more rain

Question 10

What is rainfall like at the equators?

Answer 10

Because solar radiation is most intense here, convection and low pressure systems dominate, meaning rainfall is high all year

Question 11

What is rainfall like 30 degrees north and south of the equator?

Answer 11

Air pressure rises and so precipitation decreases. Clouds rarely form here

Question 12

What is rainfall like in the mid-latitudes?

Answer 12

Air masses of different characteristics meet and low-pressure systems bring rainfall

Question 13

What is precipitation like near the poles?

Answer 13

Nearer the poles, precipitation levels fall as the air cools and sinks creating high pressure. This creates dry and dense conditions - creating polar deserts

Question 14

What actions help to regulate the composition of the atmosphere and the levels of carbon in it?

Answer 14

-phytoplankton in the oceans sequester 5-15 GT of CO2 per year through the process of photosynthesis - pumping it out of the atmosphere and into the ocean
-terrestrial photosynthesis enables plants to sequester 100-120 Gt of CO2 per year

Question 15

What are the different factors that will alter the earth’s carbon balance as it affects carbon sequestration?

Answer 15

Anything that affects the number of phytoplankton or the area of land covered by forest (deforestation, land use change)

Question 16

Which two ecosystems are particularly effective in carbon sequestration?

Answer 16

-tropical rainforests
-coral reefs and mangroves

Question 17

Which ecosystem is particularly ineffective in carbon sequestration?

Answer 17

Deserts have sparse vegetation and so little CO2 is absorbed here

Question 18

What are the three main effects of burning fossil fuels?

Answer 18

Changes the climate balance
Has implications for the climate
Arctic amplification

Question 19

How does the burning of fossil fuels impact the climate balance?

Answer 19

When carbon sources and sinks are in balance, the carbon cycle is in equilibrium. However, human activities have increased CO2 in the atmosphere, without any corresponding increased in the natural sinks. Therefore atmospheric stores of carbon have increased, increasing global temperature

Question 20

How has the increased burning of fossil fuels impacted the climate?

Answer 20

Rising levels of CO2 are causing global temperature increases. However, increases vary:
-in Europe land temps will increase more than global average
-annual precipitation is projected to increase in Northern Europe and decrease in Southern Europe - increasing the differences between the dry and wet regions
-Extreme weather events are likely to increase in both intensity and frequency

Question 21

What is the Arctic Amplification?

Answer 21

The Arctic region is warming twice as fast as the global average. Melting permafrost releases CO2 and CH4, increasing the concentration of these greenhouse gases, leading to increased global temperatures and therefore further melting.

Question 22

How is the Arctic changing?

Answer 22

Shrubs and trees previously unable to survive in tundra, have started to establish themselves as well as the red fox has started to spread northwards in Alaska, and now competes with the Arctic fox for food and territory

Question 23

Why is more CO2 being absorbed in the Arctic?

Answer 23

Increased Arctic sea ice melting means greater expanses are now exposed to direct sunlight. Increasing photosynthesis by phytoplankton is now resulting in algal blooms in Arctic waters and so more CO2 is being absorbed there

Question 24

Why do some scientists not agree that melting permafrost will release stored carbon as CO2 and CH4?

Answer 24

-Some studies show that as permafrost thaws, the stored carbon remains in the soil and is used by new vegetation
-Warmer temperatures accelerate decomposition, releasing carbon and nutrients. Nutrients then encourage plant growth and the removal of carbon from the atmosphere through photosynthesis

Question 25

What are the impacts of temperature and precipitation pattern changes on the hydrological cycle?

Answer 25

In summer months, much of Europe’s water comes from the melting of Alpine glaciers. However, by 2100, the Eastern Alps will be ice-free, affecting the hydrological system:
-precipitation in the form of snow could diminish and rainfall patterns change
-River discharge patterns change with greater flooding in winter and drought in summer

Also:
-reduced sea ice
-ENSO may be more intense as a result of a warming atmosphere
-increased permafrost temperatures
-increased evaporation rates trigger more moisture circulation and intense precipitation events

Question 25

What are the two different carbon pathways that could occur in the Arctic?

Answer 25

Pathway 1 - negative feedback loop- shrubs and trees invade the Arctic and store more carbon than being released
Pathway 2- positive feedback loop - decomposition of plant material in wet soils reduces carbon storage and releases more greenhouse gases into the atmosphere.

Question 26

What causes and consequences of climate change lead to increased atmospheric carbon?

Answer 26

-Burning fossil fuels (increased CO2 emissions)
-Coral reef bleaching (less photosynthesis)
-burning of the amazon rainforest (carbon released and less photosynthesis)
-increased desertification (little vegetation means little carbon is sequestered)
-Melting permafrost (Releases CO2 and CH4 which leads to increased global temperatures and further melting)

Question 27

What causes and consequences of climate change lead to reduced atmospheric carbon?

Answer 27

-rise in algal blooms causes more photosynthesis
-shorter winters due to climate change means less CO2 released by organic decay and more plant growth
-Arctic sea ice melting means more photosynthesis by phytoplankton
-reduced snow cover in tundra means more shrubs and trees so more photosynthesis
-Warming arctic means more decomposition, carbon and nutrients meaning greater plant growth and photosynthesis