EQ1.3 Flashcards
Explain why a balanced carbon cycle is important for sustaining other Earth systems (8) 4 points
A balanced carbon cycle is when fluxes keep carbon sources and carbon sinks acting as an equibrilluim, allowing a steady amount of co2 within the atmosphere which is vital in helping to maintain and stabilise global temperatures and ecosystems
-One such ecosystem that can be seen to rely on this balanced carbon is the oceans, one of the largest carbon stores and sinks which operates a number of carbon pumps to help sequester co2 out of the atmosphere as well as store it within the deeper ocean currents. This mainly operates by the biological carbon pump via phytoplankton in the ocean surface that use photosynthesis to sequester carbon and then this not only is then kept within the ocean as a store, it is also used by marine organisms such as coral that also absorb huge amounts of carbon. However as a result of increasing levels of co2 within the atmosphere, this is leading to the oceans to acidify, reducing the amount of co2 being able to be absorbed as organisms can not use the alkaline calcium carbonate ions needed, just further impacting on the ability for the carbon cycle to maintain a balance.
-This can also be seen within the artic ecosystem due to artic amplification as a result of melting permafrost and so releasing CO2 and methane, altering whole system with new vegetation growth and animals, further showing the impact that increasing levels of co2 are having on whole environments.
-Soils also heavily rely on a balanced amount of carbon to maintain and regulate soil health, however as increasing levels of co2 are being added to the atmosphere, and temperatures are increasing, if soils begin to dry out this will effect vegetation growth, leading to reduced decomposition. This then also means reduced ability to store water, which may then alter the whole nutrient cycle further reducing plant growth. Also if winters become shorter less CO2 may be released, effecting storage capacity, and further showing just how vital a balanced carbon cycle is.
Assess the likely impacts of climate warming on the components of the carbon cycle in a Tundra (artic) environment 12 marks
Intro- Due to increased levels of Co2 in the atmosphere this is increasing global temperatures, with this having a significant impact on the carbon cycle in particular within the tundra environments.
-the main impact that can be seen is that of the warming temperatures on the permafrost, leading to the thawing of this permafrost which is increasing both rates of decomposition and then amounts of co2 being released. Due to the increasing peat depth the further into the ground and so where permafrost is located, the rate of decomposition is much slower and so huge amounts of carbon is stored and locked within this frozen ground.
However as this permafrost is beginning to thaw, this carbon as well as methane is being released in huge quanitites which has then led to a positive feedback loop to occur. This is where as these increased gases are being released, this is then fuher adding to greenhouse gas concentrations, just adding to the warming temperatures and so leading to further melting. As this permafrost has carbon stored over many centuries, this large amount being released will clearly be significant.
-However this positive feedback loop may lead to greater vegetation growth due to the melting of ice increasing soil available for plants to be sustained. As vegetation is able to sequester carbon out of the atmosphere via photosynthesis this may lead to a balance with the amoun of carbon being released via the permafrost. However as can be seen, the amount of carbon that is actually stored within vegetation is very insignificant compared to that within the frozen permafrost and as this only stores carbon for months rather than centruries, much of the carbon is then released anyway so unlikely to act as such a store.
-Warming temperatures are also leading to the warming of soils, increasing the rate of decomposition as well s the ability for soils to store carbon from the vegetation growth. Although when looking again at peat depth, soils do not store carbon for as long as permafrost again indicating that this store is not as significant.
Overall as all of these processes are interlinked, with warming temperatures impacting on both the amount of carbon being stored and being released, the impact on the biogeochemical carbon cycle will be very significant. Howevre the main impact can be seen on the thawing of the permafrost, a previously significant carbon store that is now acting more as a carbon source instead.
Evaluate/assess the extent to which geological processes control the carbon cycle (20)- intro + 4 points + conclusion 2 PARAS PART 1
Intro- the geological carbon cycle can be seen to be the basis of the whole carbon cycle with a number of processes being involved, however with increasing influence from anthropogenic factors it could be said this is playing a diminishing role.
-The geological carbon cycle can be seen to play a large role when looking at the sheer amount of carbon that is exchanged naturally between the stores of the oceans, land and atmosphere every day. The main natural processes involved in this can be first seen when looking at the role of volcanoes, where terrestrial carbon that is held within the mantle is released into the atmosphere via outgassing during eruptions. This then combines with rainfall within the atmosphere, leading to chemical weathering which involves the dissolving of carbonate rich rocks as a result of weak acid rain produce from this mixture of carbon within the atmosphere. Through river transport this carbon is deposited within the oceans, where other carbon rich organic matter such as animal shells also sinks and builds up, only then being released in further eruptions orduring metamorphosis where these sedimentary rocks are baked along subduction zones. This therefore is a clear example of how the geological carbon cycle plays such an important role in maintaining levels of carbon with each of these natural processes being so interlinked enabling a balance between carbon released and absorbed within the cycle.
-A further way it can be seen that the geological carbon cycle plays an important role can be seen in maintaining an equilibrium in natural events that may lead to increased co2 being released. For example during volcanic eruptions, due to huge amounts of co2 being released if this was kept within the atmosphere clearly large impacts would be had, such as…. However as temperatures initially increase, this increases atmospheric moisture, leading to acid rain and so with the process of chemical weathering occurring leading to calcium carbonates to be released from rocks and then deposited into the oceans, the balance is returned.
Evaluate/assess the extent to which geological processes control the carbon cycle (20)- 2 CONTRASTING PARAS PART 2
However it must be said that the increasing influence of human action within the bio-geochemical carbon cycle is playing an increasing role in this cycle, mainly through the release of added co2 into the atmosphere. Within the natural bio-geochemical carbon cycle, the processes of photosynthesis, respiration and decomposition play an important role in determining how much carbon is stored, released, transferred and absorbed within the cycle. However the anthropogenic combustion of fossil fuels as well as human impacts on deforestation is altering this. For example sedimentary rocks that are usually help store carbon within the deep under the ground are now being extracted for things such as coal and being burned, leading to large amounts of carbon to be released and this flux occurrining very quickly, as well as reducing the carbon stored. This is then increasing co2 concentrations, and reducing the ability for the natural equibrillium to be maintained, especially due to overall increased temperatures altering the processes such as chemical weathering that may only occur periodically. Large amounts of co2 being released altering the ability of natural process to occurr. Infuence of deforestation?…..
-Although, it must be emphasized that the amount of carbon exchanged via human causes such as the burning of fossil fuels is still very little compared to that of the geological carbon cycle. For example when looking at overall flux size, much more carbon is released via natural stores such as the oceans or photosynthesis than through burning of fossil fuels, showing that although human influences are playing a role, currently the geological carbon cycle is still the main key process, although such large amounts of stored carrbon are being released + not being balanced with increase in carbon sinks/stores, this may alter its role in the future.
Conclusion- Therefore it can still be seen that geological processes still play a large role in the carbon cycle, although it could be said as energy usage and demand continuous to grow at a rapid rate, this may change in the future.
