Water, Carbon and Climate Change Flashcards
How is carbon stored in the human body?
As glucose
What does carbon do in the human body?
Carbon assist cellular respiration.
What % of carbon makes up the human body?
18%
In trees, what is the carbon content of biomass (e.g. stems, branches, roots)?
50%
How is carbon stored in plants passed on to animals?
Through food chains.
An animal has eaten a plant so has gained carbon. How is this carbon returned to the atmosphere? And in what form?
Through respiration and decomposition, carbon is returned to the atmosphere in the form of carbon dioxide.
Natural, unpolluted rainwater is naturally _____?
Acidic
What’s the pH of natural rainwater?
5.6
Why is rainwater naturally acidic?
Due to the presence of carbon dioxide, nitric acid and sulphur dioxide found int he troposphere.
What happens if air is polluted with high levels of sulphur dioxide from the combustion of fossil fuels?
Rainwater can become very acidic with a pH of 4
How does acidic rainwater affect weathering?
On contact with carbonate rocks (e.g. limestone / chalk), the acid rain converts calcium carbonate into calcium bicarbonate, which is soluble.
This process is known as carbonation.
What happens after the process of carbonation?
The dissolved carbon is carried away by rivers to the oceans where it is used for shell growth and ultimately buried to form new limestone deposits.
Some carbon is transferred directly back into the atmosphere.
Water cycle feedback loop - the Arctic?
- Ice reflects heat from the sun so less heat is absorbed by the surface.
- The size of the Arctic ice has been shrinking at an alarming rate. This exposes more water to subsequently less reflection and more absorption of heat from the sun.
- This warms the water and further melts the ice coverage.
This affects the size and magnitude of the water transfers between the land, ocean and atmosphere.
The local and regional effects of these changes could have profound impacts on Earth such as affecting patterns of precipitation and the availability of fresh water.
Also political and economic such as no Artic sea ice will affect trading routes.
Carbon feedback cycle - good?
Warmer temperatures in the Artic have led to…
Increased growing season for plants and this has increased the absorption of carbon from the atmosphere through photosynthesis.
Carbon feedback cycle - bad?
Warmer temperatures in the Arctic have led to…
The permafrost melting, particularly in Siberia.
Organic matter (plants and animals) trapped in the frozen ground act as an important carbon store.
However, on melting the organic matter in the permafrost starts to decompose as oxygen is introduced.
The bacteria involved in decomposition produce carbon dioxide and methane as a wast product. These gases bubble to the surface and escape into the the atmosphere.
