EQ1 - Planetary Health Part 2 - CARBON Flashcards
Explain the Greenhouse effect
- Solar radiation passes through the clear atmosphere most radiation is absorbed by the earth surface and warms it
- Some solar radiation is reflected by the earth and the atmosphere
- Infrared radiation is emitted from the earths surface
- Some of the infrared radiation passes through the atmosphere whilst SOEM passes through the atmosphere while some is absorbed and re emitted, this warms the earths surface
How does the greenhouse effect maintain planetary health?
- 31% of carbon is reflected by clouds and gases in the atmosphere while remaining is absorbed by earths surface and oceans
- fast carbon cycling was fairly balanced before industrial revolution
- slow carbon cycle - volcanism and sedimentation have been fairly constant
The influence of carbon on the greenhouse effect:
- climate driven by short wave solar radiation
- increases threat and means less radiation reflected as carbon is a Barrier
What is the role of ocean and terrestrial photosynthesis in regulating the atmosphere
- Physical pump - thermohaline circulation
- Biological pump - terrestrial photosynthesis
- Solubility pump - carbon stored in the upper ocean
State facts of fossil fuel combustion
- industrial revolution burnt fossil fuels at increasing rates
- is a fast flux
Intergovernmental plan suggests increased fluxes into biological stores allows: - increased soil storage in high latitudes
- loss of storage due to unfreezing of permafrost in southern oceans due to global warming
Name the 4 human activities that contribute to the enhanced greenhouse effect
- Land use change
-1/10 of annual carbon through farming practices - Amazon - 70% of deforestation for cattle ranching
- fertilisers cause methane emissions - Deforestation
- accounts for 20% fo annual carbon
- main impact is when carbon cycle is interrupted and used for purposes which reduces carbon sequestration and land becomes a carbon source rather than carbon sink - Urbanisation
- replacing countryside with infrastructure
- these areas account for 97% of all humans caused CO2 emissions
- cement contributed to 7% of global CO2 - combustion of fossil fuels
- results in CO2 beating released
What are the positive and negative feedback loops
- In a system, change in output can be redirected back at the inputs. This may dampen initial change ( negative feedback loop) or internally ( positive feedback loop)
- negative feedback loop - speeds up or amplifies ( bad )
- positive feedback loop - slows down, more vegetation
What are the importance of mangroves
- trap nutrients and is rich in sediment
- prevent coastal erosion
- provide protection against extreme weather + tsunamis
- provide fish nurseries
- sequester 1.5 metric tonnes of carbon per year
- if 2% of carbon is lost, the carbon released will be 50x the natural sequestration rate
- climate chnage poses a threat
- being cleared for tourism and agriculture
What are the implications of enhanced greenhouse effect on ecosystems
- ecosystems help regulate carbon an hydrological cycle. Global warming could impact coral reefs and tropical rainforests.
- Coral reefs
- Threatened with lower oxygen levels and high rates of magnitude of ocean acidification as well as rising temperatures which alter fondation of the food chain - Tropical rainforests
- As trees dry out, the tree will be much susceptible to fire and diseases causing the release of massive amounts of CO2 back into the atmosphere
Terrestrial photosynthesis
Ocean and terrestrial photosynthesis play an important role in regulating the composition of the atmosphere. Soil health is influenced by stored carbon, which is important for ecosystem productivity.
A balanced carbon cycle is the outcome of different components working in a sort of harmony with each other.
Photosynthesis
Photosynthesis by terrestrial and oceanic organisms plays an essential role in keeping carbon dioxide levels relatively constant and thereby helping to regulate the Earth’s mean temperature.
The amount of photosynthesis varies spatially, particularly with net primary productivity (NPP). (This is the amount of organic matter that is available for humans and other animals to harvest or consume). NPP is highest in the warm and wet parts of the world, particularly in the tropical rainforests and in shallow ocean waters. It is least in the tundra and boreal forests.
Soil Health
- soil health depends on the amount of organic carbon stored in soil which depends on inputs, outputs, erosion and use in plant and animal productivity
- active Carbon is found in top soil, organic carbon is concentrated on the top
layer and is easily eroded. Oil erosion is a major threat to carbon storage and soil health
Solubility cycle
The solubility cycle also is a key process in the oceans. The solubility
cycle is caused when the carbon dioxide absorbed by the oceans from the atmosphere forms carbonic acid which in turn reacts with hydrogen ions to form bicarbonates and then further reactions forms carbonates which are stored in the upper ocean. Some organisms use these carbonates to make shells or skeletons. When these organisms die some material sinks right to the bottom of the ocean and forms the sea bed sediment store (1750 GtC) where over time through chemical and physical processes the carbon is transformed to rocks such as limestone. This is a particularly important process in regulating the composition of the atmosphere as it locks up carbon in the long term carbon cycle and not allows it to return to the ocean surface and so possible venting into the atmosphere as the physical pump does.
