Water, Carbon, Climate and Life on Earth (Unit 1, Topic 4) Flashcards
The key role of the carbon and water stores and cycles in supporting life on Earth with particular reference to climate. The relationship between the water cycle and carbon cycle in the atmosphere. The role of feedbacks within and between cycles and their link to climate change and implications for life on Earth. Human interventions in the carbon cycle designed to influence carbon transfers and mitigate the impacts of climate change.
How do Land Impacts enhance or negate Climate Change?
Carbon moves between the lithosphere, cryosphere and biosphere with both physical and human factors resulting in positive and negative feedback
Photosynthesis, essential for plant growth and in the form of wood and fossil fuels, more Co2 leads to increased growing season for plants but also increased decay of organic matter
Permafrost covers 22% of land remaining frozen for 2+ years when temperature increases more carbons released, resulting in a positive feedback loop, currently permafrost holds 1,672 GtC
How does Ocean Impacts enhance or negate Climate Change?
Oceans cover 70% of our planet containing 38-40,000 GtC making it Earths 2nd largest store. It is believed that oceans have absorbed 38%of anthropically produced Co2 which helps to create a buffer to regulate carbon concentrations on land and in the atmosphere
30% of released Co2 is diffused into the ocean though direct chemical exchange, this creates a carbonic acid making the oceans less alkaline. Carbonic acid reacts with carbonate ions in the water to form bicarbonate. However, animals like coral and phytoplankton need these ions to make their shells.
Melting sea ice is part of a feedback mechanisms. Highly reflective ice is replaced by more absorbent water, This then absorbs more sunlight which amplifies warming but also provides a habitat for algae. The loss affects food chain from krill to bears. Decrease in salinity in the deep North Atlantis, more freshwater added to oceans, slowing down the large-scale oceanic circulation in the North East Atlantic
How do Atmospheric Impacts enhance or negate Climate Change?
Increasing Co2 is now higher than any change in the last 800,000 years and is set to increase further. This led to enhanced greenhouse effects as much as 20% of additional Co2 will remain in the atmosphere for thousands of years.
Energy is constantly flowing from the atmosphere in the form of sunlight, 30% is reflected back into space, the rest is absorbed. Vegetation removes Co2 and releases water and oxygen within dense vegetation experiencing high rates of photosynthesis and respiration. This causes the level of humidity and cloud cover which can have regional climates and rainfall
What happens after Changing Climate Budget has been Impacted?
All areas will be significantly effected with the ocean potentially experiencing tipping points for biodiversity. There could be economic crises and social problems. There will be an increase in loss of habitats, animals and plants as well as diseases and increases in sea salinity and ocean acidity. Droughts will become more common as well as flooding. USA will lose 23% GDP for every degree.
How is Climate Change Managed Globally?
Countries work together to reduce emissions e.g. Kyoto and Paris Agreements allow for the way in which global affairs affecting the whole world are managed
How is Climate Change Managed Regionally and Nationally?
Governments can reduce reliance on fossil fuels, improve public transport and design urban areas more sympathetically
How is Climate Change Managed Individually?
Use your car less, turn off lights, reduce carbon emissions
What is the IPCC?
Created in 1988 the Intergovernmental Panel on Climate Change aims to provide regular assessments of the scientific basis of climate change its impacts and future risks provide options for mitigation and adaption
What is the Carbon Trading Scheme?
A market based system aimed at reducing greenhouse gases that contribute to global warming, particularly carbon dioxide emitted by fossil fuels. Countries and businesses can pay other organisations to make them reduce their Co2 emissions whilst maintaining their own balancing their combined urban emissions
What are the 5 Global Agreements on Climate Change?
Rio Earth Summit (1992)
Kyoto Protocol (1997)
Copenhagen Accord (2009)
Agenda 2030 (2015)
Paris Agreement (2015)
What is River Regime?
A river regime shows how the discharge of a river varies over a longer period of time- usually a year
What factors affect Regime?
-Inputs
-Stores
-Transfers
-Outputs
What are the effects of Deforestation on River Regime?
Decreased Canopy- Decreased interception makes decreased evapotranspiration leading to increased surface runoff
Bare Soil- Soil compaction causes decreased infiltration and less through flow with increased surface runoff
Farming Practices- Soil compaction reduces infiltration and therefore increases surface runoff
Water Abstraction- Dry and compact soil will reduce infiltration and increase surface flow
Water from Roots released- Increased humidity causes increased precipitation meaning antecedent conditions causing saturated soils and increased surface flow
How does Deforestation cause Variation in River Regime?
A lack of evapotranspiration and moisture movement in the atmosphere has caused a lack of precipitation downwind and less discharge for the River Negro. This reduces the water reaching areas of the Amazon. Less interception also increases more runoff in some areas into rivers. Only about 30% of the water reaches the sea, lots of minerals are lost.
In October 2023 the Rio Negro recorded the lowest water level for 100 years due to deforestation. By 2020 the Amazon has lost 2.3 million hectares
How do Seasonal Changes cause Variation in River Regime?
Seasonal Changes can increase or decrease precipitation levels, air moisture, temperature and evapotranspiration levels. This could cause an increase or decrease in surface runoff, infiltration, interception and groundwater runoff.
Large volumes of rainfall causes the Amazon river to rise and fall 40ft with a 77%-88% humidity change
