Climate Change Flashcards
Significance of Ocean
Covers 70% of Earth
Estimated to absorb 38% of anthropogenic CO2
Contains 40,000 GtC of carbon - second largest store
Coral Reefs provide food and livelihoods for 500 million people
Impact of climate change - ocean acidification
More carbon in the atmosphere means more carbon can be dissolved into the ocean.
This dissolved carbon forms carbonic acid which reacts with carbonate to form bicarbonate.
This then means there are less carbonate ions for shells and corals to form, reducing biodiversity.
Since 1750, pH has decreased by 0.1
However, increased ocean acidity allows for more calcium carbonate rocks to be absorbed, increasing the supply of carbonate ions available and soaking up excess carbon.
If atmospheric concentrations of CO2 double, coral calcification rates are expected to decline by around 30%
Impact of climate change - sea level rise
Initial increase in temp. → Highly reflective sea ice caps melt and are replaced by water → dark ocean absorbs more solar radiation → ocean temp. increase → sea ice caps melt.
Melting terrestrial ice - warmer temp. mean increased rate of melting in the summer and decreased snowfall in winter - resulting in an imbalance - net gain of water
Thermal expansion - when water heats up it expands - 50% of century’s sea level rise is attributed to this.
Impact of climate change - Agriculture
Likely to affect food supply at global, national, and local levels. It can disrupt food availability, reduce access to money and affect food quality. This is due to rising temperatures, changes in precipitation patterns, and reductions in water availability. This may be amplified by other stressors, such as rapid population growth. May be more prominent in developing countries.
Impact of Climate Change - coasts
Leads on from sea-level rise. Since 1901, global average sea level has risen by 15cm. Low-altitude and islands nations are at risk of flooding or submersion. If the Maldives were to be submerged, 550,000, would be forced out of the country. A rise in 1m would see 15 million Bangladeshis displaced.
Mitigation
Reduce and prevent the emission of GHG to limit global warming - effective on all scales:
Global - countries work together to reduce emissions e.g. Paris Agreement, IPPC (International Panel on Climate Change)
Regional - government can reduce reliance on fossil fuels, improve public transportation.
Individual Mitigation - use car less
Adaptation
Ways of increasing our capacity to cope with the changing climate to reduce the severity of the impacts.
IPPC
Intergovernmental body of the UN. Its job is to advance scientific knowledge about anthropological climate change.
Carbon Trading
Buying and selling of credits that permit a company to emit a certain amount of CO2 or other GHG.
Timeline of summits
Rio Earth Summit - 1992:
UN conference developed an action plan for sustainable development that can be implemented on global, national and local scales.
Kyoto Protocol - 1997:
The first international treaty to become law. Over 170 countries agreed to reduce carbon emissions.
Copenhagen Accord - 2009:
World leaders met to tackle climate change. They pledged to reduce emissions by giving financial support to LIC’s, no legally binding contract.
Agenda 2030 - 2015:
17 sustainable development goals were developed by the UN general assembly for a more sustainable future.
Paris Agreement - 2015:
195 countries adopted first global legally binding climate deal
Adaptation - integrated rainwater harvesting
Rift Valley - Kenya
Expected to be increased rainfall but also increasing temperatures and more hot days and nights leading to water insecurity
Adaptation in village - construction of two water pans to supply water for livestock, domestic use, and subsistence irrigation
- establishment of two tree/vegetable nurseries for agro-forestry, afforestation and reforestation
-training and education in leadership and environmental conservation
-overall increased local capacity for adapting to the effects of climate change.
Adaptation - bottom-up responses
Fiji suffers from a lack of freshwater due to decreasing rainfall and higher temperatures. Locals are adapting to this by rationing water, changing diets, and setting up inter-village sharing networks.
In the Philippines, coastal flooding has led island communities to adapt by constructing houses on stilts.
Mitigation - renewable energy
Reducing the amount of CO2 being released through the burning of fossil fuels.
Wind - there has been a rise in onshore and offshore wind power in the last five years due to lowering costs and improved technology. Almost zero emissions but public acceptance may be an issue.
Solar - dramatic reduction in costs of solar panels has made it more feasible. Residential and commercial rooftops can be utilised effectively.
Mitigation - CO2 removal
Negative emissions - taking carbon out of the atmosphere:
Widespread of reintroduction of European bison could increase the amount of carbon absorbed by the grasslands tenfold. This is through natural regeneration of forests, ‘proforestation’ (allowing the forest to grow older) and natural grazing reducing combustible biomass.
