CARBON CYCLE AND ENERGY SECURITY CASE STUDIES Flashcards
Importance of Mangroves
What are Mangroves?
- A mangrove is a shrub or small tree that grows in coastal saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves
occur worldwide in the tropics and subtropics, mainly between latitudes 25° N and 25° S.
Why are they important?
* They sequester 1.5 metric tonnes of carbon per hectare per year.
* If just 2% of the worlds mangroves are lost, the carbon released will be 50 times the natural
sequestration rate.
* They prevent coastal erosion.
* They trap nutrient rich sediment.
* They provide protection against extreme weather and tsunamis.
* They provide fish nurseries.
o 520 million people rely on fisheries.
Threats
* They are being cleared for tourism, shrimp farms and aquaculture.
* Shrimp farms pose the greatest threat. Hundreds of thousands of acres are being cleared to create
artificial ponds.
* Climate change poses a threat to mangroves.
o Mangroves, according to IPCC forecasts, are predicted to decline in area, and structural
complexity.
Synoptic Link – Coasts
- Mangroves are an essential defence for coasts against coastal erosion, storm surges and tsunamis.
* A root cause of the massive fatalities during the 2001 Indian Ocean Tsunami were the loss of
mangroves along the Pacific coast.
* Mangroves were cleared to create tourism resorts and beaches, which increased the environmental
vulnerability of coastal settlements and put tourists in direct risk from tsunamis.
* The loss of mangroves is accelerating due to coastalisation.
Impact of climate change on coral reefs and associated tourism
Importance
* Coral reef structures buffer shorelines against waves, storms, floods - helping to prevent loss of
life, property damage and erosion.
* They provide tourism opportunities – e.g. snorkelling along the Great Barrier Reef.
* Their destruction would affect LICs and NICs – For example several million people live in US coastal
areas.
Tourism and climate change
* Sea level rise will affect coastal tourism infrastructure.
* Climate change will lead to changes in biodiversity (migration of species away, coral bleaching),
affecting eco-tourism.
* Increased stormy weather will discourage people from going on holiday.
Deforestation in Madagascar
- In 1950, there was 11.6 million Hectares of rainforest.
- In 1985, there was 3.8 million Hectares of rainforest.
Deforestation has a major impact on terrestrial carbon stores.
The rivers Sofia and Betsiboka have turned red due to soil erosion. More than 400 tonnes per hectare per
year of loose soil are being washed into these rivers.
Conversion of grassland to farmland in the US
The grasslands are being converted to meet the US Environmental Protection Agency’s renewable fuel
standard policy
* Increasing the use of ethanol in petrol.
* Boosting the economies of rural US states.
* Reducing international dependence.
* Reducing CO2 emissions.
Over 5.5 million hectares have disappeared, impacting wildlife hugely
