Carbon - EQ3 - Peatlands Flashcards
1
Q
Why are peatlands important
A
- Peatlands have a net cooling effect on climate, reduce flood risk, and support biodiversity
- Healthy peatlands can reduce flood risk by slowing the flow of water from the uplands, and by providing floodplain storage in the lowlands
- They provide important nesting and feeding grounds for many wading birds & habitats for rare insects and plant
2
Q
How do healthy peatlands mitigate climate change
A
- Peatlands store vast quantities of carbon - ‘locking in’ an estimated 3.2 billion tonnes in the UK alone,
- & where peat continues to form this helps to offset the effects of human activities
3
Q
What is the uncertainty about Peatlands helping to mitigate climate change
A
- However, overall, peatlands in the UK and around the world are estimated to be a net source of greenhouse gas emissions to the atmosphere,
- as opposed to a net sink,
- due to the way they have been managed now and in the past
4
Q
Why is peatland exploited by humans
A
- As a results, farmers and foresters have drained large areas of upland and lowland peat throughout the UK, as its very fertile when drained:
- upland bog - drained for conifer forestry and livestock grazing
- lowland raised bogs, epecially ‘fen’ peat - around the UK and Ireland for use as a growing medium by the horticulture industry and by gardeners
5
Q
What is the impact of peatland degredation
A
- this releases carbon into the air
- While it takes 1,000 years for 1m of peat to build up, drainage means the land surface reduces an average of 1cm to 2 cm per year through subsidence due to peat oxidation
- large areas of lowland peat ( East Anglian Fens ) are now below sea level —> flood risk
- Ditches to enable drainage —> increase flood risk downstream
- Drying out the peat soil allows shrubby vegetation to grow —> severe wildfires risk
6
Q
How much semi natural peatland vegetation is there in the UK
A
- 41% of the UK peat area remains under semi-natural peatland vegetation
- but has been affected by human activities including drainage, burn-management, livestock grazing and the cutting of peat for fuel
7
Q
How many greenhouse gas emissions are UK peatlands producing
A
- could exceed 20 million tonnes of CO^2 each year - 2-4% of UK’s total GHG emissions
8
Q
How will degrading peatlands affect farming in the long term
A
- positive - Raising water levels could benefit farmers by extending the productive lifetime of the soil, as well as reducing both COz emissions
- negative - reduction in soil health over time, affecting the long-term viability of agriculture in those areas
9
Q
Is there an economic willingness among government agencies & NGOs to reduce emissions?
A
- fully restoring the UK’s degraded peatlands could cost between £8bn-£22bn over the next 100 years, but would save £109bn in terms of reduced carbon emissions
10
Q
Why is there a particular problem with peatland emissions in South East Asia
A
- Fire is often used as a tool to clear land for cultivation, and these fires often run out of control into adjacent forests
- These fires produce toxic smog across Indonesia, Malaysia and Singapore’, contributing to dangerous levels of particulate matter
- The IPCC estimates tropical peatland cultivation generates the equivalent of 440 million tonnes of COz per year, with peat fires generating on average a further 200 million tonnes