UK weather/ climate change Flashcards
UK weather hazards
- thunderstorms
- prolonged rainfall
causes flooding across
southern England - drought/extreme heat
heat wave in Europe 2003
killed 20,000 - heavy snow/extreme cold
- strong winds
Somerset Levels
- extensive area of low-lying farmland and wetlands bordered by the Bristol channel and Quantock Hills, Mendip Hills
- drained by several rivers
the 2014 floods
causes
- sequence of SW depressions brought rainfall Jan-Feb
- high tides/ storm surges swept water from Bristol channel
- rivers clogged with sediment that had not been dredged for 20 years
impacts
- 600 houses flooded
- villages cut off
- £10mil damage
- farmland flooded
- power, roads, rail blocked
- sewage contamination
- debris clearance required
responses
- media interest generated
- boats used
- community groups/volunteers
- £20mil action plan by council
- 8km river dredged
- road levels raised
- river banks raised/straightened
extreme weather in the UK
2003 heat wave
2007,8,9,13,14,15,16 floods
2009,10 snow
could be due to global warming which:
- leads to more energy in the atmosphere which leads to more intense storms
- affects atmospheric circulation which brings floods to normally dry areas and heatwaves to normally cool areas
what is the evidence for climate change?
- fluctuations in temp for the last 5.5 million years
- Quaternary period (last 2.6mil years) fluctuations
glacial periods, interglacial
periods - oxygen trapped in layers of ocean sediments and water molecules in Arctic snow can be analysed to calculate the temp
- these direct measurements indicate warming trend with most increase since the 1970s
- rising sea levels due to ice caps melting
- seasonal changes like tree flowering/migration advancing
- sinking glaciers, melting ice- may disappear by 2035
natural causes of climate change
Orbital changes
Milankovitch cycles
- Earth’s orbit changes from circular to eliptical every 100,000 years
- Axial tilt- every 41,000 years earth’s tilt changes between 3 degrees
- Wobble effect of the axis wobbling over a period of 26,000 years
Solar activity
- surface of the sun has dark patches called sunspots
- they mark short-term regions of reduces surface temp
Volcanic activity
- ash blocks out the sun which reduces temps
- sulphur dioxide is blasted out which converts to sulphuric acid
- which act as mirrors to reflect solar radiation
Greenhouse effect
Natural
- keeps the earth warm
- greenhouse gases like CO2, methane, water vapour trap heat
- allowing radiation from the sun through to earth
- trapping radiation which would otherwise escape to space
Enhanced
- in recent years, greenhouse gases have increased due to human activities
- CO2 contributes to 60% net warming
- CO2 comes from burning fossil fuels, transport, farming, deforestation
- methane emissions from increasing livestock, rice farming, sewage treatment, landfill sites, coal mines, natural gas pipelines are growing faster than CO2
how can climate change be managed
global impacts
- alternative energy like HEP, solar, nuclear, wind, tidal
- carbon capture uses tech which captures CO2 from industry and injects it underground for long-term in geological reservoirs
- planting trees act as carbon sinks
- international agreements to act against global warming like the Paris agreement (2015)
global impacts
- reduced crop yield
- disease/illnesses
- coastal areas threatened by flood
- changing ecosystems/habitats
- extreme weather
- stronger tropical storms
- desertification
How can we adapt to climate change?
agricultural adaptation
- cope with extreme weather
- manage water supplies e.g. new irrigation systems
- plant trees for shade
- change crops/livestock to suit new climatic conditions like drought-resistance
reducing risk from rising sea levels
- already risen 20m since 1900
- threaten low-lying countries such as Bangladesh, India, Vietnam
Maldives:
- sea walls
- raised houses
- restoration of coastal forests
- artificial islands to relocate people
- entire pop. could move to india/sri lanka
