Climate Change

Climate

Climate

average weather overtime

Climate change

a long term change in the global climate or regions

Quaternary period

the current ice age with fluctuating periods of cold and hot parts

Glacial periods

cold periods, lasting 100,000 years

Interglacial periods

hot periods, lasting 10,000 years

Geological fossil evidence

form of evidence in which animals die where they lived, adaptations

• some animals may have migrated/been moved

Historical evidence

from of evidence where diaries or paintings may depict the climate/weather

• personal accounts may lack accuracy, exaggerated

Ocean sediment evidence

form of evidence by studying oxygen isotopes to calculate temperatures

• ocean sediments could've been washed down

Ice core evidence

form of evidence by studying oxygen isotopes in water molecules in the ice cores

Snow evidence

form of evidence by looking at gas trapped in layers eg oxygen isotopes

• 16 O colder earth

• 18 O warmer earth

Milankovitch cycles

Natural changes in Earth's orbit, tilt and precession causing climate change

Elliptical cycle

more elliptical orbiting cycles causes more solar radiation so warmer temperatures

• affects glacial/interglacial period

• occurs every 100,000 years

Axial tilt cycles

greater tilt means greater temperature differences in the hemisphere seasons

• tilt usually 23.5°

• ranges from 21.5°-24.5°

• occurs every 41,000 years

Precession cycles

axis wobbles in a circle as earth is not a perfect sphere

• affects length of days and nights

• occurs every 26,000 years

Natural volcanic eruptions

major volcanic eruptions eject masses of materials into atmosphere and particles block/defect sun's rays causing volcanic winters

Natural sunspot activity

dark patches appear on the sun's surface and increase energy output of the sun

• occurs every 11 years

Natural greenhouse effect

the natural process by which Earth is kept warm by gases that trap the sun's energy in the atmosphere

Enhanced greenhouse effect

human activity (factories, cars..) which releases more greenhouse gases into the atmosphere

• traps more and decreases the amount that escapes

• causes the Earth to warm up more

Global warming potential (GWP)

the potential of certain gases to trap thermal energy in relation to CO2 (GWP 1)

Carbon dioxide

• GWP = 1

• gas is 60% of global warming effect

• caused from burning trees, industrial processes, deforestation and fossil fuels

Methane

• GWP = 25

• gas is 15% of global warming effect

• caused from landfill sites, rice paddies and cow farming

Halocarbons (CFCs)

• GWP = 15,000

• gas is 15% of global warming effect

• caused from aerosols, foam packaging and refrigerators

Nitrous Oxide

• GWP = 250

• 6% of global warming effect

• caused from fertilisers and car exhausts

Negative environmental impacts of climate change in the UK

• increased UK summer heat waves, temperatures and droughts

• increased frequency and intensity of precipitation of events

Negative social impacts of climate change in the UK

• increased temperature affects UK water sources

• increased water demand from 59mil l tp 2,500mil l

Negative economical impacts of climate change in the UK

• extreme flash flooding forces Government to spend more on protecting housing

• £12bil / year by 2020

Positive environmental impacts of climate change in the UK

• increased yields due to warmer temperature for current crops, eg wheat, sugar

Positive social impact of climate change in the UK

• decrease in winter mortality rates

• reduced from 57,000 to 24,000 by 2050

Positive economical impacts of climate change in the UK

• reduction of energy demand for heating saving consumer income

• increased disposable incomes

The little ice age

coldest period during 15th to 17th century