Climate Change Flashcards
Evidence for climate change?
Ice age cycles
Proxy data - ice cores, geological, tree rings, human records
Global temps
Ice caps
Sea levels
How are ice age cycles evidence of climate change?
100,000 year glacial period, interglacial temp was meant to decrease 7,000 years ago but has not
How can ice cores be used as evidence for climate change?
Trap air bubbles which can be analysed to determine concentration of different gases and temperature
What is proxy data?
Data from a range of sources to estimate past climatic conditions as a substitute for directly measured date
How can tree rings be used as evidence for climate change?
Wider rings in warm and wet periods
Thinner rings in cold and dry periods
How can geological proxy data be used as evidence for climate change?
Fossil analysis
Glacial deposits
How is global temperature used as evidence for climate change?
Surface temp increased by 1.1 degrees since pre-industrial revolution
Even more increase near N and S pole e.g. 6 degrees in Siberia
How can ice caps be used as evidence for climate change?
13% decrease in ice cap cover every 10 years
By 2050 no summer sea ice in arctic
Why are ice caps melting and explain?
Albedo feedback loop - temp increases, ice melts, less reflection of sun rays, more absorption by darker ocean, higher surface temp and repeat
How can sea levels be used as evidence for climate change?
10cm rise in last 30 years
Majority from melting ice in Antarctica (glaciers melting increases sea level but ice is already in water so does not rise as drastically)
Natural causes of climate change?
Sun spots
Volcanic eruptions
Milankovitch cycles
Greenhouse effect
Explain how sun spots cause climate change?
Magnetic storms on sun create spot of high energy
11 year cycle
Explain how volcanic eruptions cause climate change?
Emit greenhouse gases during explosion
e.g. Snowball Earth -50 degrees 640 million years ago saved by volcanoes erupting through snow
Explain how milankovitch cause climate change?
Eccentricity - stretch of orbit every 100,000 years
Obliquity - tilt of Earth’s axis between 22.2 and 24.5 every 40,000 years
Precession - wobble of earth’s axis every 25,000 years
Explain how natural greenhouse effect causes climate change?
Some solar radiation is reflected by atmosphere but most passes through
Solar energy is absorbed, converted into heat which emits infrared radiation
Some of this infrared passes through atmosphere, some is absorbed by greenhouse gas particles and re-emitted heating up the planet as more radiation is absorbed and converted into heat
Explain enhanced greenhouse effect with stats?
Higher greenhouse gas particle concentration in atmosphere so more infrared radiation is absorbed and re-emitted
CO2 from 280 ppm to 400 ppm since 1800
Methane more than doubled to 2000 ppb
What are RCP’s and explain each level?
Made by IPCC for future trend of greenhouse gas concentration
2.6 not hapening, 4.5 and 6 possible, 8.5 worst
