Climate Change Flashcards
provide evidence for climate change
-artwork
-ice cores (co2 and methane trapped in ice. more gases= warmer. extend back 5 million years. also contain animal remains)
-tree rings (thicker in warmer, wetter conditions. 10000 years back. new ring each year)
-animal behaviour (1200 canadian polar bears put on 50-75% body fat in winter. ice melted= 10kg lighter
-sea levels rising
-pollen analysis (preserved in sediment. identify and date pollen to see species and conditions needed)
-extreme weather
-graphs (keeling curve, increased co2)
what is global warming
sharp rise in global temperatures over the last century. type of climate change
what is weather
day to day conditions of atmosphere
what is climate
the average weather conditions expected and calculated using 30 year of past weather data
what is extrene weather?
weather significantly different from average/usual pattern
explain what the quaternary period was like
began 2.6 million years ago. before was warm and stable, but had glacial cold periods lasting 100,000 years and warmer interglacial periods lasting 10,000 years. last glacial period ended 15,000 years ago. holocene epoch began 10,000 years ago
How are volcanic eruptions natural causes of climate change?
produce ash and sulfur dioxide gas (mixes with water vapour to form sulfuric acid). spread around earth and block out sun, reflecting rays back into space, cooling planet. also release co2. e.g earth cooled by 0.5 degrees after mount pinatubo in 1991
How is solar output a natural cause of climate change?
occur in cycles of 11 years. sunspots are heat in extra bursts. (caused by sun’s magnetic activity) increase temperatures. cosmic rays from clouds = cooling as more solar wind “active sun”
what is eccentricity?
more sun energy when orbit is elongated. elliptical turns circular every 100,000 years
what is tilt
earth is currently tilted 23.3 degrees but can vary between 21.5 and 24.5 . changes every 41,000 years. greater tilt=more solar energy poles recieve
what is precession
“wobble” of the earth (26000 years.) affects relationship between tilt and eccentricity.
explain some human causes of climate change
-deforestation (co2 released into atmosphere when burned for fuel)
-cement production (made from limestone containing carbon, released when made)
-burning fossil fuels
-farming (livestock produce methane. rice paddy fields. 20% of ghg)
explain some effects of cimate change
-glaciers shrink, sea ice melts, sea levels rising, loss of habitat
-more flooding, coastal erosion
-bleaching of coral reefs (expell algae and die)
-changes to rainfall
-deaths due to extreme temperatures
-migtration and overcrowding
-water availability= political tensions
-crop yields changing = malnutrition, ill health, starvation
-more money spent on reducing effects and predicting extreme weather
what is a mitigation strategy
reducing causes of climate change
what is an adaptation strategy
responding to effects of climate change
name some mitigation strategies
-carbon capture and storage (trapping co2 emissions at source so they can’t contribute to global warming. stored underground)
-planting trees (“carbon sinks”)
-alternative energy production (more renewable energy. more offshore wind farms built in uk)
-international agreements (paris agreement 4th november 2016. 195 parties signed. agreed to limit global warming. uk pledged to reduce emissions by 68% of 1990s by 2030
name some adaptation strategies
-building irrigation systems (low lats experience drought, systems built to divert water from rivers to irrigate fields of crops in summer)
-planting shade trees (protect seedlings from sunshine and prevent evaporation and water loss)
-artifical glaciers (16000 glaciers in himalayas melting. damming water freezes it in winter and melts it in spring for crops)
-water meters (recycling water with green roofs/permeable pavements)
-managing rising sea levels (predicted to rise from 0.28m to 1.01m by 2100. need flood barriers. eg thames barrier in london. raised buildings on embankments. flood shelters in maldives 3m sea wall built around male)
