Climate change Flashcards
What is the evidence that climate change is happening?
Global sea level has risen between 10-20cm in past 100 years. Glaciers are shrinking & retreating. Some may disappear altogether by 2035. Arctic sea ice has thinned by 65% since 1975. Ice cores show levels of greenhouse gases in atmosphere stretching back 400,000 years.
What are the natural causes of climate change?
Orbital changes (Milankovitch cycles) – shape of sun’s orbit changes. More elliptical orbit = closer to sun = warmer climate. More circular orbit = more time earth spends further from sun = cooler climate. Solar input – a sunspot is a dark patch that appears on sun’s surface. When sunspot activity is at max, sun gives off more heat. Volcanic activity – ash can stay in atmosphere, blocking sunlight, cooling temperatures. GHGs released from volcanoes build up & cause warming.
What are the human causes of climate change?
Enhanced greenhouse effect – humans releasing excess greenhouse gases which trap heat in the atmosphere and warm the earth.
What are the impacts of climate change?
Lower crop yields. Threats to wildlife & biodiversity. Increased risk of natural hazards and desertification. Melting ice caps & rising sea levels.
What is mitigation?
Reducing the amount of greenhouse gases emitted into the atmosphere.
How can we mitigate against climate change?
Renewable energy to reduce CO2 emissions. Carbon capture – using technology to capture CO2 before it enters the atmosphere & injecting it into underground reservoirs. Planting trees – they are carbon sinks (take in CO2) & release moisture into atmosphere = cooling effect. International agreements – e.g. Paris Climate Agreement 2015, 195 countries agreed to keep global temperature increases below 2°C.
What is adaptation?
Finding ways to manage the impacts of climate change (does not aim to reduce or stop climate change).
How can we adapt to the effects of climate change?
Agricultural change – using drought-resistant seeds & planting crops that grow in warmer weather. Managing water supply – using water transfer schemes to irrigate areas of water shortage. Reducing risk from sea level rise – building sea walls, building houses on stilts, relocating populations.
