Climate Change & Human Activity Flashcards
What gases make up the Earth’s atmosphere?
Nitrogen, carbon dioxide, oxygen, water vapour, methane, and argon.
Why is the greenhouse effect essential for life on Earth?
It traps heat, maintaining an average temperature suitable for life (without it, Earth would be about -18°C).
How does the greenhouse effect work?
Greenhouse gases let in short-wave solar radiation but absorb and trap some of the outgoing long-wave radiation (heat), warming the planet.
What is the enhanced greenhouse effect?
It’s the strengthening of the natural greenhouse effect due to increased greenhouse gases from human activities
How much has atmospheric CO₂ increased by 2020 compared to pre-industrial levels?
Over 100 ppm, reaching 420 ppm in 2020.
What are the effects of the enhanced greenhouse effect?
More heat is trapped, leading to over 1°C of global temperature rise since pre-industrial times.
What are the main human sources of carbon dioxide (CO₂)?
Burning fossil fuels (power stations, vehicles), burning wood, and deforestation (reducing CO₂ absorption via photosynthesis).
What are the main human sources of methane (CH₄)?
Decay of organic matter in landfills, manure, and crops.
What are the human sources of nitrous oxide (N₂O)?
Use of artificial fertilisers and burning fossil fuels.
What are the sources of chlorofluorocarbons (CFCs)?
Aerosols, refrigeration units, and air conditioning systems.
How have global temperatures changed since the 1980s?
All years since the 1980s have been warmer than the 1961–1990 average.
What is the evidence from glaciers and Arctic sea ice?
Glaciers are shrinking, and Arctic sea ice is at an all-time low.
How much have sea levels risen since 1880?
approximately 23 cm.
What changes in wildlife behaviour indicate climate change?
Earlier flowering, altered bird migration and nesting times, and shorter hibernations.
What types of extreme weather have become more frequent?
Floods, storms, and extreme temperatures have increased since the 1980s.
What is the projected global temperature rise by 2100?
Between 1.9°C and 4.2°C, depending on emissions.
How much are sea levels projected to rise by 2100?
Between 0.3 m and 2 m.
Between 0.3 m and 2 m.
Because of uncertainties in population growth, fossil fuel use, and lifestyle changes.
What health effects may result from climate change?
Increased spread of diseases (e.g. malaria), more heat-related illnesses, malnutrition, and worse air quality.
How might employment be affected by climate change?
Job losses in tourism and agriculture due to climate disruptions.
How might housing be impacted?
Increased flooding from sea level rise and more frequent storms could displace large populations.
What causes sea levels to rise?
Melting ice and thermal expansion of warmer water.
How much more could sea levels rise by 2050?
An additional 30 cm.
Which areas are at the highest risk of flooding?
Low-lying coastal areas and islands, like the Maldives.
