Climate change
G3 Elective Geography: Climate - syllabus K335, 2027
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Read evidence of past climate, explain today's warming and follow its effects on ecosystems and people.
- Evidence of past climates
Proxies are indirect clues to past climate. Scientists date and compare these records to reconstruct changes before thermometer measurements began.
- Natural causes of climate change
Natural climate drivers act over different timescales. Check how each changes Earth's energy balance before using it to explain a trend.
- The greenhouse effect
Greenhouse gases absorb and re-emit outgoing heat energy. Adding more of these gases warms the surface and lower atmosphere.
- Human causes of climate change
Human activities add greenhouse gases or reduce their removal. This strengthens the greenhouse effect and raises global temperatures.
- Climate change and oceans
Warmer water stresses marine life and raises sea level. Dissolved carbon dioxide also changes ocean chemistry, making shell-building harder.
- Climate change and land ecosystems
Changes in heat, water and seasonal timing affect where species can survive. Some cannot move or adapt quickly enough.
- Climate impacts on people
Climate hazards cause direct harm, then spread losses through food, water, health, culture and the economy.