This deep dive covers Evidence for Climate Change within Climate Change for GCSE Chemistry. Revise Climate Change in Atmosphere for GCSE Chemistry with 20 exam-style questions and 15 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 3 of 17 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
🔬 Evidence for Climate Change
1. Temperature Records
- Instrumental records since 1880 show a clear warming trend
- 19 of the 20 warmest years on record occurred after 2000
- Ocean temperatures have increased in all ocean basins
2. Ice Core Data
- Bubbles trapped in ice contain ancient atmosphere samples
- Show CO₂ levels for the past 800,000 years
- Current CO₂ levels are the highest in all of human history
- CO₂ concentration correlates closely with temperature in the ice core record
3. Melting Ice
- Arctic sea ice declining by 13% per decade
- Greenland ice sheet losing ~280 billion tonnes per year
- Mountain glaciers retreating worldwide (photographic evidence over decades)
- Ice loss contributes to sea level rise and reduces the Earth's reflectivity (albedo effect)
4. Sea Level Rise
- Global average rise of 23 cm since 1880
- Rate of rise has accelerated to 3.3 mm per year
- Caused by two mechanisms: thermal expansion of seawater AND ice melt
5. Changing Seasons and Ecosystems
- Earlier spring events (flowering, bird migration, insect emergence)
- Growing seasons extended in many regions
- Species ranges shifting poleward and to higher altitudes
Practice questions for Climate Change
Which statement correctly describes the difference between weather and climate?
Explain three consequences of climate change for the environment or human populations. [3 marks]
Quick recall flashcards
How have CO₂ levels changed since 1880?
Increased from 280 ppm to over 420 ppm (a 50% increase)
At what rate is Arctic sea ice declining?
13% per decade