Worksheets › Class 11 › World Climate and Climate Change › Cheat sheet
Class 11 World Climate and Climate Change: cheat sheet
CBSE Social Science. Koeppen’s groups and codes of world climate, how climate changed in the past and why, greenhouse gases and global warming.
Key ideas
- Koeppen’s empirical scheme links vegetation to temperature and rainfall: five groups shown by capital letters, with small letters for seasons.
- Groups A, C, D and E are set by temperature; group B (dry climates) by precipitation.
- Climate has changed before: warm periods long ago, Pleistocene ice ages, the Little Ice Age in Europe and warming since 1885.
- Natural causes include changes in solar output with sunspots, Milankovitch changes in the earth’s orbit and tilt, and volcanic aerosols.
- Greenhouse gases (carbon dioxide, methane, nitrous oxide, CFCs, ozone) let sunlight in but trap long-wave heat from the earth.
- Forests and oceans are sinks that take in carbon dioxide; CFCs destroy ozone, causing the ozone hole over Antarctica.
- Warming melts ice and expands sea water, raising sea level and threatening coasts and islands.
Remember
| Group A (tropical) | coldest month 18 °C or more |
| Group C (warm temperate) | coldest month between −3 °C and 18 °C |
| Group D (cold snow forest) | coldest month −3 °C or below |
| Group E (cold) | every month below 10 °C |
| Small letters | f no dry season; m monsoon; w winter dry; s summer dry; S steppe; W desert |
| Examples | Af Amazon; Am India; Cs Mediterranean; Cwa north Indian plains; Cfb north-west Europe; EF Greenland interior |
| Steady rise | rise each year = per cent × amount ÷ 100; total = that × years |
| Key dates | Little Ice Age 1550–1850; warming from 1885; Koeppen’s scheme 1918; warmest year of the century 1998 |
Watch out
- Classifying a dry place by temperature: B is decided by low rainfall.
- Reading “f” as frozen (it means no dry season).
- Forgetting the minus sign when finding the range for a cold place.
Worked example
Give the Koeppen group letter (A, C, D or E) for each humid place: (a) coldest −1 °C, warmest 7 °C (b) coldest −34 °C, warmest −4 °C
Working: A: coldest month 18 °C or more; C: coldest between −3 °C and 18 °C; D: coldest −3 °C or below; E: every month below 10 °C
Answer: (a) E (b) E
Practise World Climate and Climate Change
Revise with this page, then practise: every World Climate and Climate Change sheet in the app is new, with an answer key and working.
Coming soon for Android and iPhone.