MAINSTREAMING CLIMATE CHANGE ADAPTATION IN AGRICULTURAL EXTENSION
APPENDIX 1
2012
Slide 1
Climate change
Slide 4
Some definitions
Climate variability refers to variations in the current state of
the climate
e.g. El Nino causes lower rainfall ~ every 7 years
Or e.g. the amount of rainfall we receive varies from year to year
Climate change is a shift in the current state of the climate
over at least several decades
E.g. The Sahara used to have a rainy climate and now has a dry one.
Both of these will have an impact on day to day weather conditions
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Slide 2
Overview
What is climate
The green house effect
Affect on weather
Man-made or not?
Impacts
Climate myths
Where to find out more
Slide 5
2
The greenhouse effect
Sunlight (short wave radiation) passes through the atmosphere
and warms the Earth‟s surface. This heat is re-radiated out
towards space as long wave radiation
Greenhouse
gases include
C02, Methane,
N20…
Most outgoing heat
is absorbed by
greenhouse gas
molecules and re-
emitted in all
directions, warming
the surface of the
Earth and the lower
atmosphere
more greenhouse gases = a warmer atmosphere
so measure a global mean temperature
5
Slide 3
Some definitions
Weather is the state of the atmosphere at a specific time in
a specific place.
E.g. temperature, cloudiness, rain, wind, thunderstorms, tornadoes,
monsoons..
Climate is the average state of the atmosphere over a long
period (normally > 30 years)
E.g. Addis Ababa normally has dry winters and rainy summers.
Slide 6
3
Effect on weather
The sun can only heat part of the atmosphere at any one time,
so the atmosphere is constantly trying to readjust
Plus the Earth is spinning & the atmosphere and ocean can
interact
Everything mixes together into a highly complex, chaotic system
to give day to day weather systems
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A Training Manual on Use of Climate Information and Vulnerability and Capacity Assessment for
Agricultural Extension Staff in Zimbabwe
Page 106