0 2 6 12 16 months

0

10

20

30

40

50

1860 70 80 90 1900 10 20 30 40 50 60 70 80 90 2000 10

MauritaniaMali Niger

Sudan

solitarious gregarious

www.fao.org/ag/locusts

frontlinesecondaryinvasion

Africa is warmer than100 years ago 2-4˚C increase by 2050s greatest warming along Sahara edge (0.5˚C/decade) warming increases the spatial variability of rainfall

substantial and sustained decline in rainfall (Sahel) decrease: Sahel (Mar-Aug), Sahara (Dec-May) increase: Sahel (Jun-Aug), Sahara (Sep-Feb) Sahara will turn green like 12,000 years ago increase in the intensity of high rainfall events

+2˚C

+3˚C

+4˚C

0-0.25

mm/day

0.25-0.5

-0.25-0

IPCC3

Habitat the Sahara is in retreat in the past 15 years (satellite imagery)

Predictions rainfall under climate change scenarios in the Sahara varies and lacks consensus half the models follow a wetter trend, half follow a drier high uncertainty over Sahara due to few stations & poor quality data regional models + satellite + stations may offer more precise estimates

desert

forest

Ice Age(cold, dry)

Holocene(warm, wet)

18,000 years ago 8,000 4,500 500 5

Present

IPCC AR4

L HL

H

0˚

Keith CressmanSenior Locust Forecasting OfficerRome, Italykeith.cressman@fao.orgwww.fao.org/ag/locusts