Seite - 229 - in Loss and Damage from Climate Change - Concepts, Methods and Policy Options

9 The ImpactsofClimateChangeonEcosystemServices… 229 variability, pronounced shifts in rainfall are evident. For example, in the drylands ofMali andBurkinaFaso, the number of years that exceed theminimumrequired to grow sorghum andmillet has changed over time (Fig. 9.4). During the period 1950–69, generally recognised as a wet period for the Sahel, there was reliable rainfall for sorghum andmillet in many regions, but in the last two decades the numberof years thatmet the thresholdwas60–80%lower.This demonstrates how climaticvariabilityandchangecanthreatenfoodproduction,animportantecosystem service. Intra-annual variability is another issue.Within any growing season, large gaps in rainfall or extreme rainfall events can have important impacts on crop produc- tion—witheringcropsafter they’ve sproutedorwashing themaway.Thecombined effectsofdecadal, inter-annual(betweenyears),andintra-annual(withinyears)vari- ability have important repercussions for food provisioning, which is an important ecosystemservice. Research on losses and damages from the 2004 and 2010 droughts in northern Burkina Faso showed that villagers have become less able to copewith droughts becauseof adecline inpastoralismandan increase in cropping (Traore andOwiyo 2013).Pastoralismhaslongbeenanimportantandwelladaptedlivelihoodstrategyin theregion;herderscouldmovetheircattletoareaswherepasturewasmoreabundant toaccommodatelocalisedwaterdeficits.Thiswasawayoflifethatbroughtresilience to droughts.With recent land use change policies and conflict, severe barriers to pastoralists’freedomofmovementmakethemmorevulnerabletodroughts.Surveys found96and87%of respondents felt thenegativeeffectsofdroughtsoncropsand livestock, respectively, and that extreme droughts tend to have cascading effects. First, thewater deficits affect seedling growth and crop yields, which then affects theavailabilityof food forpeopleand feed for livestock (TraoreandOwiyo2013). At the geographic center of this large dryland region, for centuries Lake Chad—centred inWestern Chad and straddling theNiger, Nigeria andCameroon borders—washometoabundantfisheriesandlivestockherds.Temperatureincrease, rainfall unpredictability, and land use changes have negatively affected the Lake Chadbasin.OnceamongAfrica’s largest lakes, the lakehasshrunkfrom25,000sq. kmin1963 toaround1,000sq.km(Fig.9.5) (UNEP2008). A ridge that emerged during the drought in the 1970s and 1980s now divides LakeChad in two.Despite the recoveryof rainfall in the1990s, the lakenever fully recovered because irrigationwithdrawals increased from the primary tributaries to the south, where rainfall is higher (Gao et al. 2011). The lake once supported a vital traditional culture of fishing and herding. As the lake receded, farmers and pastoralists shifted to thegreenerareas,where theycompete for landresourceswith host communities (Salkida 2012). This has been compounded by violent conflict associated with the BokoHaram insurgency, which has spilled across the border fromNigeria(Taub2017).OthershavemigratedtoKano,Abuja,Lagos,andotherbig cities.ThedeclineofLakeChadillustrateshowchangingclimatepatternsinteracting withotheranthropogenicmodifications,conflictandpoorgovernanceresult inlosses anddamages toecosystemsandsocieties.