Impacts of climate change on ecosystem services
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Farmers working in fields, Burkina Faso.
Photo Credit: Zinta Zommers
In a study of UK agricultural ecosystem service, Fezzi and others 2014 ind that climate change could increase
farms’ gross margins in Northern Ireland, Scotland, and Wales, factors such as low temperatures in these areas
currently discourage plant growth. In southern and eastern England climate change will exacerbate drought
problems Fezzi et al., 2014.
Other studies suggest the impacts of climate change on provisioning services and farm income may be managed
successfully through policy interventions or changes in agricultural practices. For example, Sonneveld and others
2012 conclude that in West Africa, reduced rainfall and increased rainfall variability will diminish the yields of
maize and yams but improve the yield of cash crops such as cotton and peanuts. With the correct incentives,
expansion of cotton plantings could compensate for climate change-related income losses, although overall
impacts on human well-being are unclear as various pressures on food security may accrue. Much depends
on the scale of adaptation eforts, but hard limits will also exist. According to AR5 “Global temperature increases of
4° C or more about late 20
th
century levels, combined with increasing food demand, would pose large risks to
food security globally and regionally.”
2.2 Examples of climate change impacts on regulating services
2.2.1 Flood regulation
Global sea-level rise–the results of rapid ice sheet melt in Greenland and West Antarctic and of changes to
seawater including temperature, salinity, and density– is one of the major consequences of climate change
Church et al., 2010. The sea level rise projected to accelerate throughout the 21st century and beyond will
inundate low-lying coastal areas and coastal ecosystems will deteriorate as looding and erosion proceed Boelee,
2011 and IPCC, 2014. Coastal looding is already a major problem in many parts of the world. Flood events in
San Francisco Bay, for example, were ten times more frequent in the second half of the 20th century than
the irst half Woodworth et al., 2010. Speciic local efects of future sea-level rise are hard to predict. Global,
regional, and local factors must be considered including isostatic motion of the earth’s crust or geological factors
such as compaction or loss of coastal sediments. The consequences of rising sea levels will be felt acutely
through changes in the intensity and frequency of extreme events that variously combine efects of high
tides, storm surges, surface waves, and looding rivers”
Impacts of climate change on ecosystem services
12 Woodworth et al., 2010. For instance, Booji 2005
predicts that in the Meuse river basin in Europe will see a small decrease in the average discharge but an increase
in variability and extremes of discharge. Regardless of the speciic direction of change, it is clear that climate
change will afect the ecosystem service of lood regulation.
2.2.2 Disease Regulation
Climate change will also afect human health, particularly in relation to infectious disease such as malaria,
salmonellosis, cholera, and giardiasis Wu et al., 2016. Climate change disrupts temperature, precipitation,
and wind speeds that inluence the generation and distribution of infectious disease pathogens and their
vectors. For example, as temperatures rise, insects currently constrained to warmer regions may extend
their range to higher latitudes and altitudes. But hard limits exist as well. The development of the malaria
parasite Plasmodium falciprum and Plasmodim vivax stops between 33 to 39° C Wu et al., 2016. Ryan et al.
2015 used physiological responses of the mosquito malaria vector Anopheles gambiae to map future
distribution of P. falciprum malaria in Africa. The authors predict that modest increase in the overall area suitable
for malaria transmission, but an overall decrease in the human population at highest risk for malaria. Another
study predicts a decreased length of malaria season in West Africa, in part due to an overall drying and
warming trend resulting from human degradation of vegetation rather than climate change Ermert et
al., 2013. The authors note that, many factors afect malaria infection and some counteract the efects of
climate change Ermert et al., 2013. These include economic development, inance for malaria control, and
increased distribution of insecticide-treated bed nets. But in East Africa, higher temperatures are predicted to
lead to longer transmission seasons and an increase in highland malaria Ermert et al., 2013. Finally, changes
in the frequency of extreme weather may afect disease outbreaks, although with mixed results or associations
Wu et al., 2016.
2.3 Example of climate change impacts on supporting services
2.3.1 Primary Productivity
Climate change is also afecting ecosystem productivity. Many organisms are responding to global warming
by shifting their distribution ranges and altering their phenological cycles such as growing, breeding,
lowering, hatching, migrating, and hibernating Hurlbert and Liang, 2012; Visser et al., 2015. The efect
of climate change on net primary productivity NPP has been assessed, with mixed results. Some studies indicate
warming will increase global NPP while others predict NPP decreases. These diferent results may relect
Figure 2.2.1 Projections of global mean sea level rise over 21
st
century.
Source: IPCC 2013
