Strategic Panorama 2009 - 2010 - IEEE

Climate change and its security implications
adaptive capacity. In particular the following impacts are expected, listed
according to sector.
Fresh water resources and management
• By mid-century, annual average river runoff and water availability are
projected to increase by 10-40% in high latitudes and to decrease
by 10-30% in some dry regions at mid-latitudes and in the dry tropics,
some of which are already water-stressed.
• It is likely that drought will affect more areas. Heavy precipitation
events, which are very likely to increase in frequency, will augment
flood risk.
• Over the course of the century, water supplies stored in glaciers and
snow cover are projected to decline, reducing future water availability
in regions supplied by melt water from major mountain ranges,
where more than one-sixth of the world population currently lives.
Ecosystems
• Over the course of this century, net carbon uptake by terrestrial
ecosystems is likely to peak before mid-century and then weaken or
even reverse, thus amplifying climate change.
• Approximately 20-30% of plant and animal species assessed so far
are likely to be at increased risk of extinction if increases in global
average temperature exceed 1.5-2.5ºC.
• For increases in global average temperature exceeding 1.5-2.5°C
and in concomitant atmospheric carbon dioxide concentrations,
there are projected to be major changes in ecosystem structure and
function, species’ ecological interactions, and species’ geographical
ranges. These changes are expected to have predominantly negative
consequences for biodiversity, and ecosystem goods and services,
for example, water and food supply.
• The progressive acidification of oceans due to increasing atmospheric
carbon dioxide is expected to have negative impacts on marine
shell-forming organisms (for example corals) and their dependent
species.
Food and forest products
• Crop productivity is projected to increase slightly at mid- to high latitudes
for local mean temperature increases of up to 1-3°C, depending
on the crop, and then decrease beyond that in some regions.
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