More than one billion people lack access to safe drinking water, and more
than two billion people live without improved sanitation. While these dire
conditions already pose the greatest threat to environmental health around
the world, global warming is set to make matters even worse. More frequent
and more serious droughts and floods will increase water shortages and
cause more widespread water contamination and sanitation challenges. To
avoid an outright global water catastrophe, local, national, and global leaders
must urgently pursue a two-part strategy of reducing pollution to minimize
further climate change while preparing vulnerable communities to deal with
the changes in climate that are already occurring or are unavoidable.

The Most Vulnerable Will Be Hit Hardest
by the Water Crisis
Although developed countries are most responsible
for causing global warming, it is the poor in
developing countries that face the greatest risks
from a warmer climate. Without bold policy
action from the international community,
vulnerable nations in Africa, Asia, and Latin
America are likely to face the most devastating
shocks from global warming. For example,
although Sub-Saharan Africa currently contributes
little to the causes of climate change (producing
less than four percent of the world’s greenhouse
gases1) the IPCC predicts that by 2020, between
75 and 250 million people in Africa will suffer
increased water stress due to climate change. In
East Africa, snow is already disappearing from
mountains like Mt. Kenya and Mt. Kilimanjaro,
affecting the local communities who depend on
the rivers and streams fed by these mountain
snows.
In heavily-populated Asia, up to one billion
people could face reduced access to water and
more extreme weather events such as flooding and
droughts, even with a small rise in temperature.
Already, Chinese scientists have blamed global
warming for reducing the water flow in China’s
major rivers to historic lows. Low river flows last
summer led to severe drinking water shortages that
afflicted 18 million people.
In Latin America and the Caribbean, global
warming is expected to change precipitation
patterns, resulting in too little water in some areas
and too much in others. Increasingly severe and
frequent storms will lead to more flooding and
damaged infrastructure, particularly along the
coastal areas, where 60 of the region’s 77 largest
cities are situated.