Water
Case Studies
, Futures and uncertainties for floods
~ By 2030, a 4-inch sea level rise could:
o double the frequency of severe flooding in many parts of the world (San Francisco, and Los Angeles)
o increase the frequency of extreme flooding by as much as 25 times in the tropics (the central African
coast)
~ Scientists expect between 4-8 inches of sea level rise by 2050 and as sea levels go up, flooding gets worse - sea
level rise will turn more typical floods into extreme ones so more places will be put at risk.
~ Flooding already causes £1bn of damage every year on average but this will rise as climate change leads to more
intense rainfall, bringing more floods
o The number of households at significant risk of flooding will more than double to 1.9m by 2050, if the
global temperature rises by 4C.
o Climate change increased the chance of the 2015 UK winter’s devastating floods (Storm Desmond) by 40%
o Higher precipitation extremes in warmer climates are very likely to occur. This directly affects the risk of
flash flooding and urban flooding - storm drainage systems have to be adapted to accommodate increasing
rainfall intensity resulting from climate change
o Rapid melting of glaciers can lead to flooding of rivers and to the formation of glacial melt-water lakes
~ Up to 20% of the world’s population live in river basins that are likely to be affected by increased flood hazard by
the 2080s in the course of global warming
~ The flooded area in Bangladesh is projected to increase at least by 20% with a global temperature rise of 2°.
~ In North America, precipitation extremes correspond to the El Nino effect (which is increasing in frequency and
intensity) as some regions get heavy rainfall while others receive less extreme precipitation
, Futures and uncertainties for droughts
~ Water shortages
~ Difficulties in producing food
o Already 85% of the rich peat topsoils of East Anglia has disappeared due to drainage and erosion and
climate change will accelerate the rate of loss – could lose the remaining fertile soil within 30-60 years
o The proportion of prime farmland is expected to fall from 38% to 9% with significant warming and crop
growing in eastern England and Scotland could be ended by degraded soil and water shortages.
~ Climate change is likely to drive food prices up, with extreme weather leading to lost crops and price shocks.
o About 40% of UK food is imported, making the UK vulnerable to droughts and floods driven by climate
change around the world.
~ The global proportion of the land surface in extreme drought is predicted to increase from 1-3 % for the present
day to 30% by the 2090s.
~ Increased temperatures will lead to more precipitation falling as rain rather than snow, earlier snow melt, and
increased evaporation and transpiration. Thus, the risk of hydrological and agricultural drought increases as
temperatures rise.
o In 2011, Texas had the driest year since 1895. In 2013, California had the driest year on record.
o More than 1/6 of the Earth’s population relying on melt water from glaciers for their water supply.
In the Andes, glacial melt water supports river flow and water supply for tens of millions of people during
the long dry season. Many small glaciers in Bolivia, Ecuador, and Peru will disappear within the next few
decades - affecting both people and ecosystems.
~ Drought ranks second in terms of national weather-related economic impacts, with annual losses nearing $9
billion per year in the U.S.
,
Case Studies
, Futures and uncertainties for floods
~ By 2030, a 4-inch sea level rise could:
o double the frequency of severe flooding in many parts of the world (San Francisco, and Los Angeles)
o increase the frequency of extreme flooding by as much as 25 times in the tropics (the central African
coast)
~ Scientists expect between 4-8 inches of sea level rise by 2050 and as sea levels go up, flooding gets worse - sea
level rise will turn more typical floods into extreme ones so more places will be put at risk.
~ Flooding already causes £1bn of damage every year on average but this will rise as climate change leads to more
intense rainfall, bringing more floods
o The number of households at significant risk of flooding will more than double to 1.9m by 2050, if the
global temperature rises by 4C.
o Climate change increased the chance of the 2015 UK winter’s devastating floods (Storm Desmond) by 40%
o Higher precipitation extremes in warmer climates are very likely to occur. This directly affects the risk of
flash flooding and urban flooding - storm drainage systems have to be adapted to accommodate increasing
rainfall intensity resulting from climate change
o Rapid melting of glaciers can lead to flooding of rivers and to the formation of glacial melt-water lakes
~ Up to 20% of the world’s population live in river basins that are likely to be affected by increased flood hazard by
the 2080s in the course of global warming
~ The flooded area in Bangladesh is projected to increase at least by 20% with a global temperature rise of 2°.
~ In North America, precipitation extremes correspond to the El Nino effect (which is increasing in frequency and
intensity) as some regions get heavy rainfall while others receive less extreme precipitation
, Futures and uncertainties for droughts
~ Water shortages
~ Difficulties in producing food
o Already 85% of the rich peat topsoils of East Anglia has disappeared due to drainage and erosion and
climate change will accelerate the rate of loss – could lose the remaining fertile soil within 30-60 years
o The proportion of prime farmland is expected to fall from 38% to 9% with significant warming and crop
growing in eastern England and Scotland could be ended by degraded soil and water shortages.
~ Climate change is likely to drive food prices up, with extreme weather leading to lost crops and price shocks.
o About 40% of UK food is imported, making the UK vulnerable to droughts and floods driven by climate
change around the world.
~ The global proportion of the land surface in extreme drought is predicted to increase from 1-3 % for the present
day to 30% by the 2090s.
~ Increased temperatures will lead to more precipitation falling as rain rather than snow, earlier snow melt, and
increased evaporation and transpiration. Thus, the risk of hydrological and agricultural drought increases as
temperatures rise.
o In 2011, Texas had the driest year since 1895. In 2013, California had the driest year on record.
o More than 1/6 of the Earth’s population relying on melt water from glaciers for their water supply.
In the Andes, glacial melt water supports river flow and water supply for tens of millions of people during
the long dry season. Many small glaciers in Bolivia, Ecuador, and Peru will disappear within the next few
decades - affecting both people and ecosystems.
~ Drought ranks second in terms of national weather-related economic impacts, with annual losses nearing $9
billion per year in the U.S.
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