Page 80 - The World About Us

Hubbard Glacier
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How can climate change impact on our world?

Whatever the main causes of climate change, whether Social impacts: those affec ng people's lives and
physical or human induced, there is no doubt that our lifestyles.
climate has been warming significantly over the last 100
years, with nine of the ten ho est years on record occurring Economic impacts: those to do with prices, trade
in the 21st century. A warming climate is already having an and the costs of coping with climate change.
impact across the globe. These changes are likely to increase
in scale and scope over the coming decades. The effects can Environmental impacts: those affec ng the physical
be summarised by looking at their various impacts. world and natural ecosystems.

1. Sea level rise.
As temperature rises, water in the oceans expands. In addi on, water locked up as ice on the land begins to melt and
returns to the oceans leading to a global (eusta c) rise in sea levels. At the peak of the last interglacial, 125,000 years ago, sea
levels were up to 9 metres higher than today. This suggests that there was significant mel ng of the ice sheets in both
Greenland and western Antarc ca. Sea levels have risen by 20cm since 1900. Modelling by the Intergovernmental Panel on
Climate Change (IPCC) suggests that sea levels will rise between 20cm to 82cm by 2100.
R Millions of people live in low- R Loss of low-lying agricultural R Loss of coastal wetlands could
lying coastal areas, such as river land such as that found in the impact on biodiversity.
deltas. They will face more regular Ganges, Nile and Mekong deltas, Degenera on of reefs and the loss
flooding or be forced to abandon will result in a rise in global food of mangrove forests could see
their homes as the seas rise, crea ng prices, par cularly affec ng the poor. increased damage from coastal storms.
millions of environmental refugees. R Protec ng valuable coastal property such R Fresh water supplies in rivers and
R Small island na ons, such as Tuvalu, as ci es and transport infrastructure will aquifers could become increasingly
Kiriba and the Maldives may disappear place increasing demands on government contaminated with salt, a process called
altogether as their coral atoll islands resources. salinisa on, that will affect humans and
become uninhabitable. R A loss of coastal and beach property will wildlife alike.
damage the tourism industry, the world's
largest provider of jobs.

2. Ocean acidification.
Co₂ is emi ed into the atmosphere by the burning of fossil fuels. Much of it ends up dissolved in the water of the oceans.
While this is slowing the pace of climate change, it is gradually changing the pH of oceanic waters. The dissolved CO₂
becomes a weak carbonic acid in water. While the oceans remain alkaline (pH greater than 7) there appears to have been a
slight fall in oceanic pH from 8.25 in 1750 to 8.14 today. This acidifica on may affect sea creatures, especially those that build
a calcium carbonate shell, such as molluscs and hard corals.
R Acidifica on may impact on R A collapse in ocean food chains R Reduced resilience by coral
oceanic food chains, for example by could destroy fishing industries species could see increased coral
reducing the abundance of key already dealing with over-fishing bleaching events and the loss of
species such as the sea bu erfly and declining catches. This could produc vity and biodiversity of the
(which is actually a sea snail which swims lead to the loss of jobs, rising fish prices and world's reefs.
feely in the ocean using its enlarged foot). A the decline of coastal fishing communi es. R Declining reef resilience could result in
decline in sea bu erflies would impact on R The poten al loss of fish proteins used in the collapse of many fish popula ons, many
the fish, squid and other sea food relied animal feeds could see a rise in global meat of which are central to human and natural
upon by millions of people for their daily prices. food chains.
protein.
3. Changing patterns of disease.
Diseases such as malaria and dengue fever are spread by Anopheles and Aedes mosquitoes. A rise in temperatures will
allow such disease 'vectors' to spread to higher la tudes and higher al tudes so spreading diseases to new areas.
R A higher incidence of illnesses R Loss of working days, as people R Changing disease pa erns will
such as malaria will result in are sick or stay at home to nurse sick impact on natural ecosystems,
declining life expectancies unless rela ves, can reduce family incomes especially those already weakened
successful and rela vely cheap and the produc vity of the economy. by climate change.
vaccines can be developed.

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Climate change has consequences.