Evaluate the role of climate change in the increased rate of coastal flooding. (20)
There are two types of sea level change: eustatic and isostatic. Eustatic changes when the
sea level itself rises or falls and is always global. Isostatic change is when the land rises or
falls, relative to the sea and is always local. However, with climate change, isostatic and
eustatic change are like a cycle, for example, if the ice caps are melting then the land is
falling but the sea level is rising and when water heats up it expands so the sea levels rise
with increasing temperatures even if the volume of water in the ocean stays the same. The
IPCC predicts that by 2050 sea levels would have risen by 30 cm.
Global sea levels have risen dramatically since the last glacial period. This is normal, but the
sharp increase in the last 100 years is concerning. For example, sea levels generally
fluctuate, changing by 5 cm over 200 years, however since 1800, sea levels have risen
almost 20 cm. During the last glacial period Places that hold current ice stores would have
held much less ice, as the world was equally cold and not just concentrated in the poles.
Land levels were higher and more land was exposed and not yet flooded.
storm surges are changes in sea level caused by intense low-pressure systems and high wind
speeds. During high tide and in low-lying areas, the results of coastal flooding can be deadly.
Climate change increases the frequency and severity of storm surges in areas with low-lying
land. This can be seen during any hurricane season in the USA, particularly in recent years
with Hurricane Katrina and others affecting the SE United States. Therefore it can be said
that climate change is responsible for the increase in coastal flooding.
Kiribati, in the Pacific Ocean, is one of the most low-lying nations. Its land is permanently
flooded due to global warming. One island, with a population of 6000, has permanent water
contamination and all agricultural land is underwater due to floods so the residents have to
migrate to the already overly populated mainland to survive. Scientists from the IPCC have
predicted that the Kiribati people have less than a century left on their islands. There are
some management programmes in place, like the construction of sea walls and planting of
mangroves, but as sea level rise is so rapid, a lot of these management programmes are
ineffective. Also, because the nation is so poor and underdeveloped, they don't have as
many resources in place to combat climate change as an AC in the western world.
China, in eastern Asia, suffers from coastal flooding caused by human interference. due to
the rapid industrialization of China, water dredging is a common action taking place on
coasts. This together with sea levels rising 2.6 millimetres annually and two metres of land
lost yearly has a huge impact on rural villages. also, Chinese corporations and TNCs have
destroyed lots of farmland and natural environments, taking away the natural defences
from coastal flooding, making 70% of Chinese coastlines prone to erosion. Also in China,
tectonic plates could be playing a part in isostatic change. Extreme weight on plates can
cause the land levels to fall. In China, the Three Gorges dam is a viable explanation for this
as it is so astronomically large. China also experiences earthquakes that can decrease space
in ocean basins causing sea levels to rise
Bangladesh, in Central Asia, is one of the most susceptible nations in the world to coastal
flooding. It is the most densely populated country in the world and lies on the flood plains of
three major rivers. Bangladesh also lies below Nepal and the Himalayas. As increased snow
melt - due to global warming - flows into rivers, more water is flowing through Bangladesh,
making this soil lack resistance to erosion and therefore increasing the impacts of coastal
flooding. coastal management schemes have again been put in place, but because
