● RISING TEMPERATURES
The most extensive reports into climate change are those compiled by the IPCC, these predict temp rises between 1.8°C and 4.0° by the end of the century.
● EFFECTS ON WEATHER
Precipitation has increased some 10% overall but this isn’t evenly distributed across the planet. Many places have seen increased rainfall, some have seen less; this has led to an increase in both flooding and droughts.
Storms are likely to become more frequent, widespread and severe. In the last 50 years the number of category 5 hurricanes has doubled. Hurricanes have crossed the equator and now occur in the southern hemisphere.
In 2003 a heatwave in Europe, one of many in recent years, claimed up to 35,000 lives, indications are that heatwaves will become more frequent.
● DESERTIFICATION
Shifting weather patterns mean some areas receive less rainfall; the ground becomes barren and unable to sustain crops. In many parts of the world the topsoil is very thin and unstable. The dry, dusty soil is readily blown away and the area becomes desert. African and Asian countries are particularly hard hit. In China some one million people have been forced from their homes because their land has turned to desert.
● WAR AND CONFLICTS
Two consequences of climate change are the loss of agricultural land and the scarcity of water. This has already led to several political battles and the war in Darfur is being fuelled as the opposing sides fight for control of the remaining agricultural land.
● AGRICULTURAL IMPACT
Rising sea levels have resulted in the loss of some agricultural land and this is progressively getting worse, the consequences of which will be population migration, famine and / or the need to import food. Again, it will be the African and Asian countries that are hardest hit with crop production falling by up to a third.
● RISING SEA LEVELS
Sea levels are rising faster than at any time since the last ice age. Before the onset of industrialisation sea levels were rising by 0.1mm a year, today they’re rising 30 times as fast with some places, such as the Sundarman Delta, seeing levels rising by more than 30mm a year.
Many low-lying communities have been affected including Kenya, Kiribati, Marshall Islands, Tuvalu, Bangladesh, Papua New Guinea, Micronesia, Maldives, Antigua and Bermuda.
Predictions indicate rises of between 600 and 1400mm by the end of the century. In the US this would affect many coastal regions especially the coastlines of Florida and the Gulf of Mexico, cities affected would include Boston, New York, Charleston, Miami and New Orleans.
● MELTING ICE CAPS
The edges of the Antarctic Ice Sheet are breaking apart, in 2002 the Larsen B Ice Shelf broke off, this ice covered 3250 square kilometres and weighed half a trillion tons, this is the same as the amount of ice that is being lost each year from Greenland and Antarctica.
● DROUGHT AND FAMINE
The heat is likely to increase the number of forest fires, reduce timber production, impact on agricultural land and lead to more insect infestation.
Rising temperatures impact on food production, a 1°C rise equates to a 10% loss in grain production, areas already facing food shortages will be hardest hit. Warmer temperatures create severe drought conditions; billions of people could be affected by contaminated water, a lack of water or both.
● POPULATION MIGRATION
Large numbers of people are finding it increasingly difficult to remain in their present locations and for many this is proving impossible. In Bangladesh some 13 million people will be forced to move if the sea level rises by just one metre, half a million have already abandonned their homes.
● MARINE ENVIRONMENT
Oceans absorb carbon dioxide, some of which dissolves to form carbonic acid and this is affecting the alkalinity of the oceans. Many forms of marine life are highly sensitive to this. The formation of corals is being affected as is plankton, which forms the basis of the marine food chain. The increasing levels of CO2 make it harder for many species of fish and shellfish to breathe and reproduce. Changes in the ecology and chemistry of the seas and oceans reduce their ability to absorb CO2, which consequently increases the rate of global warming.
● ECOSYSTEMS
Parts of Antarctica are now covered in grass and there is a global migration of animals towards the polar regions, these migrations extend an average of 6.1km further from the equator each decade. Butterflies have extended their territory by some 200km.
The habitats of polar bears and emperor penguins are being threatened. The waters of the Hudson Bay for example, are now ice free for three weeks more each year than 30 years ago. Polar bears are starving because they need to venture onto the ice to hunt food. In the worst case scenario, in another 10 or 20 years, there may no longer be polar bears in this region and within a hundred years they could be extinct.
A quarter of the species of animals and plants could be extinct by 2100. More than three million square kilometres of Arctic sea ice has melted threatening the habitat of polar bears, experts predict that their numbers will ‘plummet’. Other threatened species include grizzly bears, penguin, turtle, caribou, walrus, plankton, krill, whale, crab and seal.
● HEALTH AND DISEASE
There are fewer deaths from cold related conditions but more from heat related conditions. Globally there are more heat related deaths than cold related deaths so the net impact is a loss of life.
Warmer temperatures increase air and water pollution thus increasing the risk to humans from infection and respiratory conditions.
Warmer temperatures are conducive to the breeding and spread of rats, mice, other rodents, ticks, mosquitoes, parasites, bacteria etc. This has lead to an increase in the number of people affected and an expansion into previously unaffected areas.
In 2007 one person is dying every three minutes as a result of global warming, this figure is expected to double by 2020. The World Health Organisation predicts that rising temperatures will result in an additional 300,000 deaths and 10 million illnesses a year by 2030. This is in addition to the tens of millions of additional cases of malaria the WHO expects to see.
● WATER SCARCITY
Rising sea levels contaminate groundwater rendering it undrinkable. Higher temperatures lead to greater evaporation of fresh water from reservoirs. This is impacting on the human population as well as plants, animals and agriculture.
Changing climate patterns mean some areas are receiving less rainfall. In other areas when the rain does fall, it does so on hard, sun-baked ground that is unable to absorb it. Instead of replenishing groundwater supplies the water runs off causing flash flooding and a lowering of the water table.
● MOUNTAIN ENVIRONMENTS
Glaciers are melting faster than has been known before - up to 40 metres per day in some places. In the last 100 years 50% of the world’s glaciers outside the polar regions have melted. The effects include flooding, landslides, avalanches and loss of habitat. In some mountainous regions melt water provides a year round water supply and without the glaciers there will be near drought conditions.
● ECONOMY
Sir Nicolas Sterm the former Vice Chairman and Chief Economist of the World Bank calculated that increased adverse weather is already costing some $600 billion a year. A temperature rise of 2 or 3°C would reduce global economic output by 3% in the short term and up to 20% ($12 trillion per year) in the long term.
● THERMOHALINE CIRCULATION
A possible effect of global warming is the failure or slowing of the ocean conveyor belts. Research is continuing and it's unclear at this time what effect, if any, global warming will have. One theory is that the melting of polar ice could reduce salinity and introduce cold water into the oceans, this could trigger a slowing or shutdown of thermohaline circulation. If this happens then parts of Europe would return to ice age conditions.
● CIVIL ENGINEERING
Costly engineering schemes need to be constructed in order to protect coastal cities. Many countries are not able to afford such schemes and low lying communities may need to be evacuated.
Greater contraction and expansion resulting from fluctuating temperatures and greater temperature ranges weakens roads, railways, runways, pipelines and other structures.
● DEVELOPING NATIONS
The developing nations have so far been the worst affected by global warming. Decreasing rainfall, drought, insect infestation and severe weather have impacted on crop production contributing to famine and starvation. Economic development is likely to be restricted whilst at the same time poverty increases. The poorer countries of the world are the ones that have the least resources to mitigate the effects of global warming.
● OTHER EFFECTS
Other impacts include: increased power outages, marine food chain disruption, changes to bird migration patterns, more wildfires, erosion, disappearing beaches, damage to tundra regions, impact on ozone layer, insect infestation, threat to boreal forests, coastal erosion, threat to mountain environments, loss of wetland and marshland habitats, decline in bird population, thawing of permafrost, increased allergens, coral destruction and bleaching, impact on winter sports etc.