WHAT IS CLIMATE CHANGE?

“There is over whelming scientific consensus that the earth is warming, that this warming trend will worsen, and that human activity is largely to blame”. (Eileen Claussen, President PEW Center on Global Climate Change). ¹

Global warming refers to an increase in the average global temperature, mainly due to human influence. Greenhouse gases trap a fraction of the sun's heat that is reflected back into space from the earth’s surface. This natural greenhouse effect enables the earth to maintain a temperature much warmer than would otherwise be possible.

The most influential greenhouse gas, and biggest contributer to what is known as the “enhanced green house effect”, is Carbon dioxide. Human activities such as the burning of fossil fuels (coal, oil, gas), particular farming methods, and changes in land use, are responsible for an increase in the amount of carbon dioxide and other greenhouse gases entering the earth’s atmosphere. This intensification of atmospheric greenhouse gases is causing an artificial warming of the earth’s lower atmosphere and surface.²

WHY WORRY ABOUT CLIMATE CHANGE?

It may be the case that humans are not facing the immediate threat of extinction due to global warming. However, the risks to our economy and environment are high.

The 20^th Century saw a rise in global air temperatures by 0.6 degrees C. The predictions relating to climate shifts in the 21^st Century are wide-ranging, with estimates landing anywhere between an increase of 1.4 to 5.8 degrees C in annual global mean surface area temperature.³ The United Nations Framework Convention on Climate Change (UNFCCC) describes this element of uncertainty as reflecting the “complexity, interrelatedness, and sensitivity of the natural systems that make up the climate”.⁴ The consequences of climate change could vary anywhere from troublesome to devastating. Even taking into consideration the least drastic climate change predictions, it is a certainty that that impact of global warming will be felt by every living species on the planet.

POTENTIAL CLIMATE CHANGE IMPACTS

Extreme Weather Events and Disasters

Numerous parts of the world are experiencing rising sea levels, extended dry seasons, more powerful storms, and shifts in rainfall patterns. The most noticeable symptoms of these weather changes have been floods and droughts of growing catastrophic nature. The World Water Council has reported a ten-fold increase in economic losses due to weather and flood disasters over the past 50 years.⁵

During the five-year period from 1983 to 1987, the number of people affected globally by floods was approximately 31 million. The five-year period from1993 to 1997 saw this figure grow to 130 million - a four-fold increase from the previous decade.⁶

In relation to the first point, a rise in sea-surface temperature is expected to increase cyclone and hurricane activity in some regions. Over the course of the 2005 North Atlantic storm season, hurricanes reached record heights for their intensity. Hurricane Katrina was one such hurricane, and its impact caused the deaths of more than 1,300 people in Mississippi and Louisiana.⁷ A recent study conducted by scientists at the Georgia Institute of Technology strengthens this link between rising sea surface temperatures and severe hurricanes. The study revealed a doubling in category four and five hurricanes since 1990, and found a link between the hurricane activity and a rise in the global temperature of tropical oceans.⁸

In 2005, meteorologist Kerry Emanuel of the Massachusetts Institute of Technology released a paper that correlated the growing frequency and intensity of hurricanes with global warming. When interviewed, Emanuel reflected on what the results of his study could mean for greater humanity:

“…in the United States we have been enormously successful in reducing the loss of life…so our problem is economic…But in the rest of the world, in the developing world, the problem is loss of life…tropical depression Jean last year…killed almost 2,000 people…Hurricane Mitch in 1999 killed 11,000 people in Central America. And a decade before that a hurricane in Bangladesh killed 100,000 people”.⁹

Emanuel’s comments highlight the difficulties facing developing countries as hurricanes become more frequent and severe. Lacking in the resources and infrastructure to deal with the effects and aftermath of intense weather events, the potential risk to lives is huge.

Most countries are not financially equipped to cope with the increase of devastating natural disasters presently occurring. National economies will seriously struggle to cope with the growing number of climate change related disasters.

Health Impacts

Human health will be affected by changes in weather patterns. An increase in climate extremes due to global warming (drought, floods, hurricanes etc) will cause population displacement, economic damage, raise issues of food security, and put water quality and availability at risk. The risks of infectious disease epidemics are increased when populations face damage to their water and food sources. A breakdown in public health or sanitation infrastructure due to the occurrence of extreme weather events also increases the risk of disease outbreaks.

Many serious diseases are spread via vector organisms (eg. fleas, ticks, mosquitos), which do not regulate their own internal temperature. These organisms are highly sensitive to the temperature and humidity of their environments. Indirect effects of climate change could enhance the transmission of vector-born diseases such as encephalitis, malaria, yellow fever, leishmaniasis and dengue, through an expansion in the season and range for vector organisms. Climate is an important controller when it comes to distribution and spread of vector-born diseases. The Intergovernmental Panal on Climate Change (IPCC) notes that temperature can also “influence the reproduction and maturation rate of the infective agent within the vector organism, as well as the survival rate of the vector organism,¹⁰ adding to its influence on disease transmission.

An increase in the incidence or intensity of heat waves due to climate change will impact on the rates of human mortality and morbidity. The urban poor and older age populations face the biggest threat from extreme heat temperatures.l¹¹

Coastal Areas and Marine Ecosystems

The IPCC states that global warming will change the biological, biochemical, and physical characteristics of the coasts and oceans. They will experience alterations in their ecological composition, and to the commodities and services they supply to humanity.

The IPCC Third Assessment report (2001) lists the following large-scale impacts of global warming on oceans:

• Increases in sea level and sea-surface temperature

• Decreases in sea-ice cover

• Changes in salinity, alkalinity, wave climate, and ocean circulation.¹²

Large-scale impacts of global warming on oceans will place many species at risk of local, or even total, extinction. The removal or displacement of any one species in an eco-system can drastically alter the food chain, and hence the cycle of life, in the marine environment. In response to the dramatic decline in zooplankton levels recently discovered by scientists, Dr Phil Williamson, marine biologist at East Anglia University, warns that "[r]emoving the bottom link in the food chain could have profound and unpleasant results" for the marine life further up the food chain.¹³

Coastal ecosystems such as estuaries, mangrove forests, coral reefs, and wetlands are exceptionally vulnerable to climate change. Such ecosystems are recognised as being some of the most biologically dynamic environments in the world. The IPCC Third Assessment Report lists the following impacts of global warming and sea-level rise on coastal systems:

• Increased levels of inundation and storm flooding

• Accelerated coastal erosion

• Seawater intrusion into fresh groundwater

• Encroachment of tidal waters into estuaries and river systems

• Elevated sea-surface and ground temperatures.¹⁴

Again, it will be the less wealthy coastal regions that will more strongly experience the negative impacts of climate induced environmental changes to their coastal homelands. Many of the small Pacific Islands are currently facing issues of food security, as tides wash through their crop gardens. Salt-water intrusion is a serious issue for the islands, as it seriously reduces the productive capabilities of the land.

Rising Sea Levels

The Intergovernmental Panel on Climate Change (IPCC) projects a sea-level rise anywhere between 9 and 88cm by 2100.¹⁵ Approximately one hundred million people worldwide live within one metre of current sea levels. There is a population of over 10 million people living within one metre of sea level in Bangladesh alone.¹⁶ Even if we could stabilise greenhouse gases today, the sea levels would still continue to rise for hundreds of years due to the amount of global warming that has already occurred.¹⁷

The CSIRO Marine Research group (2001) lists the following ways in which the impacts of rising sea levels will be seriously felt:

• Increases in intensity and frequency of storm surges

• Increased erosion

• Loss of important wetlands and mangroves

• Impact on coastal ecosystems i.e. Coral reefs

• Impact on human settlements. ¹⁸

Rising sea levels pose a serious risk to coastal populations across the globe. Low-lying areas in developing countries and island nations will find it extremely difficult to cope and adapt to the changes to their environment and loss of land.

Arctic Regions

Tim Flannery (2005), comments on the bleak future facing the arctic eco-systems in his recent book “The Weather Makers: The History and Future of Climate Change”:

“The changes that we’re witnessing at the Poles are of the runaway type…unless greenhouse gases can be limited – and quickly – there can be no winners among fauna and flora unique to the region”... “Any polar bears or seals surviving in zoos, which have been kept in the hope of one day re-creating their icy realm, will remain captive, for after persisting for millions of years the North polar cryosphere will have vanished for ever”.¹⁹

During the summer of 2002 the Greenland ice cap experienced the largest decrease in size ever recorded, shrinking by 1 million square kilometers. It is predicted that if the current rate of decline continues then none, or very little of the Arctic ice cap will remain at the end of the century. Alaska’s Columbia Glacier has shrunk by 12 kilometers over the past 20 years, and estimates show that America’s Glacier National Park will be devoid of glaciers in a few decades time.²⁰ Such a rapid loss of ice mass cannot occur without disrupting the delicate ecological balance of plant and animal life in the regions.

The Inuit people, native to the Arctic region, are facing a serious threat to their livelihood due to the effects of global warming. There are around 155,000 Inuit who continue to practice a traditional way of life in Greenland, Alaska, Far East Asia and Northen Canada.²¹ Sheila Watt-Cloutier, chair of the Inuit Circumpolar Conference (ICC), spoke out at a UN meeing on climate change, telling her audience that the issues facing her people were those of life and death: "We go out to hunt on the sea ice to put food on the table. You go to the supermarket".²² Watt-Cloutier describes the effects of global warming that she has seen:

“Over the last decade our hunters have been witnessing changes in certain areas...some are saying that polar bears seem to be much thinner, and they have been finding bears closer and closer to food sources, places where they did not [previously] venture. The weather has become very unpredictable and that creates a lot of havoc not only with those of us who hunt on the sea ice, but with animals, as well. New species of fish and birds have been spotted up in the Arctic that are not indigenous. People [have also] witnessed changes where ice forms later [and] the river ice breaks up so much earlier; it used to be in mid-June, and now it has been as early as mid-May.... In terms of summertime, in the course of my own life it was very rare that we ever used to wear shorts and T shirts because it never got warm enough. But today because there are such long heat waves where it is 30 Celsius [86 degrees Fahrenheit] for an entire month, the whole community goes to the beach and swims”.²³

Considering that scientists are predicting that polar regions will warm on a much more drastic scale than the rest of the world, the survival of the Inuit way of life is a issue of grave importance.

Human Displacement/ Climate Refugees

Many of the above impacts of climate change, such as sea level rise, drought and hurricanes, will affect food and water security, which will lead to an increased number of climate refugees around the world.

In the years to come, we can expect to experience a growing tide of humanity seeking refuge from global warming: this is already happeing in the Pacific, with the island nation of Tuvalu signing an agreement with the New Zealand government to relocate most of its citizens to New Zealand over the coming decades.

For more information on this issue please refer to the Friends of the Earth’s ‘A Citizens Guide to Climate Refugees’. http://www.foe.org.au/download/CitizensGuide.pdf.