Global Warming Many Environmental Experts

Global Warming

Many environmental experts as well as scientists and medical experts are becoming increasingly concerned about the effects of global warming over the past few decades. This sense of alarm is fueled by the fact that many hypothetical theories and predictions previously made about the probable effects of extreme weather and climatic changes and believed to be an indication of global warming, are in reality occurring worldwide. These events have caused scientists to forecast even more extreme effects of global warming for the future.

The litany of global warming hazards is now familiar. Changing temperatures and rainfall may harm agriculture and stress natural ecosystems. Rising sea levels and severe storms may erode and inundate coastal zones. Especially worrisome is mounting evidence that nasty surprises, such as an abrupt shift in climate, become more likely as carbon dioxide and other "greenhouse gases" accumulate in the atmosphere.

Experts are predicting that the survival of millions of people around the world are at risk from the effects of global warning including shortages of food supplies, the increase in infectious diseases and changes in the various biological ecosystems of the world, which are already having profound effects on human life and health.

Definition and overview

The term 'global warming' refers to the increase in temperature in the environment throughout the world. A more thorough definition is as follows.

Global warming by definition is the gradual rise of the earth's surface temperature. It is thought to be caused by the greenhouse effect and responsible for changes in global weather patterns. Global warming has occurred in history as the result of natural influences, but today the term is often referred to the warming predicted to occur as a result of increased emissions of greenhouse gases.

The issue of global warming was first brought to the fore at the beginning of the Twentieth Century by the Swedish scientist Arrhenius, but the full significance of global warming was not realized until decades later. More recently there have been increasing signs of temperature increases.

According to the world's leading commercial forecaster, Accu-Weather, "Global air temperatures as measured by land-based weather stations show an increase of about 0.45 degrees Celsius over the past century." Data from satellite views of the earth also indicate "... A slight cooling in the climate in the last 18 years. "

There are also other indications that global warming is in fact taking place. A wide range of evidence suggests that there has been a significant rise in temperature over time since the start of the last century. For example, "since the beginning of the 20th Century, the mean surface temperature of the earth has increased by about 1.1° F (0.6°Celsius)" and "over the last 40 years, which is the period with the most reliable data, the temperature increased by about 0.5 " F (0.2-0.3°Celsius)."

It has been found that the amount of warming during the Twentieth Century was greater than at any time during the past 400 to 600 years.

3. The causes of global warming

There are many theories about the causes of global warming. The most well-known is the greenhouse effect. This theory states that global warming is caused mainly by the anthropogenic or human generated output of carbon dioxide.

In essence, global warming "results primarily from human activities that release heat-trapping gases and particles into the air."

There is common consensus that global warming is caused by humans and not other factors "the human role in a rapid warming of the Earth has become nearly incontrovertible."

This is an important aspect as it relates to the possible solutions to this phenomenon. Kathy Maskell and Irving M. Mintzer, writing in the British medical journal Lancet, describe the balance of carbon in the environment, which points to human intervention in this natural process..

Over the past 10,000 years, the concentration of CO2 and other greenhouse gases has remained fairly constant, and this represents a remarkable balancing act of nature. Every year natural processes on the land and in the oceans release to and remove from the atmosphere huge amounts of carbon, about 200 billion tons (gigatons) in each direction. Since the atmosphere contains about 700 gigatons of carbon, small changes in natural fluxes could easily produce large swings in atmospheric concentrations of CO2 and Chapter 4 [methane]. Yet for ten millennia natural fluxes have remained in remarkably close balance. (Maskell and Mintzer 1993, 1027)

The most common causes of the increase in temperature are gas emissions due to the burning of fossil fuels such as coal, gas, and oil. Another important factor is deforestation by industry of large tracts of natural foliage, such as the Amazon jungle. This deforestation reduces the natural absorption and "cleansing" of the environment that is the ecological function of these areas. Forests are essential in maintaining environmental balance by absorbing carbon dioxide and releasing oxygen into the atmosphere yet a steady elimination of forests continue which is contributing to the detrimental effects of global warming.

In past millennia, forests maintained a rough balance between the biomass of the world's vegetation and carbon dioxide. Forests kept increases in carbon dioxide (mainly from volcanic activity) in check by converting carbon into cellulose and releasing oxygen through photosynthesis. However, only about half the world's forests that existed a thousand years ago remain. Moreover, the concentration of carbon dioxide in the atmosphere has been increasing steadily since 1850. Billions of tons of greenhouse gases have been spewed into the atmosphere by burning fossil fuels and have thrown the system out of balance.

Other aspects to consider are methane gas emissions as well as the release of nitrous oxide chemicals into the atmosphere. Gasses are also released into the atmosphere by rice cultivation, cattle and livestock populations, gas pipelines, and landfills.

4. The effects of global warming

The most serious risk lies in the change of climate and its effect on the environment, as this will in turn affect everything else, including human health. The increase in temperature will inevitably result in radical climatic changes in areas of the world. This will cause the sea to rise with resulting floods and loss of agricultural lands. There will also be heat waves and an increase in the number and severity of droughts throughout the world, which in turn will have a direct impact on food-yielding crops and diminished fresh water resources.

Another important aspect is the increase in serious diseases as a result of global warming. Global warming will result in "... A greater potential for heat-related illnesses and deaths as well as the wider spread of infectious diseases carried by insects and rodents into areas previously free from them."

The increase in global warming is also likely to intensify conditions in those areas in which serious diseases such as Dengue fever, Malaria, West Nile virus, and Yellow Fever are already prevalent.

Further effects of global warming that cause concern are the inevitable increase in pollution and rise in sea level which will have a drastic effect on marine ecosystems with large quantities of dead fish adding to the problem. Changes in temperature which are sustained over a period of time can also seriously impact and endanger wildlife and entire ecosystems. This can have a serious effect on already endangered wildlife species as well as fauna and flora. Changes in temperature can also impact on the economic systems that are dependent on these ecosystems for agriculture and other resources. Some researchers predict that if the rate of global warming continues to increase, it could result in environmental changes as severe as the last ice age.

In the light of the above possibilities, the effect on human life if global warming continues is predictable. The World Health Organization (WHO) has predicted that by 2030 climatic changes will cause the deaths of 300, 000 people annually.

For example, in Asia a rise in the sea level coupled with an increase in the intensity of tropical cycles "would displace tens of millions of people in low-lying coastal areas... trigger decreases in agricultural productivity and diminish food security."

Increase in temperature can also have a more direct effect on human health. Very high temperatures, as a result of global warming, can cause large numbers of human deaths. "Extremely hot temperatures increase the number of people who die on a given day for many reasons: people with heart problems are vulnerable because one's cardiovascular system must work harder to keep the body cool during extreme hot weather. Heat exhaustion and some respiratory problems increase." (see below)

Higher temperatures can also have a direct effect on the amount of ozone in the atmosphere. While many assume that more ozone is a positive factor as it protects us from harmful radiation, too much ozone in the lower parts of the atmosphere can cause serious health risks. Ozone is in fact a harmful pollutant and can cause damage to the lungs. It is particularly harmful to those people with asthma and various lung diseases. "Even modest exposure to ozone can cause healthy individuals to experience chest pains, nausea, and pulmonary congestion. In much of the nation, a warming of four degrees (F) could increase ozone concentrations by about 5%."

As mentioned, increased pollution is one of the results of global warming; and this can also have an effect on human health.

One of the health hazards is the increase of respiratory illness due to the connection between heat waves and air pollution. Another related factor is that it has been found that increased levels of carbon monoxide are related to increases in the pollen count which affects various respiratory ailments. "Photochemical smog and carbon dioxide are factors that have been found to boost pollen production by ragweed. This alone may help account for part of the tremendous rise in asthma. In addition, extreme weather events are becoming more intense and projected to become more frequent.

Solutions and controversy

There is a general consensus among most nations that solutions to this growing problem have to be found. This will of necessity involve policy changes in many countries towards the environment.

A the world now faces the challenge of designing an effective policy response. International cooperation will be required because greenhouse gases are long-lived in the atmosphere -- emissions from every country spread worldwide to create a truly global problem. Cooperation is also required because controlling emissions may be costly.

Furthermore the world's leading authority on global warming, the Intergovernmental Panel on Climate Change (IPCC), has stated that