February 15, 2012

Impact of Greenhouse Effect - G1 Mains - Paper4

The greenhouse effect's impact is to make life as we know it possible on planet Earth, but the greenhouse effect may also bring an end to life as we know it.

The greenhouse effect refers to the trapping of heat by certain gases in the atmosphere, including carbon dioxide and methane. Although these gases occur in only trace amounts, they block significant amounts of heat from escaping out into space, thus keeping the Earth warm enough for us to survive.

Humans have been adding greenhouse gases in excessive amounts to the atmosphere ever since the Industrial Revolution, which is enhancing the greenhouse effect and resulting in what is now known as "global warming." This increase in greenhouse gases has the potential to cause catastrophic problems for Earth and its inhabitants.
The Biggest Problem – Sea Level Rise

The most dangerous aspect of global warming is probably sea level rise. In fact, the world's oceans have already risen 4-8 inches.[1] That may not sound like much, but it has been enough to cause the erosion of some islands.

People have had to relocate to higher ground on low-lying islands in the South Pacific and off the coast of India as a result of the effects of global warming. Further sea level rise could cause great suffering. In Bangladesh alone, there are 15 million people living within 1 meter of sea level and another 8 million in a similar circumstance in India.

Inhabited land could be inundated if sea levels continue to rise. Much of the world's best farmland is low-lying, as are many of the world's largest cities. Even a very modest rise in sea levels would have an enormous impact on millions of people around the world.
Droughts and Floods

Ironically, changes in the climate due to excess greenhouse gases are causing both increased drought and increased flooding.

Violent storm activity will increase as temperatures rise and more water evaporates from the oceans. This includes more powerful hurricanes, pacific typhoons, and an increased frequency of severe localized storms and tornadoes. As these storms often result in flooding and property damage, insurance premiums are skyrocketing in coastal areas as insurance companies struggle to cover escalating costs.

Warming also causes faster evaporation on land. Many dry areas, including the American West, Southern Africa, and Australia are experiencing more severe droughts. The amount of land on the Earth suffering from drought conditions has doubled since 1970. This has occurred even as total global rainfall has increased by an estimated 10%!
The Human Price of Climate Change

Drought is driving current increases in food prices around the world, in combination with increased use of grains for fuel. Globally, the number of malnourished people decreased up until the late 1990s. Now that number is increasing.

Disease carriers will expand their territory, either by moving to higher elevations in mountainous areas or by expanding their territory further from the equator. This expansion will expose millions of humans to the often deadly infectious diseases that these animals transmit.

150,000 annual deaths worldwide have been tied to climate change already, according to a 2005 World Health Organization report. Climate related deaths are expected to double in 25 years. Industrialized countries may be sheltered from the current impacts of climate change, but others are not.

Heat waves and droughts are responsible for these deaths, as well as floods and more powerful storms linked to climate change.
Approaching a Slippery Slope

Global temperatures have risen about .8° Celsius or 1.4° Fahrenheit already. As a result of this increase, the vast arctic tundra is melting, releasing enormous volumes of both carbon dioxide and methane into the atmosphere. This creates the possibility of a self-reinforcing loop of climate change: as more carbon dioxide and methane are released from the arctic tundra, the greenhouse effect will be further enhanced.

The world's oceans are losing their ability to absorb carbon because of rising water temperatures, according to accumulating evidence. This is significant because the world's oceans hold 50 times more carbon than do the world's forests and grasslands. The decreasing capacity of the Earth's carbon sinks to absorb carbon could further increase the likelihood of runaway climate change.
Rapid Climate Shifts

Scientists are becoming convinced that past cycles of climate change on the Earth have been anything but slow and incremental, ever since the idea that the Earth may warm over time as a result of human-created climate change has reached the public consciousness.

Climate change happens suddenly and violently. Research indicates that the Earth's climate exists in a stable state for many thousands of years. Then, pressure for change builds from increases or decreases in carbon levels as well as changes in solar radiation. At some point, the Earth reaches a tipping point where global climate systems and ocean currents are radically altered over the course of only a few years, or even months.

Once that threshold is crossed, the Earth's climate goes through a period of dramatic disequilibrium, finally settling down in a new stable state that is very different from the previous one.

There is no turning back if we cross the threshold and reach a tipping point. Weather patterns all over the world may be disrupted, ending life as we know it. We must not gamble with all of life on Earth. You should work to take decisive action to avoid devastating climate change.


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