Global Change of the Earth and its consequences

The greenhouse effect

- Before the advent of the industrial age, the concentration of CO2 in the atmosphere was 280 ppm (parts per million).

- Today the level is 360 ppm. This represents an increase of nearly 30% in less than 300 years.

For the earth, this is an unprecedented exchange rate, approximately 10,000 years of change compressed into 100 years. Today there is more CO2 in the air than there were during the entire period of human evolution. The land is used to slow changes, not quick. The slow changes give time to the biosphere and the species to adapt. Rapid changes can cause biological chaos and disrupt agricultural production. Carbon dioxide is critical in controlling the balance of the temperature of the earth because it absorbs infrared radiation (IR), which is basically heat.

Oceans

The global rise of the oceans is caused by two factors.

The first is the arrival of the ocean of water from such sources as melted ice of glaciers and polar icecaps.

The ice cap on Mount Kilimanjaro may be gone in 20 years. About one third of Kilimanjaro’s ice has disappeared in the last 12 years and 82% has vanished since his first mapped in 1912.

Antarctic ice masses impressive have plunged into the sea with alarming rapidity.

By interrupting a huge ocean current, melting Arctic sea ice can trigger a severe drop in temperatures in Europe and North America.

Global warming could plunge North America and Europe in a deep freeze, probably in just a few decades.

This is a theory that is gaining credibility among many scientists who study climate. The thawing of sea ice covering the Arctic could disturb or even halt large currents in the Atlantic Ocean. Without the immense heat provided by these ocean currents – similar to the energy output of a million nuclear power plants – Europe’s average temperature could drop 5 to 10 degrees Celsius (9-18 degrees Fahrenheit), and parts of North America would cool just a little less. This change in temperature would be similar to global average temperatures toward the end of the last ice age about 20,000 years ago.

Some scientists believe that this change in ocean currents can occur suddenly in an unexpected way – in a period as short as 20 years – according to Robert Gagosian, president and director of the Woods Hole Oceanographic Institution.

The second factor is the thermal expansion of ocean water. As the ocean water temperature rises and the seas become less dense, they will spread, occupying more surface of the planet. A temperature increase would accelerate the rate of increase in sea level.

Over the past 50 years, sea level has risen 0.18 inches per year, but over the past 12 years, the proportion is 0.3 inches a year. This increase in sea levels is a direct consequence of global warming melts the polar icecaps.

Along relatively flat costs such as the Atlantic, or along coastlines bordering fertile river deltas and densely populated, a rise of 1 mm in sea level causes a decline in cost of 1.5 meters.

Changing Climate

The 10 warmest years on record have occurred since 1983 and the 7 warmest years have occurred since 1990. The year 1998 was the warmest in history, followed in 2002, 2003 and this year will be the warmest ever recorded in recent times.

It is proven in recent studies that global temperature increases by half a degree per decade. From 1980 until today and has increased more than 1 degree.

Land areas will warm more rapidly than the global average, as the temperature of the oceanic areas will be moderated by the heat capacity of water.

Will be greater warming at high latitudes, as in the past, climate changes have affected the Earth’s polar regions a greater degree.