What Causes Global Warming

One of the main causes of what causes global warming is perceived to be the increase of carbon dioxide in the atmosphere. This greenhouse gas is accumulating in the Earth's atmosphere at an increasing rate, according to a new study released by the National Oceanic and Atmospheric Administration in the US.

A study has found that average atmospheric concentration of carbon dioxide in 2005 reached 381 parts per million. The annual rate of increase, which has been recorded since the 1950s, now exceeds 2 ppm for three of the past four years. This is an unprecedented increase; 50 years ago, the annual increase was less than 1 ppm. The real problem is that this is likely to rise at an increasingly exponential rate as more and more countries such as China and India industrial progress increases. Apart from this the existing highly developed countries are doing virtually nothing to contain their increases in carbon dioxide output.

The burning of fossil fuels, currently emitting approximately 7 billion tons of carbon per year produces the extra carbon dioxide (CO2), and roughly half is absorbed by vegetation and the oceans. The atmospheric concentration of carbon dioxide is now higher than experienced on Earth for at least the last 400,000 years, and the rise is expected to continue. Over the past two decades, only half of the CO2 released by human activities such as fossil fuel burning, is still in the atmosphere; about 30% has been taken up by the ocean, and 20% by the terrestrial biosphere.

The main vegetation on earth is in our forests, which are decreasing at a rapid rate due to logging. Absorption by our forests thus will be less and less increasing the problem of global warming.

Until recently the largest increases in concentrations of CO2 always occurred during El Nino years, when tropical vegetation grows more slowly due to lack of rain and fires occur in dried-out rainforests. The greatest recorded increase of 2.7 ppm occurred in the El Nino year of 1998. However, for the past three years of near-record increases none have coincided with an El Nino event.

Not only are plants slowing their rate of CO2 absorption, but coastal carbon sinks are shrinking as well. Mangrove forests, which play a large role in absorbing carbon from the atmosphere and dissolving it into the ocean, are disappearing rapidly. A research team studied how much mangroves contribute to the organic carbon dissolved in ocean waters off the coast of Brazil. They came to the conclusion that even though mangrove forests cover only 0.1% of the earth's surface, they contribute up to 10 per cent worldwide of the ocean's dissolved organic carbon. This is approximately equal to the amount reaching the ocean from the Amazon River, the largest single source of dissolved organic carbon.

Mangrove forests have declined by nearly fifty percent during the past century due to increasing coastal development and habitat damage, such as the draining of swamps for agriculture. As the habitat has changed, fewer mangrove trees are available to bind and export dissolved organic matter into the ocean.

These are only some of what causes global warming. But the cause of the cause is essentially because of man and man does not seem to want to do anything about it.