Environmental, Climate and Global Warming Issues » Carbon Dioxide

Greenhouse Gases from Anthropogenic Sources (I)

mzPOTTER — Thu, 18 Mar 2010 00:00:13 +0000

The main source of emission of carbon dioxide (CO2) into the atmosphere is the burning of fossil fuels and biomass (natural gas, oil, fuel, wood) in industrial processes, transportation, and household activities (cooking and heating). The forest and grassland fires are also an important source of atmospheric CO2. The atmospheric CO2 concentration rose from 280 ppm in the period 1000 to 1750, to 368 ppm in 2000, representing a percentage increase of 31%. It is estimated that the current concentration is greater than occurred during any period in the last 420,000 years, and is likely to also be the maximum of the last 20 million years.It should be stated that carbon in the atmosphere in the form of CO2 is a very small portion of the total of this element in the climate system. The figure shows the main reservoirs of carbon in the system and annual flows between them occur. The carbon in the atmosphere is estimated at 730 PgC while CO2 dissolved in the oceans is approximately 38,000 PgC. Moreover, in the Earth system is estimated there are about 500 PgC in plants, and they are fixed in the form of carbohydrates in the process of photosynthesis, and another 1,500 PgC in organic material in varying states of decomposition. Eventually all the carbon transferred from the atmosphere to the biosphere is returned to it in the form of CO2 that is released by decaying dead plant material or fire associated with the combustion of natural or anthropogenic. On an annual basis, the carbon fluxes atmosphere-ocean and atmosphere-Earth system are approximately zero. This means that about 90 PgC are exchanged in both directions between the atmosphere and oceans, and about 120 PgC between the atmosphere and the Earth system. It should be noted that these exchanges represent a considerable fraction of the total accumulated in the atmosphere, so it is important to understand how human activity can modify them.

It is estimated that between 1990 and 1999, the man gave the atmosphere an average of 6.3 PgC of carbon per year (1 PgC = 1 Peta-gram carbon = 1000 million tons). Moreover, in the same period the annual rate of change of atmospheric carbon to the biosphere was estimated at 1.4 PgC / year and into the ocean at about 1.9 PgC / year. This man helped to increase the concentration of atmospheric carbon reservoir at a rate of 3.0 PgC / yr during this period.

Reference figure: IPCC 2001 report

Source: http://www.atmosfera.cl/HTML/TEMAS/CALENTAMIENTO/calen2.HTM

Dodging a Glacial

Sharon Keisha — Wed, 03 Feb 2010 10:12:06 +0000

Between 5,000 and 8,000 years, methane emissions of both carbon dioxide and began presenting an upward trend.

It is likely that the accumulation of these greenhouse gases in the atmosphere over the last few thousand years has stopped the start of a new glacial cycle, as those who have been in constant intervals every 100,000 years during the last million years.

Each glacial period was marked by regular, predictable changes of Earth’s orbit, known as orbital variations.

Because of these variations in Earth’s orbit, although the solar luminosity is almost constant over millions of years, the average amount of radiation received by each hemisphere fluctuates, what times of extreme cold.

According to scientists, without the action of human beings today we would probably find one of those times.

Global warming is Not Due to Any Carbon Dioxide

Lourdez — Sat, 05 Dec 2009 03:23:57 +0000

Global warming has been attributed to the past in general, bled atmospheric carbon dioxide levels increase. U.S. U.S. National Science Foundation in a recent study that is not the case. The investigation of the amount of carbon dioxide content analysis of the last ice age about 1300 years into the global warming began. The study shows that CO2 increase is the result of global warming, not because of global warming. researcher Lowell Stout is not the first that brings out this kind of research, but his work is one more detail.
Slotting research differs from other studies dealing with global warming in the fact that he questioned CARBON correlation between global warming and climate. Although CO2 is a component of climate change, its role would have to be re-evaluated. The new research also undermines the belief in the fact that the recent increase in carbon dioxide in the atmosphere would be created by man. Increased carbon dioxide in the atmosphere is due largely to Totting sea change in circumstances.

According to the study of changes in the atmosphere have increased the Antarctic against the sun’s radiation. Ice floes large withdrawal from the sea has eroded Albedo or reflectance of solar radiation over. Because of this, at least one thousand years have contributed to the phenomenon a result of sunlight is reflected back into space anymore as much as before, the climate is gradually warmed.