How much gigatons of man made Co2 ?

Question

Hi,
I would like to know how much C02 gaz was produced and released in the athmosphere by human (industrial) activities in a recent year, in gigatons ?

I would like to know also how much co2 was released in the same period of time by natural phenomenon (volcanoes, sea, biomass....)

Please quote your source.

Thanks,
Cyril

Answer 1

Elizabeth Kolbert is one of my favorite Scientists on this subject.
This is just a fraction of her artical you need to read the whole thing. it is very interesting.
Caldeira is another scientist I like on this matter. they both make you think about the future
There really is no exact estimate of how much emissions humans alone caused CO2 to rise, but it is enough to have catastrophic effect on Earth's population both marine and land.

Adding carbon dioxide, or any other greenhouse gas, to the atmosphere by, say, burning fossil fuels or levelling forests is, in the language of climate science, an anthropogenic forcing. Since pre-industrial times, the concentration of CO2in the earth’s atmosphere has risen by roughly a third, from 280 parts per million to 378 p.p.m. During the same period, concentrations of methane, an even more powerful (but more short-lived) greenhouse gas, have more than doubled, from .78 p.p.m. to 1.76 p.p.m. Scientists measure forcings in terms of watts per square metre, or w/m2, by which they mean that a certain number of watts of energy have been added (or, in the case of a negative forcing, subtracted) for every single square metre of the earth’s surface. The size of the greenhouse forcing is estimated, at this point, to be 2.5 w/m2. A miniature Christmas light gives off about four tenths of a watt of energy, mostly in the form of heat, so that, in effect (as Sophie supposedly explained to Connor), we have covered the earth with tiny bulbs, six for every square metre. These bulbs are burning twenty-four hours a day, seven days a week, year in and year out.

If greenhouse gases were held constant at today’s levels, it is estimated that it would take several decades for the full impact of the forcing that is already in place to be felt. This is because raising the earth’s temperature involves not only warming the air and the surface of the land but also melting sea ice, liquefying glaciers, and, most significant, heating the oceans — all processes that require tremendous amounts of energy. (Imagine trying to thaw a gallon of ice cream or warm a pot of water using an Easy-Bake oven.) It could be argued that the delay that is built into the system is socially useful, because it enables us — with the help of climate models — to prepare for what lies ahead, or that it is socially disastrous, because it allows us to keep adding CO2to the atmosphere while fobbing the impacts off on our children and grandchildren. Either way, if current trends continue, which is to say, if steps are not taken to reduce emissions, carbon-dioxide levels will probably reach 500 parts per million — nearly double pre-industrial levels — sometime around the middle of the century. By that point, of course, the forcing associated with greenhouse gases will also have increased, to four watts per square metre and possibly more. For comparison’s sake, it is worth keeping in mind that the total forcing that ended the last ice age — a forcing that was eventually sufficient to melt mile-thick ice sheets and raise global sea levels by four hundred feet — is estimated to have been just six and a half watts per square metre.

There are two ways to operate a climate model. In the first, which is known as a transient run, greenhouse gases are slowly added to the simulated atmosphere — just as they would be to the real atmosphere — and the model forecasts what the effect of these additions will be at any given moment. In the second, greenhouse gases are added to the atmosphere all at once, and the model is run at these new levels until the climate has fully adjusted to the forcing by reaching a new equilibrium. Not surprisingly, this is known as an equilibrium run. For doubled CO2, equilibrium runs of the GISS model predict that average global temperatures will rise by 4.9 degrees Fahrenheit. Only about a third of this increase is directly attributable to more greenhouse gases; the rest is a result of indirect effects, the most important among them being the so-called “water-vapor feedback.” (Since warmer air holds more moisture, higher temperatures are expected to produce an atmosphere containing more water vapor, which is itself a greenhouse gas.) GISS’s forecast is on the low end of the most recent projections; the Hadley Centre model, which is run by the British Met Office, predicts that for doubled CO2the eventual temperature rise will be 6.3 degrees Fahrenheit, while Japan’s National Institute for Environmental Studies predicts 7.7 degrees.

In the context of ordinary life, a warming of 4.9, or even of 7.7, degrees may not seem like much to worry about; in the course of a normal summer’s day, after all, air temperatures routinely rise by twenty degrees or more. Average global temperatures, however, have practically nothing to do with ordinary life. In the middle of the last glaciation, Manhattan, Boston, and Chicago were deep under ice, and sea levels were so low that Siberia and Alaska were connected by a land bridge nearly a thousand miles wide. At that point, average global temperatures were roughly ten degrees colder than they are today. Conversely, since our species evolved, average temperatures have never been much more than two or three degrees higher than they are right now.

This last point is one that climatologists find particularly significant. By studying Antarctic ice cores, researchers have been able to piece together a record both of the earth’s temperature and of the composition of its atmosphere going back four full glacial cycles. (Temperature data can be extracted from the isotopic composition of the ice, and the makeup of the atmosphere can be reconstructed by analyzing tiny bubbles of trapped air.) What this record shows is that the planet is now nearly as warm as it has been at any point in the last four hundred and twenty thousand years. A possible consequence of even a four- or five-degree temperature rise — on the low end of projections for doubled CO2 — is that the world will enter a completely new climate regime, one with which modern humans have no prior experience. Meanwhile, at 378 p.p.m., CO2 levels are significantly higher today than they have been at any other point in the Antarctic record. It is believed that the last time carbon-dioxide levels were in this range was three and a half million years ago, during what is known as the mid-Pliocene warm period, and they likely have not been much above it for tens of millions of years. A scientist with the National Oceanic and Atmospheric Administration (noaa) put it to me — only half-jokingly — this way: “It’s true that we’ve had higher CO2levels before. But, then, of course, we also had dinosaurs.”

David Rind is a climate scientist who has worked at GISS since 1978. Rind acts as a trouble-shooter for the institute’s model, scanning reams of numbers known as diagnostics, trying to catch problems, and he also works with GISS’s Climate Impacts Group. (His office, like Hansen’s, is filled with dusty piles of computer printouts.) Although higher temperatures are the most obvious and predictable result of increased CO2, other, second-order consequences — rising sea levels, changes in vegetation, loss of snow cover — are likely to be just as significant. Rind’s particular interest is how CO2levels will affect water supplies, because, as he put it to me, “you can’t have a plastic version of water.”

http://www.wesjones.com/climate2.htm...
http://www.livescience.com/environment/0... also a good artical
I have done a paper on this subject back in May this year did well on it. http://blog.360.yahoo.com/blog-dmwgrys6a... I leave it as my blog as a refrence to get back to being that many people (fortunaly) are concerned.