http://deepblue.lib.umich.edu/bitstream/...
It existed in various places both in the biological and geological carbon cycles. Much more of it existed in the biological carbon cycle than today though.
The issues of global warming and fossil fuel usage are certainly closely connected. The use of oil and natural resources will decline in a decade. But this would not reduce the carbon dioxide emissions automatically; the replacements with coal, heavy oil and tar sand contain even more carbon, if to make them produce the same amount of energy they will produce twice more carbon. But the fact is that all transport, roads and airports for this transport are useless without oil. To create a new transport system is a task for the whole society, not for an individual, besides it would need money, time, natural resources and a lot of brain power. So the previous arguments concerning a lot of money spent on the stopping or at least slowing the global warming can be put aside against these ones.
The projections made for the future state that Earth will be an ice planet without greenhouse effect, the Earth will get warmer, by the 2100 the temperature will be 1.5 C - 4.5 C warmer, the increase will be less in the southern hemisphere and greater in the northern hemisphere. The global temperature is connected with carbon dioxide level and methane level, which at the moment exceed greatly the past levels.
I stand corrected. All of the carbon in fossil fuels was in the biological carbon cycle, not in the air per se. Only some of it was actually in the air. But if we burn all the coal and oil, the carbon won't be all in the air, either. It will be absorbed in the oceans, it will form plant and/or animal biomass, and so on, only some of it (probably a similar fraction) will end up actually in the air.
In other words, in terms of atmospheric CO2, we are unlikely to significantly exceed the levels in the air back however many millions of years ago the deposits of fossil fuels first formed. Meaning we are also unlikely to substantially exceed the temperatures of that era.
edit: Bob, note the qualifier "substantially". I don't think the sun is *that* much hotter than it was back then...
son of edit: You have a point, Bob. If we return *all* of that carbon to the biological carbon cycle, we may exceed those temperatures to an unprecedented degree. Still probably nowhere even remotely near "sterilize the planet" ranges, however...
No intelligent "warmest" says that warming is going to kill us all.
Deniers say that, and scare people who don't understand.
CLearly people can live all around the world.
However, there are very few people living in the middle of the Sahara desert.
There are some, but, other than at an oasis, no permanent residents.
There are no people living on Antarctica without outside assistance.
The problem is not that we'll all die.
That's not going to happen.
However, with the change in temperature and rainfall, we'll not be growing the same food in the same place we do now.
Maybe you read about the dust bowl.
It's not at all impossible that that will happen again.
The Ogalala aquifer is something like 50% depleted.
Once that's gone, there'll be a serious problem farming in the midwest.
Global warming will make that far worse.
<
This would be true if GHGs were the *only* factor in determining planetary temperatures. Look up the standard solar model.
But I'm not sure to what this conversation is in regards. Is Paul still prognosticating The End of All Things?
- - - - - -
Chem,
The majority of fossil fuel deposits were formed in during the carboniferous period some 300 million years ago. Using the standard solar evolution model, we can calculate that the Sun has increased its luminosity by about two and a half percent, which doesn't seem like much, but equates to a Top-Of-Atmosphere forcing of around 9 Wm-2, which is pretty substantial. Given differences in global circulation and albedo, placement of continents, long equilibration times, and the decidedly non-linear nature of the feedback system, it's difficult to ascertain the exact effect of this forcing, but it's safe to say that it's not nothing.
Carbon is everywhere, you breath out carbon carbon is a gas thus it will be in the air. You will, however, NOT want to bring back all the carbon from way past. That is why the burning of fossil fuels is really bad because people are adding carbon that has been sequestered inside our earth back to our current environment!! This is the reason why shells come out deformed birds lay eggs without shells, ozone depletion, polar bears drowning in water even though they are sea creatures. So you don't want to bring back carbon that has been "sealed" from today's atmosphere. ^_^
There were pterodactyls, mosquitoes, birds, maybe even some bats and flying squirrels, so it WAS in the air!
It is possible that before life appeared on our Earth our atmosphere was similar to Mars and Venus 95% CO2 and then cyanobacteria evolved and later others like algae and plants which eventually converted almost all the CO2 to carbon and oxygen.
Over 99% of carbon is and always was in rocks.
http://en.wikipedia.org/wiki/Carbon_cycl...
A moderate wrote: "All of the carbon in fossil fuels was previously in the air, several million years ago (I believe). Earth was by no means too hot for life at that time. Therefore, even if we return all of that carbon into the air (which would be... difficult), it is very unlikely that we will make Earth too hot for life."
I'm having trouble believing the "carbon" was in the air. Wasn't it in the bodies of animals and/or plants?
