You're right - it is from the pipe.
http://www.epa.gov/climatechange/emi...08_Annex_4.pdf
Now, back to the point at hand - where is the rest "coming from"?
You haven't dispelled the notion that our activities, which reduce the Earth's capacity to absorb emissions, are to blame for the 'extra' increase in co2 in the atmosphere.
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Originally Posted by Oregon Elephant
1) As trees are removed (deforestation), that allows new trees to grow and begin filtering out CO2. For many trees (but not all), they stop growing atfer awhile but continue living. While a tree is not growing, it is removing very little CO2. Growing trees remove the most CO2. However, some trees continue to grow as long as they live.
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A forrest is forever renewed with new life. If forrests are damaged or destroyed by humans, they are not typically replaced by a replica (or better) forrest - it is cleared permanently. IF they are replaced at all - it is for 'sustainable' logging. The density of forest (ie life and co2 absorbtion capability) is nothing like the same as it used to be due to continual purging/burning and poisoning. The forests ability to absorb co2 is lessened. There is a particularly potent difference between a rainforrest and a plantation forrest.
I have a chart in front of me, which i cannot find online - despite a fair amount of effort!
The source is identified as the "Science, IPCC" and the chart was drawn by "Graphic News".
It shows "typical co2 emissions grams per km".
The chart is about biofuels.
Production, vehicle use:
Petrol: 120
Biomass: 35
Corn Ethanol: 96
BUT - when you factor in land conversion - you add:
Petrol: +0
Biomass: +179
Corn Ethanol: +230
This land conversion (but one example of human caused indirect co2 emissions), according to your info - is
not included in the emissions - yet it has contributed to an increase in emissions.
It points out "conversion of forest or grassland to arable land causes loss of organic carbon and subsequent rise in carbon dioxide emissions"
"Increase in co2 emissions over 30 years (tonnes per hectare)"
replace tropical wetland with arable land: up to 1146
replace tropical forest with arable land: up to 824
replace tropical grassland with arable land: up to 305
..more co2 than if left alone.
This ably demonstrates the impact of humans with regard to indirect emissions. The IPCC says this:
Wiki
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very likely and likely mean "the assessed likelihood, using expert judgment", are over 90% and 66% respectively.
Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.
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Originally Posted by Oregon Elephant
2) As glaciers melt and go from a solid to a liquid, they increase the amount of CO2 that the oceans can hold. Solid water is not capible of have a gas disolved within it, but liquid water is. So the more liquid water that we have, the more capibility to hold more disolved CO2.
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Interesting and quite possibly true (reference please). However - what about the previously safely captured co2 and methane (and whatever else) in the ice and permafrost, which is released as it melts. Also, regardless of the ice melt, the ocean still has a limit to what is can safely absorb before it begins to damage life and even become uninhabitable. This is part of the "difficult to predict the impacts of" feedback loops of climate change.
We increase enough co2, and lots else kicks in to amplify our stuff-up many times over.
We know it to be the case with permafrost, we know it to be the case with water vapour.
This is old, well-established science.
Google Search
The ocean will keep soaking up co2 (to a point - and not enough to offset our emissions if we don't adjust). The cost will be catastrophic for the oceans however as acidification kills just about everything.
Wiki
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Leaving aside direct biological effects, it is expected that ocean acidification in the future will lead to a significant decrease in the burial of carbonate sediments for several centuries, and even the dissolution of existing carbonate sediments[20]. This will cause an elevation of ocean alkalinity, leading to the enhancement of the ocean as a reservoir for CO2 with moderate (and potentially beneficial) implications for climate change as more CO2 leaves the atmosphere for the ocean[21].
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We know that the ocean won't be able to keep up - because we know how much co2 it took last time to destroy a huge swathe of ocean via acidification.
I think people look at history and say "yeah, it happened before and life went on". But things took tens of thousands of years to stabilise - and at great biological cost.
Ocean Acidification
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The upper panel shows calculated carbonate saturation state for pre-industrial times (atmospheric CO2 = 280 ppm). Under those conditions, all Pacific and Caribbean regions are in an optimal state for carbonate rock production. The lower panel shows calculated carbonate saturation state for 2070 (CO2 = 517 ppm). Under those conditions, most tropical reef areas are in a marginal state; a small area of Caribbean is in an adequate state.
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What the Past Tells Us
To emphasize the projected future carbonate situation, paleoceanographic evidence indicates that there was a massive carbonate disappearance in geological history. This occurred in the Paleocene-Eocene Thermal Maximum (PETM), 55 million years ago. Sediment cores show that there was an abrupt event where no carbonates survived in the sediment record while carbonates are abundant directly below and above (earlier and later periods respectively). The record indicates that the carbonate disappearance was sudden, occurring in less than 10,000 years and that it recovered naturally in about 100,000 years. The exact cause of the PETM is not well explained but it is thought that there was a relatively sudden massive release of methane gas which contributed to global warming and that the methane was oxidized to CO2 causing ocean acidification.
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On a side note, some evidence that some oceans at least are less able to absorb more co2 in the last ~20 years.
Saturation of the Southern Ocean CO2 Sink Due to Recent Climate Change -- Le Qur et al., 10.1126/science.1136188 -- Science
Southern ocean carbon sink weakened (Media Release)
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Scientists have observed the first evidence that the Southern Ocean’s ability to absorb the major greenhouse gas, carbon dioxide, has weakened by about 15 per cent per decade since 1981.
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