How strong is the case for "CO2 as a positive feedback theory" ?

Question

I have noticed a lot of talk lately about Co2 being responsible for warming trends in the past using the "positive feedback " theory. The problem with this is....We would never suspect C02 of this in the past and nor should we of today. To say Co2 can magically change from a minor GHG to a super runaway powerhouse gas capable of being a dominant force in big warming trends , is to play around with the laws of physics as we know them. Co2 must be first (which it is) assumed to have Negative Feedback qualities until clearly proven otherwise. If Co2 did indeed have the power of Positive Feedback , then forget about industry.... it would be dangerous just to exhale it from your lungs . You might start a chain reaction and destroy life on earth!!!

http://www.coyoteblog.com/coyote_blog/2007/04/the_800year_lag.html

Answer 1

The CO2 you breathe:

The CO2 you breathe is not related to global warming. The CO2 which is in the short cycle (biosphere) is roughly in balance (except for the deforestation). It will be transformed to carbon by trees as part of the life cycle and then to methane and CO2 again. This works in an almost close cycle with little exchange with geologic layers. You can almost imagine this as a close bottle.

The problem is that we add to this cycle carbon from geologic layers (coal, oil and natural gas). This fossil carbon has not been part of the short (biosphere) carbon cycle for millions of years.

The positive feedback:

It is presently observed that methane concentrations over Siberia are higher than elsewhere on earth. This is because as the permafrost is melting and oceans are warming, methane is being released. This is an example of "positive feedback".

Answer 2

co2does'nt have anything to do with the cause of global warming. it decipates long before it gets to high.

Answer 3

Seriously now... if you were to break down the Vostok ice core record down by year... you will see, that CO2 is sometimes on the rise and temperatures fall, and visa-versa.  You don't honestly believe that CO2 'only' lags temperature levels, year after year after year, 650,000 times do you?

But despite all that, what is concerning to us is how drastically this harmony between CO2 and temperature levels has changed all of a sudden, just in the last couple of hundred years.  To suggest that isn't something we should try to understand, and perhaps reverse if at all possible until we actually do, now that... is irresponsible.

Now per you exhaling CO2 setting off a chain reaction, and comparing that in any way to industrious CO2, please, you have to understand one simple difference between the two here.  CO2 from your lungs, burning trees, seasonal warming trends in the oceans, ice caps and elsewhere, etc... are all already existing in a closed loop.  CO2 sinks, and is redistributed, and sinks and is redistributed throughout the earth's entire eco-system.  Industrious CO2 is significantly and simply different in the fact that the CO2 from Industry, and 99% of all anthropogenic CO2 emissions in fact, comes from 'ancient' 'buried' fossil fuels.  Meaning, we are taking vast amounts of carbon which was not part of the earth's current CO2 cycle, re-introducing it in the form of Carbon Dioxide gas and releasing it carelessly without regard to consequence into the atmosphere.   This much is not a theory, it is a fact, it also explains why or how we have significantly raised the earth's CO2 levels and is supported by the influx of CO2 levels according to all available historic data methods since the beginning of the Industrial Revolution.

So we know where the 'additional' CO2 came from.  Do we fully yet understand what that could mean?  Perhaps not, but it's not looking pretty.  Say what you want about Science which attempt to make sense of it.

So I hope that is clear, breathing, does nothing to add or take away CO2 from the cycle.  Filtering CO2 into the ground through some advanced and powerful technological means, could, and pumping it out from something outside the loop, exponentially, year after year... well, that could too.

Now adding to that... If it is possible, by taking into account, we're already in a 'peak' temperature period in an interglacial cycle, and 'then' we introduce all this alien CO2 (I say alien because most of it was in the form of goo or rock buried for millions of years before we came along, dug it up and burned it forming CO2 gas), a gas that no one argues is an important GHG.  Then is it really that impossible to believe, raising CO2 in the atmosphere from under 300ppm (parts per million), to nearly 400ppm by ourselves, not to mention the many hundreds of parts per million extra which have already sank into the oceans thus increasing CO2 levels there as well..  just might explain the increased global average mean temperature over the past century?  Just maybe?  Science today seems to concur with that.  Global Warming skeptics either are taking the less realistic and scientific approach that raising CO2 does absolutely nothing.  Or they are trying to find all kinds of ways to say, only nature has either increased CO2 or temperature over the past century (and of course those, who will even argue that the planet is cooling and not warming at all).  But regardless of their reasoning, that in no way is enough for us to stop trying to understand the real potential risks and/or benefits of all the 'additional' CO2 we, with out a doubt, have added and are continuing to add, more so in fact, every year.  Furthermore, if we can all agree, earth was a kind and habitable place for humans before the boom of fossil fuels... than just maybe it is a safe bet to keep the planet's CO2 levels where they once were... naturally.

We need to understand what the consequences of CO2 pollution (by this, I mean, humans introducing something undesirable which wouldn't exist there otherwise) are -'before' potentially doing any further damage (should that be the case).  

So any measures to reduce CO2 from fossil fuels should be a matter we should seriously consider.

Now that we understand that the CO2 we've added to the cycle from chemically altering fossil fuels is not the same as CO2 we breathe out.  This is how the feedback loops play a role.

Feedback loops from CO2 works like this...

CO2 green house gasses increase significantly over a short but sustained period of time (200 years).  Whether that be from a sudden influx of constant volcanic activity (assuming there's no ash, soot, debris to add to the mix, just CO2), disturbances in a billion year star cycle (fluctuations of sun spots and solar flare radiation from our sun) or that some intelligent species in staggering numbers, burn up enourmous amounts of fossilized, ancient sunlight energy deposits thus transform them into huge quantities of green house gasses... that, for ...some ...reason, dramatically increased more and more every year for the 200 years which gives us the current CO2 levels we are recording... also a fact (but leaving out how there) ...or how this really occurred (now what we also is mainly upheld to be true), and that is, we humans raised it.

Just trying to first establish, taking our scenerio; CO2 is higher, it increased since the Industrial revolution and we can easily attribute man made burning of fossil fuels.

Now back to feedback loops...

The point being, more CO2 equals, more GHGs, and that equates to, the earth's atmosphere, absorbing more heat to which the result is, the earth's temperature rises.  And evidently, the rising temperature, is much more pronounced at the poles, than elsewhere, i.e. the equator.

This is how a feedback loop comes into play... the increase temperatures at the poles, cause and increase in ice melt, the ice melting ALSO releases CO2 and other gasses (i.e. methane, which we've contributed to that from burning fossil fuels as well) from the trapped gasses within the ice.  

In the vast places where permafrost exists, which is also closer to the poles, is also increased melting... thus more gasses, not too mention, also, gasses trapped 'beneath' the ice, are no longer trapped and release as well, thus, increasing the amount of CO2 which is released even more.

All this extra GHG release, combined with our already out of control GHG contribution, only further accelerates the effects of the increased GHG levels, that primarily being, escalated increasing temperatures.  The result of which, causes ice and permafrost, to melt even faster, so on and so forth.  And when more and more ice melts each year, more land and ocean is exposed.  

Snow and Ice have extremely important 'reflective' properties when it comes to the suns energy and bouncing it back out to space.  Oceans on the other hand have a very low-albedo (ice has a very high-albedo).  Which means, oceans 'absorb' much more of the sun's energy.  This for example, contributes to the warming of the oceans directly in itself.  Warming oceans and other bodies of water... can also lead the rise of CO2 and methane as a result, the worst being... melting methane hydrate deposits.  

Anyway, that's what feedback loops basically are.  They exist because again, we're in a peak warm period anyway, and we are doing something which may seem small and insignificant, but enough to put things over the edge to the point that feedback loops like these can cause an out of control chain reaction.

Many Scientists have concluded, we may have already pushed the envelope too far and have already reached, a point from which we can't return.

Many more scientists remain optimistic there is still time for us do something about reducing GHG levels, at least, enough that we can buy ourselves more time to deal with whatever comes.

And a small minority of scientists... say, this is all being blown out of proportion, we don't understand enough about global warming and CO2, etc.  So we shouldn't make a big deal out of it like the Kyoto Protocol for example.

Where you fit into this... that's your business, but to believe it is all NOTHING to remotely worry about... I'm just glad not everyone shares your opinion on that, because I think it is better to be pro-active about this than to be in denial over it altogether and just continue with 'business as usual'.

[Edit]

Per your comment to me aceking52…

The cycle in which positive and negative climatic feedback loops eventually works itself out, but now is very different.  If you think of our planet as an ecological biosphere, it has found a sort of equilibrium which has lasted millions and millions of years.  But until now, this had only included all natural variability.  Again… at a point in earth’s consistent rhythm of cycles in-between ice ages and interglacial periods, and the warm periods like we see today, we are at the warmest peak at any point of it.  

The only time in earth’s history in the last 55 million years that we know the earth has gotten warmer than what it is now… is never.  The only time CO2 levels have been as high as they are now, for at least, the last three ice ages on the planet, is now.  

These are facts that may explain why a very rare phenomenon known only as global warming, is occurring.  It is not the fault of nature; nature merely got us alllll the way up to this warm point, at the tippy-top of the warm-temp cycle.  

I'd go on, but it is not possible to put any more text into this answer and response.  I just hope you'll eventually understand, this is something we can't ignore any more.

Answer 4

For so long we've been told that we're reaching the tipping point where the positive feedback will take over.  Dr. Stephen Hawkins even has stated that our temperatures will reach 450 degrees and it will rain sulfuric acid!

However history doesn't support these doomsday scenarios.  Ice core data can go back 450,000 years and they clearly show that co2 lags behind temperatures by some 800 years.  Co2 continues to increase even when temperatures are in rapid decline.

Russian scientist are far ahead of the Americans in this research.  This is because American scientist are under threat of being fired or having research grant money being refused if they don't follow the man made global warming line.  

Here's what the Russians have discovered:

""Global warming results not from the emission of greenhouse gases into the atmosphere, but from an unusually high level of solar radiation and a lengthy - almost throughout the last century - growth in its intensity," Abdusamatov told RIA Novosti in an interview.

"It is no secret that when they go up, temperatures in the world's oceans trigger the emission of large amounts of carbon dioxide into the atmosphere. So the common view that man's industrial activity is a deciding factor in global warming has emerged from a misinterpretation of cause and effect relations.""

http://en.rian.ru/russia/20070115/590789...

Answer 5

It's not really a theory.  CO2 is a known greenhouse gas.  Ice cores have shown that CO2 has increased in the past and global temperature has followed suit closely.

http://globalwarmingart.com/wiki/Image:I...

This makes sense because greenhouse gases absorb and re-radiate heat.

I'm not sure why you think CO2 is a minor greenhouse gas.  It's currently responsible for 1.6 W/m^2 of radiative forcing, which is the largest forcing, about 15 times stronger than the forcing from the Sun.

http://www.grida.no/climate/vital/04.htm

The CO2 we breathe is part of the natural carbon cycle.  It does not cause global warming.  See Myth #7 here, and the associated sub-myth:

http://greenhome.huddler.com/wiki/global...

Answer 6

Spencer describes this in a testimony to congress:

t is certainly true that (1) greenhouse gases warm the lower atmosphere, (2) carbon dioxide is a greenhouse gas, and so (3) increasing carbon dioxide concentrations can be expected to warm the surface. But one must ask: To what extent? Climate modelers know that the direct surface warming effects of even a doubling of carbon dioxide concentrations would be very small – only about 1 deg. F, probably sometime late in this century. The greatest concern, then, centers around the positive feedbacks exhibited by climate models which amplify this small warming tendency. But just how realistic are these positive feedbacks? The latest published comparison of the sensitivity of climate models to changes in radiation reveal that all climate models tested are more sensitive than our best available radiation budget satellite data suggest (Forster and Taylor, 2006, Fig. 3). Taken at face value, this means that all the models produce too much global warming.

Most researchers who believe in substantial levels of global warming claim that water vapor feedback is surely positive, and strong. They invariably appeal to the fact that a warming tendency from the extra carbon dioxide will cause more water vapor to be evaporated from the surface, thus amplifying the warming. But again we see a lack of understanding of what maintains tropospheric water vapor levels. While abundant

amounts of water vapor are being continuously evaporated from the Earth’s surface, it is precipitation systems that determine how much of that water vapor is allowed to remain in the atmosphere -- not the evaporation rate. This, then, is one example of researchers’ bias toward an emphasis on warming processes (water vapor addition), but not cooling

processes (water vapor removal). The fact that warmer air masses have more water vapor is simply the result of the greater amounts of solar heating that those air masses were exposed to; it is not evidence for positive water vapor feedback in response to increasing carbon dioxide levels.

Climate models are usually validated by comparing their average behavior, such as the monthly average temperature at different locations, to observations of the real climate

system. But recently, it has been persuasively argued that meaningful validation of climate models in the context of their feedbacks can only be made by comparing the instantaneous

relationships in climate models and observations (Aries and Rossow, 2003; Stephens, 2005). For instance, daily changes in clouds, radiation, and temperature can be measured by satellites during interannual variations in the climate system. This makes physical sense, since it is at daily time scales where most weather action takes place. At UAH, we have begun doing just that, and we have documented a negative

feedback due to changes in precipitation systems (Spencer et al., 2007, now in peer review for publication). As rain system activity and tropospheric warmth reach peak levels during tropical intraseasonal oscillations (ISOs), we measured an increase in outgoing infrared radiation (Fig. 3) which was traced to a decrease in cirrus cloudiness (Fig. 4). This evidence, at least at the intraseasonal time scale of the ISO, supports Lindzen’s controversial “infrared iris” hypothesis of climate stabilization (Lindzen et al., 2001).

Answer 7

Extremely strong.  No real scientist doubts it.  The science is dead simple. CO2, a greenhouse gas warms the Earth (basic physics).  Warmer ocean waters can hold less CO2 (basic chemistry) and release even more CO2.

Two science things people need to understand, to understand this.  Second nature for scientists, not so obvious for lay people.

The first is that natural CO2 we exhale is completely irrelevant.  That CO2 was recently extracted from the air by plants, and putting it back is no big deal.  

There are a great many natural sources and sinks for carbon dioxide.  But the present global warming is (mostly) the result of man made CO2 from burning fossil fuels.  There is a natural "carbon cycle" that recycles CO2.  But it's a delicate balance and we're messing it up.

Look at this graph.

http://gaw.kishou.go.jp/cgi-bin/wdcgg/qu...

The little squiggles are nature doing its' thing. CO2 falls a bit during summer when plants are active, and rises during the winter. The huge increase is us, burning fossil fuels. The scientists can actually show that the increased CO2 in the air comes from burning fossil fuels by using "isotopic ratios" to identify that CO2.  The natural carbon cycle buried carbon in fossil fuels over a very long time, little bit by little bit. We dig them up and burn them, real fast.  That's a problem.

The second thing is that CO2 is not the only thing that CAN change temperature, just the most important thing NOW.

Solar radiation can vary enough to overcome CO2, due to large changes in solar radiation brought about by "Milankovic cycles".  

How do we know that's not going on now?  Really simple, we measure the Sun.  The Milankovic cycles cause changes we could easily see.  We've looked - they're not there.

So, even if CO2 makes things hot, eventually a solar radiation decrease will cool things down.  But, in this case, eventually is almost certainly thousands of years off, way too late to save us from big problems.