Why is the greenhouse effect not proof that CO2 can drive global warming?

Question

In another question, AGW deniers were asked what proof they require before they accept the theory. Several answered that they required proof that CO2 has driven climate change in the past.

http://answers.yahoo.com/question/index?qid=20080821183449AAzRPLV&r=w#RsR4WTC1UGLXAOZlOfd26Pr22G__DAD6hVJeJW5TpX.ayPFJ4ZHX

However, it seems to me that this ignores basic physics. We know CO2 is a greenhouse gas. We know the planet would be 33 deg C colder if not for greenhouse gases in the atmosphere (from a simple blackbody radiation calculation). There is no doubt that greenhouse gases like CO2 can and do warm the planet. There is also no doubt that atmospheric CO2 concentrations have increased 37% over the past 150 years, and coincidentally virtually no doubt that this increase is due to human actions.

Now, if you want to argue how much warming this CO2 increase has caused, that's one thing. But when people require past examples of carbon dioxide driving climate change as proof that CO2 *can* cause warming, isn't this a denial of the basic physics of the greenhouse effect?

Answer 1

because co2 occurs in such small amounts. Not a denial of the basic physics of the greenhouse effect. 37% of nothing is still nothing. Also, it doesn't fit the bill. The heat is supposed to come 800 years later, not right away. You continue to downplay the effects of the sun. Even though we know other planets are warming and ice sheets are melting. Satellites are measuring the heat bla bla bla. But we don't understand the relationship between the the sun and the earths temp.

Answer 2

Because CO2 driven global warming is nothing but a weak theory, designed to scare and manipulate people.  However, the sun is real and both warming and cooling are direct results of solar activity.  CO2 doesn't cause increased temperatures at greenhouse levels, it just helps to sustain them within a small range.

Answer 3

CO2 isn't the only greenhouse gas, which your question makes it seem like it is. It in fact is one of the least abundant if not the least. You should know this Dana. So yes, greenhouse gases do cause warming. The question is, is the tiny amount that humans emit the main cause of todays climate change?

If CO2 was the only GHG, and it increased 37% because of us, then yes you are right, but it isn't the only GHG.

EDIT: Also, I'm not being sarcastic here Dana. I'm really interested to know your view about the 800 year lag in CO2 and temp. I've heard the theory that CO2 amplified temp, but it could also be that CO2 was reacting to temp change, while something else was driving temp.

EDIT: Also like interpol said, stop referring to "the last 150 year". From about 1900 to 1940, human emissions were negligible and temp increased, then CO2 by humans boomed and temp went down and then started rising around the 1970's. So, in essence the whole argument for AGW is based on the last 30 years or so.

EDIT: If I remember right CO2 make up about .054% of the atmoshpric gases, and percentage of CO2 that is by humans is something like .34%. Definitely not a majority gas. If anyone would like to look it up and verify those numbers, I'm not 100% sure but I know I'm close.

EDIT: Joe got it basically right. CO2 might and probably affects climate, but the question is just how much and how much of human CO2 changes temp.

Answer 4

Why don't you prove the greenhouse effect is happening in the first place ? Can't can you ?

Answer 5

Let's get a couple of points straight here, "Master of Science":

There has never been any argument that greenhouse gases - of which CO2 is a small proportion of them - are responsible for the suitable weather on our planet for our type of life. That's a given.

The historical records show that CO2 rises AFTER the heating, pure and simple. CO2 is given off when oceans heat up, plants expire more and the myriad other reasons things "give up" their CO2 when heated. It is simple SCIENCE. Try it for yourself; heat up some water to boil in a pot and measure the CO2 increase...

And why do all you "The Sky is Falling" types keep referring to the last 150 years? Not because there was some sort of suggestion that the Industrial Revolution wasd the start of this CO2 rise is it? You bet it is; just another way from the Anarchists amongst us to peddle their anti-technology nonsense... but I digress 8-)

150 years ago, when the IR fired up, do you reallly think that the burning of coal and wood in tiny parts of the world to run miniscule steam engines hjadf any effect whatsoever on the climate of this planet? How can you people possibly say that the temperature is Anthropogenically-driven from that time when we didn't get into REAL oil-burning until well into the 20th century?  

Answer 6

Fewer than 30% of US students have taken a high school course in physics.  A high school course in physics just touches on Newton's laws and some wave mechanics.  http://www.aip.org/statistics/trends/hig...

A real understanding of the topics comes from a graduate level education in physics.  The Master's enrolments are given here

http://www.aip.org/statistics/trends/hig...

Note that only about 300 Masters degrees in physics are produced annually in the US and only 200 are US citizens.  The PhD enrolments are higher.  The current annual US production of physics PhD graduates is about 2750, of which 1500 are US citizens.

http://www.aip.org/statistics/trends/hig...

An upper limit on the number of qualified US physicists (not all graduate and some die before the end of their career) is approximately 1700 per year * 40 year career = 68000.  This represents about 0.02% of the US population and most of this 0.02% have IQ's in the top 1% of the population.  You can make the argument that global warming is a logical consequence of molecular physics to this small segment of the population.  The result is near unanamous endorsement of the theory of global warming.  

Oreskes, N. 2004. Beyond the ivory tower: The scientific consensus on

climate change. Science 306(5702): 1686.

The other 99.98% of the US population matter politically, but are frankly irrelevant to the physics discussion.  In a forum like YA, the discussion is necessarily political and perception is more important than truth. A majority of the population percieve that the scientific elites are right, but for a vocal minority of deniers stating the scientific case does not matter.  

Answer 7

As long as you are going to dance on the subject of physics, H2O is the most abundant and powerful greenhouse gas in the atmosphere, and without it the world would be about 31 - 33 degrees colder on the surface. That is your fallacy, you continue to dismiss water vapor as merely a feedback, without our current proximity to the sun large quantities of liquid water (oceans) could not exist and regulate our climate. For every molecule of CO2 in the atmosphere there are 131 molecules of H2O (assuming water vapor is 5% of the atmosphere), and H2O overlaps CO2 in the absorptivity spectrum. CO2 does not drive Earths climate, the oceans do, that is why temperatures have dropped sharply over the last 18 months, and the reason why it was not predicted is because we do not understand ocean circulation patterns and their role in climate.

If you will notice on the graph below there is a lagtime of weeks maybe months from most of the peaks of water vapor followed by the peaks of atmospheric temperature. The only logical assumption is that in most cases ocean evaporation increased the atmospheric H2O content caused by changes in sea surface temperatures, which in turn modulated the greenhouse process.

http://www.ssmi.com/rss_research/climate...

Answer 8

Here's a simple logical proof.

A green house gas lets sunlight through, but traps heat in the atmosphere. (definition of a green house gas)

More heat warms the planet and affects climate. (basic physics)

Therefore, green house gasses affect the climate. (conclusion from above)

Carbon dioxide is a green house gas. (a property of CO2)

Since CO2 is a green house gas, and green house gasses affect the climate, then CO2 affects the climate.

Humans are releasing large amounts of CO2 into the atmosphere. (fact)

A change in CO2 means a change in the climate.

Therefore, humans are changing the climate. (but how much is not certain).

Answer 9

We know the greenhouse effect is real, if it didnt exist the planet would be cold and dead. It is essential to life (as is co2), it traps the suns energy that would otherwise be lost to space.

There is no doubt that it has an important role in controlling temperature on earth and causes a warming effect. c02 accounts for around 0.054% of the greenhouse layer, of which only around 3% of that is attributed to humans, and some belieive this is even lower (0.02%).

Co2 is believed by some to be a mild greenhouse gas that does not cause any significent wamrning, whilst some scientist believe it is neutral and other believe it may be a mildly cooling greenhouse gas.

The issue is whether the tiny proportion given off by man is causing any increase in warming, or wether the warming that has been observed over the last few hundred years is just part of the natural cycle. Historically it has always warmed first, this increase in temperature has warmed the sea, and the sea has then released co2. Co2 historically has never been responsible for warming the atmosphere in the past. also many physisists claim that co2 can not absorb as much energy as is required to cause any warming.

The signature for global warming is warming of the troposphere, a layer above the earths surface where the heat becomes trapped. Any observation of this confirms that global warming is driving the earths temperature. This is what the IPCC's model predict as happening first, however, records of the troposphere show it has not warmed in areas, and in other areas it has warmed at a rate slower than the earths surface. This proves that the sun is instead driving the warming and not the greenhouse layer. This is why many suspect co2 is not the problem but instead the warming is linked to the suns activity and changes in the duration of earths revolutions

Answer 10

You are once again misstating your hypothesis.  The hypothesis that you state is acknowledged by many skeptic climatologist including Lindzen, Christy and Spencer.  

There is the second part of the hypothesis where the skeptics have problems with.  The increase in temperatures due to increased atmospheric co2 will be minor (without any feedbacks).  You are saying that this minor increase (Even the IPCC says it will be minor) will be amplified many times over.  That is not proved science.  But without this positive feedback we can not get catastrophic warming, and co2 cannot become a major driver of climate change.  And that is your hypothesis.  If we do not cut back on co2 emissions we will get catastrophic warming.

Answer 11

For all the skeptics or deniers...

Did any of you stop to think that in the historical cases you mention, without reference of course, CO2 rose after warming began because there were not 6.5 billion people on the planet using fossil fuels? If one of the reasons you don't believe in human induced climate change is due to CO2 rising after warming, well, check that one off your list. It's rising before this time.

Yell as loud as you want. The next president will begin to do something about it, and I suspect you won't like it. But that is the nature of a democracy. Can't please everyone and you happen to be on the can't please list.

Answer 12

idk alot on this subject but the guy above said something about sun spot activity. scientist no longer think its CO2 now and sun spots that makes earth warmer, which makes sense i guess and i herd theres suppose too be a big burst or something i think its called a flare or something in 2011 or 2012 scientist predict

Answer 13

Because the theory can only be proven in a laboratory under controlled circumstances.

As we have seen in the real world, the climate model's and theories don't adhere to reality.

If the greenhouse effect was actually working, then we would have increasing temperatures without fail because we have effectively not stopped or changed our emissions of co2. But temps have been plateauing since 1998 and went down 1/2 a degree in 2007. Which was attributed due to less sun spot activity.

There just are too many factors in the real world, and man isn't smart enough to identify , catalog or incorporate them in any real model to predict the climate. The left has been been predicting all sorts of catrastrophy's and none have panned out.

They've claimed there would be more frequent and violent hurricanes..............they were wrong.

They've even found that hurricanes aren't influenced significantly by warm weather.

They said polar ice caps were melting......then they discovered underwater volcanoes.

They claim pollution and co2 effect the temperatures yet during America's industrialization from WW2 to the 70's we were poluting the country with wreckless abandon...and the temperatures were actually going down. And going down to the point that the media outlets were claiming we were heading for a mini Ice-age.

Hansen from Nasa claimed we only had 20 years to live but we are still here with no significant changes.

Another expert claimed the oceans would be ruined in 10 years....its still there, still the same height and no problems.

Air and water quality has improved since the 70's due to responsible people understanding that we just can't polute at will. Many initiatives were introduced, we started recycling, we made stiffer policies. People started ad campaigns to conserve energy and about pollution awareness.

This change didn't happen from "Green Warrior" ACT NOW chicken little mentality people you see in todays movement. These people are forcing bad policy, effecting the cost of food and energy, they've raised the cost of living even among the poor that depend on staples. They've introduced new economies like the carbon trading farce...which is only making these people rich, not changing a thing...much less saving the planet. They've invested and wasted much time, resources and money trying to present "green" initiatives like making clothes from bamboo, hybrid cars and other products which produce just as much pollution if not more in the making  and processing of them. This is not helping America, This is not helping the world, its ruining our economy, wasting our precious time, resources and money. All so some socialist johnny come lately tree huggers can feel good about themselves.

In a sane world of the pollution conscious, Ethanol would have been a project that got shot down. Personally I think Pelosi is whacked out of her gord on Natural Gas vehicles too. We already have the technology, we have deisel engines that can be converted to run on vegetable oil...and the best source i've found for that is these vertical grow systems with algea. No one for the most part eats Algea, you can make different grades of vegetable oil from them, and there wouldn't be any need to retool auto manufacturers or disturb the economy as much as other options.

Answer 14

To know more about    

  greenhouse  

   Please feel free to visit   http://learnmoreon.com/greenhouse/

Answer 15

CO2 Concentration is rising

http://scrippsco2.ucsd.edu/data/mlo.html

Temperature is not rising

http://hadobs.metoffice.com/hadcrut3/dia...

As a greenhouse gas CO2 sucks!

Answer 16

also in the earths history there have been multiple times where co2 lags behind tempreture for many centuries!