So can you explain how during the medieval warm period it was warmer than it is now and the fact that there was less man-made CO2 then than now?? Also explain to me how for around 3,000 years that the temperature stayed warmer than it was even during the medieval warm period, this period is called Holocene Maximum??? Where were the SUV's then?? Why does CO2 levels lag behind almost 300-800 years when temperatures actually rise??? During the time from the 1940's and the 1970's temperatures actually fell but CO2 went up, so what happened there?? Is that time period an exception?? This is an EXTREMELY FLAWED science and the computer models are only as good as the people putting the data into them. Do you honestly think the media is relaying the other side to us??? So if we have 380 parts per million of carbon dioxide then which is more powerful, 380 parts per million or 0.00000380??? Its all about how you present it, and they way it is presented it is WRONG. Like I said before I believe we are warming, but not because of CO2 but instead it is the sun. There is more solar activity now than there was 150 years ago. Humans are a minute portion of this Earth and always will be.
1) CO2 forces temperature increases...but that doesn't mean that it is the only thing that forces temperature increases. Solar forcing can raise temperatures as well (obviously without the sun we wouldn't heat). It could have been warm in the past without increased CO2 levels...but it would have been warmer if there had been increased CO2 levels.
2) I love how you throw out these temperature measurements as fact, but that you can't accept that CO2 forcing climate is fact. I'm sorry - but it is more of a fact that CO2 forces climate than these temperatures are fact. We have to accept and work with the temperature "measurements" you cite because it is all we have to work with - but it is not like thermometers were used to get those. We have to use ice core samples, tree rings, corals, and other proxy data to get the temperatures...and there are large errors in these. But...like I said, you work with what you have.
3) The Holocene Maximum (that is, the maximum temperature period seen in the Holocene) is explained by solar orbit. However, we are not in the same orbital position now that we suspect we were in then. We are in a period of increased solar activity right now...but that is the sun's activity...not our orbit. That increased activitiy has been recorded as increased heat flux to the earth by sattelites and that is factored into the analysis of how much anthropogenic CO2 is forcing temperature increases....and how much of it is increased solar flux.
4) The cooling period we witnessed in the 20th century is now understood (by pretty much all climate scientists) to be a direct result of increased aerosol concentration in the trophosphere and stratosphere from emissions (sulfur, carbon black, etc.) and volcanic activity ...
from the Economist, September 9th, 2006
"The mid-20th centry blip turns out to have been the consequence of anouther byproduct of human activity: sulphur and other airborne particles that bounce back sunlight before it can hit the Earth, thus offsettign the greenhouse effect."
5) The CO2 lag behind temperature argument by 300-800 years is one of the most often repeated arguments against "CO2 driving climate." Lindzen even mentioned this one (I think) in the movie you referenced...which really makes me want to puke...because he has to know better..but likes to have fun by throwing that one out there. Solar forcing (like the orbit you mentioned) caused cycles of temperature increases throughout history (as you know). As temperature increases, it slowly warms the ocean...but that takes a lot of time...especially to get to the deep ocean. As the temperature of a liquid (water in this case) increasese, the solubility of gases in it decrease (CO2 in this case)...and they are released to the atmosphere. The CO2 increase you see was a result of global warming that was caused by the sun. Yes, CO2 did not cause this warming. But, it is 100% inaccurate to use this as an example of how "history shows us that temperature forces CO2 ... not the other way around." That is false logic. It shows us that temperature forces CO2...but it doesn't say anything about whether CO2 also forces temperature...there was no huge human emission source pouring CO2 into the atmosphere back then...so of course CO2 wasn't starting the warming. An interesting fact, however, is that the temperature increases that are thought to have been seen are probably too large to be just described by the solar cycle...and models show that only after you include CO2 forcing (from the increase of CO2 released from the oceans), then do you get the degree of temperature increase that was seen. However, these calculations are hard because the historical data has huge error bars.
6) As I have told you before, it doesn't matter what the media is relaying to me because that is not how I get my information on the science of climate change. There are VERY few climate scientists who do not support the notion that CO2 forces climate. In fact, Lindzen is about the only one I know that won't admit it...and I think that he just has a huge axe to grind. I don't care whether the media says 380 ppm ... 0.38 ppb, or 0.00038 (not 0.00000038 ... that would be 380 ppb if I'm not mistaken)...it doesn't matter to me how they slice it because I know what 380 ppm or 0.00038 fraction can do to climate. I trust this part of the science very much.
The difficult part is figuring out how much of an effect CO2 will have on rainfall, sea level rise, and even temperature rise to some degree. The largest uncertainty is in regional predicitons - like which areas will see increased rainfall and which areas will see decreased. I have no problem with Bill Gray coming out and saying that global warming increasing hurricane activity (and even intensity) is a big bunch of crap..he's right...to predict that with accuracy is pretty silly...we can't do that. Bill Gray's problem with global warming science isn't that the earth won't warm...he just whole-heartedly rejects the idea that we can predict with accuracy.
7) The "humans are a minute portion of the earth" argument is used a lot too....and I can see what you're saying to a point. But, I disagree in general with this notion. Will humans kill the earth? No. It isn't a matter of humans sustaining the earth...the earth will be just fine....the problem is ... will the earth sustain us? And, the answer is no ... not if we continue to emit large amounts of green house gases unchecked. Our way of life will alter sigificantly. The earth will have no problem making our lives hell if we don't watch our step.
