There’s enough scientific agreement about the dangers of secondhand smoke that I wouldn’t smoke near my child.
Obviously they feel the science is firm enough to warrant such advice, but they may be following the much-heard-about “precautionary principle.”
By the way, if you want to debate whether there is scientific consensus on AGW, it’s probably a good idea to define what you mean by “consensus.”
I tried to get you to do that but you dodged the question entirely. Again, what percentage of practicing climatologists would have to support the proposition that the current episode of climate change is significantly caused by human activity, for you to consider it consensus? I know if I state what I mean by it there’ll be this argument that my meaning of it is incorrect. I’m probably happy to work with your definition, but what the hell is it?
Sure, because I’m not the one who is claiming that there definitely is a consensus or definitely isn’t a consensus. Also, I don’t attach a lot of significance to the existence or non-existence of consensus.
So why should I be the one who defines the word? If you think “consensus” exists and is very important to the AGW debate, it’s up to you to tell me what you mean by “consensus.”
Otherwise, I am happy to discuss AGW without discussing whether or not there is a “consensus.”
No? You’ve mentioned it in almost every post:
Because I’m foreshadowing that whatever definition anyone else uses you’ll nitpick, as you already have. Very well.
I’ll contend that the community of working climatologists, the community of scientists working in the general area of climate, and the community of working scientists as a whole, all conform to these definitions of consensus by having widespread agreement as to the general thrust of the anthropogenic climate change hypothesis. In numerical terms the percentage of working climatologists who support the hypothesis is overwhelming (I don’ have numbers for the other groups I mention). Working from memory there were 4,500 who worked on the summary of the latest ICC report who broadly agreed with it; none who worked on it disagreed with it; and the largest number of dissident climatologists I’ve seen quoted anywhere is 50. So that makes the consensus roughly 98.9%.
I doubt it is the most important consideration in anyone’s opinion; the plausibility of the hypothesis as a whole and the solid factual backing of that hypothesis would probably count as being the most important considerations in most people’s opinions. That doesn’t mean consensus is not an important consideration.
That’s false, and even if it were true, the mere fact that I mentioned “consensus” doesn’t contradict my point.
If “nitpicking” means pointing it out when other people make false statements, then yeah, I may nitpick you.
I trust that you will never ever point it out if somebody makes a false statement in a debate.
Cite?
I’ve never claimed that consensus is unimportant in general. But in the case of a theory that is essentially untested; politically fashionable; and based on research that isn’t fully disclosed, I don’t put a lot of weight on it.
co2=1% of greenhouse gasses
water vapor=66% greenhouse gasses
global warming proponents have $$ motives
opponents do not
earth was once all ice
melted w/o the help of man.
ozonle hole occurs with lack of o3 layer
o3 layer created ny heating of 02 layer by sun
hole only opens where sun does not go for 6 month periods ( the poles)
when sun heats up 02 layer…hole closes
Not sure where you are getting these numbers from but if you want to look at the fraction that each of these gases contribute to the natural greenhouse effect, the contribution from water vapor and clouds together is ~66-85% and that from CO2 is ~9-26%. The reason for the ambiguity in the numbers is that the absorptions overlap and are thus not additive. So, if you start with the current concentration of greenhouse gases and take all the CO2 out while leaving the other concentrations constant (which would be hard to do in practice but we can do in our imagination), the natural greenhouse effect would be reduced by ~9%. However, if you started with an atmosphere empty of greenhouse gases and then added the current level of CO2, you would get about 26% of the natural greenhouse effect.
Note that the natural greenhouse effect warms the planet by a whopping ~33C so even ~9% is not a small amount. Also note that because water vapor’s short residence time in the atmosphere and the prodigious quantities available, our emissions of water vapor are not relevant to the global climate. The only way we can significantly change the amount of water vapor in the atmosphere is to raise the average temperature (by, say, increasing the levels of CO2) so that the equilibrium vapor pressure rises. Hence, the saying that “water vapor is a feedback, not a forcing”. In fact, the effect of this feedback is to roughly double the warming due to the CO2 increase alone.
I am not sure why you feel this is so and it seems to be belied by the fact that most of the contrarian scientists on climate change have direct affiliations with conservative / libertarian think-tanks that in most cases have received funding from companies such as Exxon that have strong $$ motives.
Of course, in science, there will always be people with different motives, both monetary and otherwise. However, the way the scientific process proceeds tends to minimize the effects of these motives…i.e., it is very hard to let such motives dominate science although they will certainly dominate a few individual scientists.
It is strange if you are trying to use it to argue against AGW. It is akin to arguing that gunshots to the heart can’t cause death because then how would you explain all those deaths in pre-gun days when spears and swords were driven through people’s hearts and that presumably caused them to die?
Of course, a doctor would tell you that it is exactly from understanding how people die from a spear through the heart that we can determine that a gunshot to the heart is a major perturbation to humans and can cause death. Likewise, a climate scientist will tell you that it is precisely by studying the past ice ages and such that we can get some measure of how sensitive the climate is to perturbations and can thus estimate how large a change we will produce by the known perturbation we are making to the climate system (what climate scientists call a “radiative forcing”) by increasing the greenhouse gas levels.
So, in fact, far from providing evidence against the idea of anthropogenic global warming, the paleoclimate evidence actually provides support for the notion that the earth’s climate system is sensitive enough to perturbations that it is and will continue to react significantly to the one we know that we are currently producing by increasing the levels of greenhouse gases.
Not sure why you digress here to talk about the ozone hole. However, while your description has a germ of truth in it…namely, the idea that the ozone hole does have a cyclical yearly cycle, you are confused about the causes and, in fact, it is in spring and not winter that the ozone hole occurs:
Note that the fact that such a cyclical yearly cycle occurs in no way diminishes the fact that the extent of the ozone depletion is controlled to a large degree by the ozone-depleting chemicals that humans have put into the atmosphere.
manmade co2 = 1% of the 9-21 % co2 gases
or man contributes. 05% of greenhouse gases.
I dont really understand the hole in the heart.
Man will die not matter what.
Nothing we do will change that
nothing we do will change the natural cycle of temps.
http://environment.newscientist.com/channel/earth/climate-change/dn11638
Nice to know that it is not the AGW proponents that actually predict doom. 
However, as I mentioned before Me and many climate scientists don’t see the end of the world coming, only that a good chunck of humanity will be affected by the changes and we all need to be ready.
http://environment.newscientist.com/channel/earth/climate-change/dn11658
well Ill throught this in…
as most of these scientist do not believe in intelligent design…
humans will evolve and survive any enviroment change …aint that right…lol
…aand nice to see an admission from you that indeed a good number of people are not accepting evidence on GW because some religions are twisting the scientific evidence. (Of both GW and evolution).
I don’t think anyone is claiming that humans would not survive (hypothetical) AGW.
Actually, it doesn’t follow from a belief in evolution that this is necessarily the case. In the past, many species have gone extinct when their environment changes rapidly. Real evolution is generally a fairly slow process.
At any rate, I agree that in the case of man, we will survive the environmental changes. However, the question is why we would want to when there are things we can do to make our future a lot more pleasant. Is it really that horrible to contemplate cutting down on your CO2 emissions or spending money to sequester CO2 or whatever that we should just throw up our hands and give up. Do you propose the same solution to all the problems that we face?
It depends how much it costs.
And even if AGW were real, and even if we could accurately predict the weather consequences of AGW, it’s unlikely that we can predict the future directions of society and technology well enough to anticipate the problems facing humanity 100 years from now.
First of all, your 1% number isn’t even right…It is more like 3% of the gross emissions. Second of all, it is the wrong number to quote because there are large exchanges between the ocean and atmosphere and the land/biosphere and atmosphere but these exchanges were in equilibrium before we came along. By contrast, the carbon that we are liberating from stores of fossil fuels has long been locked away from the atmosphere. So, the more relevant number is not the gross emissions but the net emissions and we are actually responsible for all of that…In fact, the biosphere and oceans are actually taking up about 1/2 of what we put out but is not able to store all of it.
A good analogy would be a fountain where the water that goes down the drain gets recycled and sprayed out of the fountain again. Now, if I start adding additional water from another source, the water level in the fountain will slowly rise and overflow even if the amount I am adding is small compared to the amount coming out of the fountain spout.
As GIGObuster has noted, as a result of our additions of CO2, CO2 levels have gone up 35% since pre-industrial times (with ~60% of that rise having occurred since 1970) and are at their highest levels in over 700,000 years (which goes back through several ice age - interglacial cycles) and likely somewhere like 10 to 20 million years.
I don’t understand what you don’t understand. It is an analogy not an exact correspondence…although I would note that with the heart case, the person in question will also eventually die no matter what. And, the point is that we are not talking about a natural cycle here. What we are talking about is an effect due to rising greenhouse gases that we are producing. We know how much the greenhouse gases have risen, can estimate how much they will continue to rise and know the “radiative forcing” that such rises produce. Using this and some estimate of the sensitivity of the climate to a given radiative forcing (as determined both from past events like ice age – interglacial cycles or the eruption of Mt. Pinatubo and from climate models), we can estimate how large a temperature change we will produce. We can also look at the magnitude and “fingerprint” of the current temperature changes that we have been seeing and compare it to the predictions of the climate models.
Well, the IPCC estimates the costs of the most rigorous contemplated stabilization as lowering the GDP growth by less than 0.12% per year.
All the more reason to not hamstring society with such a major change to our environment and to the environment of the other species on the planet, many of which are already stressed by other problems such as pollution and loss of habitat.
Cite?
We have no idea if such a change would hamstring society. And that’s assuming that we know that global warming is real and can predict the weather consequences.
Go here and click on the Summary for Policymakers for the Working Group III Report “Mitigation of Climate Change” and see Table SPM.6 on p. 27.
Well, we have some idea of the sort of consequences involved. (See the Working Group II IPCC report.) Are you the type of person who doesn’t buy fire insurance until you know your house is on fire? It certainly doesn’t seem wise to me to bet on the hope that the consequences won’t be as bad as predicted. Furthermore, we will have wean ourselves off fossil fuels eventually anyway since they are a finite resource. Better we set up the incentives to do that now so that it occurs sooner rather than later and we actually manage to preserve something resembling our current climate in the process.
I looked at it. The “estimate” seems pretty sketchy. For example, it’s apparently average of a bunch of studies. Many (most? all?) of the studies made assumptions about changes in technology. i.e they are wild-ass guesses.
Many of the studies apparently projected an INCREASE in GDP as a result of CO2 stabilization. Maybe that’s true . . . and maybe my wife will agree to bring another woman into our relationship.
The IPCC “estimate” reminds me of the old Chinese story of how you figure out the length of the Emperor’s nose without actually measuring it. What you do is you poll a few thousand peasants and ask them how long the emperor’s nose is. Then you average all the estimates and voila, you have a precise consensus estimate.
Or as they say in the West, Garbage in, Garbage out.
No, but I wouldn’t buy it 50 years in advance either. I buy insurance once a year. That’s a reasonable balance between caution and overcaution.
I have no flood insurance for my house, which is located 300 feet above sea level. Nor do I have earthquake insurance.
The point is that you can go overboard in caution.
That’s pure speculation. Is it possible that in the year 2107, people will say “Wow, they really should have conserved more oil/gas/coal back in 2007.”? Sure, but it’s also very likely that we have no idea what issues will be important in 2100.