At What Point Will You Accept the Existence/Non-Existence of AGW?

[Jmister]

I have been curious about this for a while. While this has nothing to do with actual projections, what threshold would we have to cross before you admit you're incorrect about the existence or non-existence of AGW??

[Jonger]

Most here agree that at least some AGW has occurred, we just differ on effects and amount.

[blizzard1024]

Most here agree that at least some AGW has occurred, we just differ on effects and amount.

yep. But if you don't buy the higher end scenarios you get treated like you

are a flat earther, non-scientist, anti-gravity, sun revolves around the Earth

science denier. The folks who believe in smaller amounts of warming tend

to be nice and professional. It is the global warming advocates who treat the other

people with disrespect on this forum. They resort to name calling, insults etc. 

 

We will never really know how much is CO2 related. There have been times

in the Earth's past where the climate warmed for centuries (in the Holocene)

with no man-made cause. So the current warming cycle could be completely

natural with some man-made component. Climate models can be programmed

to be as sensitive as they want to whatever component they think is important.

Right now all the focus is on CO2 which has some small effect by itself. 

It is a non-linear system with many combinations of variable changes that can lead 

to the same outcome.  That is part of what non-linear means. 

 

Bottom line...we will never know for sure unless it warms insanely which has

not occurred at all. We are well within the bounds of natural variability

in the present interglacial.  

[skierinvermont]

Kind of a hard question. Sort of like asking how high would you have to see someone jump before you stopped believing in gravity.

 

Because as far as I understand, the fact that doubling CO2 concentration leads to 1.2C of warming is about as rock solid as the theory of gravity. Of course it's possible that objects stop falling at 9.8m/s/s, but not a reasonable one.

 

The uncertainty is about feedbacks. 

[ORH_wxman]

The question is not clear as phrased...it states "You finally admit AGW is occurring and is a major global issue....."

 

 

What does "major global issue" mean? How do we define this? Does it mean adverse effects or positive effects?

 

 

If we stick to just actual scientific acronyms like AGW, then there is no real debate, AGW is occurring and exists.

[blizzard1024]

Kind of a hard question. Sort of like asking how high would you have to see someone jump before you stopped believing in gravity.

 

Because as far as I understand, the fact that doubling CO2 concentration leads to 1.2C of warming is about as rock solid as the theory of gravity. Of course it's possible that objects stop falling at 9.8m/s/s, but not a reasonable one.

 

The uncertainty is about feedbacks. 

 

Actually objects will stop falling at 9.8 m/s2 due to air resistance of the body. The drag force of the body itself will eventually equal the force of gravity and the acceleration will stop and the object will fall at its terminal velocity.  In addition the force of gravity is not exactly equal to 9.8 m/s2 because the Earth is an oblate spheroid. There are some variations as well to this. You actually have to account for the Earth being slightly out of round. Gravity also varies somewhat with altitude also.  Science is never as easy as one thinks it is.

 

And yes doubling CO2 in the atmosphere does lead to an external forcing of 3.7 w/m2 at the top of atmosphere...but this is related to radiation code and there could be some error in this as well but it is pretty much accepted to be close to this. Using the S-F equation you get around 1.2C of warming all else equal. Nobody is arguing against that. But the earth system can react in many ways and I don't think anyone understands fully the implications of this forcing or what the transient climate response will be or how long it will take to equilibriate.  It could be hundreds of years. This part of climate science is far from settled.    

[skierinvermont]

Actually objects will stop falling at 9.8 m/s2 due to air resistance of the body. The drag force of the body itself will eventually equal the force of gravity and the acceleration will stop and the object will fall at its terminal velocity.  In addition the force of gravity is not exactly equal to 9.8 m/s2 because the Earth is an oblate spheroid. There are some variations as well to this. You actually have to account for the Earth being slightly out of round. Gravity also varies somewhat with altitude also.  Science is never as easy as one thinks it is.

 

And yes doubling CO2 in the atmosphere does lead to an external forcing of 3.7 w/m2 at the top of atmosphere...but this is related to radiation code and there could be some error in this as well but it is pretty much accepted to be close to this. Using the S-F equation you get around 1.2C of warming all else equal. Nobody is arguing against that. But the earth system can react in many ways and I don't think anyone understands fully the implications of this forcing or what the transient climate response will be or how long it will take to equilibriate.  It could be hundreds of years. This part of climate science is far from settled.    

 

Wow thanks for explaining air resistance and a bunch of other irrelevant obvious things to me that have nothing to do with what I said. 

 

The point is that a 1.2C response to doubling CO2 ignoring feedbacks is comparable to the theory of gravity. You've just further elaborated a bunch of irrelevant details to the theory of gravity which I left out because things like air resistance are obvious to most people that have taken high school physics.

[blizzard1024]

Kind of a hard question. Sort of like asking how high would you have to see someone jump before you stopped believing in gravity.

 

Because as far as I understand, the fact that doubling CO2 concentration leads to 1.2C of warming is about as rock solid as the theory of gravity. Of course it's possible that objects stop falling at 9.8m/s/s, but not a reasonable one.

 

The uncertainty is about feedbacks. 

 

You said it. Not me. The bold is a false statement and you said it was not a reasonable one. Wrong my friend. 

[StudentOfClimatology]

I have faith in our scientists and the laws of physics, and would consider significant CO2 induced warming to be undeniable based on our current knowledge and observations of atomic/subatomic dynamics.

That said, you can never be 100% certain of anything. There is one potential wrinkle in our understanding of the 2nd law of thermodynamics, which only comes up when applying it within a gravitational field. This was debated by Maxwell, Boltzmann, and Loschmidt, and frankly is not really testable and is unresolved. It's actually a decent read: http://books.google.com/books?id=-nWyk7jH5_EC&pg=PA202&lpg=PA202&dq=loschmidt+vs+boltzmann+gravity&source=bl&ots=51uaJH-URI&sig=SPOB7H6xW6ODfa6OrFKQbHlbSWU&hl=en&sa=X&ei=IRocU-DZBtDx0wHNsoDwAw&ved=0CCoQ6AEwAQ

As of right now, the physicist community is mostly siding with Boltzmann and Maxwell. So that's where I side as well. However, if Loschmidt is correct, we might have a problem on our hands.

[Jmister]

Yeah sorry for the poor wording of the question; it was harder to phrase than I thought. 

 

I also agree with what has been said. It is already established that a doubling in CO₂ will provide a known increase in the energy (im)balance, but there are still unknowns as to how that translates into surface temperatures. This poll is based on that uncertainty. 

 

 

As an aside: it's been great learning about all this climate-related information on this subforum. I've seen far more information here than in my 6 years of meteorology at PSU. You're a very knowledgeable group of climate nerds enthusiasts.   Thanks!

[Msalgado]

You said it. Not me. The bold is a false statement and you said it was not a reasonable one. Wrong my friend. 

 

What he said was worded poorly but its not wrong.  The theory of gravity has nothing to do with air resistance or the speed at which objects fall.  Its a measure of a the force resulting from gravity's actions.  Near the surface of the earth, that force is a certain amount that results in that acceleration.  Whether or not the air applies an acceleration in a different direction does not change the amount that gravity effects an object near the earth's surface.  

[AvantHiatus]

The reason I voted high is because I think, according to current knowledge and literature, that ECS is very high. Perhaps not reaching 2c by 2050 would imply that we do not understand how the Earth Systems work in tandem with each other. In contrast to posters like Blizzard1024 who think 1.0 C above baseline is a walk in the park in terms of impacts.

 

Most conservative forecasts including the IPCC have an average rise of 1.0 C -  2.5 C by 2050 (Above 1980-2010 mean), so even including 0.5 C as an option seems ludicrous.

[blizzard1024]

What he said was worded poorly but its not wrong.  The theory of gravity has nothing to do with air resistance or the speed at which objects fall.  Its a measure of a the force resulting from gravity's actions.  Near the surface of the earth, that force is a certain amount that results in that acceleration.  Whether or not the air applies an acceleration in a different direction does not change the amount that gravity effects an object near the earth's surface.  

i was merely illustrating that things in science especially atmospheric science are much more complex than what we think. that's all. I know most people know about terminal velocity and that the Earth's gravitation field is not exactly 9.8 m/s2 at all locations. 

[blizzard1024]

The reason I voted high is because I think, according to current knowledge and literature, that ECS is very high. Perhaps not reaching 2c by 2050 would imply that we do not understand how the Earth Systems work in tandem with each other. In contrast to posters like Blizzard1024 who think 1.0 C above baseline is a walk in the park in terms of impacts.

 

Most conservative forecasts including the IPCC have an average rise of 1.0 C -  2.5 C by 2050 (Above 1980-2010 mean), so even including 0.5 C as an option seems ludicrous.

 

 

+ 1.0C is MUCH  better than - 1.0C!!!!

[skierinvermont]

You said it. Not me. The bold is a false statement and you said it was not a reasonable one. Wrong my friend. 

 

Yeah if you want to be a technical smartass and point out obvious details that are irrelevant to the general point. I'm not going to delve into every detail related to gravity just to act smart and immune myself from smartasses like you trying to one up everything I say. 

[TerryM]

Sorry but the Arctic Sea Ice is my Canary in the coal mine & that bird is not much livelier than Monty Python's Parrot.

Terry

[Jonger]

Sorry but the Arctic Sea Ice is my Canary in the coal mine & that bird is not much livelier than Monty Python's Parrot.

Terry

 

The arctic looked almost as bad 80 years ago.... Was that when the canary died? Or is this like a Dr. Who reincarnation type scenario?

[Msalgado]

I'm a data driven person.  I would believe AGW theory to be incorrect when the data said so.  Not expecting that to happen anytime soon.

[blizzard1024]

Yeah if you want to be a technical smartass and point out obvious details that are irrelevant to the general point. I'm not going to delve into every detail related to gravity just to act smart and immune myself from smartasses like you trying to one up everything I say. 

you missed my whole point. 

[blizzard1024]

Sorry but the Arctic Sea Ice is my Canary in the coal mine & that bird is not much livelier than Monty Python's Parrot.

Terry

how do you explain the record antarctic sea ice?  Why do people ignore this fact. 

[Sundog]

how do you explain the record antarctic sea ice? Why do people ignore this fact.

Who's ignoring it? There are several explanations that are actually in line with a warming world that can explain the increase in Antarctic ice. Two such explanations is melt water from the continent/ "stable" sea ice around it freshen the water and therefore make it easier to freeze. Another is increased precipitation at higher latitudes due to a poleward shift in the jet stream also freshens the water and allows for easier freezing. There's more reasons but I don't remember them.

Btw the loss in the Arctic is much more significant than any gains in Antarctic, albedo being one of the culprits.

[FPizz]

how do you explain the record antarctic sea ice? Why do people ignore this fact.

blinders

[LakeEffectKing]

Who's ignoring it? There are several explanations that are actually in line with a warming world that can explain the increase in Antarctic ice. Two such explanations is melt water from the continent/ "stable" sea ice around it freshen the water and therefore make it easier to freeze. Another is increased precipitation at higher latitudes due to a poleward shift in the jet stream also freshens the water and allows for easier freezing. There's more reasons but I don't remember them.

Btw the loss in the Arctic is much more significant than any gains in Antarctic, albedo being one of the culprits.

Do we see such a phenomenon around the often hyped Greenland meltdown??

[TerryM]

The arctic looked almost as bad 80 years ago.... Was that when the canary died? Or is this like a Dr. Who reincarnation type scenario?

Jeez Jong

Do I have to drag out the Ellesmere Island driftwood data every month?

Do you have memory lapses like this in other areas?

Terry

[AvantHiatus]

blinders

Wat, there are blinders on both sides of the argument. (joking)

 

Antarctic mass loss has doubled exponentially since the 2000's. Ice is being melted from below...one of the main reasons why we observed a huge jump in sea level rise in 2012. Basically, Antarctica is lagging behind the arctic by about 20-30 years.

 

 

[ORH_wxman]

Do we see such a phenomenon around the often hyped Greenland meltdown??

 

 

No, which is why I don't really buy that theory...at least as the primary reason. Southern ocean has been cooling significantly for over 30 years, so I think the explanation lies somewhere in what has caused the more extreme circumpolar jet in that region.

 

The sea ice was actually steadily decreasing when antarctica and surrounding waters was warming rapidly between the late 1950s and 1970s. When the warming stopped, the sea ice started gaining.

[TerryM]

No, which is why I don't really buy that theory...at least as the primary reason. Southern ocean has been cooling significantly for over 30 years, so I think the explanation lies somewhere in what has caused the more extreme circumpolar jet in that region.

 

The sea ice was actually steadily decreasing when antarctica and surrounding waters was warming rapidly between the late 1950s and 1970s. When the warming stopped, the sea ice started gaining.

Link please?

Terry

[ORH_wxman]

Link please?

Terry

 

 

 

 

 

 

 

 

 

 

 

 

The first one is satellites and the 2nd one obviously goes back to before satellites so it probably is quite unreliable early in the period...however, we are only interested in the 1950s-onward for the sea ice discussion.

 

 

 

Sea ice is hard to come by for anarctica before the early 1970s...but you can see how it was already in steady decline in the early 1970s...and then it reversed in the early 1980s.

 

 

\

 

 

 

Here's the CT graph which goes beyond 2000 since the graph above is from TAR

 

 

 

 

 

 

 

 

SST data I just ripped from one of Bob Tisdale's graphs, but you can reproduce them here:

 

 

SST data: http://www.esrl.noaa.gov/psd/data/gridded/data.noaa.ersst.html

 

 

 

Anarctica sea ice data back to 1972 was from the IPCC TAR: http://www.ipcc.ch/ipccreports/tar/wg1/images/fig2-16.gif

 

 

 

You can clearly see the warming southern ocean up until the 1980s.

[TerryM]

Why on earth would you "rip" from a denier's blog?

 

Bob Tisdale is a small step above Steve Goddard. Surely you can do better.

 

Terry

[Jonger]

Why on earth would you "rip" from a denier's blog?

 

Bob Tisdale is a small step above Steve Goddard. Surely you can do better.

 

Terry

 

Are you disputing the numbers? Who cares what site says 1+1=2.... Its the same fact whether its SKS or WUWT.