What is the correct value of Climate Sensitivity?

[On Guard for Thee]

Bio-diversity is a meaningless catch all used by environmentalists to avoid having a meaningful conversation about the trade offs. What matters are concrete evidence that the new collection of fauna and flora is sufficient for our needs. The simple fact that there may be fewer species is not evidence of a problem. That is why I say it is an unknown hypothetical. Which brings us back to the only real problem that anyone has identified: the loss of water storage capabilities and dams are more than sufficient to address that real problems.

And I see you ignored the weather issue.

[eyeball]

A warmer world will be a better world in many ways

When? Next year, next business cycle, next decade, century or millennium? Do you think having as good a sense of that as possible would be important to the policy makers, engineers and economists etc.

I mean if there's reason to think it could be 2000 years before formerly cold, dry and unproductive regions become warm, wet and fertile enough to make up for areas that lose the productivity we've relied on, is our economy and growing population expected to sit tight and hang tough?

[-1=e^ipi]

Arent glaciers basically ice sheets...But more importantly how do you propose your dam will succeed in feeding the biodiversity currently provided for by the cyclical seasonal flow from glaciers once they are gone. And, what effect do you think their loss will have on already warming climate.

I think the context that TimG was referring to was that you were claiming that loss of glaciers would provide a problem because human settlements that rely on the glacier runoff as a water source would no longer have a seasonally stable source of water. TimG's response was that a dam could act as a controllable water reservoir that would help these human settlements store water and have a seasonally stable source of water.

I think scientists refer to it as a tipping point.

The 'tipping point' usually refers to feedbacks exceeding 1 and therefore creating runaway global warming. Runaway global warming is not physically possible and isn't taken seriously by the climate science community. There is no 'tipping point'; it doesn't exist (although one might exist in 2 billion years when the sun gets bright enough).

[-1=e^ipi]

When? Next year, next business cycle, next decade, century or millennium?

Your question is a bit meaningless and cannot be evaluated without some sort of emission scenario. Though I suspect you are looking for something along the lines of a climate impulse response function. Anyway, if you take both the climate impulse response function and the rate at which CO2 is absorbed by the bio-sphere + oceans then maximal warming occurs in approximately a decade after CO2 is emitted into the atmosphere by humans. http://iopscience.iop.org/1748-9326/9/12/124002/article

I mean if there's reason to think it could be 2000 years before formerly cold, dry and unproductive regions become warm, wet and fertile enough to make up for areas that lose the productivity we've relied on, is our economy and growing population expected to sit tight and hang tough?

Your scenario doesn't make sense to me. Are you suggesting that there will be a time period of centuries during which formally productive land will be unproductive but formally unproductive land will not be productive yet?

Polar regions warm faster and more than equatorial regions. This is what is observed empirically and what is expected from basic physics. The Earth will become wetter at a similar rate at which it becomes warmer (the water vapour feedback is relatively quick); although ocean temperature increase takes longer (a few decades) to reach equilibrium. 2000 years is roughly the time it takes to reach the Earth System Sensitivity (ESS).

I've tried to answer your question but it isn't adequately defined enough to answer.

Edited May 11, 2015 by -1=e^ipi

[On Guard for Thee]

I think the context that TimG was referring to was that you were claiming that loss of glaciers would provide a problem because human settlements that rely on the glacier runoff as a water source would no longer have a seasonally stable source of water. TimG's response was that a dam could act as a controllable water reservoir that would help these human settlements store water and have a seasonally stable source of water.

The 'tipping point' usually refers to feedbacks exceeding 1 and therefore creating runaway global warming. Runaway global warming is not physically possible and isn't taken seriously by the climate science community. There is no 'tipping point'; it doesn't exist (although one might exist in 2 billion years when the sun gets bright enough).

I guess it depends on what portion of the scientific community you are choosing to accept. I see a lot of them referring quite often to tipping point. And I dont think you have to be hugely scientifically oriented to understand that, just like you may do on a cold winters night, pulling up another blanket helps lock in heat. Just that in the GW situation, throwing off that blanket is not as easy as it is for you in your bed.

[-1=e^ipi]

I guess it depends on what portion of the scientific community you are choosing to accept. I see a lot of them referring quite often to tipping point.

Like basically the entire scientific community unless we start redefining the scientific community to include creation science, homeopathy and other pseudoscience. The mainstream scientific community views runaway global warming as completely unrealistic based on our understanding of radiative physics and on paleoclimate data. Even the IPCC agrees.

"A runaway greenhouse effect is a process in which a net positive feedback between surface temperature and atmospheric opacity increases the strength of the greenhouse effect on a planet until its oceans boil away.^[1][2] An example of this is believed to have happened in the early history of Venus. On the Earth, the IPCC states that "a 'runaway greenhouse effect'—analogous to [that of] Venus—appears to have virtually no chance of being induced by anthropogenic activities."^[3]"

http://en.wikipedia.org/wiki/Runaway_greenhouse_effect

I sort of get where you are coming from. 1. There is a lot of green propaganda and lack of scientific literacy in society. 2. There were a few outliers in the scientific community such as James Hansen, who held the position that runaway global warming could occur. Although recently it appears that even people like James Hansen have come around and now admit that runaway global warming is not a possibility, or so I was told recently in the comment section on Judith Curry's blog.

"Hansen no longer holds that a Venus-like runaway is possible in less than a billion year time-scale. Reason: improved accounting of “non-radiative vertical energy transport”."

http://judithcurry.com/2015/05/06/quantifying-the-anthropogenic-contribution-to-atmospheric-co2/#comment-700817

And I dont think you have to be hugely scientifically oriented to understand that, just like you may do on a cold winters night, pulling up another blanket helps lock in heat.

Something causing warming does not imply runaway warming. Runaway warming means that positive feedbacks are sufficiently strong (greater than 1). If I cover myself in a blanket, is it going to cause runaway warming that will boil me in my sleep?

[eyeball]

Your scenario doesn't make sense to me. Are you suggesting that there will be a time period of centuries during which formally productive land will be unproductive but formally unproductive land will not be productive yet?

I'm definitely suggesting there will be a gap between the time productivity drops off in one region and picks up in another. I'm simply inquiring how long the period will be 1, 10, 100, 1000 years etc. I would think policy makers would want to know this so they can ensure there are enough food reserves on hand to last us. Or does that even matter?

I've tried to answer your question but it isn't adequately defined enough to answer.

How long until a wet productive Texas picks up the slack that a dry unproductive California is leaving in the food supply? Is that defined enough?

[On Guard for Thee]

Like basically the entire scientific community unless we start redefining the scientific community to include creation science, homeopathy and other pseudoscience. The mainstream scientific community views runaway global warming as completely unrealistic based on our understanding of radiative physics and on paleoclimate data. Even the IPCC agrees.

"A runaway greenhouse effect is a process in which a net positive feedback between surface temperature and atmospheric opacity increases the strength of the greenhouse effect on a planet until its oceans boil away.^[1][2] An example of this is believed to have happened in the early history of Venus. On the Earth, the IPCC states that "a 'runaway greenhouse effect'—analogous to [that of] Venus—appears to have virtually no chance of being induced by anthropogenic activities."^[3]"

http://en.wikipedia.org/wiki/Runaway_greenhouse_effect

I sort of get where you are coming from. 1. There is a lot of green propaganda and lack of scientific literacy in society. 2. There were a few outliers in the scientific community such as James Hansen, who held the position that runaway global warming could occur. Although recently it appears that even people like James Hansen have come around and now admit that runaway global warming is not a possibility, or so I was told recently in the comment section on Judith Curry's blog.

"Hansen no longer holds that a Venus-like runaway is possible in less than a billion year time-scale. Reason: improved accounting of “non-radiative vertical energy transport”."

http://judithcurry.com/2015/05/06/quantifying-the-anthropogenic-contribution-to-atmospheric-co2/#comment-700817

Something causing warming does not imply runaway warming. Runaway warming means that positive feedbacks are sufficiently strong (greater than 1). If I cover myself in a blanket, is it going to cause runaway warming that will boil me in my sleep?

No it wont of course because the heat generated is from your own body, so when you get a bit too warm, you can throw off the cover and let that heat escape. The earth isnt quite the same, the heat comes from elsewhere as I suspect you know. The problem is, to follow the metaphor, is that we are covering ourselves in a blanket we cant so easily throw off.

[-1=e^ipi]

I'm definitely suggesting there will be a gap between the time productivity drops off in one region and picks up in another. I'm simply inquiring how long the period will be 1, 10, 100, 1000 years etc.

Why do you think that a gap will even exist, or that this gap won't be negative?

How long until a wet productive Texas picks up the slack that a dry unproductive California is leaving in the food supply? Is that defined enough?

No this isn't defined enough, although better. How are we measuring productivity of agriculture and how are we determining slack length (climate change is continuous, not discrete)?

Also, I'm not even sure if Texas will become wetter. The mechanism of changing wind direction at the latitude of California to be more easterly should cause California to become drier; but Texas will become wetter. However, there are other mechanisms in play. For example, the regions between the Hadley and Ferrel cells are high pressure regions, which is one of the reasons why you see so many deserts around 30 degrees N/S. However, if this high pressure system moves poleward, then that could cause both California & Texas to dry out (but then parts of Mexico should become wetter).

[-1=e^ipi]

No it wont of course because the heat generated is from your own body, so when you get a bit too warm, you can throw off the cover and let that heat escape. The earth isnt quite the same, the heat comes from elsewhere as I suspect you know. The problem is, to follow the metaphor, is that we are covering ourselves in a blanket we cant so easily throw off.

Look, it's called the stefan boltzman law. Black body radiation is proportional to temperature to the power of 4. That's what prevents the Earth from going into runaway warming. The 'blanket' will warm until outgoing radiation equals incoming radiation and the Earth is in radiative equilibrium with the Sun.

http://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law

The only way runaway warming can occur is if you have a sufficiently strong positive feedback (such as water vapour if the Earth was as close to the Sun as Venus).

[On Guard for Thee]

Look, it's called the stefan boltzman law. Black body radiation is proportional to temperature to the power of 4. That's what prevents the Earth from going into runaway warming. The 'blanket' will warm until outgoing radiation equals incoming radiation and the Earth is in radiative equilibrium with the Sun.

http://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law

The only way runaway warming can occur is if you have a sufficiently strong positive feedback (such as water vapour if the Earth was as close to the Sun as Venus).

Unfortunately what we have with global warming that is incoming radiation exceeding outgoing due to that blanket we add to each day as we start up our car or coal fired power plant. And yep, we are already enjoying that increase in increased water vapor.

[eyeball]

Why do you think that a gap will even exist, or that this gap won't be negative?

It's seems reasonable to think there'll be a gap and I can't see how anyone would consider a disruption in our food supply would be a positive thing. I mean, I would think a disruption of even a couple of years could be potentially devastating, especially in any sort of just-in-time-production/consumption business model.

No this isn't defined enough, although better. How are we measuring productivity of agriculture and how are we determining slack length (climate change is continuous, not discrete)?

I don't know, I'm just a layman. Your over-arching message seems to be don't worry be happy so....

It's obvious why politicians prefer the optimism of skeptics.

[Bonam]

Bio-diversity is a meaningless catch all used by environmentalists to avoid having a meaningful conversation about the trade offs. What matters are concrete evidence that the new collection of fauna and flora is sufficient for our needs. The simple fact that there may be fewer species is not evidence of a problem.

I would argue that there is some intrinsic value to the existence of a greater number of species. A world populated only by humans and they're food crops and farm animals seems to me a far less interesting one than a world filled with tens of thousands of species, only a small subset of which are cultivated by humans.

[TimG]

I would argue that there is some intrinsic value to the existence of a greater number of species. A world populated only by humans and they're food crops and farm animals seems to me a far less interesting one than a world filled with tens of thousands of species, only a small subset of which are cultivated by humans.

If used this properly this argument has merit (i.e. we should not kill off species for no reason). In practice, this argument used like 'god in the gaps' arguments that creationists use. It is an assertion of blind faith that cannot be questioned and it designed to torpedo any proper cost-benefit analysis. I am saying that assertions of blind faith are not enough. If there is a tangible cost to preserving species in any specific scenario then there is a need to show tangible benefits if one wants to argue for paying the cost of preservation. Edited May 11, 2015 by TimG

[-1=e^ipi]

Unfortunately what we have with global warming that is incoming radiation exceeding outgoing due to that blanket we add to each day as we start up our car or coal fired power plant. And yep, we are already enjoying that increase in increased water vapor.

You add CO2 and the planet will warm, which will get amplified by feedbacks, until a new equilibrium is reached. Why is that such a difficult concept for you to understand?

It's seems reasonable to think there'll be a gap

Based on what? The fact that it helps you dogmatically support a certain conclusion?

Based on my understanding of the timescale of various feedbacks, I don't see a 'gap', although it is difficult to demonstrate since what you are asking for is not well defined.

Your over-arching message seems to be don't worry be happy so....

That's not my message. Stop strawmaning me.

[On Guard for Thee]

You add CO2 and the planet will warm, which will get amplified by feedbacks, until a new equilibrium is reached. Why is that such a difficult concept for you to understand?

Based on what? The fact that it helps you dogmatically support a certain conclusion?

Based on my understanding of the timescale of various feedbacks, I don't see a 'gap', although it is difficult to demonstrate since what you are asking for is not well defined.

That's not my message. Stop strawmaning me.

Much of the extra warmth doesnt get fed back unfortunately, bit of a one way street. Much of it gets stored in the oceans, which among other troublesome affects teds to grease the skids under the Thwaites ice sheet. Im sure you have heard of it...

[-1=e^ipi]

Much of the extra warmth doesnt get fed back unfortunately, bit of a one way street. Much of it gets stored in the oceans, which among other troublesome affects teds to grease the skids under the Thwaites ice sheet. Im sure you have heard of it...

The ice-albedo effect is a feedback.

Edited May 11, 2015 by -1=e^ipi

[On Guard for Thee]

The ice-albedo effect is a feedback.

The Thwaites ice sheet sliding off the land is sea level rise. Many feet of it. I am hopig my property values will rise as the ocean approaches and I become waterfront. Hope you dont live in Florida.

[-1=e^ipi]

The Thwaites ice sheet sliding off the land is sea level rise. Many feet of it. I am hopig my property values will rise as the ocean approaches and I become waterfront. Hope you dont live in Florida.

You are moving goalposts here. We were discussing whether runaway global warming and whether it is physically possible or not.

[On Guard for Thee]

You are moving goalposts here. We were discussing whether runaway global warming and whether it is physically possible or not.

Dont know what you mean by possible or not, its happened before, a few times.

[-1=e^ipi]

Dont know what you mean by possible or not, its happened before, a few times.

No, runaway global warming never happened on Earth. It happened on Venus, but not Earth.

[cybercoma]

Ice cover changes can, when measured over time, be evidence, yes. Isolated extreme weather events (thing that has varied over the last decade) are not any kind of evidence.

So the "ever recorded" part didn't tip you off that this is a comparison over time?

[eyeball]

That's not my message. Stop strawmaning me.

What the heck is it with you and straw?

I only said what your message SEEMS to be not WHAT it is. I actually don't what it is at all. Why don't you just spit it out?

[On Guard for Thee]

No, runaway global warming never happened on Earth. It happened on Venus, but not Earth.

Afraid so. Ever heard of the permian, triassic, or mid cambrian periods...

[cybercoma]

What the heck is it with you and straw?

I only said what your message SEEMS to be not WHAT it is. I actually don't what it is at all. Why don't you just spit it out?

Because it's easier to be vague and never actually put forward any clear arguments. That way you can just claim people are committing the strawman fallacy, when really they just have no idea what the hell you're on about because your arguments are incoherent.