"Study: Climate change is nothing new, in fact it was happening the same way 1.4 billion years ago"

[rushmc 18]

kallend

***
If it happened before and wasn't a big deal then no problem.

How do you know it wasn't a big deal then? Please explain how you know this.

How do you know if it would be a big deal today?

"America will never be destroyed from the outside,
if we falter and lose our freedoms,
it will be because we destroyed ourselves."
Abraham Lincoln

[kallend 1,621]

rushmc

******
If it happened before and wasn't a big deal then no problem.

How do you know it wasn't a big deal then? Please explain how you know this.

How do you know if it would be a big deal today?

Where did I say it would be?

...

The only sure way to survive a canopy collision is not to have one.

[rushmc 18]

kallend

*********
If it happened before and wasn't a big deal then no problem.

How do you know it wasn't a big deal then? Please explain how you know this.

How do you know if it would be a big deal today?

Where did I say it would be?

I knew you would not answer the question

"America will never be destroyed from the outside,
if we falter and lose our freedoms,
it will be because we destroyed ourselves."
Abraham Lincoln

[lawrocket 3]

Quote

There have been several less extreme climate events in the Earth's history that seem to most people to be "no big deal" now (tens or hundreds of millions of years later) but they were a big deal to the species alive (and afterward not) at the time. What is your definition of a "big deal"? Certainly the extinction of humanity would be a "big deal", but no-one realistically expects that to happen. A sizeable fraction of the human population lives on river deltas, and those areas are also some of the richest farmland (think of Bangladesh for example).

Fair point. What is a big deal? IT's a matter of opinion, but in my opinion the big deals have been when it gets colder and not when it gets warmer. Back in the Medieval Warm Period the Europeans were convinced they could colonize Greenland and did for a few hundred years. Until it got cold again when the climate changed. By 1400, those left on Greenland were short, deformed and malnourished and soon died.

Yes, it would be a big deal if the sea level rose three meters much less thirty. Look at how much the sea rose 10k years ago. We're talking 100 meters in 10k years. For people we can ask whether it was helpful or detrimental as a whole. While value judgments are no doubt made, we can look at lifespans and population and see that warmer temps haven't really affected us too badly.

Quote

In reply to:
It isn't going to happen for the next several hundred thousand years and well after all fossil fuels are used up.

Is that a prediction? Based on what model? Or is it your opinion?

IT's a prediction based on some simple math. Look at Greenland. IT's been suggested that Greenland is losing, on average, .15 inches per year of ice (I think it was Krabill who did the study and found this). Assuming this is true, take the depth of of the Greenland ice cap (2 miles, but I'll use 10,000 feet) and we have 120,000 inches. Divide by .15 and you get 800,000 years to melt it all.

OR, wlook here. http://www.skepticalscience.com/print.php?r=143

THey're talking around 10k years to melt everything. I haven't seen anything suggesting that fossil fuels will be around on Earth for more than 2k years.

And this assumes only that there will be ablation and no additional accretions at higher levels. Places like the Greenland Ice Sheet will see a large increase in the amount of precipitation to offset losses in lower elevations.

That's the hypothesis based on theory. Maybe the prediction will be off. We'll see. As a side note, assuming that climate sensitivity to doubling CO2 is 3 degrees C. We've been directly measuring CO2 since 1960 or so, when it was 315 ppm. This means that doubling CO2 concentration will be about 630 ppm and it'll be 3 degrees warmer, on average. TO get another 3 degrees it'll have to be up to 1260 ppm.

The daily mean temperature at McMurdo is -17 Degrees Celsius. TO get to 15 degrees of forcing would necessitate CO2 concentration of 10,080 ppm. And it would still be a net less-than-freezing.

This is math. Humans start feeling lousy at .5% CO2. 1% will make for a really bad time and will kill much animal life. It won't be melting ice sheets that would be worried about so much as toxic air.

I like to go through the math. It gives a better idea of what people are talking about. And how one can say, "Wait a minute here." Without understanding the concepts, people start doing weird stuff. Think of those who ask why it took a spacecraft doing 24k mph when the motor stopped took three days to get to the moon when it was 250k miles away. Understanding the concepts and limitations explains it.

Quote

Which model is more accurate? I guess we are doing that experiment right now.

Bingo. The experiment and observations are ongoing. We are in the process of science and it's too soon to be too confident in our predictions. I'm not really confident in mine but I find them for myself to be a bit more in line with parsimony and already established observations. This does not include other variables, however, so I know it's a simplification.

ps - awesome reading regarding the vectors.

My wife is hotter than your wife.

[billvon 2,384]

>This means that doubling CO2 concentration will be about 630 ppm and it'll be 3 degrees
>warmer, on average. TO get another 3 degrees it'll have to be up to 1260 ppm.

Based on which model? As CO2 increases, the atmosphere becomes saturated in that band, so consecutive doublings have less and less effect. However, as the planet warms, methane levels rise and albedo drops, both of which tend to increase warming. I have not seen any model that says those two will balance exactly. Most models I have seen have shown that - given a linear increase in CO2 - the rate of warming will increase, due to positive feedback mechanisms overwhelming saturation effects.

[lawrocket 3]

billvon

>This means that doubling CO2 concentration will be about 630 ppm and it'll be 3 degrees
>warmer, on average. TO get another 3 degrees it'll have to be up to 1260 ppm.

Based on which model? As CO2 increases, the atmosphere becomes saturated in that band, so consecutive doublings have less and less effect. However, as the planet warms, methane levels rise and albedo drops, both of which tend to increase warming. I have not seen any model that says those two will balance exactly. Most models I have seen have shown that - given a linear increase in CO2 - the rate of warming will increase, due to positive feedback mechanisms overwhelming saturation effects.

That's eh I went with CO2 explicitly and limited it. There is the thought that the runaway greenhouse effect will occur as sea water evaporates, holding more warmth, causing more seawater to evaporate. On the other hand, we don't know whether clouds will increase or what kind of clouds. Will the primary effect be albedo increase or further warming?

Mystery. No fact established yet. Much to be learned.

I went with only CO2 sensitivity and indicated that it's a vast oversimplification. L

My wife is hotter than your wife.

[kallend 1,621]

rushmc

************
If it happened before and wasn't a big deal then no problem.

How do you know it wasn't a big deal then? Please explain how you know this.

How do you know if it would be a big deal today?

Where did I say it would be?

I knew you would not answer the question

It was asked and answered previously. Learn to use the "search" function. It will save us all a lot of aggro.

...

The only sure way to survive a canopy collision is not to have one.

[SkyDekker 1,121]

rushmc

************
If it happened before and wasn't a big deal then no problem.

How do you know it wasn't a big deal then? Please explain how you know this.

How do you know if it would be a big deal today?

Where did I say it would be?

I knew you would not answer the question

Coming from the guy who never answered the question asked in the first place.

[billvon 2,384]

>That's eh I went with CO2 explicitly and limited it.

Right - but even that's not linear due to changes in saturation.

>Mystery. No fact established yet. Much to be learned.

This is getting very close to an "argument from ignorance." Creationists use this argument all the time to argue against evolution - "how did the HOX gene complex come to be? We don't know. And if we don't know how evolution works, you can't possibly teach it as fact! You just admitted you don't know how it works."

We do, in fact, know a great deal about both evolution and climate change and are learning more all the time. A great deal of fact has been established already. There is much more to be learned. That shouldn't stop us from teaching what we do know.

[lawrocket 3]

billvon

>That's eh I went with CO2 explicitly and limited it.

Right - but even that's not linear due to changes in saturation.

>Mystery. No fact established yet. Much to be learned.

This is getting very close to an "argument from ignorance." Creationists use this argument all the time to argue against evolution - "how did the HOX gene complex come to be? We don't know. And if we don't know how evolution works, you can't possibly teach it as fact! You just admitted you don't know how it works."

We do, in fact, know a great deal about both evolution and climate change and are learning more all the time. A great deal of fact has been established already. There is much more to be learned. That shouldn't stop us from teaching what we do know.

I think you are putting some kind of motivation that isn't there. I was asked how I knew that the polar ice sheets aren't in danger of melting away due to fossil fuels any time soon. Then I explained a couple of things. First was that by one measure from the early 2000s in Greenland I could calculate 800k years. The second was that not even skeptical science could support something less that 10k years to melt all of Greenland. And then I asserted that fossil fuels will likely run out in a couple thousand years. Even assuming something like 1000 years for the CO2 to clear out that still leaves another 7k years without AGW.

Then I explained just how much warmer it has to get in order to melt the ice caps. I cited the temperature at the coast - McMurdo. And showed that there mean temp there is 15 degrees below freezing. To warm it up would mean doubling CO2 five times from 1960 temperatures assuming a climate sensitivity of 3 degrees.

You are positing the mechanism of positive feedback from water vapor and the like. I get that. He consensus is that thedirect effect of CO2 is 1.2 degrees C for CO2. However, the IPCC AR4 summarized total climate sensitivity as "likely to be in the range 2 to 4.5°C with a best estimate of about 3°C, and is very unlikely to be less than 1.5°C. Values substantially higher than 4.5°C cannot be excluded, but agreement of models with observations is not as good for those values."

This sensitivity includes the other feedbacks that you mentioned. I didn't just pull 3 degrees out of my ass, Bill. I went directly with the IPCC's estimate. The consensus is that by no means is this estimate certain for total sensitivity. But it is where the models are tending to converge.

Taking 3 degrees of sensitivity I just calculated it out. But I actually accounted for the stuff you described.

And no, it is not an argument from ignorance. I'm not going. Back and saying that we don't know from what exploding star all this carbon came from. I am saying that there is a lot of uncertainty about the future. We do not know. The feedback processes are chaotic and that's why GCMs have to run billions of iterations to get the underlying trend. I'm sure you are aware that individual studies have CO2 sensitivity anywhere from 1.5 degrees to 10 degrees. The IPCC cannot rule either of these out but sees 1.5-4.5 to be the most probable range.

Some suggest that climate sensitivity effectively doubles for every doubling of CO2. Is that what you are getting at? I think it was Hansen a few years ago who suggested that due to other feedbacks that sensitivity is more linear. It was interesting but I haven't seen it really take on life. He may be right but we don't know.

My wife is hotter than your wife.