It's all over but for the sweating?

[jamesqf]

Originally Posted by Arragonis

Famous "fact" from my youth is that everyone on Earth can fit onto the Isle of White

The Isle of Wight - not White - has a surface area of 384 km^2, or 3.84 * 10e8 m^2, per Isle of Wight - Wikipedia, the free encyclopedia Earth's population is currently about 7 * 10e9, meaning you'd need to fit a bit over 18 people* on each square meter. I'd suggest the only way you are going to manage this is with hydraulic presses.

Now if you'll refer back to my original post, I believe I said that there is not enough area for everyone to live a DECENT lifestyle, including sufficient open space - a minimum of several acres per person - for mental and physical health. That some of us - an unacknowledged elite - can manage to do this is only due to the fact that a large fraction of the population has been forced or persuaded into cramming themselves into cities.

*Coincidentally, that's about the number you can cram into a Volkswagen Beetle. The record is 20, but they use small people.

[jamesqf]

Originally Posted by TheEnemy

Global Warming these would happen no matter if the cause is natural or caused by us.

True, but irrelevant, since we know beyond any rational doubt that the warming is caused by humans adding fossil CO2 to the atmosphere. It's just basic physics, no different in principle than using physics to figure out that if you jump off a cliff, you will hit the ground and go splat.

[freebeard]

I note they term CO2 a long lived gas - how long does it last - e.g. if I breathe out now when does the CO2 content get removed, and where does it go ?

I'm not sure about the long-lived part part; maybe that's compared to Helium which will exit to Inner Space, or complex gases like methane that will disassemble in sunlight.

When you breath out the CO2 is added to a pool that is drawn from when plants are in sunlight and *growing*. Mike Cheikey addresses this in that Solve For X talk.

[Arragonis]

Originally Posted by jamesqf

The Isle of Wight - not White

Damn you Firefox spell autocorrect (well thats my excuse).

I'll put joke around anything next time

[Arragonis]

Originally Posted by freebeard

When you breath out the CO2 is added to a pool that is drawn from when plants are in sunlight and *growing*. Mike Cheikey addresses this in that Solve For X talk.

So assume I drive to the supermarket, what happens to that CO2 then - what makes it "special" ?

[Arragonis]

Originally Posted by jamesqf

True, but irrelevant, since we know beyond any rational doubt that the warming is caused by humans adding fossil CO2 to the atmosphere. It's just basic physics, no different in principle than using physics to figure out that if you jump off a cliff, you will hit the ground and go splat.

If that is true then why has warming stopped or slowed as CO2 has risen ? Surely if it is the key driver then temps would continue to rise. Surely we should be burning up even now due to feedbacks.

And given we only have accurate (thermometer) records since around 1850 can we say with any accuracy that the warming in the 20th century was unusual in the history of the planet ?

If so, how ?

[Arragonis]

PS to the above - Bishop Hill (a skeptic) posted this recently :

What is the consensus? That carbon dioxide is a greenhouse gas? Yup. That man's activities are increasing carbon dioxide levels? Certainly. That temperatures went up at the end of the twentieth century and have not gone up since? Definitely. That human beings can affect the climate? Without a shadow of doubt.

Anything else? I don't think so. Even simple questions like whether observed temperature rises are anything out of the ordinary remain hugely controversial. The extent to which mankind has affected and will affect temperatures is likewise unknown, a great amphitheatre of ignorance dimly illuminated by a handful of aged CFLs - the climate models that scientists have pinned their hopes on - and little else. That these models are wrong is not in doubt - all models are wrong after all - but how wrong and how useful they are as tools to guide public policy is just another mystery. How can there possibly be consensus in these circumstances?

The impacts of climate change and the economics of climate change and policy responses to climate change are likewise entirely up in the air, with new hypotheses flown every day and shot down every evening and a mishmash of often contradictary empirical observations lending colour to the chaos. A glance tells you that there is no consensus.

So let us be clear, we don't even know if we have a big problem or a small one.

[NeilBlanchard]

What matters is where the carbon comes from. Animals breath out carbon that they recently ate, and plants take it in and then they shed oxygen as they do photosynthesis. This had reached a stable plateau for the previous ~650,000 years - life had stabilized it between ~180-280ppm.

Burning fossil fuels brings carbon back out of the ground that had been sequestered there for millions and millions of years. Humans have added enough in just 150 years to bring it up to almost 400ppm - this means we have better insulation and the atmosphere loses heat less quickly than it did before we added the carbon dioxide.

The facts about this were quantified by the US Air Force at Hanscom Field right here in MA when they were designing heat seeking missiles. Carbon dioxide blocks a fairly broad piece of the infrared spectrum, but not all of it, and they had to figure that out. Water vapor blocks a smaller and slightly different part of the spectrum, and other GHG also have their own "signatures" in the part of the spectrum.

Most of the carbon in the atmosphere is carbon 12 and that means it comes from burning old plants - i.e. fossil fuels.

[TheEnemy]

Originally Posted by jamesqf

True, but irrelevant, since we know beyond any rational doubt that the warming is caused by humans adding fossil CO2 to the atmosphere. It's just basic physics, no different in principle than using physics to figure out that if you jump off a cliff, you will hit the ground and go splat.

But the majority of the warming isn't caused by us. The majority is caused by a slight increase in solar output. It is also basic physics that if you put more heat into a system that system will warm up.

I will repeat again... the recognized solar increase is calculated raw, WITHOUT feedbacks. The contributions from CO2 are WITH feedbacks.

Arragonis: It could still be weather cycles that has stalled the increase, it will take another decade or two to be sure. Gotta love these long term systems that leave us hanging.

One of the things that really annoys me about the way that climate science is handled is the reliance on computer models for data. We use computer models at work, with things that are well understood and only moderately complex. They can still have 30% or more error between the model and the actual system. With the climate models we have a very complex system that is poorly understood, but its supposed to be accurate, and much of the data that is used is either processed through, or taken directly from the models.

[gone-ot]

...reminds me of the Statistician's comment: "...what answer do you want, and what answer do you need?.."