Ocean acidifcation .

[Exile]

Originally Posted by jackdale

Human respiration is not using sequestered carbon to add to the CO2 levels.

True, but adding billions of people to the planet may be.

Originally Posted by jackdale

Carbon isotope analysis says otherwise.

Where is this measured?

[Reefmagnet]

Originally Posted by MartinR

The climate is changing naturally, and life can adapt to it, by moving habitats for example. But normally climate is changing on a very long time scale. Now the pace is much faster. What this will do to the adaptability of animals and plants we can only guess at.

Anything is possible. I suspect there will be winners and losers as niches open and close. Should any niches remain after all wilderness areas have been transformed into petting zoos or urban sprawls, of course.

[jackdale]

Originally Posted by Exile

I understand the gist of the mainstream theory as you've repeated it many, many times (as if it's the "only" theory). But you're obviously choosing not to answer my follow-up question, so I can only assume you are unable to analyze the NOAA dataset to uncover the variations which you claim would distinguish between natural & human-derived sea level rise off the coast of Australia. Either that or there is no appreciable variation to uncover, and therefore no data to support the assertions you're making above. It's all getting rather clear.

Natural forcing would result in a sea level decline.

[jackdale]

Originally Posted by Exile

True, but adding billions of people to the planet may be.

Nope.

Originally Posted by Exile

Where is this measured?

CO2 is a well mixed GHG gas. It can be measured at any one of the CO2 monitoring stations around the world.

[Kenomac]

We go round and round on the same subject, same cast of characters.

http://www.cruisersforum.com/forums/...rs-158143.html

[Exile]

Originally Posted by jackdale

Natural forcing would result in a sea level decline.

Not if that natural forcing amounted to warming, which the long term trend says it has. Seawater expands with heat, does it not? Or are you retreating once again to the (minority) scientific theory that Milankovitch cycles would have us cooling right now?

[jackdale]

Originally Posted by Kenomac

We go round and round on the same subject, same cast of characters.

http://www.cruisersforum.com/forums/...rs-158143.html

Yep - Makes me wonder why folks dismiss science. Let us have a discussion about gravity. There are two theories for that; neither one of those has been proven.

[Reefmagnet]

Originally Posted by Exile

And one which suggests there are sources other than fossil fuel emissions which may account for the added CO2.

Once an exhaust gas enters the environment it becomes part of the natural cycle. CO2 builds up in the atmosphere because the sinks can't keep up with the sources. How much land area has been bulldozed and paved over since 1850?

[Reefmagnet]

Originally Posted by jackdale

Nope.



CO2 is a well mixed GHG gas. It can be measured at any one of the CO2 monitoring stations around the world.

Measure it just outside LAX and you might change your mind about how well mixed it is.



Sure, they probably don't measure CO2 there. But I bet they measure temperature.

[jackdale]

Originally Posted by Exile

Not if that natural forcing amounted to warming, which the long term trend says it has. Seawater expands with heat, does it not? Or are you retreating once again to the (minority) scientific theory that Milankovitch cycles would have us cooling right now?

What evidence do you have that Milankovitch cycles are a minority view?

[Exile]

Originally Posted by jackdale

Nope.



CO2 is a well mixed GHG gas. It can be measured at any one of the CO2 monitoring stations around the world.

Gotcha. But what I was asking is where the isotope that distinguishes fossil-fuel derived vs. "natural" CO2 is utilized? I don't think it's directly from the atmosphere or we wouldn't be debating this. Put another way, we know that humans are likely responsible for the additional 100+ppm of CO2 in the atmosphere, but I'm not sure whether we can determine if that added CO2 comes from fossil fuel emissions or from other human-derived sources. It's not a trick question, I just don't know.

[jackdale]

Originally Posted by Reefmagnet

Measure it just outside LAX and you might change your mind about how well mixed it is.



Sure, they probably don't measure CO2 there. But I bet they measure temperature.

Of course cities will have a higher CO2 level. Global CO2 levels vary about 10 ppm on average.

BTW - The BEST study discounted a role for UHI. Their UHI paper analyzing this indicates that the urban heat island effect on their global estimate of land temperatures is indistinguishable from zero.

http://www.scitechnol.com/2327-4581/2327-4581-1-104.pdf

[jackdale]

Originally Posted by Exile

Gotcha. But what I was asking is where the isotope that distinguishes fossil-fuel derived vs. "natural" CO2 is utilized? I don't think it's directly from the atmosphere or we wouldn't be debating this. Put another way, we know that humans are likely responsible for the additional 100+ppm of CO2 in the atmosphere, but I'm not sure whether we can determine if that added CO2 comes from fossil fuel emissions or from other human-derived sources. It's not a trick question, I just don't know.

Historic data comes from tree rings. Current measures from the atmosphere and oceans.

[jackdale]

Originally Posted by Reefmagnet

Once an exhaust gas enters the environment it becomes part of the natural cycle. CO2 builds up in the atmosphere because the sinks can't keep up with the sources. How much land area has been bulldozed and paved over since 1850?

Fossil fuel CO2 retains its isotope signature.

You are correct sources outweigh sinks.

For 100's of thousands of years sources and sinks were in sync. This is clear from Antarctic ice cores which show fluctuations between 180 and 300 ppm for at least 800,000 years.

[Exile]

Originally Posted by jackdale

What evidence do you have that Milankovitch cycles are a minority view?

Not that the mere existence of Milankovitch cycles is a minority view, but that it would result in a cooling cycle right now but for AGW. This would mean that all of our warming must be human-caused. My understanding is that the majority view -- to the extent it's even ascertainable -- is more conservative, namely warming results from a combination of human & natural factors. The "official" view from the IPCC, NOAA, NASA, etc. is that the human contribution has "significantly" contributed to warming, but even that is inconsistent with your stated position on Milankovitch cycles.

I've repeated this dozens of times, btw, without any pushback from you. So given the "official" view that warming is a combo of natural & human factors, what evidence do you have that your view is not a minority one? You never hesitate, after all, to present it in absolutist terms, so where's the evidence that it amounts to the dominant position of the science community?