Col Bennett, Australia

* Modeling Impacts of Vegetation Cover Change on Regional Climate : McAlpine, et al, Univ Of Queensland, Australia.

Also interesting reading –

For some interesting reading, see “THE RABBIT FENCE EFFECT” / Prof Tom Lyons.

[JR: In no scientific sense is that true. We have, however, 0.8°C in the past century, thanks primarily to greenhouse gases as every major scientific analysis has shown.]

With concentration of population to the cities, the urban heat island effect is significant & recognised, with urban temperature risen to a greater degree than the “country-side” as a whole – & “corrections” to the urban
“temperature record” made.

However, man, over the past couple of centuries, has not only built larger cities, but also cleared vast tracts of natural vegetation for farming.

In my home country, Australia, since white settlement, & particularly in the Murray-Darling basin in Australia’s east & in the south west of Western Australia (>10% of Australia), extensive land clearing of the “country-side” for grazing / cropping has resulted in climate change.

Studies show that surface albedo has increased, the climate has become drier with lower humidity / rainfall / cloud cover, greater wind velocity (even change in wind direction) & hotter*.

Some 0.2 – 2 C hotter in the Murray-Darling region of eastern Australia over the last 150 years (& 10% lower rainfall), these changes being land clearing changes & not due to any change in CO2. Similarly, in the south-west of Western Australia, temperature has risen some 0.6 C due to LCCC. This land clearing / heating over the past 150 years accounts for a large chunk of the world’s observed temperature rise over this time.

With regional land change heating a country town weather station, far from any urban heat island effect, there is an attendant increase to the temperature “record” – anthropogenic, but not CO2 (the same effect as Al Gore’s (incorrect) type example of the world’s receding glaciers – Kilimanjaro).

The “country-side” temperatue rise above true background is real, & it needs to be recognised & corrected for in the same way as the urban heat island effect.

And with World temperature failing to rise, despite (China’s rapidly) increasing output of CO2, perhaps one needs to “dust off” Henrik Svensmark’s “Sun magnetic activity / cosmic / cloud cover / Earth temperature” natural climate change theory, which postulates an explanation for the bulk of observed temperature change.

Not much left over for any effect for increasing CO2?

Col Bennett, Australia

* Modeling Impacts of Vegetation Cover Change on Regional Climate : McAlpine, et al, Univ Of Queensland, Australia.

Also interesting reading –

For some interesting reading, see “THE RABBIT FENCE EFFECT” / Prof Tom Lyons.

The Segalstad paper you are referring to should be taken with a lot of salt, most references about CO2 measurements in air and ice are completely outdated and unreliable. E.g. chemical measurements were mostly taken on land at places with (very) large local CO2 sources/sinks and don’t represent the global air composition of that time, while careful measurements of ice core bubbles do represent ancient air compositions.

I have made a web page with a comprehensive overview of all arguments why the current increase of atmospheric CO2 is quite certainly man-made, see: http://www.ferdinand-engelbeen.be/klimaat/co2_measurements.html

Joe, on the other hand, one need to be careful with statements like a “lifetime of tens of thousands of years”, as that is highly misleading. That statement is about the total lifetime, where the last influence of human CO2 still is measurable, but with a half lifetime of about 40 years, if we stop the emissions today, after 120 years only 12.5% of the excess CO2 still is in the atmosphere, the influence of this CO2 is near negligible…

“Recent work indicates that recovery from a large input of atmospheric CO2 from burning fossil fuels will result in an effective lifetime of tens of thousands of years.” See

http://geosci.uchicago.edu/ ~archer/ reprints/ archer.2005.fate_co2.pdf

[JR: Since this publication is not peer-reviewed, your comment is irrelevant. It does not take a brave editor to publish long-debunked analysis in a newsletter, just an ignorant one.]

If you are honestly seeking information, ask at Realclimate.org. By the way, can you give the citation for where the paper in your link was published (peer-reviewed journals only, please)?

I read your comments to my post and have noticed how you are a prolific poster on your site so I thought I might go fishing for information which is off topic for this thread.

First off, full disclosure – I place myself firmly in the “denier” camp. There are multiple reasons for this that I won’t bore you with, but I do look to keep informed on the subject and am always open to pertinent information. One paper I found quite convincing when I was coming to my position was this one relating to the life time of atmospheric CO2: http://folk.uio.no/tomvs/esef/ESEF3VO2.htm

I have tried to find papers justifying the “believers” view that it is 100 to 200 years but have been unsuccessful. The best I could find at the IPCC was that they do not dispute the low end numbers for CO 2 life time of 5 to 10 years: http://www.grida.no/climate/ipcc_tar/wg1/016.htm

I’ve asked at AGW blogs and haven’t received a response. I’m hoping to get directed to some papers that are based on empirical evidence illustrating the view for the long lifetime for atmospheric CO2.

I would much appreciate it if you could pass something along so I can evaluate, compare and make a more informed judgement on this one subject of the issue.

There is a point at which the vast majority of evidence points in a certain direction, so science really does move on to the more interesting and detailed questions, of “where”, “when”, “how much” and “how exactly” — and leaves “whether” as being answered. THIS is what is meant by “science moves on”. Dragging us back again and again and again to debunk the same old “new” objections, all the while declaring to the public that “the theory is on its last legs” in absolute defiance of what is being published in the mainstream of the field, does nothing but create confusion and devalue scientific effort amongst non-scientists and waste the time and resources of the scientists who have to try to counter it.

T Thompson — unless you can explain why your work is more accurate than Solanki’s work — and unless you have submitted your work to the criticism and deconstruction by experts in the field, such as most professionals have to undergo — then expect people not to take your “proof” very seriously at all. You have roughly the same credibility as an electrical engineer who has “disproved” evolution.