i understand that methane is ten times worse that carbon, yet greenies INSIST on home composting [home compost 'bins' are like having a cow [producing methane [no wonder veget-airians complain about cows ][to distract us from home composting methane issue]

we have these 'alternatives' but as people have stated these expensive 'envioronment friendly' cars take 5 years to recover the carbon THEIR PRODUCTION PRODUCED

also air travel seems to be favoured by a particularily low carbon debt [considering many are built over swamp land,s and recovered sea [leaching methane as well as environmental vandilism] not to mention their electricity consumption [and getting to or from them]

there is ALLWAYS a special intrest thinking how can we scare people into accepting a NEW tax [especially one we can get the average joe to pay] it is not enough the powers that be can deflate the worth of our dollar at whim [they now demand a global tax that pays WHATEVER the market prices these carbon credits at

like everything else the 'TAX' will be set low to get it in [from there we will have the market forces do the rest[wait till the speculaters DRIVE UP THE PRICE
[just like with bandwidth[or water rights] or our privatised bankers and their bank fees [or those who stole our other 'utilities'[and even our roads/bridges/airports [the list gets extensive but who cares what games po-lie-trick ians [polutitions] concieve then deliver to their pals.

While I agree with most of the points John raises, this one caught me off-guard. How on earth did he come to the conclusion that because XYZ renewable power source COSTS the same as coal, it therefore emits as much carbon? Isn't it that case that renewables could — for the sake of argument — cost a thousand times as much, but still not represent the same amount of carbon?

However, the overall energy cycle is a very, very important discussion that the modern world needs to have, and will help illustrate why a hydrogen economy is not viable. It is simply not economically and energetically viable to take expensive, lowish ERoEI renewable ELECTRICITY and waste MOST of that electricity splitting water to make hydrogen to then compress, run through a fuel cell, only to turn it back into.... electricity!

That's like taking 10 units of expensive, low ERoEI electricity and turning it into 2 or even 1 unit of forward motion.

It would be far better just to use the electricity directly. And there's the rub. In a low ERoEI world, we need a national electric rail transport system, and yet 97% of our freight is driven by truck. It's time to get cracking building trains, trams, and trolley buses... as fast as we can, and then rezoning our city planning laws to encourage New Urbanism around the railway stations. Over the next generation a surprising percent of our population could be living modern lifestyles that are "more European than European" in trendy New Urbanism streets, yet not needing cars in the first place. And that, my friends, will go a good way towards solving both peak oil and global warming, as well as many social isolation issues.

To "Under One god"

The physics of Co2 are standard and easily verifiable.
http://tinyurl.com/ywneqb

Lots of scientists study absorption spectra of various molecules. They do this in labs using a spectrometer, and employ the long established science of spectroscopy. I understand this science also gave us other "conspiracies" like microwaves and the fiber-optics which power the internet. ;-)

Then there's the Radiative Forcing Equation which analyses how much extra Co2 creates how much extra energy in the atmosphere.

This stuff is fairly verifiable, testable, repeatable physics... it's not as if they've committed "Post Hoc Ergo Propter Hoc" with some bit of historical information.

Your reference to the world "Cooling" since 1998 ignores the facts.
http://eclipsenow.blogspot.com/2008/10/uk-met-office-on-1998.html

The world is hotter now than it has been for millions of years. Measuring JUST from 1998 is called "Cherrypicking data" and ignores the fact that 12 of the last 13 years have been the hottest on record.

You would want to dumb down climate science so that CO2 increases ALWAYS equalled temperature increases exactly. I call this the "Exact Correlation Strawman". Climate science doesn't work that way... you can't rule out El Nino and La Nina as having an impact, or a dozen other forcings. If it's too complicated for you to take in, try reading the comics but don't display your ignorance here please.

The start of the article is promising in that it discusses the need to assess the consequences of investment and purchase choices across the supply chain, but are net energy analysis concepts such as Input-Output analysis really a sensible or particularly useful choice of tool for such policy choices?

As EclipseNow wrote
"Isn't it that case that renewables could — for the sake of argument — cost a thousand times as much, but still not represent the same amount of carbon?"

I would agree with this line of argument and suggest it might be more worthwhile expending more public funding on developing life cycle analysis (LCA) expertise in Australia and gathering accurate life cycle inventory (LCI) data.

But still, there is the problem even with LCA (which if done properly with a good understanding of appropriate systems boundaries is a reliable way of assessing quantitative environmental impacts). Although giving more useful information than analysing economic I-O tables, neither does it measure non-quantifiable impacts such as on biodiversity (except very indirectly through climate change, eutrophication, sulfur dioxide emissions).

Example would be: clear-felling a native forest then using the land for biomass production in plantations instead of running a coal-fired powerplant might be calculated to be better for carbon-dioxide emissions, but worse for eutrophication, better for acid rain etc. But neither LCA nor I-O tables can tell you that you would make x species extinct.