I am saying the best way to address health issues is not through climate legislation but by addressing the direct causes.

Is charging a coal fired power station for CO2 emissions the best way to reduce its mercury emissions?

This will likely cause investment in CO2 reducing technology to crowd out investment in mercury reducing technology.

Is a tax on agricultural emissions the best way to reduce heart disease? No this will likely cause research in reducing agricultural emissions to crowd research that may have occurred looking into ways to reduce the fat in cattle and sheep. It may also crowd out government spending on health care research and investment.

How much warming will it take…

You know back in 1998 (and until 2005ish) I was actually more or less convinced. If I was asked to pick a position I would have said AGW, although without your certainty and enthusiasm.

“When the facts change I change my mind, what do you do sir?” (OK I admit I stole the use of that line in this context, Carter was it??)

You may claim that we have not had a cooling trend, however I am sure you will agree that temperatures have not shown a warming trend for 11 years. Can I say that?

It would require the re-establishment of a warming trend, and for this to be sustained for at least 3 years, with one year greater in warmth to 2005.

I have not set very strict criteria because the non-AGW believers are predicting a cooling trend, therefore only moderate warming is required to cast significant doubt on their theory.

The problem with alcohol at present is the low net energy. By the time you have grown, collected and transported it to final use you can be in negative net energy country. I do see a role where it is sourced from a waste stream, processed on site and used on site or adjacent.

Not much role for alcohol Doug? I’m disappointed..I was going to plant a field of beets and buy a still…and if some of it made it to the fuel tank that would be a happy accident.

Whether they emit less emissions depends on what is used to produce the fuel, how emissions are measured (tailpipe versus lifecycle) and what pollutant is being assessed (e.g. CO2 or local pollutants). For example biodiesel reduce emissions of particulates, HCs and CO but can result in increased oxides of nitrogen (can be dealt with with a cat converter).

Alcohol fuels are similar but due to lower energy content a slight increase fuel consumption.

The key question from a sustainability perspective is always what feedstock and the production chain that is used to produce and deliver the fuel.

My expectation that biodiesel will be used to displace diesel for freight and probably aviation and electricity for land based passenger transport. I don’t see much of a role for alcohol due to land competition issues and low EROIs limiting it to use near source.

However, none of these options will provide the level of transport service that we currently get from petroleum. So we also will need to change our expectations, behaviour and socio-economic systems. I think that these changes will be exciting and over hte long term beneficial.