Re: Shaw's article

[Thomas Barr <tcbiii at earthlink_net>]

> In reviewing her work to the press, first author Rebecca Shaw commented, ³We
> think that by applying all four elements in combination in a realistic
> situation, some other nutrient becomes a limiting factor to growth.²
> 
> That ought to give you a major hint, there. Hah! Sometimes even the pros are
> stumped by nutrient limitation...
> -Y-
> David A. Youngker
> nestor10 at mindspring_com

I find this issue interesting. I can think of a few different things that
can happen. Plants grown in and adapted to high CO2 levels(say 700ppm) vs
plants grown in and adapted to (say our 365-370ppm level) respond
differently.
This has been shown in a number of plants such as Ludwigia(Bowes).

They likely took that into account? Maybe?
Multiple interactions between nutrients happen quite often that give
unexpected effects but the individual isolated studies are still very
useful. I found it unexpected also. And not good for the pro CO2 folks.

But the arguments are far from over about this issue of reducing the CO2.

I find great hypocrisy when it's policy to be "safe than sorry" when it
comes to protecting oil markets, but not the planet?

It does not seem wise waffling on whether or not to do a huge gigantic
entire Earth size CO2 gas experiment acid base titration that effects not
just the Us/Iraq for a few years, but the entire planet for a few thousand
years. If things go bad, there nowhere else to go. Only got one shot.

Agricultural markets drive a very large part of the world's markets, messing
with those is not wise. A steady supply is a good thing in a food
market(need steady weather).

Research based on wetland plants does seem to show that this group more than
any other will do better in the future as the CO2 levels rise. Other plants
will not fair so well. But wetland plants are not water limited, CO2 and
nutrients, namely Nitrogen. Most are vile weeds. Nitrogen is being added to
both the soil and as air pollution which comes down as rain and lands on
wetlands.

It'd be interesting to see how a wetland and dry Mediterranean grassland
would compare with this study. Heck of a lot of work though.
But someday, all we'll have to do is add plain old air through an air stone
to get enough CO2 for the plant tank. Scary really.

Regards, 
Tom Barr