On Feb 12, 3:45*pm, "boozn" wrote:
"Fran" wrote in message

...
On Feb 11, 3:47 pm, wrote:





boozn wrote:
EXACTLY!
Our atmosphere is starved of CO2

Depends from whose point of view you are coming from - if you have any
consideration for the 2 billion-year evolutionary heritage of life-on-
earth as we now know it, or the 100,000-year heritage of human life on
earth, your statement is utterly false.

and a new green revolution would occur if
we bumped it up.
1000 ppm might be a reasonable level.

Got any research to back that view?

Since when was CO2 an important limiting factor for plant growth,
anyway?

In theory it would be, but in practice, it hasn't been, and that's the
point. Nobody on the AGW side of this issue proposes reducing CO2 to
below the levels it was at prior to 1850, and there is no cost-
feasible means of doing so in the foreseeable future. There is simply
no good evidence that the kinds of increase in CO2 likely to occur
between now and 2050 would be of any measurable advantage in
commercially marketable plant yields
************************************************** *********************

EXTRACT FROM Roy Spencer Climate Skeptic Speaks

I think the assumption that CO2 is necessarily bad is a philosophical
assumption, not a scientific statement.


It's not a philosophical assumption but a naysayer strawman. *Nobody*
says CO2 is necessarily bad. Scientifically literate people say
continuing to permit an uncontrolled experiment in what might happen
to the biosphere when rapid increases in atmospheric GHG concentration
take place is bad policy, and threatens a foreseeable catastrophe.

Nature has picked a certain balance, but I don't see it as preordained, or
necessarily the best balance.


And yet, Mr Spencer is a god botherer ... a creationist no less ...

If you talk to some plant physiologists they make it sound like life on
Earth is actually starved for CO2.


No, Mr Spencer says that. Plant physiologists would know better than
to make such a sweeping claim.

The fact of the matter is that the most important life on Earth --
humans -- developed under a CO2 regime between about 180ppmv and
290ppmv. About 100,000 years ago, there were possibly about 4000
breeding pairs of humans. In that time we have flourished as a
species, domesticating a wide variety of plants and animals and on
that basis now fill virtually every habitable piece of land on the
planet, and plenty that are marginal. Had humanity not lost about a
quarter of its population during the first stages of the black plague,
and suffered the plague after that for about 300 years, and become
involved in persistent wars, we'd almost certainly have reached our
current population about 100 years sooner. During the last 10000 years
we have gone from being illiterate and innumerate hunter gatherers, to
being a largely literate, numerate and urban dwelling species living
off the proceeds of industrial-scale agriculture and global trade.

That doesn't read like life on Earth is "starved" of CO2. It sounds
like we've had just the right amount.

Fran