Does Python cause tides?

[Roel Schroeven]

Terry Hancock wrote:

> "Plants consume CO2 and make O2"
> 
> Well, yes, but they also consume O2, just like animals.  *On balance*,
> the statement is *usually* true.  But most plants would probably
> die in a pure-CO2 environment (unless they can drive the atmosphere
> to a better composition fast enough).

Ha, finally one I can comment one with a reasonable level of confidence. 
On balance, plants consume CO2 and produce O2 *as long as they are 
growing*. You see, they use the C from the CO2 to build the material 
they are made of. Once they are full-grown, the amount of O2 produced by 
their photosynthesis is balanced by the amount of O2 consumed by their 
respiration; the same goes for the CO2 produced in consumed in both 
processes.

This can be generalized to whole forests too. Often people think that 
the Amazon rain forests produce large quantities of O2, but that's just 
not true. During their initial growth, they indeed produced large 
quantities of O2. As long as they stay the same size (the same amount of 
biomass actually), there is no net effect. Now that large areas are 
burnt to make place for roads and agriculture, the CO2 comes back in the 
atmosphere while O2 from the atmosphere is consumed in the flames.

It's very well possible that this is a simplification that glosses over 
a few details such as other sources of carbon, but in general it's good 
enough.

-- 
If I have been able to see further, it was only because I stood
on the shoulders of giants.  -- Isaac Newton

Roel Schroeven