How many trees do we actually need?

[hmkpoker]

I have a weird question.

How much flora is actually necessary to sustain comfortable levels of oxygen for people and animals in the world? How many acres of rainforest can we continue to bulldoze before we actually start running into an "oxygen shortage"?

[yukoncpa]

This may help. From the Straightdope

[hmkpoker]

That's interesting. I'm wondering how much deforestation contributes to global warming.

[Lestat]

I've thought about this myself. You'd think that it could be calculated somehow.

[yukoncpa]

Cecil comes close to answering both yours and Lestat's questions here and here

[Siegmund]

There's an amusing site that calculates how many trees you need to plant in order to balance the amount of carbon your lifestyle puts into the air each year: http://www.carbonfootprint.com/calculator.html

I can't speak to the details of what assumptions they make about the size or lifespan of the trees you plant.

[NobodysFreak]

HMK,

I could be wrong, but its my understanding that sea algae produce somewhere between 70 and 80 % of the world's oxygen. Now, I don't think that means we could go around cutting every tree with no consequence, but I think the oxygen production of forests is probably overblown.

[llayner]

Its not so much an oxygen shortage, but decrease in carbon dioxide absorbtion. There's enough O2, but multiply the CO2 output by people, cars, planes and industry thats overloading the forest's ability to absorb enough CO2 to maintain a balance.

[FortunaMaximus]

[ QUOTE ]
HMK,

I could be wrong, but its my understanding that sea algae produce somewhere between 70 and 80 % of the world's oxygen. Now, I don't think that means we could go around cutting every tree with no consequence, but I think the oxygen
production of forests is probably overblown.

[/ QUOTE ]

Hardly overblown, and an obvious cause for concern. Using your numbers, 20-30% of oxygen production is a LOT. Consider the size of the biosphere and what a 0.0001% difference might do in sheer volume of oxygen. Draw your own conclusions.

[wacki]

[ QUOTE ]
I have a weird question.

How much flora is actually necessary to sustain comfortable levels of oxygen for people and animals in the world? How many acres of rainforest can we continue to bulldoze before we actually start running into an "oxygen shortage"?

[/ QUOTE ]

People would die from CO2 poisoning before we die from a lack of oxygen.