Oxygen and Carbon Dioxide balance in plants.

[iankirby]

When I read Botany, admittedly a long time ago, I understood that the Carbon Dioxide taken in by plants during photosynthesis was balanced out by the CO2 given off during plant respiration, this over a year. I.e. the plant is Carbon, and Oxygen , neutral.
If this is still understood as correct, and I am willing to concede that more recent research may have changed ideas, then how does planting a tree(s) make someone who flies abroad carbon neutral?

[jake-the-peg]

It doesn't - frankly it just postpones the release or carbon dioxide, or it may actually make it worse!

If you plant a deciduous tree it will take carbon and make leaves which will produce methane when they rot - this is about 60 times worse than Carbon dioxide as a greenhouse gas I believe.

You will over the lifetime of the tree gather the tree's carbon mass but again if it rot's it's back in the atmosphere - it only really helps if it ends up making coal and I'll bet not many of the trees planted in these schemes will end up doing that!


It's the oceans that are the real sink's - the food chains there end up depositing on the ocean bed and get subducted into the Earth's crust to be part of the long term carbon cycle again.

Thing is it's hard to offset your flight by planting 100 tonnes of phytoplankton!

[gen2]

Photosynthesis in plants does NOT balance out with respiration and never has. Plants are net users of carbondioxide, which together with water form the bulk of the material in the plant (sugars, starches and celluloses). As jake says, this only ties up the carbondioxide for a little longer than the life of the plant and at its best may only delay global warming. The problem with flying is that it uses fossil fuels which were not part of the active carbon cycle until burnt. Ideally these need to be taken back out of the cycle permanently before we can consider ourselves carbon-neutral.

[dawkins]

like most of these plans its popular because its easy to do and it sounds environmentally positive.

The same can be said for recycling. Surely it would be miles better to develop reusable packaging; cut down on excessive packaging; and source as much food/services as possible locally.