reply to post by Oneolddude
Yes, back more than 40 years ago when I was a kid in school, we were also taught that the Amazonian rainforests supplied a large percentage of our
atmospheric oxygen. You are right to raise this point as we shouldn't lose sight of it. The combination of negative forces at work here is
compounding matters alarmingly.
The fact is, though, we were wrongly taught back in our school days if the focus was on the Amazon and similar large, forested regions. They are
certainly highly important, but there is an even more important source of atmospheric oxygen that often seems to get overlooked: our oceans.
Around 70% of the world's atmospheric oxygen comes from the oceans, with a fair chunk of that deriving from phytoplankton photosynthesis. Best
estimates are that around 50% of all the world's atmospheric oxygen derives from this one source (meaning that the phytoplankton are not the only
marine source of oxygen). The other 30% of our planet's atmospheric oxygen is derived from other sources, the forests in Sth America and also the
vasts tracts of forest in Russia being a significant part of that. But 70% comes from the oceans.
I could post numerous links to back this up, but all anyone has to do is search "70% of oxygen comes from oceans" and they will get many, many hits
that link to learned and reliable sites, most of which will cite the above percentage. Some even claim up to 80% but if we go with the typical 70%
figure, we are not likely to be far wrong.
So here's the concern: if something has a significant impact on those phytoplankton, reducing their ability to capture sunlight and/or reproduce
themselves, then their oxygen output will proportionately reduce. While it's doubtful that the current oil/gas leak in the GOM will create enough
pollution to pollute all of the world's oceans, it doesn't have to. A combination of a few percent drop in ocean-based oxygen production combined
with an increase in atmospheric methane levels could be very harmful for many species -- including ours.
This is especially pertinent when we consider that warm-water ocean areas tend to have a greater ability to produce this oxygen, for the simple reason
that the phytoplankton like warmer and sunny conditions. The GOM is one of those regions where these plants thrive, and is probably part of the reason
for its abundance of sea life.
EDIT to add: to the OP -- my apologies! I also wished to thank you for your post. S&F! This is indeed a grave problem, especially if this leak cannot
be stopped and the pollution continues to spread. The above comments I've made are just a pointer to another worry we might have to deal with.
[edit on 17/6/10 by JustMike]