Why wouldn't natural negative feedback mechanisms work to cancel the increases of CO2 in the amtosphere?

Question

A number of simple photosynthetic organisms need little else to survive but CO2, Water, and Sunlight. Many of these thrive in oceanic environments. Why wouldn't the rise in CO2 simply result in a general increase in their population and a general reduction in atmospheric CO2?

Atmospheric nitrogen may be 70%, but that doesn't guarantee that it can be used by the organisms I discussed. It COULD be the limiting factor. However, I know there are microbial organisms that convert atmospheric nitrogen into other usable forms. Couldn't these work in conjunction with the other types?

Answer 1

There is clearly a natural cylce in atmospheric CO2, and plants probably play a role in this. Thus, increasing the plant biomass could be considered a part of the solution to increased CO2 levels in the atmosphere.

The problem is, the current levels of atmospheric CO2 are significantly higher than preindustial maximums (roughly 30% higher in fact) and this may overwhelm the natural controls.

Of course, current temperatures are still well below preindustrial maximums so there is some question as to what the real effect of the high CO2 levels is.

Answer 2

Carbon dioxide reacts in water to form carbonic acid.

Do you think massive acidification of the oceans is going to be a good thing? The oceans are largely an unbuffered solution. Marine life is evolved to handle a certain pH range. Dropping that range will do three things

(1) have a profound impact on marine life
(2) result in increased hazards for ocean water use by humans
(3) its a finite sink. Eventually the ocean won't be able to absorb that much more CO2 (the more acidic it gets, the truer this is).

A peer-reviewed scientific article by Sabine et. al in Science [1]estimates that nearly half of the human-generated CO2 is absorbed currently. While the upward limits of CO2 absorbtion are somewhat under contention [2][3][4][5] all sources agree that it is finite (this is good chemistry).

The oceans have already displayed a measurable drop in pH of 0.1.[6] While that might not look like "a lot", it represents an increase in protons (acid) of a factor of 30%[7]. This drop already has a demonstratable negative affect on marine life.[8]
All studies agree that the absorbing effect of the oceans and other feedback mechanisms is (1) finite (2) still encumbered with negative outcomes for many current lifeforms (3)potentially hazardous to human activity.

This is a good question, and very serious to policy and personal decisions in the future. I hope that I've been able to point you in the right direction for serious reading about this important topic.

Answer 3

A truly great question.

There is a small, but significant group of scientists that think this will happen. The problem is that the numbers don't work. The increase in plants is not enough to outweigh how fast we're pumping greenhouse gases into the atmosphere. Those scientists are reduced to waving their hands and claiming a miracle will occur.

The majority of scientists believe the feedback will be positive. Global warming melts ice and exposes ground. The ground absorbs more heat instead of reflecting it.

Answer 4

I don't believe that CO2 is the limiting factor in additional plant growth. Usable Nitrogen is the limiting factor in plant growth, so the shortage of N is what prevents the increased plant gorwth and removal of excess CO2 from the atmosphere.

Answer 5

A VERY good question. In fact, natural negative feedback DOES clear up such spikes as put out be volcanic action all the time. And since the earth's atmosphere consists of 70% Nitrogn, that's hardly a limiting factor, is it?

Answer 6

It might. But then again it might not. The levels of CO2 in the air are high now and still rising, so if there is some feedback mechanism that will start to lower it, it hasn't kicked in yet!

Answer 7

the rate of increase is so high due to human activities that it is not neutralised.... it is just like how a river floods... it constantly does drain its water into ocean but when the rain is too high it floods... same way human activities releare lots of co2... in addition they cut down trees.... so there is a steep increase.... that is not balanced by nature!