Regarding Michael Richardson's March 21 article, "Are Earth's oceanic 'carbon sinks' filling up?": The author was correct in some of his reports and observations but quite wrong in others. For example, it is well established that the loss of ocean plant growth in terms of carbon dioxide is 4 billion to 5 billion tons per year over the past 30 years. Thus if we were to restore ocean plants only to the condition of 30 years ago, 4 billion to 5 billion tons of CO2 would be taken up each year. This is much higher than the 1 million tons the author reports.

The author's comment that replenishing the oceans with iron is not advised at this time due to lack of knowledge is utterly wrong. We know perfectly well that replenishment with iron as well as the restoration of oceans to the condition of 1980 will produce the same beneficial conditions the oceans enjoyed at that time.

russ george