James,
The cost of scientific research of microorganisms has dropped to a fraction of what it was 20 years ago whereas military research has increased! To discover new materials to mask and protect war machines, for example is in the US$ tens of billions, whereas finding mutant organisms that have a few percent more efficiency in trapping carbon dioxide is in the range of US $10-30 million.
At this time we have, (almost for free), decades of detailed ocean and atmospheric 3D data on the earth's biosphere. It is a side product of our eyes in space. Look at this stunningly beautiful
movie!
Craig Ventner's research ship,
Sorcerer II, in the Galapagos islands has already sequenced many novel organisms and so we have banks of novel genes to study and potentially exploit. To get a glimpse of where science is, read
this description of Venter's company's achievement in building the first self-replicating organism by synthetic means from scratch.
I imagine that any future plan to modify an existing organism would be only about $30,000,000 and with about 10 attempts, we would have a working new plankton, if we knew exactly what was needed. Over the next 10-50 years, costs would drop and eventually we will be able to brew plankton safely and clean up the planet if all other means fail.
All the needed research is already in progress.
Still it would be helpful if we limited fossil fuel use while we get to know the natural cycles of plankton fixation of carbon.
I am pretty optimistic!
Asher