A weird one. Planktos is a for-profit company that appears to intend to sequestrate CO2 by causing algal blooms. Anyone with more info on this is invited to comment.
And they will sell you CO2 offsets. For example: The average international flight is 9-20 hours long and produces 2 tons of CO2 per passenger. 4 tons of CO2 equivalents will be retired on your behalf to negate 100% of your carbon footprint for this return flight is only $20. How can the average flight be 9-20 hours long and yet produce exactly 2 tons?
But more importantly, why should you believe that they ar doing anything to earn this money? They say At sea, Planktos uses a process called iron replenishment to restore declining plankton growth in the open seas. We revive plankton populations by adding iron dust to the ocean. Iron is a critical micronutrient needed by plankton for photosynthesis. It normally reaches the oceans in wind-borne iron-rich dust from arid lands, but that dust supply has fallen 30% over the past 30 years, resulting in a 10% decline in plankton populations since the late 1970s. Extensive research projects have shown that adding tiny amounts of iron can powerfully regenerate plankton growth. Stimulating plankton blooms not only captures global warming CO2, but also restores ocean ecosystems, as plankton is the base of the food chain. but are rather short on any details: who says iron dust has fallen? how much extra plankton has planktos created? how much CO2 has that sequestered? has anyone verified this? And so on… But perhaps In 2007, Planktos will begin plankton restoration… is the answer: they haven’t actually started yet.
Doing this commercially seems to be wildly premature: both because we dont know if it will work (so how can you sell credits, apart from the obvious answer of “anyone can sell credits to anyone dumb enough to buy them”) and we don’t know it won’t have unplesant side-effects.
[Update: the SOLASS statement is worth reading: ...Given our present lack of knowledge, the judgement of the SOLAS SSC is that ocean fertilisation will be ineffective and potentially deleterious, and should not be used as a strategy for offsetting CO2 emissions... -W]
[Update: silly me: RC did this a while ago -W]