LONDON, England (CNN) -- Research published last month paints an increasingly gloomy picture of the accelerating rate of climate change, raising genuine fears that efforts to combat carbon emissions may already be too late to restrict seismic changes in the earth's temperatures.
Plankton bloom off the coast of Norway as seen from the ESA satellite Envisat on 10 June 2006.
Compiled by a group of eminent scientists and published in the U.S. journal 'Proceedings of the National Academy of Sciences (PNAS)the report suggests that greenhouse gases are rising at a faster rate now than they did in the 1990's.
The scientists cite three main causes for this alarming rise; Growth in the world economy, increased fossil fuel emissions since 2000 and a decline in the efficiency of the ocean and land 'sinks' to absorb carbon emissions.
In the wake of this troubling new data about ocean carbon absorption, a range of geo-engineering solutions are being hotly debated in the scientific community and piloted by eco-businesses. The hope is that by intervening in the ocean's eco-system we will be able to reverse or stabilize the rates of growth in global warming.
The oceans are natural 'CO2 sinks' (a reservoir that absorbs atmospheric carbon). Phytoplankton -- microscopic organisms that congregate near the ocean surface - absorb atmospheric CO2 through photosynthesis. At the end of their lifetime -- usually only a few days -- they fall to the ocean floor carrying with them the CO2.
Scientists have known for some time that large swathes of the earth's oceans harbor extremely low densities of phytoplankton. These areas are known as HNLC (high-nutrient, low-chlorophyll) zones and are thought to be caused by a scarcity of iron.
This iron-deficiency theory was first postulated in the 1930's by English scientist Joseph Hart.
But it wasn't until the 1980's that the American oceanographer John Martin measured the iron content of the seawater in HNLC zones and found negligible amounts.
He argued that the sea gets it iron from dust swept into the sea from the land, and that wind currents weren't carrying iron to HNLC areas. Martin tested his hypothesis in Antarctica and found that phytoplankton thrived in jars of seawater infused with iron.
Martin's discoveries set in motion further research in this area and it was in the spirit of his work that a ship named Weatherbird II set sail for the tropical waters of the eastern Atlantic earlier this month.
Its mission is to carry out Martin's experiment on a much grander scale, pouring iron ore into the ocean in an attempt to stimulate plankton growth and assess the wider effects on sea life.
The pilot study has been organized by Planktos, a Californian-based eco-restoration company.
"This really might be an incredible solution," Planktos CEO Russ George told CNN.
"In climate change we talk about a tipping point, but in oceans and ocean life we are far over that tipping point," he said.
George has been involved in the carbon credit business for over 30 years. He started a tree planting company in British Columbia and estimates that he has planted over a quarter of a billion trees in Canada alone. A subsidiary company, KlimaFa Ltd is currently restoring forests in the European Union with over 100,000 hectares of land in Hungary being replenished.
It was when the Kyoto accord was first signed in 1997 that George started thinking of new ways to sell carbon credits and started researching iron fertilization. He is confident that it will be a success.
"20 years and 100-200 million dollars of public funds have identified this iron tonic solution as a way to restore the productivity of the ocean," he said.
Yet Planktos is a constant target for groups who don't buy into the idea of carbon offsets.
In a joint statement in August 2006 Greenpeace, the WWF and Friends of the Earth said: "Carbon offsets should only be seen as a last resort" and that "purchasing offsets can be seen as an easy way out for governments, businesses and individuals to continue polluting without making changes to the way they do business or their behavior".
George has had to put up with protesters continually claiming that the technology that Planktos is trialing isn't regulated.
"Any new technology in climate change that produces offsets has to go through a multi-tiered independent third party, transparent certification process. It's the most rigorous regulatory process on earth for any new technology," said George.
But opponents remain unconvinced. The Sea Shepherd Conservation Society, a vocal critic of Planktos, has, according to George, threatened to 'intercept' the Weatherbird II if attempts are made to carry out research.
George believes that the technology is the world's best hope. "We've lost 17 percent of all plant life in the Atlantic, 26 percent in the North Pacific and in the sub-tropical oceans 50 percent or more of plant life has disappeared," he said.
The pilot study is scheduled to last several months and the results will be keenly monitored by scientists.
CNN spoke to Professor Jef Huisman from the Institute for Biodiversity and Ecosystem Dynamics in the Netherlands about iron fertilization.
"It is often discussed among scientists and we have mixed feelings about it," he said. "We know it could potentially reduce the levels of CO2 in the atmosphere, but we don't know what the consequences are."
Asked about the research about to be conducted by Planktos, Professor Huisman said: I think it's an interesting idea as well as a dangerous idea. Interesting because we know that if we can increase the primary production and there will be a larger intake of carbon dioxide in to the ocean.
"But is also dangerous. Just as you fertilize on land you will change the eco-system. Whereas we have experience of what happens in a meadow, we have no experience of what would happen with the eco-system species composition in the ocean. What happens if you do large scale iron fertilization? We have no idea which species are going to profit or whether it will cause harmful algal blooms.
Professor Huisman predicts that once the iron goes into the ocean that there will be a strong increase in phytoplankton species.
"I would expect the small phytoplankton species -- that have a fast growth rate - will be there first," he said. "Secondly you would have slow plankton species that would catch up and start grazing on the phytoplankton species."
Huisman, an expert in aquatic microbiology, is currently researching the phenomenon of the deep chlorophyll maximum -- a layer of phytoplankton found in tropical and sub-tropical oceans. He thinks that iron fertilization studies should be done in water tanks before heading out to sea.
"You could put an entire community from the pacific ocean in a 50 meter tank. There you could have a controlled experiment and the iron will not be eroded by ocean currents," he said.
Despite constant haranguing from eco-protesters, Planktos' Russ George remains defiant and somewhat evangelical about the potential of "iron-seeding".
"We are all here at the behest of the green plants in the ocean," he said. "4 percent of the planet is covered in rainforest. 72 percent of the planet is ocean. In the last five years we've lost all the rainforests worth of ocean plant life."
If the pilot study is successful, George envisages container ships "re-booting" the oceans back to levels they where at 30 years ago. "It is the single great hope we have," he said.
According to two eminent British environmental thinkers, increasing the uptake of CO2 by the oceans could be effected by vast vertical pipes beneath the surface of the ocean.
Writing in the journal Nature, James Lovelock, creator of the Gaia hypothesis and Chris Rapley head of London's Science Museum argue that pumping nutrient-rich water from the depths of the oceans up to the sea's surface would allow the ocean to absorb more CO2.
The idea is to have literally millions of pipes -- 100 meters long and 3 meters wide -- reaching down to the depths of the ocean. They could, the inventors suggest, sequester a sizable chunk of annual human carbon emissions.
Professor Huisman isn't so sure that the plan would work though. "Concentrations of CO2 are higher in the deeper oceans," he said. "The major effect would be that carbon dioxide levels deep in the ocean would be brought to the surface. It is the opposite of what you would want."
But he remains positive about utilizing the oceans. "If you could increase the uptake of the oceans it would really help with the greenhouse effect."
