Phytoplankton may stimulate uptake of CO2
Phytoplankton may stimulate uptake of CO2
In a story about a month ago you reported at Adding Iron To Oceans Not Effective - Study
The headline and the significantly spin mastered content are now shown to be rather poor work. The interpretations drawn from a data set that was known to inadequately cover the experiment in question is now shown in a new light.
Only long term data can reveal the reality of ocean plankton blooms, not a couple of weeks of data taken at the beginning of a bloom. Read the following news item and pick up a copy of Science tomorrow. It would then be good to see a new story telling the world that there is still hope to save our oceans.
Russ George The Planktos Foundation http://www.planktos.com/
Phytoplankton may stimulate uptake of CO2
CORVALLIS - New research has revealed that phytoplankton may be one of the main historic controls on global warming, and that fertilizing the oceans with iron results in increased phytoplankton productivity - a hypothetical way to offset the effects of global warming.
Through photosynthesis, these tiny, free-floating aquatic plants can convert carbon dioxide to organic carbon, and there appears to be a prehistoric relationship between iron in the ocean and atmospheric levels of carbon dioxide.
Burke Hales, an assistant professor in the College of Oceanic and Atmospheric Sciences at Oregon State University, is one of a number of scientists who collaborated on a new study which involved field research in the ocean near Antartica and will be published Friday in the journal Science.
He described the research as "tremendously successful" because it very clearly shows an induced biological response in the oceans to fertilization with iron.
"During the glacial periods, atmospheric carbon dioxide, or CO2 levels decrease substantially, while during interglacial periods, such as we are now in, those levels increase," said Hales. "There is also a striking inverse relationship between implied, historical iron fluxes to the ocean and atmospheric CO2 concentrations. These relationships suggest some sort of feedback system between iron and CO2 levels during glacial periods that keep the temperature low."
The carbon cycle is a complicated system of causes and effects that are not completely understood, but researchers have long suspected that the oceans are the main regulator of the Earth's atmosphere, said Hales. For example, during the ice ages more of the Earth's water is locked up in glaciers, creating arid, windy conditions and a lot of dust. This iron-rich dust is blown out to sea, stimulating productivity of phytoplankton throughout the world's oceans and reducing CO2 levels.
"In order for the phytoplankton to be a long-term sink for carbon, they somehow have to get deposited in the deep ocean, and that doesn't always happen," said Hales. "If the phytoplankton are just eaten at the surface, or don't sink to any great depth then the carbon is eventually released back into the atmosphere."
Another complication in phytoplankton production is the availability of silicate, which is potentially a limiting factor in the growth of certain types of phytoplankton. Diatoms are a large type of phytoplankton that have siliceous shells, and because of their relative bulkiness have a higher probability of sinking into the deep ocean for longer periods of time. So it seems logical that iron-fertilized, low silicate waters might not be as efficient carbon sinks as iron-fertilized high silica waters, but the results of this study disproved that idea for the first time.
"This was the first experiment of this nature in low silicate waters where it didn't seem as though there would be enough silica for the diatoms to grow," Hales said. "However, our results showed an enhanced uptake of atmospheric CO2 in the fertilized region despite the low availability of silicate."
Since humans starting burning fossils fuels, CO2 levels have skyrocketed and there has been increasing concern over the role that has played in global warming.
"The difference between the amount of CO2 in the atmosphere today and during pre-industrial times is about the same as the difference between interglacial and glacial periods," said Hales. "There is definitely a correlation between the amount of CO2 in the atmosphere and global warming, but the relationship is hard to define."
Hales' role in the study involved developing apparatus to sample the ocean water and measure the concentrations of various chemicals, such as nitrate, phosphate, silicates and dissolved CO2 in order to determine the impact on levels of atmospheric carbon dioxide.
"We needed very high spatial resolution measurements of chemicals in the fertilized regions, so the technology we used allowed us to take fairly continuous samples," said Hales. "The sampler was something like a little underwater airplane that continuously pumped water up to the ship while soaring up and down in the water as we towed it."
Although Hales is excited about the scientific implications of the research, such as the insight it provides into the relationship between the glacial and interglacial cycles with the CO2 record, he is reluctant to make any claims that fertilizing the ocean with iron would realistically help control global warming.
"There are so many repercussions that we can't foresee," said Hales. "This is a very expensive and uncertain way of going after an issue that is not fully understood. For example, in the process of gathering up iron and steaming out to sea, you would burn up more fossil fuel than you would compensate for in the result. Besides that, there's also the issue of shifting an ecosystem structure that the food web is based upon by adding iron. We really have no idea what sort of positive or negative effects that would have."
Another huge unknown in the experiment are the effects of time, cautioned Hales. The time scale of the experiment, 42 days, is not at all comparable to the time scale of the glacial/interglacial cycle, which is thousands of years.
"We weren't even out there long enough to observe the season to season changes, so we don't know if the carbon was really being exported to the deep oceans or not," Hales said. "A longer term study would be necessary to draw more concrete conclusions."
By Celia Schiffman, 541-752-9868 SOURCE: Burke Hales, 541-737-8121
Oceans in Peril -We Sometimes Worry About The Right Thing For The Wrong Reason.
(April 2004 The Planktos Foundation)
The global community worries about global warming or more rightly global climate change. What we have all not been told is that this "global warming" is likely the last and least effect that we will experience as part of global climate change. A hundred years before the predicted few degrees of warming becomes palpable vast changes to the Earth's ecosystems will have wrought monumental changes in the way we humans live and behave on and with this small blue planet. Unlike Global Warming these changes are not some debatable future scenario they are upon us today. The most significant changes we see today are in the world's oceans. The ocean environment is in real peril now. Why is this?
The cause of this change and warming is known to be greenhouse gases, primarily CO2, that are accumulating in our atmosphere as a result of the burning of fossil fuel. We know for certain that the concentration of CO2 in the atmosphere has risen, since the dawn of the fossil fueled industrial age 150 years ago, from roughly 250ppm to 380ppm. We can predict and project the continued rise of CO2 to levels in the very near future beyond 500ppm and reaching even beyond 1000ppm over the next century or two.
The first and most dramatic effects of 150 years of rising CO2 are seen in eco-systems that are part of and responsive to powerful feedback systems. Delicately balanced eco-systems respond to the slightest shift that we apply with monumental leverage. The first evidence of such a feedback eco-system couple is seen in the desert - ocean system. It is a remarkable part of the natural balance of our planet that the wettest and driest eco-systems on this planet are so intimately intertwined. Here is how it works as we now understand as a result of the massive experiment we have been conducting in altering those two eco-systems by raising the CO2 concentration of the atmosphere by 50%. Had this massive atmospheric enrichment experiment called fossil fuel burning not occurred we might not have seen the desert and ocean link.
We know plants absorb CO2 from the atmosphere and give back oxygen. They do this the same way all life on the planet exchanges gases with the air. They have to expose wet tissues to the air where the gas exchange takes place. We humans do this by opening our lungs and drawing in air to expose it to the wet tissues in our bodies. Plants do this by open cells on their leaves called stomata and allowing the air to exchange gases with wet tissues inside the leaf. We all pay for our oxygen CO2 exchange with molecules of water that evaporate from those wet tissues. We can see this water when we exhale into cold air and see our breath form a cloud. We are no different than plants in that the majority of water we lose is via our breath.
For plants that have access to a relative abundance of water they can afford to trade water for CO2. For desert and dry land plants it is a very different story. Desert plants have evolved to have short fast life cycles so that they can live their lives in the short period that water is available. They trade precious water with the air for the CO2 they need to use in photosynthesis. Remember we are all "carbon" based life forms on this planet. All of that carbon comes from CO2 that is changed via the photosynthesis of plants which combine it with nutrients and minerals from the soil into what we animals find delicious and nutritious.
NOW... today we see that the air has 50% more CO2 than it did a mere hundred years ago. Desert and dry land plants are very happy about this. They now obtain the CO2 they need at far less expense in terms of water loss. This water saving preserves their life for many days, they grow larger, and they produce more foliage and more viable seeds. For the deserts and dry lands of earth this higher CO2 concentration in the air is a fantastic bounty and we see those deserts and dry lands of the Earth becoming greener over greater areas and for longer periods each year. We know that the best way to reduce the loss of topsoil and dust from blowing from the land is to better cover the land with vegetation. To be certain the dry lands and deserts still dry out and become dusty deserts but that dry dusty period becomes smaller and for a shorter time each year. This may be good news for deserts but there is a price to be paid.
Enter the relationship of the deserts and dry lands with the oceans. We know that the ocean plants, phytoplankton, like their desert cousins have evolved a short life cycle. They live in an abundance of water but live in a desert of with regard to the nutrients and minerals that plants on earth take from the soil. So where do ocean plants get these nutrients and minerals... As it happens they get these from the land and the process of erosion that slowly wears down the earth and washes it into the oceans. However some very critical mineral nutrients do not last long in the ocean ecosystem as being rather insoluble they dissolve slowly and sink quickly to the bottom. Chief in importance of these trace minerals required for photosynthesis and life on this planet is iron. Iron acts like a catalyst in photosynthesis with a very tiny amount being needed to empower a very great amount of photosynthesis. Evolution has adapted ocean plants to make use of iron in concentrations almost too small for us to measure.
So where do ocean plants obtain their iron? They obtain it from the deserts of the earth where that abundant red dust is red because of the iron it contains. The dust that blows from the deserts feed the ocean plants the tiny amounts of iron they need to survive and flourish. When these dust storms pass episodically over the oceans they dip down here and there in a random fashion and deliver the precious iron to the waiting ocean plants. As this is a rare and somewhat unpredictable event ocean plants have evolved to grow at much reduced level of productivity as their normal life. But if additional iron arrives via a fortuitous dust storm the have the capacity to bloom like the desert after a spring rain and bloom they do.
In a few short days a deep blue ocean can turn into a green pea soup as the ocean plants rush to make use of every last atom of iron before it sinks into the abyss. Along with this dusty iron stimulated bloom comes a growth of the entire food chain as tiny krill and other zooplankton rise to the dinner table and feed on the temporary bounty. The bloom is temporary as the other macro-nutrients that the plants need is in limited abundance as well and as it becomes exhausted like a wet spring in the desert the ocean bloom rapidly comes to an end. This particular patch of ocean water will not be able to bloom again until the slow mixing of the ocean replenishes the water with the dissolved macro-nutrients. This is natures way and it keeps our oceans rather more blue than green.
It is this delicate system that is now staggeringly out of balance due to rising CO2 in the atmosphere. It is a feedback system that is now spinning up like a giant typhoon gaining strength from the weakness of the oceans that threatens to change this planet in ways the likes of which our earthbound and earth focused climate modelers have never dreamed, and it is happening faster than we know.
There is now evidence that is unchallengeable that shows both atmospheric CO2 is 50% higher than it was 150 years ago. There is correspondingly quantitative evidence showing the dramatic greening of dry and desert regions and the reduction of dust that is blowing from these regions. We also know from studies from satellites and ships that the baseline productivity of the world's great oceans is now stunningly reduced. The major oceans like the Pacific, Atlantic, and Southern oceans are 10-30% lower in productivity of ocean plants than they were a mere 25 years ago. If this rate of decline continues the oceans will become the deserts of this planet long before we humans notice a little warming and switch to a lighter jacket or sweater when we go out.
What is worse is that the amount of CO2 the now diminished oceans are already failing to remove from our atmosphere, which remember the oceans cover over 70% of this blue planet. This is the power of a feedback system. As the oceans die our atmosphere is losing the most powerful CO2 removal mechanism on the planet. This will result in a rise of atmospheric CO2 at a far greater rate than the earth bound atmospheric scientists have predicted. This is already apparent in the actual rates of rising CO2 concentration that are reported as being mysteriously faster than the models have predicted.
But this is not a story of inevitable doom and gloom. We can do something about this. As it happens the concentration of iron in the ocean on average is but a few parts per trillion. This number 1/ 1,000,000,000,000 is incredibly small and offers the opportunity for a form of eco-judo to be practiced. We know that raising the concentration of iron in a patch of ocean by only a few additional tens of parts per trillion can stimulate an ocean bloom. We also know that iron is super abundant on this earth in the form of iron ore which is indeed the same form of iron Mother Nature dusts her oceans with. With a very small effort relative to what we earthlings spend on countless luxuries we can replenish the dust that the oceans are dying for. In the bargain we will scrub the CO2 that we spew from our tailpipes and power plants from the air using the free sunlight energy, we will replenish the food chain of the ocean that all ocean life and those of us who eat fish from the sea depend on, and we be able to do this in an affordable safe manner. No small effort is required but the effort is not so large that we cannot succeed in a timely fashion. If we start now we may be able to save the oceans and ourselves.
"Twenty years from now, you will be more disappointed by the things you did not do than by the things you did do. So, throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover." Mark Twain.
Come along with us on our voyage of discovery and help with our work to save the oceans from this peril. It can be done.
Russ George - Founder
The Planktos Foundation Half Moon Bay, CA