Ocean Fertilization as a Geoengineering Approach

Geoengineering can be divided into two broad approaches. The first is to deflect sunlight back into space through such techniques as, mimicking volcanoes by dispersing sulfate aerosols in the stratosphere, making ocean clouds more reflective, painting roofs white, etc. The second broad approach is to remove CO2 from the atmosphere.

In this second category, fertilizing the oceans with iron to enhance algae growth is an approach that has received a lot of attention for many years. Algae presently absorbs large quantities of CO2, converting it to additional plant material which then becomes part of the ocean food chain. The portion of ocean life which dies and sinks to the ocean depths becomes permanently sequestered carbon. Iron is a limiting nutrient in most sea water, so adding more iron does increase algae growth, which in turn consumes more CO2. The main questions are: How much of this CO2 will become permanently sequestered? and, What are the side effects on other ocean processes?

Because of the high level of interest in ocean fertilization, UNESCO scientists prepared a 20 page report on the subject (released in late Jan, 2011). The report not only raises serious concerns about the side effects, such as “risk of toxic algal blooms, ....sub-surface oxygen levels, biogas production and ocean acidification”, but it also predicts that the effectiveness of CO2 removal will be no where near as great as previously estimated:

“even using the highest estimates for both carbon export ratios and atmospheric uptake efficiencies, the overall potential for ocean fertilization to remove CO2 from the atmosphere is relatively small. Thus recent calculations of cumulative sequestration for massive fertilization effort over 100 years are in the range 25-75 Gt (gigatonnes) of carbon, in comparison to cumulative emissions of around 1,500 Gt carbon from fossil fuel burning for the same period under business-as-usual scenarios.”

So the risk to benefit ratio, at least for now, seems to place ocean fertilization down in the list of possible geoengineering approaches.

Understanding the Current Cold

This is an update about the Arctic Oscillation discussed on Dec 18, 2010. The latest image from NASA Earth Observatory even more dramatically highlights the temperature anomalies of the northern hemisphere, with the arctic being up to 18 degrees warmer than the past historical average (red), and much of the US being up to 18 degrees colder (blue). The linked article describes the mechanism, but as best I read it, does not explain the cause.

And if that image is not amazing enough, check out the amazing agreement between four different sources of global mean temperature for the past century. This NASA link also explains how temperatures for areas without weather stations are arrived at through interpolation.

Note: Setting adjustments have been made to the "Comments" option on this blog to make commenting easier. Bill

Whales and Geoengineering

This link is from an April 2010 article in Nature Reports. Not real current, but as it has somewhat of a link to geoengineering, which deals with human intervention in climate processes, I wanted to point it out.

In a nutshell, feces from the great whales contain "on average, ten million times more iron than Antarctic sea water". Iron is a limiting element needed by phytoplankton. Phytoplankton consume CO2. So from a geoengineering standpoint, we humans can continue to support NOT harvesting the great whales of the world, particularly the baleen whales like Humpback, Blue, Minke, etc. And maybe the Japanese, who do support Kyoto, will cut back on their "research" harvest of whales.

Humpback Whale, Antarctic waters. Photo by Bill Fintel

Adding iron to the oceans, to increase phytoplankton growth, to capture more CO2 from the atmosphere, is an oft discussed geoengineering approach to reducing atmospheric CO2. It does not have a lot of support because of the potential side effects of human introduction (from ships), which leads to poor distribution, both time-wise and spatially. So what can be more natural than turning iron (re) introduction back over to the great whales!

Note: most new iron in sea water now comes from dust blown off the land. This will continue, so with more great whales recycling it through the phytoplankton-krill-whale food chain, the CO2 absorbing rates will increase. Not the answer to achieve 350 ppm, but a healthy approach that will help!

Geoengineering - How effective is it calculated to be?

Since it unfortunately appears that CO2 emissions for the next several decades, at best will continue more or less constant, and at worst will increase, the obvious question is: If needed, could geoengineering offset the high CO2 greenhouse effect and return Earth's climate to its present state? The answer appears to be, yes, for the most part.......HOWEVER, potential adverse side effects of geoengineering are still unknown.

Following is a summary of the title link study led by Casper Ammann of the University Corporation for Atmospheric Research: "Results of the study show that a major, hypothetical geoengineering project, launched in the 2020s, could indeed return Earth’s mean surface temperature to the levels of 2000.

To achieve this, however, the tropics would need to be cooled below 2000 levels in order to offset the warming at higher latitudes. This is partly because the poles by the 2020s are projected to have lost so much sea ice, which reflects solar heat, that they would not be very sensitive to the impacts of geoengineering...... 'The changes in the Arctic may be so profound in the next couple decades that trying to ‘fix’ the climate there might turn out to be futile,' Ammann says."

Bottom-line: Even if we resort to geoengineering, and even if it works, it does not appear to be able to return Earth's climate back to the way it was in 2000 for ALL regions.

Since precipitation is a very important climate factor, Ban-Weiss and Caldeira of the Stanford looked at both global temperature and precipitation in response to sulfate aerosols, and compared optimizing one versus the other using a uniform and a parabolic (more at poles) aerosol distribution. Their results also show major improvements, but they too conclude that Earth's climate can not be engineered back to exactly as it was as long as CO2 levels remain high.

In the the last sentence of their abstract they add a further qualifier: "It is important to note that this idealized study represents a first attempt at optimizing the engineering of climate using a general circulation model; uncertainties are high and not all processes that are important in reality are modeled."

Conclusion: Geoengineering needs a LOT more research before it is considered as a serious option. Of course a rapidly deteriorating climate, with rising sea levels, more intense storms, more severe and widespread droughts, will spur on research and consideration.

A World 29 degrees F Hotter!!!

The title linked article by Jeffrey Kiehl from the University Corporation for Atmospheric Research (UCAR), states that if we continue burning fossil fuels at the current rate, atmospheric CO2 will reach 1,000 ppm by 2100. Based on studies of Earth's past, between 35 and 100 million years ago, Earth's atmosphere contained this level of CO2, and the Earth's temperature was roughly 29 degrees F warmer than pre-industrial temperatures (27 deg F above present).

Now this does NOT mean Earth's temperature is forecast to rise 27 degrees by 2100, even if CO2 rises to 1,000 ppm. The rise will take centuries longer because of delayed effects, like glaciers and ice sheets melting. Kiehl points out that as the Earth warms and ice cover melts, less of the sun's radiation is reflected back into space, and so the warming effect of more CO2 is amplified. Additional amplification comes from more water vapor (a greenhouse gas) in the atmosphere, and release of other greenhouse gases, like methane.

'If emissions continue on their current trajectory, “the human species and global ecosystems will be placed in a climate state never before experienced in human history,”..........'

Note: To learn more about UCAR and NCAR, and their broad stated goal of, Fostering a deeper understanding of the atmosphere, Earth, and Sun, click here.

Melting Arctic and Global Warming

East coast of Greenland on April 14, 2010. Photo by Bill Fintel

The title link is to a Los Angeles Times article reporting on research studies published in the journal Nature Geoscience. The bottom line is that melting arctic sea ice, northern hemisphere glaciers and snow cover have a larger effect on global climate than previously calculated. From the article:

'The "albedo" effect, in which the blinding white cover reflects sunshine, has been calculated in numerous computer-generated climate models. But the new study goes beyond those theoretical calculations. Using field measurements and satellite observations, a team led by University of Michigan researcher Mark Flanner found that the warming effect of the loss of snow and ice is "substantially larger" than was predicted in the estimates of 18 climate models.'

Tied for Warmest

Actually, 2010 was the warmest year ever, but not by a statistically significant amount, so it gets ranked as tie with 2005. The above graph is from the NASA press release in the title link.

GMOs and Feeding the World

"The continuing distaste for  GMOs and their consequent absurd over-regulation means that the most up-to-date, environmentally benign crop protection strategies are used almost exclusively for the mega-crops that are profitable for biotech companies. The public agricultural research sector remains largely excluded from using modern molecular technology. Will this change soon? I don’t think so, although there are signs of movement here and there. India’s getting there with brinjal, China seems to be creeping up on biotech rice." Nina Fedoroff, a life sciences professor at Pennsylvania State University.

Now compare that statement with the title link's lead photo:

Definitely some controversy about the GMO approach to improving plant yields through genetic engineering. Note: Brinjal is eggplant, a major food crop in India.

Feeding a World of 9 Billion People

"The problem is not so much that we don’t have or can’t develop the technology to increase food and feed production, it’s that urbanization has rendered an ever increasing fraction of humanity unable to produce its own food — and more than that — totally unaware of what it takes. (What’s the problem? I just run over to the grocery store.)" - Nina Fedoroff, a life sciences professor at Pennsylvania State University. This quote was part of Andrew Revkin's Dot Earth Jan 10, 2011 blog titled "Varied Menus for Sustaining a Well-Fed World" (title link).

What I find so interesting is that Bill McKibben in his excellent book, EAARTH, believes that a key means of increasing food supplies will be the return of backyard vegetable gardening, like the Victory Gardens of WWI & II. McKibben points out that this is already occurring in the U.S. to a significent degree, ".... serious people have begun to rethink small-scale agriculture" (p. 166). He further states that this is a far better and safer approach to a warming climate, because it permits a faster, more fine-tuned response to changes in temperature, rainfall, and pests, which accompany climate change. Bill Mckibben has convinced me, and I am currently planning a major expansion of my "edible garden". Bill is also the founder of 350.org, a web site dedicated to "building a global movement to solve the climate crisis", with a specific goal of getting CO2 levels back down to 350 ppm.

The world population will almost certainly reach 9 billion by 2050, AND, if the present growth rate continues unchanged, the world population will grow from a current 6.9 billion, to 11 billion in 2050. The source for this last alarming figure is  Population Connection, an organization which "works to ensure that every woman around the world who wants to limit her childbearing has access to the health services and contraceptive supplies she needs in order to do so. Typically, when woman have access to affordable birth control, they have fewer children, regardless of income or educational levels."Also see the FAQ's on the About Us page of their web site.

Solar PV versus Solar Thermal

As a Chemical Engineer, I have always had a kindred feeling for solar thermal because, other than the computer-controlled mirrors, the rest of the technology is well established engineering, i.e., high pressure boilers, heat exchangers, steam turbines, electric generators, etc.

However, I also believe in the simple approach to solving a problem, and what can be more simple than having sunlight impinge on a silicon wafer and come out as electricity?

So who is winning? Well the linked news story from The Street indicates the simple approach just took a quantum leap ahead. You be the judge. I am guessing it will still take a lot more time to really sort this out, and maybe both approaches will have a place in our future.