Matthews DL, Cao L, Caldeira K. 2009. Sensitivity of ocean acidification to geoengineered climate stabilization. Geophysical Research Letters 36: L10706.

Although climate stabilization through geoengineering is a means of slowing climate changes, it is less viable for the other CO2 problem; climate engineering may increase the rate of ocean acidification.

In their study, Matthews and Caldeira from Concordia University and Carnegie Institution of Washington respectively, found that climate engineering modifies ocean chemistry through changes to CO2, temperature, salinity, DIC, and alkalinity.  These effects were mediated by increased CO2 solubility, however, and changes in ocean pH were far less severe with equivalent atmospheric CO2 levels.

The notion that geoengineering will not mitigate ocean acidification was previously assumed, but this study confirmed the assumption.  Second-order interactions between climate engineering, the global carbon budget, and ocean chemistry may slightly increase or decrease the rate of ocean acidification, depending on changes in future terrestrial carbon sinks.  The study highlights the fact that changes in ocean chemistry are not only the direct result of pH influences, other factors play large roles in ocean acidification.

The Use of Iron Fertilization for Carbon Sequestration

Am. Assoc. for the Adv. Of Sci. 304, 414-417 (2004).

Researchers are looking into new techniques of carbon sequestration to help counteract the negative effects on the climate due to the anthropogenic emission of carbon dioxide.

Ken O. Buesseler, John E. Andrews, Steven M. Pike and Matthew A. Charette performed an experiment called the Southern Ocean Iron Experiment (SOFeX), where they fertilized two sites with four enrichments of iron fertilization. The patch of fertilized water was monitored by 3 boats for 1 month in 2002.

The researches found that in a 1000 km² patch during 21 days, SOFeX resulted in an enhanced flux at 100 m of 1800 tons of carbon. However, because of remineralization that the researchers estimate to have occurred, the true estimate of carbon sequestration is about 900 tons. However, they concluded that because this is such a small amount compared to the 6.5×10⁹ tons/year emitted by humans, there needs to be more research conducted to make this technique useful on a global scale to mitigate climate change.

Sensitivity of ocean acidification to geoengineered climate stabilization

GEOPHYSICAL RESEARCH LETTERS, VOL. 36, L10706, doi 2009

Although climate stabilization through geoengineering is a means of slowing climate changes, it seems to be less viable for the other CO2 problem; climate engineering may increase the rate of ocean acidification.

In their study, Matthews and Caldeira from Concordia University and Carnegie Institution of Washington respectively, showed that the global carbon cycle can be affected by the strong relationship between global temperatures and the rate of CO2 uptake by carbon sinks.  They represent this pair with an intermediate-complexity global model.

The notion that geoengineering will not mitigate ocean acidification was previously assumed, but this study confirmed the assumption.  Second-order interactions between climate engineering, the global carbon budget, and ocean chemistry may slightly increase or decrease the rate of ocean acidification, depending on changes in terrestrial carbon sinks in the future.  The study highlights the fact that changes in ocean chemistry are not only the direct result of pH influences, other factors play large roles in ocean acidification.