Shell Seminar, “Saving the World One Teragram at a Time.”

Many aspects of climate change still need to be further researched by scientists. At a time when taking care of Earth’s global environment is more important than ever, William S. Reeburgh from the University California Irvine is interested in investigating certain elements of climate change and discovering if previous assertions hold any truth in them. Applying massive scale geochemistry as well as chemical engineering, Reeburgh’s main purpose for his research is to study biological oxidation, predominantly the oxidation of methane gas, and come up with the largest and most effective methane sink. The modeling and prediction calculations done in this project are more to be used for determining the global importance of specific parts of climate change.

Reeburgh originally began his project when he read articles published in scientific journals abhorring the eventual claims of cataclysmic outcomes of arctic glacier melting. One of the claims mentioned is that melting glaciers release dangerous gases into the atmosphere. Reeburgh noted, “Recently we heard about Arctic Armageddon, but never talked about biological oxidation…it’s deadly.” Utilizing various methods of measuring methane gas emission, such as substrate limitation modeling and reverse methanogenesis, Reeburgh concocted a general prediction of how much methane gas is released into the atmosphere each year from different sources.

Reverse methanogenesis involves sampling small quantities of an atmosphere over a specific environment and counting how much methane gas fills that space up. It turns out that the ocean actually emits methane gas, while scientists had previously conjectured it absorbs it. In biological oxidation, there are two ways methane gas can be oxidized: through aerobic or anaerobic reactions.

One tool Reeburgh used to get a precise measurement of methane gas emission over the ocean was through the use of accelerator mass spectrometry, simply put atom counting, therefore making this process very sensitive as opposed to other methods of measuring methane gas emission. However, Reeburgh encountered an obstacle in that these reactions needed priming to speed up the process, otherwise the research would be spending inordinate amounts of time collecting data to the point where no analysis could be performed reasonably. After weeks of pulling data from scientists across the nation, Reeburgh concluded that the ocean emits and oxidizes roughly 1,588 teragrams of methane gas each year through aerobic and anaerobic reactions, which is significantly larger than the amount of methane gas that would be released from the arctic glaciers melting. Researchers do agree that methane will be released from arctic glaciers, but that amount is definitely not catastrophic.

Now equipped with this knowledge of the amount of methane gas being oxidized around the world, Reeburgh looks to develop a way to reverse oxidation and lower oxidation rates around the world in various ecosystems, done especially through inverse chemical engineering. Before concluding his presentation, Reeburgh emphasized, “Predictions of climate change are too important to be left to modelers and bloggers,” and encouraged the practical use of science to solve important problems.