Petar Todorov | Lab Notes
Dialing down the thermostat
Published: Tuesday, October 22, 2013
Updated: Tuesday, October 22, 2013 08:10
Climate change is a hot-button issue on our campus and in domestic and foreign politics. Scientifically, there is little dissent. The greenhouse effect driving the process was described by Svante Arrhenius over a century ago. The minor difference between then and now, however, is that Arrhenius, a Norwegian, wanted to pump carbon dioxide into the atmosphere and warm the planet. Since then, researchers have established that humanity is facing the opposite problem.
A 2009 report in “The Lancet” medical journal by Anthony Costello and colleagues sums up the bleak findings of climate research: The most conservative models presage a two to seven degrees Fahrenheit temperature increase and a sea level rise of five to 30 inches within the next century; more dynamic models accounting for the additive effects of warming warn of a more dire future, with temperatures jumping nine degrees Fahrenheit and sea levels climbing nearly 40 feet by 2050. These rapid changes have the potential to disrupt ocean currents and bring biting winters and scorching summers.
Looking to the past, we know that even small changes in the environment can be catastrophic to complex human communities. The Little Ice Age, an episode of global cooling during the 15th century, stunted population growth and nearly doubled the number of wars worldwide. A paper in “Science” by Douglas Kennett and colleagues suggests that the 2,000-year-old Mayan civilization was toppled by a minor but prolonged decrease in rainfall. More recently, it has become apparent that modern developed nations are not immune to the ills of rising temperatures: During the summer of 2003, heat waves killed more than 70,000 people in Europe.
Man-made global climate change is underway. Even if humans stopped releasing carbon dioxide into the atmosphere this second, it would proceed under its own momentum for some time. Despite Arrhenius’ proposal to heat the planet over a century ago, little research has been done on how to cool the Earth. The popular TV series “Futurama” comically suggested shaving blocks of ice off nearby comets and dropping them in the ocean to lower its temperature. The real ideas floating around are just as untested and perhaps only half as bizarre.
The most mundane of these “climate engineering” proposals is to paint roofs white and reflect heat. This approach is already effective on an individual level: It makes buildings cooler, reduces electrical consumption from air conditioning and provides an incentive to consumers who want to save money. But it’s unlikely that white roofs on every building will gain worldwide adoption or result in global effects.
A more radical and less tested approach calls upon algae to sequester carbon dioxide in the ocean. Normally, the growth of algae and oceanic bacteria is limited by the lack of inorganic nutrients like nitrogen and iron in seawater. A proposed approach here is to “fertilize” the ocean with iron dust and create a rapid growth of algae. The algae would pull carbon dioxide from the water and the air and then take it to the bottom of the ocean as they die and sink.
Political maneuvering had denied entrepreneurs the ability to go forward with their projects until late 2012, when a businessman managed to seed the ocean near Alaska, creating an algal bloom visible from space. Scientists were quick to condemn the practice. Prickly international legislators changed the London Protocol governing such activities last Friday to permit only sanctioned researchers to carry out ocean fertilization and deem all others polluters.
Only one thing is certain in this situation: Scientists and legislators may be reluctant of examining ways to dial down the global thermostat, but they must. The alternative is accepting the climate change as projected, or letting private companies and individuals attempt these methods with unknown results.
Petar Todorov is a senior majoring in chemistry. He can be reached at Petar.Todorov@tufts.edu.