Could Iron From AMD Help Reduce Global Warming?
by Andy McAllister, Watershed Coordinator
To those of us involved in Abandoned Mine Drainage (AMD) remediation, iron deposits and iron sludge are a fact of life. In fact, most of us are either busy trying to get the iron out of our creeks or find innovative ways to re-use the iron. However according to some, iron could be used to reduce Global Warming.
As concerns about Climate Change increase, people continue to look for new ways to lessen the amount of carbon dioxide in our atmosphere. Carbon dioxide, a gas known to promote global warming, is also called a “greenhouse gas”. This strategy of reducing carbon dioxide is known as “carbon sequestration” or carbon capture.
Because all growing vegetation absorbs carbon dioxide, promoting plant growth (eg. planting more trees) is just one method of carbon sequestration that is encouraged. A specific type of plant, the marine algae, also absorb carbon dioxide. Experiments using iron to promote phytoplankton (oceanic algae) blooms have been going on for several years and the laboratory results have shown some correlation between increased iron levels and phytoplankton growth.
Iron is just one of many substances that are important for phytoplankton growth. Iron levels in the ocean are naturally very low, and it is thought that phytoplankton growth tends to be limited because of these low iron levels. The experiments with iron and phytoplankton show that when iron levels increase, the phytoplankton populations increase dramatically (and so does their absorption of carbon dioxide). Recently, this controversial subject has resurfaced in the environmental headlines where researchers are once again, talking about dumping iron into the oceans to create algae “blooms”. The logic is this: by promoting oceanic algae blooms, we can increase absorption of atomospheric carbon dioxide and thereby reduce the levels of that particular greenhouse gas throughout the globe.
Today, we offer you links to several articles on the subject as food for thought.
“Fertilizing the Ocean with Iron” from CHEMICAL AND ENGINEERING NEWS
“Ocean Carbon Fix Using Iron Is Unproven, Marine Scientists Say” from Bloomberg.com
“Ocean Gardening Using Iron Fertilizer” from ProQuest/CSA