Iron from Melting Ice Sheets May Buffer the Effects of Global Warming

A newly discovered source of iron from melting ice sheets may help buffer the effects of global warming.

It is well known among the scientific community that bioavailable iron boosts phytoplankton growth in many of Earth's oceans. What possibly some don't realize is that phytoplankton capture carbon in the atmosphere, thus combating global warming's harmful carbon emissions.

The plankton also feed into the bottom of the oceanic food chain, thus providing a food source for marine animals.

A UK team, responsible for the discovery, collected meltwater discharged from the Leverett Glacier in Greenland during the summer of 2012, which was subsequently tested for bioavailable iron content. They found that water melting from the ice sheets contained significant amounts of iron, a fact that had previously been unrealized.

"The Greenland and Antarctic Ice Sheets cover around 10 percent of global land surface," lead author Jon Hawkings added in a statement.

Iron is the fourth most abundant element in Earth's crust, but it is usually not biologically available because it's present in unreactive minerals in natural waters.

In the past there has been some controversy about iron's role in the environment. Some had even taken to dumping the mineral right into the oceans to boost phytoplankton growth and thereby capture more carbon dioxide to help the planet.

This research indicates that Mother Nature does this sort of dumping naturally via melting ice sheets.

Based on results, researchers estimate that 400,000 to 2,500,000 tons of iron is unloaded annually in Greenland, and 60,000 to 100,000 tons per year in Antarctica. This is the equivalent to the weight of around 125 Eiffel Towers, or around 3000 fully-laden Boeing 747s being added to the ocean each year.

"This is a substantial release of iron from the ice sheet," Hawkings commented.

Although, this iron release will be localized to the Polar Regions, and it is unclear as to how much additional iron will be carried down from ice sheets into the sea.

The findings were published in the journal Nature Communications.