Could urea be a savior when it comes to reducing atmospheric carbon dioxide? By now we all know about injecting urea into diesel engine exhaust to reduce emissions of nitrogen oxides. An Australian company has now received permission from the government of the Philippines to dump urea into the Sulu Sea of that country's coast.

However, this isn't just a scheme to dump waste offshore. This is actually being done in an attempt to mitigate global warming. The idea is pour the urea into the water to promote plankton growth, because plankton absorb a lot of atmospheric carbon dioxide as they grow. In theory this should be a good thing. In practice, however, little is understood about the possible side-effects of the plankton growth. But of course those sorts of side-effects never happen in the real world. Do they? This seems like a prime candidate for the law of unintended consequences.

More on plankton:

• Using geoengineering to combat climate change?
• One more feedstock to consider: biofuel from plankton

[Source: Wired]

Biofuels are often criticized for using too much land that could otherwise be used for farming food. Turns out, one of the better sources of biofuels, acre for acre, is algae and it grows great where real estate is a steal: the sea! There are also fresh water algae fuel projects and there have been tests conducted using iron to cause algae blooms in the ocean, a wacky solution to global warming. Researcher John Munford did some number crunching and an algae farm the size of the North Sea (pictured) could produce enough fuel to replace all the fossil fuels we use today. There are real questions of how to harvest algae in the sea but whoever cracks that nut will be rich. There is simply not enough land to spare to grow biofuel crops economically. But, wiht the Earth being 70 percent ocean, I think of that moment in The Graduate: if you are a smart, young, kid not sure where to focus your research, I got two words for you: saltwater algae. That's how it went, right?

Related:

• How about mobile carbon capture to feed algae for biodiesel?
• Boeing likes algae as a source for new biofuels
• GreenFuel's algae to biofuels technology growing soon in South Africa

[Source: The Economist]

In a report in the Geophysical Research Letters (GRL), a team of scientists says that carbon-dioxide induced "changes in ocean chemistry within the ranges predicted for the next decades and centuries present significant risks to marine biota" and that "adverse impacts on food webs and key biogeochemical process" would result. The problem is severe enough that the CO2 content in our water could violate EPA water quality criteria standards set back in 1976 within a few decades if drastic steps to curtail our CO2 emissions are not taken. Why is this so serious? From our source article:

"About 1/3 of the CO2 from fossil-fuel burning is absorbed by the world's oceans," explained lead author Ken Caldeira from the Carnegie Institution Department of Global Ecology. "When CO2 gas dissolves in the ocean it makes carbonic acid which can damage coral reefs and also hurt other calcifying organisms, such as phytoplankton and zooplankton, some of the most critical players at the bottom of the world's food chain. In sufficient concentration, the acidity can corrode shellfish shells, disrupt coral formation, and interfere with oxygen supply. "

According to the EPA report from 1976, CO2 concentrations must remain below 500 ppm or else the pH (potential of Hydrogen) levels will be too low, making the water acidic. An effort must be made to avoid this scenario, and our emissions of CO2 must be cut drastically in short order to keep from damaging our waters.

[Source: Carnegie Institution]