Carbon dioxide is now gushing into Earth's atmosphere at the fastest pace in human history, trapping heat that fuels global warming. But higher temperatures and stronger storms are only part of the problem: Manmade CO2 emissions are also absorbed by Earth's oceans, making them roughly 30 percent more acidic in the past 250 years.

Scientists know this is killing coral reefs and dissolving the shells of marine animals, but the overall danger of ocean acidification is still poorly understood. To fix that, the X Prize Foundation announced a new bounty this week: $2 million for anyone who can figure out how to figure out what all this extra CO2 is doing to the pH of our planet's oceans.

Named the Wendy Schmidt Ocean Health X Prize, the 22-month competition is scheduled to kick off in early 2014 and name its winner(s) in 2015. The $2 million jackpot is divided into two purses, which can be won separately or by the same team. The X Prize Foundation provides this description of the potential winnings on its website:

  • Accuracy award ($750,000 first place, $250,000 second place): To the teams that navigate the entire competition to produce the most accurate, stable and precise pH sensors under a variety of tests.
  • Affordability award ($750,000 first place, $250,000 second place): To the teams that produce the least expensive, easy-to-use, accurate, stable and precise pH sensors under a variety of tests.
This is the latest of many such trophies from the X Prize Foundation, which launched in the 1990s with a $10 million contest aimed at spurring commercial space travel. (It was inspired by the Orteig Prize, a $25,000 jackpot won by aviator Charles Lindbergh when he flew across the Atlantic Ocean in 1927.) The original X Prize went to aerospace firm Scaled Composites in 2004, whose technology is now part of Virgin Galactic's SpaceShip Two.

The new award is also the second environmental-themed collaboration between X Prize and philanthropist Wendy Schmidt, the wife of Google executive chairman Eric Schmidt. The two previously worked together on the $1 million Wendy Schmidt Oil Cleanup XChallenge, a response to the 2010 Deepwater Horizon oil spill that focused on more efficient ways to remove crude oil after it spills or leaks into seawater.

"Ocean acidification is a serious threat we are only beginning to understand," Wendy Schmidt says in a press release about the latest prize. "It could have significant ecological and societal implications, changing the health of entire ecosystems, affecting the global economy and the biodiversity of the planet. As we did with the Oil Cleanup XChallenge, we aim to inspire innovators around the world to get behind the creation of better, more efficient methods to monitor and measure ocean health, and ultimately to improve it."

Earth's oceans are still slightly alkaline, not acidic, but their pH levels have been falling in recent centuries as humans release unprecedented amounts of CO2 by burning fossil fuels. Roughly 8 billion tons of CO2 are now absorbed by seawater every year, creating carbonic acid that has driven surface pH levels from an estimated 8.25 in 1751 to 8.14 in 2004. Some climate models forecast another 150 percent rise in ocean acidity by 2100.

CO2 absorption by seawater can be fatal to coral, shellfish and other marine animals. (Source: NOAA)

This poses serious risks both to ocean ecology and human economies. Some 2 million plant and animal species depend on coral reefs to survive, and the U.N. estimates about 30 million people also directly rely on reefs for food and income. Corrosive seawater endangers a wide array of other animals that grow seashells, too, from tiny plankton to oysters and clams. Oyster farms in the U.S. Pacific Northwest, for example, have recently suffered major collapses that scientists link to declining pH levels.

Yet much of the problem remains shrouded in mystery, due to a dearth of cheap, accurate sensing technology that can be deployed all around the world. Scientists still lack important information about the speed and regional patterns of ocean acidification, a void that Schmidt and X Prize hope to fill by luring the Charles Lindbergh of ocean sensing.

"Just as we have sensors to monitor our body's vital signs, we need a device to help determine the acidity of our oceans before we can determine the best solution to improve its health," says X Prize's Paul Bunje. "To accomplish this, we hope to incent innovators around the world, across disciplines, to compete for this prize not only for the ecological benefits, but for the market potential worth far more than the prize purse itself."

Related ocean acidification stories on MNN:

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.

New X Prize: $2 million to track ocean acidity
The X Prize Foundation is offering a small fortune for answers about ocean acidification.