An online "game" could engage citizen scientists to help improve knowledge of the sources of greenhouse gases, Arizona State University scientists say. The online effort on a website called Ventus (Latin for wind) has a simple interface in which users enter basic information that will help climate scientists locate all the power plants around the world and quantify their carbon dioxide emissions, a university release said Wednesday. ASU researchers estimate there are as many as 30,000 power plants around the world burning fossil fuels. While a list of those facilities does exist, scientifically accurate information needed to map each power plant's location and carbon dioxide emissions does not. "Of all the fossil fuel CO2 emissions in the world, power plants account for almost half -- so a pretty big portion of the climate change problem is due to the production of electricity everywhere in the world," climate scientist Kevin Gurney said. "While you might imagine that we would know where they are and how much they're emitting, it turns out we don't. With the growth in countries such as China, India and Brazil, this lack of information poses challenges for both basic science and climate change solutions." Ventus participants who know the amount of CO2 emissions from a specific power plant have valuable information to contribute, the researchers said, and often can provide three other pieces of vital information: the location of the facility (within a few hundred yards,) the fuel used and the amount of electricity produced. "Ventus uses a Google Earth map which allows someone playing the game to drop pins on the power plants," said Darragh O'Keefe, the ASU research scientist who built the website. "Our logic is that for every power plant in the world, there are probably at least a dozen people who live near it, work at it, or know someone who works at it. "With the proliferation of phones and GPS, it makes it pretty easy to locate things."