Permanent removal of greenhouse gases out of the Earth's atmosphere

https://www.virgin.com/content/virgin-earth-challenge-0

http://en.wikipedia.org/wiki/Virgin_Earth_Challenge

The Virgin Earth Challenge is a competition offering a $25 million prize for whoever can demonstrate a commercially viable design which results in the permanent removal of greenhouse gases out of the Earth's atmosphere, so as to contribute materially to avoid global warming. The prize was conceived and financed by Sir Richard Branson, a successful British entrepreneur, and was announced in London on 9 February 2007 by Branson and former US Vice President and 2007 Nobel Prize winner Al Gore, creator of the 2006 film An Inconvenient Truth on climate change.

Among more than 2600 applications, 11 finalists were announced on November 2, 2011. These are Biochar Solutions, from the US; Biorecro, Sweden; Black Carbon, Denmark; Carbon Engineering, Canada; Climeworks, Switzerland; Coaway, US; Full Circle Biochar, US; Global Thermostat, US; Kilimanjaro Energy, US; Smartstones - Olivine Foundation, Netherlands, and The Savory Institute, US.

The challenge

The Prize will be awarded to "a commercially viable design which, achieves or appears capable of achieving the net removal of significant volumes of anthropogenic, atmospheric GHGs each year for at least 10 years", with significant volumes specified as "should be scalable to a significant size in order to meet the informal removal target of 1 billion tonnes of carbon-equivalent per year". It should be noted that one tonne of carbon-equivalent (C) equals 3.67 tonnes of carbon dioxide (CO2). (Because of the relationship between their atomic weights, more precisely 44/12.) At present, fossil fuel emissions are around 6.3 gigatons of carbon.

The prize will initially only be open for five years, with ideas assessed by a panel of judges including Richard Branson, Al Gore and Crispin Tickell (British diplomat), as well as scientists James E. Hansen, James Lovelock and Tim Flannery. If the prize remains unclaimed at the end of five years the panel may elect to extend the period.

Around two hundred billion metric tons of carbon dioxide have accumulated in the atmosphere since the beginning of the industrial revolution, raising concentrations by more than 100 parts per million (ppm), from 280 to more than 380 ppm. The Virgin Earth Challenge is intended to inspire inventors to find ways of bringing that back down again to avoid the dangerous levels of global warming and sea level rise predicted by scientific organisations such as the Intergovernmental Panel on Climate Change.