Google has launched a satellite imagery tool that it says will make an unprecedented amount of environmental data available freely online.

The Earth Engine aims to enable scientists to monitor and measure changes in the Earth's environment, such as global land cover, and hopefully help slow deforestation in the process.

“The images of our planet from space contain a wealth of information, ready to be extracted and applied to many societal challenges,” says Google on its official blog.

“Scientific analysis can transform these images from a mere set of pixels into useful information—such as the locations and extent of global forests, detecting how our forests are changing over time, directing resources for disaster response or water resource mapping.”

The site will be a repository for satellite and other spatial data from around the world.

Google said at the Cancun climate conference that it plans to donate ten million CPU-hours a year over the next two years to the Google Earth Engine platform, to strengthen the capacity of developing world nations to track the state of their forests and land.

The platform includes Landsat satellite data archives from the last 25 years for most of the developing world as well as other datasets including MODIS. It will soon offer a complete global archive of Landsat.

Google released a prototype version of the platform at the climate talks in Copenhagen last year.

The platform is seen as important because it will give developing countries a way of measuring deforestation.

Talks in Mexico have revolved around developing a methodology for allowing developed countries to pay to prevent deforestation in developing countries.