Google is putting a new spin on its global mapping program, with a goal of not just peering into locations around the world but also carefully tracking environmental changes that are under way.

For a few years now, NGOs and environmental groups have been using the satellite imagery available in Google Earth to get their point across. The nonprofit group Appalachian Voices, for example, uses the tool to show the world what mountaintop removal mining has done to their homeland. Defenders of forests throughout the country have also used Google Earth to reveal illegal logging practices.

Now, the tool is poised to become an integral component of the United Nations’ Reducing Emissions from Deforestation and Forest Degradation in Developing Countries (REDD) program.

In broad strokes, REDD allows wealthy countries to pay developing countries to not cut down their trees, by placing a value on the carbon dioxide that those trees sequester and on the host of other environmental services active forests provide, such as wildlife habitats.

It has been a contentious program for a variety of reasons. Indigenous rights groups like Survival International are concerned that making the forests valuable could lead to practices that place forest protection in front of indigenous rights; policy writers worry that REDD will give countries an easy way around legislating carbon emissions; and environmentalists fret that there’s no way to really double-check whether a forest is or isn’t being protected, and that many of the forests covered by REDD were not in any danger of being cut to begin with, rendering moot the emissions reductions gained by protecting them.

Google Earth can’t resolve all of those issues, but it can fix the monitoring problem, and it can go one step further and improve scientists’ understanding of forests and other ecosystems.

At the Copenhagen climate summit late last year, Google unveiled a prototype tool that would allow scientists to run algorithms against the copious amounts of historical and real-time satellite data collected by Google Earth. While that might just sound like just some fancy new web app, it is in fact a game-changer.

“Scientists in Brazil said to us, ‘We can’t monitor the Amazon effectively with our own resources,’” says Rebecca Moore, creator of Google Earth Outreach, a program that exists to help NGOs, indigenous groups and environmentalists figure out how to use Google Earth to their benefit.

“The amount of satellite data that exists about the Amazon — it’s billions of gigabytes — and the science exists to extract meaningful information about forest loss or gain from satellite imagery, but scientists haven’t been able to do that at scale, because just to run one simple change-detecting algorithm over the entire Amazon takes weeks or months.”

Moore says the Brazilian scientists she met in 2008 when she and her team were in the country to present the Portuguese version of Google Earth (and to work with groups who could get the tool to the Amazon’s indigenous tribes) asked if Google would build a platform that could host satellite images for the Amazon, and ideally all forests and ecosystems, and provide access to cloud computing resources.

“That was intriguing to us — we already have the satellite imagery, but we only make it available for viewing, and they were asking us to make it available for analysis so that they could not only see deforestation, but measure it,” Moore says.

The company’s nonprofit arm, Google.org, sponsored a prototype, built with data from Brazil, Peru and a few other countries, and demonstrated it at Copenhagen.

“We found that an algorithm that could take months to do on a desktop could be done in seconds using this tool,” Moore says. “It changes the game completely.”

One of the Brazilian scientists Moore had initially spoken with, Carlos Souza, has used the new tool to build an alert system linked to deforestation. He gets daily satellite imagery and uses an algorithm to determine where there are currently hot spots of suspicious activity. The software then generates an alert, which could be used to mobilize people on the ground in that area, in real time, to prevent further deforestation.

“A significant amount of logging in the Amazon is illegal, but people don’t find out until it’s too late, and then it’s all over,” Moore says. “But if you had a system in place that detected change every day and then could mobilize local NGOs or Greenpeace, for example, they could potentially intervene and stop it from going any further.”

The New Tool: Google Earth Engine

Called Google Earth Engine, the new tool will roll out completely by the next international climate conference planned for Mexico later this year.

In addition to the various algorithms that scientists will be able to create and use in the system, Moore says she expects REDD auditors, policy makers and journalists to be using the tool as well. REDD requires that those receiving compensation for reducing deforestation produce open, transparent and independently verifiable reports on what they are doing.