Scientists have teamed up with Google and the U.S. government to create the first high-resolution map of the world’s forests, using detailed satellite imagery to document growth and loss of some of the planet’s key ecosystems over time.

Geographers and climate scientists have been using satellites for a few decades in order to observe the Earth’s surface, but the resulting images were “big, blurry messes,” says Matthew Hansen, a professor of geographical sciences at the University of Maryland who led the research team.

“This project is a really big deal in terms of special detail,” he told Al Jazeera in a telephone interview. “It’s a long-held goal of our discipline to do accurate mapping of Earth’s and the land’s surface and how it changed over time.”

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Using archived imagery captured by a NASA satellite called Landsat, Hansen and his team used Google Earth Engine computing to map a detailed view of global forests at 30-meter resolution that they say is a vast improvement over previous knowledge of forest cover. It has allowed them to quantify forest gain and loss each year from 2000 to 2012, whether from logging, fires or storms. Users of the map have the ability to zoom in on small regions of the globe and see how forest cover has changed over time.

And what the scientists found in terms of deforestation, as detailed in a paper published Thursday in the journal Science, alarmed them. Between 2000 and 2012, some 880,000 square miles of forest were lost, largely in tropical and subtropical areas. Only 309,000 square miles of forest were gained during that period.

What’s more, while the satellite images confirmed that the rate of deforestation in Brazilian rain forests — once the highest in the world — is on the decline, and indeed has been cut in half, “intensive forestry” in developing countries in Africa and Asia more than offset the gains achieved in Brazil.

In fact, tropical climates exhibited a distinct trend of forest loss that increased by 811 square miles each year, the scientists found. That means countries like Paraguay, Malaysia and Cambodia, which had the highest rates of forest loss of all the countries studied, are engaging in massive deforestation to produce items — like timber, soybeans and palm oil — linked to industrial development that the researchers say is harmful to biodiversity.

And closer to home, the team found that 31 percent of the subtropical forests in the Southeastern United States had either been lost or regrown, and that those forests were being disturbed at four times the rate of South American rain forests from 2000 to 2012.