New satellite alerts reveal how forests changed this month

With data from satellites, there is generally a trade-off between resolution and the frequency of updates – that's why most of the alerts already on Global Forest Watch are 500- or 250-meter resolution.

The GLAD alerts are breaking this convention to give us the best of both worlds: The alerts are higher resolution and more frequently updated than other alerts. They are fine enough to detect loss from activities like logging, illegal mining, and small-holder agriculture, all major drivers of deforestation that were previously too small-scale to be picked by alert systems on Global Forest Watch.

The alerts are also the closest to real time we have available. New alerts are triggered with every new, cloud-free Landsat image (as often as every eight days for any particular location) and are updated weekly on the website.

To learn more about the alerts read the full methodology paper, published today in Environmental Research Letters.