Watch four decades of planetary change on Google Earth

16 Apr 2021

Image: Google Earth

In Google Earth’s biggest update in years, users can now witness how our planet has changed between 1984 and 2020.

A few years back, Google Earth Timelapse introduced us to a whole new way of looking at the planet – through time. It used 5m satellite photos from between 1984 and 2016 to create a video that let you see how the Earth had changed over the course of 32 years.

Now, in its latest update, Google Earth has gathered 24m satellite photos from the past 37 years to create an interactive 4D experience. Google said users can now “watch time unfold and witness nearly four decades of planetary change”.

It highlighted a number of interesting changes that users can see in its time-lapse videos, such as the expansion of Las Vegas in Nevada and the pace of agriculture in the middle of a desert in Al Jowf, Saudi Arabia. Users can browse 2D and 3D videos covering changing natural landscapes, urban expansion and more.

Timelapse was developed with experts at Carnegie Mellon University’s CREATE Lab. They also helped Google examine emerging themes in the time-lapse data, which included forest change, urban growth, warming temperatures, sources of energy and “our world’s fragile beauty”.

The tech behind Timelapse

Since its launch 16 years ago, Google Earth has allowed users to view a 3D replica of the world.

Google said that “pixel crunching” in Earth Engine – its cloud platform for geospatial analysis – was necessary for developing a planet-sized time-lapse video. The 24m satellite photos were collected between 1984 and 2020, representing quadrillions of pixels.

“It took more than 2m processing hours across thousands of machines in Google Cloud to compile 20 petabytes of satellite imagery into a single 4.4 terapixel-sized video mosaic,” the company said, adding that this is the equivalent of 530,000 videos in 4K resolution.

The team removed artefacts from the imagery, such as clouds, and computed a single pixel representing every location on the planet and for every year in the timeframe. Time-lapse videos were then “draped” over the planet using advanced 3D graphics rendering techniques.

Google said it will collaborate with its partners to update Google Earth with new Timelapse imagery every year for the next decade. “From governments and researchers to publishers, teachers and advocates, we’re excited to see how people will use Timelapse in Google Earth to shine a light on the issues facing our planet,” it said.

“We hope that this perspective of the planet will ground debates, encourage discovery and shift perspectives about some of our most pressing global issues.”

Lisa Ardill was careers editor at Silicon Republic until June 2021