Several years ago, I stumbled on a map so shocking to my modern workaday sensibilities that I couldn’t quite believe my eyes. “Oh, zounds, look at this old thing,” I almost certainly thought.


A global methane composite created by Laura Mazzaro at Descartes Labs using Sentinel-5P data. It shows average measured levels in the atmosphere from January to August, 2019. Brighter areas represent higher registrations of methane. Darker areas represent either low methane concentrations or no data. Curious why the Sahara is so bright? Read on below.

The European Space Agency’s launch of the Sentinel-5P satellite in October of 2017 ushered in a new era of atmospheric monitoring from space. The instrument provides near-daily global measurements of ozone, NO₂, SO₂, formaldehyde, aerosol, carbon monoxide and, crucially, methane, a substantial component of global greenhouse gas emissions.

The enormous insight that Sentinel-5P provides into planetary emissions is extraordinary — but there’s a catch. Because, while some of these gases are relatively easy to measure from space (and drawing conclusions from their measurements is thus a fairly straightforward exercise), other gases are not so cut and dry.


A sampling of maps featured in advertisements in Fortune magazine, 1930s-1960s.

☞ I explicitly excluded any overtly offensive images from this rundown that I could identify. Even so, some of the subject matter (as well as their occasionally unnecessary embellishments) may strike modern audience members as inappropriate. The images are a reflection of both their era and medium (magazine advertising). While it is not my intention to romanticize these images, my hope is that, with their historical context in mind, they collectively tell a story worth considering about the way Fortune’s advertisers chose to depict the world throughout decades of global change.

Fortune magazine is known for its rich legacy of…


Illustrations from U.S. Patent Office filings for globes and robots.

Let’s cut to the chase. Artificial Intelligence (A.I.) is a buzzword that is applied to so many things that it almost has no meaning at all.

What isn’t A.I. these days?

We have A.I. on our phones and in our homes. (“Hey Siri, tell me how Alexa defines, ‘Ok, Google.’” … … 💥). We have endless videos of humans laughing at or “tormenting” robots in our social media feeds. A.I. has been a prominent thread in Hollywood for decades. It’s a whole big, sprawling phenomenon that can essentially be defined as any computer system with the ability to achieve goals…


Albrecht Dürer to Agnes Denes: 100+ map projection illustrations and explainers (of various accuracies and precisions).

World map (cordiform, or heart-shaped, projection) | 1511

Kilauea lava flow as seen by Landsat 8 at night on June 24, 2018.

You know that feeling of desperation you get when you walk into a darkened movie theater in the middle of a beautiful sunny day and you can’t see a darn thing?

Ohhh, I think I see the exit sign! But where the heck are the seats? WHY IS THIS TRAILER SO GLOOMY?!

Then you play chicken with your date. No, YOU pick our seats! And you proceed, hoping beyond hope that you don’t accidentally sit on someone’s jumbo Pibb Xtra (formerly known as Peppo, apparently).

Without getting into eyeball mechanics, you’re having trouble seeing because your eyes are primed for…


Nikhil Sharma at Descartes Labs created a global composite of Nitrogen Dioxide (NO₂) over August and September of 2018. Here, the highest levels of NO₂ are shown first and the rest fade in slowly. No, this is not just another population map.

Unless you completely avoided modern society in August and September, you helped make this map.

If you were in a car, bus or train with a combustion engine, if you were in an electric vehicle that was charged using non-renewable energy or if you consumed something that was shipped to you on an actual ship—chances are, you contributed to this global composite of nitrogen dioxide (NO₂) made using data from ESA’s Sentinel-5P satellite.

NO₂ is a nasty-smelling, gaseous pollutant that is mostly the byproduct of the combustion process. It is, unsurprisingly, not good for you.

In a city, almost all…


Descartes Labs built a machine learning model to identify tree canopy globally using a combination of lidar, aerial imagery and satellite imagery. Above are trees nestled around Baltimore highway interchanges.

Note: This post was updated on January 3, 2019 to clarify that lidar was used as ground truth data to train the model only. Lidar is not needed to run the model; it requires only ~1m resolution four-band imagery (near infrared, red, green and blue) as inputs.

Much fuss has been made over city trees in recent years. Urban trees reduce crime and help stormwater management (yay!). Cities and towns across the U.S. are losing 36 million trees a year (boo!). But, hold up—climate change is accelerating the growth of urban trees in metropolises worldwide (boo/yay?). Urban trees are under…

Tim Wallace

Geographer

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