Street lamps along a dark and lonely highway, towering skyscrapers, and flares burning on top of an oil rig — these are some of the things that illuminate the otherwise dark night sky.
They can also be seen from space.
In April, NASA scientists released the clearest and most detailed images of human settlements across the globe at night. And you can see below what the world looked like as of 2016.
There are clusters of lights along booming coasts and on naval bases in the middle of the ocean. There are also large swaths of the world in relative darkness.
John Nelson, a cartographer at Esri, a digital mapping company, was curious what these lights could tell us about how the world around us had changed over time. Had some areas grown brighter while others had dimmed? And if so, he wondered, what was behind these changes?
So Nelson used NASA’s satellite images from 2012 and 2016 and calculated the difference in light pixels to see which areas of the world had grown more luminous and which areas went dark.
The resulting maps shows where lights have increased in blue and where lights have diminished in pink in the past five years.
You can see areas of Southeast Asia have become increasingly electrified, while areas of Western Europe have actually grown darker (which Nelson attributed to less light pollution and more efficient lighting technology).
But as Nelson told me, the reasons why an area grows dimmer or brighter is an odd mixture of progress and setbacks.
“When the lights go dim, it’s weird,” he said. “People could be taking initiative to reduce nighttime pollution … but on the other hand, sometimes whole cities are gone, or people have left and electrical infrastructure has been knocked out.”
To see what nighttime illumination and light density can tell us about the world, Nelson zoomed in on specific locations. Here are some of the most fascinating findings.
1) Rural areas in India get electrified
The bright blue clusters in this image are areas that emanated significantly more light in 2016 than they did in 2012. The reason India has so many glowing blue blobs? The Indian government undertook a massive effort to electrify the country starting in 2003, and it appears to now be paying off.
In 2014, the World Bank estimated that nearly 75 percent of India’s 1.3 billion people had an electrical connection and that renewable energy made up 12 percent of the country’s electrical grid.
But nearly 300 million Indians are still without electricity, according to the World Bank, and as the Economic Times in India pointed out, the definition of “electrified” in India still has a long way to go. (The government’s definition only mandates schools, health centers, and other public spaces in addition to at least 10 percent of homes be electrified to qualify.)
2) In America’s heartland, suburban areas are dimming, while oil rigs are brightening West Texas
There’s a lot going on in the map above — Texas cities like Houston and Fort Worth are outlined and an almost purple hue emerges, showing both light lost and light gained.
Nelson said it’s not entirely clear what is happening across the US when it comes to fewer nighttime lights, but speculated that we’re seeing a combination of attempts to reduce light pollution in some areas and economic depression in others.
But in West Texas, we’re actually seeing a huge boom in nighttime lights — that’s the bright blue speck you see above. And the reason is oil. According to Baker Hughes, a research company that collects data on the US oil industry, almost two-thirds of new rigs added last year were located in either West Texas or eastern New Mexico.
The reason oil rigs are so visible in the nighttime sky is because they are often topped with a flare stack — or an open gas flame. While this might sound wasteful or even dangerous, they’re actually a critical safety feature that helps release pressure and reduce the risk of explosion.
3) More offshore drilling along the West African coast
Another development that caught Nelson’s eye was increased illumination in the world’s oceans — particularly along the West African coast, spanning from Nigeria to Angola.
What’s causing Africa’s shoreline to light up at night (even more so than the interior)? Thousands of oil rigs dotting the night sky.
Nigeria has been a leading oil producer in the region for years and at the center of many different corruption controversies involving crude oil theft from the state. But now the change in lights can literally show us where companies are moving up and down the coast, seeking new places to drill for oil.
4) The toll of the ongoing civil war in Syria
The Syrian civil war is a complicated, messy ongoing saga that began in 2011 when Syrians revolted against President Bashar al-Assad’s government as part of the Arab Spring protests against dictators in the Middle East. The death toll in Syria from the war has now climbed into the hundreds of thousands.
And as you can see in the map above, the destruction has been extensive, as the region is now eerily dark at night. But nearby areas in Jordan, Iraq (excluding war-torn areas in the north), and Turkey appear to have become more densely illuminated as people flee, seeking refuge from the ongoing fighting.
According to the United Nations High Commissioner for Refugees (UNHCR), 11 million Syrians have fled their homes since 2011. And of those 11 million, 4.8 million have fled to Turkey, Lebanon, Jordan, Egypt, and Iraq.
5) Puerto Rico’s economic decline
In the map above, Puerto Rico is that tiny island that is now entirely pink, meaning it has lost a significant amount of nighttime light in the past five years. But why has the island suddenly gone dark?
Financial hardship and a concerted effort to reduce light pollution. Miguel Román, a scientist at NASA’s Goddard Space Flight Center, told the Puerto Rican newspaper El Nuevo Día that they’d observed a greater use of energy efficient LED lights in individual homes. But Román also noted that many families may be cutting back on energy use because of tough economic times in the country.
Just this May, Puerto Rico filed for bankruptcy relief in federal court, making it the first state or territory to do this in American history. And according to the New York Times, the island’s financial situation is dire. Puerto Rico is roughly $123 billion in debt, which far exceeds Detroit’s bankruptcy in 2013 for $18 billion.
6) Some areas, like North Korea, are still off the grid
North and South Korea separated at the end of World War II in 1945 and have remained divided as the result of failed Cold War negotiations. The image here reveals a stark dividing line, with the South heavily illuminated and the North almost entirely shrouded in darkness.
For areas where there was no change in light, Nelson made the background transparent so the satellite imagery could be clearly seen. This means the dark North Korean night sky (excluding the sole bright dot that is capital of Pyongyang) isn’t a recent development — it has been shrouded in darkness for a long time now.