NASA, in cooperation with TIME and Google, has unveiled startling timelapse images of Earth from orbit collected by NASA's Landsat program since 1984. This program, created not for spycraft but for monitoring the way in which humans are rapidly altering the surface of the planet, consists of eight satellites that have collected millions of pictures in the course of two generations. When sifted through, cleaned up and stitched together, these pictures come together to create a high-definition slideshow that reveals some of the drastic changes our planet is undergoing - most notably through widespread urbanization.
The story of the past century has been the not-so-gradual migration of people from the rural countryside to the city, first in the West and now in South America, the Middle East, Africa and Asia. It is in the developing world that these migrations can be seen and felt the most, with villagers moving into continuously-expanding megacities that swell with skyscrapers and slums alike.
2008 was the first year in which more than half of the world's population lived in cities, and that number is quickly rising. Right now 3% to 5% of the world’s surface qualifies as urban, but urban territories are expected to expand by more than 463,000 sq. miles (1.2 million sq. km) by the year 2030, eventually covering about 10% of the planet. More than 75% of that increase is expected to occur in Asia alone, especially in countries like China which already has more than 160 cities with at least 1 million people. The urbanization wave will be even larger in Africa, where urban area - which amounted to only 16,000 sq. miles (41,000 sq. km) in 2000 - is predicted to grow by 590% (Google Timelapse).
Shanghai, featured in the above timelapse, is probably the best example of out-of-control growth. The city's population has grown from 13.3 million in 1990 to over 23 million in 2010 with new urban settlements sprawling out from the historic city center in every direction, most famously across the river where futuristic skyscrapers dot the landscape. With limitless urbanization, however, come consequences: air pollution, traffic and water contamination.
In Dubai's timelapse, we see a metropolis rising out of the desert sands, growing in population from a mere 300,000 in the 1980's to more than 2.1 million today. With the construction of the tallest skyscraper in the world and even artificial, palm-tree shaped islands out into the sea, Dubai has become a city of glamor and grandeur not only for the Middle East but for the entire globe. But, as always, the show comes with a cost: inefficient waste treatment, scarcity of electricity and the negative effects of water desalination.
Another desert city that is eating up resources is the US's very own Las Vegas, also featured in the timelapse. Its population growth is very similar to that of Dubai's, expanding from a little under 500,000 in 1980 to about 2 million now. From 2000 to 2010, the city’s population grew by nearly 50% and in the outward direction as more and more housing developments popped up, many of which suffered foreclosure in the recession. In addition to being economically unsustainable, Vegas is also one of the least environmentally sustainable cities in America, receiving almost no rainfall and relying entirely on nearby Lake Mead, where water level has fallen from over 1,200 ft. (365 m) to 1,125 ft. (343 m). The lake's shrinkage can be clearly seen in the timelapse.
As frightening as this urbanization and densification may seem, it can have its benefits if handled correctly. As cities become more compact, people use less energy and should have a much lower carbon footprint. They are also less likely to have large families, curbing overpopulation. If anything, Google's Timelapse sequences can help everyone from the average college student to the megacity planner better understand the positive and negative effects of recent case studies and the potential betterment of future cities on our planet.