Since our introduction to this planet, we have been replacing nature and other species to become dominant. At the same time, knowingly or unknowingly, we have been transforming this planet into something different. For centuries, we have been clearing forests, rivers and moving animal species from one corner to another; causing many of them to become extinct. Our habits have surely had a severe impact on our planet. For years, NASA has been tracking the major transformations mankind has caused via satellites. Through the series, “Images of Change and World of Change”, NASA shows us before and after photos of locations all around the world. Here are some of the most revealing changes.
1. Shanghai, China, taken on April 23, 1984.
The images captured by Landsat 5 and 8 gives us a glimpse of China’s urban expansion within the last four decades. During the 1980’s, the population of Shanghai was 12 million but in 2016, the numbers drastically increased. Today, the largest city in China has a population of 26.32 million, more than double what it was when the Landsat 5 flew over Shanghai on April 23, 1984.
Another image captured on July 20, 2016, shows the rapid urban expansion over the last four decades:
A closer analysis of these images also shows that the city’s area ballooned from 119 square miles (308 square kilometers) in 1984 to 503 square miles (1,302 square kilometers). During the transformation, the green forests were replaced by concrete buildings, which led to the creation of an urban heat island effect. According to NASA, Shanghai saw an 81% increase in area affected by higher temperatures within the past four decades.
2. Wildfire near Ashland, Kansas. Image captured on March 1, 2017.
On March 2017, a wildfire swept out of control that forced the 850 residents of a rural town to evacuate at a moments notice. “This fire started in Oklahoma and came across the border in southwest Clark County,” said Millie Fudge, Clark County Emergency Preparedness coordinator. “It’s non-stoppable. All we are doing is protecting houses. That is all we can do”.
The same location on March 17, 2017, days after the raging fires:
The burned areas appear black in the image that was captured by the Operational Land Imager onboard Landsat 8. The group of four large fires managed to ravage 780,000 acres and cost millions in damage.
3. Images taken on November 27, 2001 and November 12, 2012 show the rapid expansion of United Arab Emirates.
When it comes to utilizing available land, some countries decided to become creative and expand their ground by reclaiming land from the sea. The images captured by the Enhanced Thematic Mapper Plus sensor onboard Landsat 7 shows the rapid growth of Dubai, in the United Arab Emirates, between 2000 and 2011.
A chain of artificial islands was built within a period of 11 years.
The UAE decided to utilize land at sea by building hundreds of artificial islands along the sea shore. Sand was dredged from the shores to build these islands and are surrounded by rocky barriers that prevent soil erosion. The barriers also protect the artificial islands from the waves. Two of the biggest islands are shaped like a palm tree, which is a symbol of civilization and resilience.
The man-made islands are also one of Dubai’s main attractions, which brings in more than 15 million visitors every year. It is estimated that by 2020, Dubai will have more than 20 million tourists visiting the Emirates every year. The growth of Dubai on land can also be seen through the images above that show barren deserts replaced by irrigated land and roads.
4. Images captured in 2000 and 2007 shows the oil sands boom in Alberta, Canada.
Oil sands are a mixture of sand, water, clay and bitumen. Bitumen is an oil that is too heavy or thick to flow or be pumped. So, it has to be heated or diluted in order to be extracted. It is found within 70 meters (200 feet) of the surface, and a majority of it is found even deeper. By early 2000’s, oil prices started surging and so did the demand. So, companies started to move towards the vast oil sands buried beneath the boreal forests in Alberta, Canada. The image on the left was captured in 2000 by NASA’s Terra satellite, which shows the beginning of oil sand mining near the Athabasca River.
The sand is mined and mixed with hot water to extract bitumen. Once the bitumen is separated, the sand and water mixture is dumped outside. The growth of sand mines and the sand/water mixture dumped can be seen through the image on the right. The mines have a negative impact on the landscape surrounding them, that also adversely affects birds and other animals. Since the growth of mines was rapid within a period of just seven years, Canada’s regulators require that mining companies restore the land once the mining project is completed.
5. A manmade fire rages through the grasslands and woodlands surrounding Etosha National Park.
As humans kept making progress in the field of science and medicine, we would think that by now, we would know how to manage wild-fires at a large scale. When the US Forest Service was established on February 1, 1905, they adopted the strategy of preventing wildfires at all costs. In 1907, the Etosha National Park in Namibia was founded and the forest rangers followed the same strategy; put out wildfires as quick as possible. As it turns out, this was a bad idea.
Savannas need occasional fires to keep the ecosystem healthy, but as the rangers started putting out fires of all sizes at a fast pace, the vegetation started growing, leading to larger and uncontrollable fires. The rangers only understood this by 1981 and today, it is used as a tool to control the ecosystem. However, things can spiral out of control, even when it’s a planned wildfire. The images above, taken on June 5, 2012 and June 16, 2012, show a controlled wildfire spreading out of control ,when strong winds picked up the flames. Fortunately, no animals were harmed.
6. The Aral Sea was once the world’s fourth largest lake. It’s rapidly shrinking due to diversions of the rivers that sustained it.
Situated between Kazakhstan and Uzbekistan, the Aral Sea was once the world’s fourth largest lake. In order to grow cotton in the desert, Soviet engineers began diverting the two rivers that sustain it. Within a century, the lake had lost 80% of its water and most of the fish. By 2005, more than 60,000 people lost their jobs, as fishermen depended on the lake to survive. By 2009, NASA’s Terra Satellite recorded that the lake had lost an additional 80% within just three years.
According to NASA: “As the lake dried up, fisheries and the communities that depended on them collapsed. The increasingly salty water became polluted with fertilizer and pesticides. Blowing, salty dust from the exposed lakebed became a public health hazard and degraded the soil. Croplands had to be flushed with larger and larger volumes of river water”. Today, it is roughly 10% of its original size. The images above shows the Aral Sea as seen in 2000 and 2014, taken by the Moderate Resolution imagine Spectroradiometer (MODIS) on board NASA’s Terra satellite.
7. Images taken on July 28, 1986 and July 2, 2014 show Alaska’s Columbia Glacier rapidly receding.
Alaska’s Columbia Glacier was discovered in 1794. When British explorers surveyed the glacier, they discovered that its nose extended to the northern edge of Heather Island, near the mouth of Columbia Bay. Until 1980, the glacier held that position and by 1986, it began to retreat rapidly. The images captured above by the Thematic Mapper onboard Landsat 5 on July 28, 1986, and the Operational Land Imager onboard Landsat 8 on July 2, 2014, shows how much the glacier has retreated. Today, it is one of the fastest receding glaciers in the world.
According to NASA, “The glacier has thinned so much that the up and down motion of the tides affects its flow as much as 12 kilometers (7.5 miles) upstream, until the glacier bed rises above sea level and the ice loses contact with the ocean”.
8. Images captured on January 31, 2002 and February 17, 2002 show how fast Antarctica’s Larsen B ice shelf is disintegrating.
In the summer of 2002, scientists monitoring daily satellite images of the Antarctic Peninsula noticed something unusual. In just over one month, the entire Larsen B Ice Shelf splintered and collapsed; 3,250 square kilometers, or 1,250 square miles disintegrating rapidly. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured the images above, which shows the leading edge of the C-shaped shelf splintering. According to NASA, the shelf collapsed due to a series of unusually warm summers, that created melt ponds that acted as wedges and sped up the disintegration process.
While the ice shelf disintegrating does not raise the sea levels, the ice behind these massive sheets on the land can. When an ice shelf disintegrates, the ice behind it can start melting and flow into the sea quickly; raising sea levels.
9. The United States tackling air pollution over a period of six years.
Not everything that’s happening in our planet is negative. The Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite collected data over a period of 10 years, which shows how the United States is tackling air pollution by reducing nitrogen dioxide emissions. Nitrogen dioxide (NOx) contributes to the formation of photochemical smog, which is known to cause significant impacts on human health. According to the U.S. Environmental Protection Agency (EPA), NOx is one of the six common pollutants that are regulated.
NOx is formed during gas combustion in vehicles and coal is burned in power plants. With more than 276 million cars and 222 million licensed drivers, one would think that the pollutants would only increase. The reason for the rapid decrease in air pollutants such as NOx is due to the regulations implemented by the EPA, technology improvements and economic changes.
Images captured by Aura satellite shows how much NOx has been reduced within a period of six years. The first image was captured in 2005, which shows the NOx level to be high (red) and the second image was captured in 2011, that shows the NOx level to be low (blue). The EPA first started cracking down on carbon emissions and NOx levels in 1971 to achieve the significantly positive result.
10. Dry Summers cause Iran’s Lake Urmia to dry out and change its color.
During the 1970’s, Lake Urmia was twice as large as Luxembourg and the largest salt-water lake in the Middle East. Iran was proud of the lake but by 2008, the lake lost half its size and today, it has shrunk by nearly 90%. In 2008, a 9 mile (15 kms) road was made to shorten the travel time between the cities of Urmia and Tabriz. This however, had a severe impact on the lake and the eco system surrounding it. The images taken on April 23, 2016 and July 18, 2016 by the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard NASA’s Aqua satellite, shows how fast the lake is drying.
The color changed from green to red due to the combination of algae and bacteria that is rapidly developing within the lake. The lake once attracted thousands of tourists from all over the world but today, it’s nothing more than a vast salt-white barren land with beached boats.