Watch Earth de-Earthed
Deforestation is the conversion of forested areas to non-forested areas. The main sources of deforestation in the Amazon are human settlement and development of the land. Prior to the early 1960s, access to the forest’s interior was highly restricted, and the forest remained basically intact. Farms established during the 1960s was based on crop cultivation and the slash and burn method. However, the colonists were unable to manage their fields and the crops because of the loss of soil fertility and weed invasion. The soils in the Amazon are productive for just a short period of time, so farmers are constantly moving to new areas and clearing more land. These farming practices led to deforestation and caused extensive environmental damage.
Between 1991 and 2000, the total area of forest lost in the Amazon rose from 415,000 to 587,000 km2, with most of the lost forest becoming pasture for cattle. Seventy percent of formerly forested land in the Amazon, and 91% of land deforested since 1970, is used for livestock pasture. In addition, Brazil is currently the second-largest global producer of soybeans after the United States. The needs of soy farmers have been used to validate many of the controversial transportation projects that are currently developing in the Amazon. The first two highways successfully opened up the rain forest and led to increased settlement and deforestation. The mean annual deforestation rate from 2000 to 2005 (22,392 km2 per year) was 18% higher than in the previous five years (19,018 km2 per year). At the current rate, in two decades the Amazon Rainforest will be reduced by 40%.
Between 1973 and 2006 dramatic changes along the coast of the United Arab Emirates follow the development of Dubai, one of the country’s seven emirates. The country is located along the eastern coast of the Arabian Peninsula where the land tapers to a sharp tip that nearly separates the Persian Gulf to the north from the Gulf of Oman to the south. This trio of images from NASA’s series of Landsat satellites shows the remarkable transformation.
Going back in time, the evidence of human engineering nearly vanishes. In the top image, captured on October 11, 2006, artificial islands shaped like palm trees stretch along the shore. Inland, irrigated vegetation stands out in red (the image is enhanced with infrared light) against the tan-colored desert. Developed areas, including numerous roads, appear cement-colored. In the middle image, captured on August 28, 1990, the number and density of roads and buildings is far less than in 2006. The area to the southwest of image center is particularly less developed. Going all the way back to January 22, 1973, the roads reaching into the desert from the coast are indistinct or absent. Very little development appears to exist along the coast. Empty sand stretches southwestward from the inlet in image center.
The city of Dubai is home to more than 1.2 million people, and it is still growing rapidly. The city’s emergence as a major metropolis and tourist destination is evident in these images.
Once the world’s fourth-largest saline body of water with an area of 68,000 km2, the Aral Sea has been steadily shrinking since the 1960s, after the rivers Amu Darya and Syr Darya that fed it were diverted by Soviet Union irrigation projects. By 2004, the sea had shrunk to 25% of its original surface area, and a nearly fivefold increase in salinity had killed most of its natural flora and fauna. By 2007 it had declined to 10% of its original size, splitting into three separate lakes, two of which are too salty to support fish. The once prosperous fishing industry has been virtually destroyed, and former fishing towns along the original shores have become ship graveyards. With this collapse has come unemployment and economic hardship.
The Aral Sea is also heavily polluted, largely as the result of weapons testing, industrial projects, pesticides and fertilizer runoff. Wind-blown salt from the dried seabed damages crops and polluted drinking water and salt- and dust-laden air cause serious public health problems in the Aral Sea region. The retreat of the sea has reportedly also caused local climate change, with summers becoming hotter and drier, and winters colder and longer.
The plight of the Aral Sea is frequently described as an environmental catastrophe. There is now an ongoing effort in Kazakhstan to save and replenish what remains of the northern part of the Aral Sea (the Small Aral). A dam project completed in 2005 has raised the water level of this lake by two metres. Salinity has dropped, and fish are again found in sufficient numbers for some fishing to be viable. The outlook for the far larger southern part of the sea (the Large Aral) remains bleak.
***(video courtesy of Youtube )