Glaciers are melting, seas are disappearing, cities are growing - this is what NASA satellite images show. These allow us to look at how humans are changing landscapes around the world. These are before and after photos that prove how quickly our planet is changing.
A little over a century ago, one of the first explorers took the first photographs of the glacier Muir in Alaska, in the same location that is unrecognizable today. By 2005, the glacier had completely shrunk and disappeared from view, the mountains covered with trees instead of snow and ice.
These photos are part of a collection Images of Change, exhibited by NASA in 2009. Each week, a team of researchers sifts through NASA's photo collection and photos of places and landscapes that are being created on the fly to select ones that demonstrate how fast cities are growing and how fast we are changing the landscape, or what impact climate change has on all of this.
Not every change is negative; a couple of pictures show how forests are growing back in Uganda and a couple of pictures show how air pollution is slowly disappearing in certain places in the USA.
READ MORE: Is this what the world will look like in the future?
Check out some before and after photos in the gallery that prove how quickly our planet is changing.
The Aral Sea in Central Asia, which has completely dried up - the photo on the left was taken in 2000, and the photo on the right was taken in 2014.
Beijing: Beijing's population rose by 17 million over the years - the left photo was taken in 1977 and the right photo was taken in 2011.
Glacier in Alaska - the left photo was taken in 1986 and the right photo was taken in 2014.
The dust of the Mongolian desert, which traveled all the way to Colorado along with the polluted air.
Muir Glacier, Alaska - left photo taken in 1890, right photo taken in 2005.
Lake Powell, USA, which has dried up - the left photo was taken in 1999, the right photo was taken in 2014.
Lake Chad in Africa has shrunk as much as twenty times - the left photo was taken in 1972, the middle photo was taken in 1987 and the right photo was taken in 2002.
Lake Mar Chiquita in Argentina is shrinking and becoming saltier due to drought - the photo on the left was taken in 1998 and the photo on the right in 2011.
Nairobi's population increased by 320% - left photo taken in 1970, right photo taken in 2005.
The glacier in Iceland is changing so fast that people are forced to move every year.
Over the years, Singapore has increased in size by as much as 25% through the artificial addition of coastline - the left photo was taken in 1973, the right one represents Singapore today.
Tuscon, Arizona: The population is growing relentlessly, the drought is getting worse every year. Arizona could run out of water in six years - the photo on the left was taken in 1984 and the photo on the right in 2011.
Riyadh, Saudi Arabia: Around 1970, three times as many people lived in the countryside as in the city. In the 1990s, the picture changed. The photo on the left was taken in 1970, the photo in the middle was taken in 1990, and the photo on the right was taken in 2000.
