ROCKY MOUNTAIN NATIONAL PARK NOW: A hillside of dead pine trees killed by mountain pine beetles shows the effects of warming temperatures in the mountain ranges. In the past, freezing temperatures reduced insect populations. The beetles are now able to survive the milder winters, leading to devastating infestations.
AP Photo/Will Powers
THE GREAT BARRIER REEF BEFORE: Considered one of the most biologically diverse regions in the world, Australia’s Great Barrier Reef covers around 135,000 square miles, or an area that’s nearly the size of Texas. Ocean acidification and temperature increases from climate change are the reef’s biggest long-term threat.
AP Photo/Queensland Tourism
THE GREAT BARRIER REEF NOW: Warmer water temperatures trigger widespread coral bleaching, when coral turns white and is more susceptible to death. Coral is vital to supporting ocean life.
THE DANUBE RIVER BEFORE: The Danube, Europe’s second-longest river, flows eastward from its source in Germany to the Black Sea in Romania. The Danube River basin is critical to supporting industry, transport, agriculture, and fishing.
THE ALPS BEFORE: Matterhorn, one of Europe’s tallest peaks in the Alps on the border between Italy and Switzerland, is pictured with a blanket of snow and ice August 16, 1960.
THE ALPS NOW: The Swiss peak, pictured August 18, 2005, is eroding as a result of melting glacier water at the summit. The water sinks into cracks and creates bigger fissures after several cycles of freezing and thawing. The disintegration of Matterhorn is anecdotal of the effects of climate change in most of the Alps.
David Arnold/Panopticon Gallery, Boston, MA/NASA
MUIR GLACIER NOW: By 2005, Muir Glacier had retreated more than 31 miles. Although this picture was taken from the same location as the early black-and-white photograph, the glacier is out of view. There’s an abundance of vegetation looking to the west, and the beach in the foreground is now covered by pebbles, which came from sediment deposited by Muir Glacier and by melting icebergs on the ground.
LAKE CHAD BEFORE: Africa’s Lake Chad, pictured in the 1930s, was once the world’s sixth-largest lake. It provided water to at least 20 million people in Nigeria, Chad, Cameroon, and Niger.
SAN BLAS ARCHIPELAGO BEFORE: The San Blas islands in Panama are home to the Guna people. Their traditional thatched-roof houses and ancient way of life are being threatened by climate change.
Shutterstock/Jarno Gonzalez Zarraonandia
SAN BLAS ARCHIPELAGO NOW: The Caribbean island communities are flooded for several days every rainy season as a result of rising ocean levels caused by global warming. In the foreground, a traffic sign reading “Slow Down” is partially submerged.
CORAL REEFS NOW: The reef was devastated in 2008 by harmful algae blooms known as red tide, potentially linked, in part, to increased greenhouse gases and rising ocean temperatures. The tide kills sea life by depleting the oxygen in the water.
WHITBY HARBOUR NOW: The port is quiet, flanked by empty pots and nets and dried-out fishing boats as global warming has pushed fish stocks northward. Only about 200 fishermen remain in Whitby.
CARBON DIOXIDE LEVELS 2003: An infrared image from July 2003 shows the concentration of carbon dioxide in our atmosphere. The red areas indicate that carbon-dioxide concentration is at or above 380 parts per million.
CARBON DIOXIDE LEVELS 2007: The same image of the globe, taken three years later in July 2007, shows that atmospheric carbon-dioxide levels are rising. The color bar used for 2003 had to be adjusted to account for the increase in carbon dioxide around the globe. Otherwise, the “2007 map would be saturated with reddish colors, and the fine structure of the distribution of carbon dioxide obscured,” explains NASA.
BONUS: These maps compare temperatures in each region of the world to what they were from 1951 to 1980. Earth’s average surface temperature has increased by about 1.3 degrees Fahrenheit since 1880.