As Earth Day nears its Golden anniversary, with 2016 marking the annual event's 46th year in existence, renowned scientist Bill Nye the Science Guy remembers being at the inaugural demonstration in Washington D.C.; and remembers a slightly different message.

Nye grew up in Washington D.C., and recalls taking green friendly transportation then as a youth to the first Earth Day event at The National Mall. "I rode my white bicycle down to the National mall and walked it to a flagpole, which you could do back then," he continued.

SEE ALSO: Bill Nye warns that a stunning natural wonder is turning into a 'Muddy Hillside'

The top focus of Earth Day back in 1970 was not climate change, but the proliferation of pollution which was causing mass devastation. "Rivers were so polluted, the Kyoga river caught on fire, people in Pennsylvania died in their sleep breathing bad air," Nye remembered. "The idea of climate change really didn't emerge until ten or thirteen years later."

Click through NASA images from space that show the Earth changing:

47 PHOTOS NASA images of change on earth from space See Gallery Bill Nye predicts major shift in climate change debate Lava eruption, Iceland

September 6, 2014 to January 3, 2015 Since August 2014, lava has gushed from fissures just north of Vatnajökull, Iceland’s largest glacier. As of January 6, 2015, the Holuhraun lava field had spread across more than 84 square kilometers (32 square miles), making it larger than the island of Manhattan. Its thickness is estimated to range from about 10 to 14 meters (33 to 46 feet). The eruption shows signs of slowing down but could continue for years. Images taken by the Operational Land Imager onboard Landsat 8. Source: NASA Earth Observatory Images taken by the Operational Land Imager onboard Landsat 8. Source: NASA Earth Observatory Shrinking ice cap, Iceland

September 16, 1986 to September 20, 2014 More than half of Iceland's numerous ice caps and glaciers lie near or directly over volcanoes. Seen here is Mýrdalsjökull, Iceland's fourth largest ice cap, which covers the Katla volcano at the country's southern tip. In the 2014 image, the depressions at the southwest-central part of Mýrdalsjökull are ice cauldrons caused by geothermal heat from below. Along the northern part of the ice cap, ablation has exposed brown bands of ash from past eruptions. But not all of the changes are associated with volcanic activity. Most of the monitored glaciers have been shrinking since the 1990s, including Sólheimajökull (lower left), which has been retreating as much as 50 meters (164 feet) per year. A parking lot near this glacier is moved almost annually to accommodate tourists. Images taken by the Thematic Mapper onboard Landsat 5 and the Operational Land Imager onboard Landsat 8. Source: NASA Earth Observatory, using data from the U.S. Geological Survey. Images taken by the Thematic Mapper onboard Landsat 5 and the Operational Land Imager onboard Landsat 8. Source: NASA Earth Observatory, using data from the U.S. Geological Survey. Shrinking glacier, Alaska

July 28, 1986 to July 2, 2014 Alaska's Columbia Glacier descends through the Chugach Mountains into Prince William Sound. When British explorers surveyed the glacier in 1794, its nose extended to the northern edge of Heather Island, near the mouth of Columbia Bay. The glacier held that position until 1980, when it began a rapid retreat. 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. Images taken by the Thematic Mapper onboard Landsat 5 and the Operational Land Imager onboard Landsat 8. Source: NASA Earth Observatory, using data from the U.S. Geological Survey. Images taken by the Thematic Mapper onboard Landsat 5 and the Operational Land Imager onboard Landsat 8. Source: NASA Earth Observatory, using data from the U.S. Geological Survey. River delta changes, China

May 1, 1985 to May 1, 2014 China's Huang He (Yellow) River is the most sediment-filled river on Earth. Each year, it transports millions of tons of soil from a plateau it crosses to a delta it has built in the Bohai Sea. These images show the delta's growth from 1985 to 2014. The latter image also shows another change: ponds that hold shrimp and other seafood (seen here as dark geometric shapes along the coastline) were built on what were once tidal flats. Images taken by the Thematic Mapper onboard Landsat 5 and the Operational Land Imager onboard Landsat 8. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery "Huang He Delta and Lauzhou Bay," U.S. Department of the Interior / USGS and NASA. Images taken by the Thematic Mapper onboard Landsat 5 and the Operational Land Imager onboard Landsat 8. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery "Huang He Delta and Lauzhou Bay," U.S. Department of the Interior / USGS and NASA. Shrinking lake, central Asia

August 25, 2000 to August 19, 2014 The Aral Sea was the fourth largest lake in the world until the 1960s, when the Soviet Union diverted water from the rivers that fed the lake so cotton and other crops could be grown in the arid plains of Kazakhstan, Uzbekistan and Turkmenistan. The black outline shows the approximate coastline of the lake in 1960. By the time of the 2000 image, the Northern Aral Sea had separated from the Southern Aral Sea, which itself had split into eastern and western lobes. A dam built in 2005 helped the northern sea recover much of its water level at the expense of the southern sea. Dry conditions in 2014 caused the southern sea’s eastern lobe to dry up completely for the first time in modern times. The loss of the moderating influence of such a large body of water has made the region’s winters colder and summers hotter and drier. See also this image. Images taken by the Moderate Resolution imagine Spectroradiometer (MODIS) on board NASA’s Terra satellite. Source: NASA’s Earth Observatory Images taken by the Moderate Resolution imagine Spectroradiometer (MODIS) on board NASA’s Terra satellite. Source: NASA’s Earth Observatory Air pollution reduction, northeastern United States

2005 to 2011 Nitrogen dioxide (NO2) is a yellow-brown gas that can cause respiratory problems, contribute to the formation of other pollutants, and serve as a proxy for air pollution in general. It is produced primarily during the combustion of gasoline in vehicle engines and coal in power plants. Thanks to regulations, technology improvements and economic changes, air pollution — including NO2 — has decreased despite an increase in population and number of cars on the roads. These images represent the improvement seen in the northeast corridor of the U.S., from Boston to Richmond, where some of the largest absolute changes in NO2 have occurred. Source: NASA News Release. Data source: NASA's Aura satellite. Image credit: NASA Goddard's Scientific Visualization Studio/T. Schindler Source: NASA News Release. Data source: NASA's Aura satellite. Image credit: NASA Goddard's Scientific Visualization Studio/T. Schindler Drought, Arizona and Utah

March 25, 1999 to May 13, 2014 Prolonged drought coupled with water withdrawals have caused a dramatic drop in Lake Powell's water level. These images show the northern part of the lake, which is actually a deep, narrow, meandering reservoir that extends from Arizona upstream into southern Utah. The 1999 image shows water levels near full capacity. By May 2014, the lake had dropped to 42 percent of capacity. Images taken by the Landsat series of satellites. Source: NASA's Earth Observatory Images taken by the Landsat series of satellites. Source: NASA's Earth Observatory Drought, California

2011, 2013, and 2014 California is undergoing its most severe drought in decades, due in part to decreased rainfall and reduced winter snowpack in the Sierra Nevada mountain range as seen in these images. In 2013, California received less precipitation than in any other year since it became a state in 1850. Water conservation efforts are already in place for many locations and the potential for wildfire and major agricultural impact is high. Images taken by the Enhanced Thematic Mapper Plus onboard Landsat 7 and the Operational Land Imager onboard Landsat 8. Source:U.S. Geological Survey (USGS) Landsat Missions Gallery "Drought Conditions in California, USA," U.S. Department of the Interior / USGS and NASA. Images taken by the Enhanced Thematic Mapper Plus onboard Landsat 7 and the Operational Land Imager onboard Landsat 8. Source:U.S. Geological Survey (USGS) Landsat Missions Gallery "Drought Conditions in California, USA," U.S. Department of the Interior / USGS and NASA. Urban growth, South Korea

September 5, 1981 to September 16, 2013 The shoreline area of Incheon, South Korea, has changed dramatically over the past 32 years. Marsh areas have been turned into usable land and urban development has expanded. Islands have been connected to accommodate Incheon International Airport, which opened in 2001 and is now one of the largest and busiest in the world. The new Incheon Bridge (also called the Incheon Grand Bridge), which opened in October 2009, is visible in the 2013 image. Images taken by the Multispectral Scanner onboard Landsat 2 and the Operational Land Imager onboard Landsat 8. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery "32 Years of Change: Incheon, South Korea," U.S. Department of the Interior / USGS and NASA. Images taken by the Multispectral Scanner onboard Landsat 2 and the Operational Land Imager onboard Landsat 8. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery "32 Years of Change: Incheon, South Korea," U.S. Department of the Interior / USGS and NASA. Flood, Cambodia

May 17, 2013 to October 24, 2013 In October 2013, Typhoon Nari followed heavy seasonal rains to create substantial flooding along the Mekong and Tonlé Sap Rivers in Cambodia. The flood affected more than a half million people, and more than 300,000 hectares (about three-quarters of a million acres) of rice fields are believed to have been destroyed. The capital city of Phnom Penh is just south of the image center. Images taken by the Operational Land Imager onboard Landsat 8. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery"Flooding in Cambodia," U.S. Department of the Interior / USGS and NASA. Dam impact, Pakistan

August 2, 1999 to June 8, 2011 The Mirani Dam on the Dasht River in southern Pakistan was completed in 2006. The resulting reservoir provides water for drinking, irrigation and hydroelectric power. Though the dam also helps to control flooding, heavy rains in 2007 increased the reservoir depth from 244 to 271 feet (74 to 82 meters) with attendant flooding that displaced more than 15,000 people. The left-hand image shows the region before the dam was built. The right-hand image shows the dam in 2011 with the expanded agriculture that the dam’s water supports. Images taken by the Enhanced Thematic Mapper Plus onboard Landsat 7 and the Thematic Mapper onboard Landsat 5. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery "Mirani Dam," U.S. Department of the Interior / USGS and NASA. Images taken by the Enhanced Thematic Mapper Plus onboard Landsat 7 and the Thematic Mapper onboard Landsat 5. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery "Mirani Dam," U.S. Department of the Interior / USGS and NASA. Typhoon, Philippines

June 28, 2013 to November 11, 2013 Among the destruction that Typhoon Haiyan inflicted was flooding caused by massive swelling of the Agno River, the fifth largest river system in the Philippines, on the island of Luzon. More than 2 million people live in the Agno River Valley. Images taken by the Operational Land Imager onboard Landsat 8 and the Enhanced Thematic Mapper Plus onboard Landsat 7. Source:U.S. Geological Survey (USGS) Landsat Missions Gallery "Agno River Valley flooding, Philippines (Typhoon Haiyan)," U.S. Department of the Interior / USGS and NASA. Images taken by the Operational Land Imager onboard Landsat 8 and the Enhanced Thematic Mapper Plus onboard Landsat 7. Source:U.S. Geological Survey (USGS) Landsat Missions Gallery "Agno River Valley flooding, Philippines (Typhoon Haiyan)," U.S. Department of the Interior / USGS and NASA. Lake change, New Mexico

June 2, 1994 to July 8, 2013 Elephant Butte Reservoir dwindled to its lowest level in 41 years during the summer of 2013, despite monsoon rains in early July. It had been filled nearly to capacity for most of 1985 to 2000; the left-hand image from 1994 shows it about 89 percent full. At right, it has been reduced to about 3 percent. Elephant Butte is fed by the Rio Grande and is New Mexico's largest reservoir. It provides water for about 90,000 acres (364 square kilometers) of farmland and nearly half the population of El Paso, Texas. Spring runoff from mountain snowpack was well below average in spring, 2013, and anemic rains throughout the beginning of the year left 80 percent of New Mexico grappling with either "extreme" or "exceptional" drought, the two most severe categories. Images taken by the Operational Land Imager onboard Landsat 8. Source: NASA Earth Observatory Images taken by the Operational Land Imager onboard Landsat 8. Source: NASA Earth Observatory Fire, Colorado

April 27, 2013 to June 22, 2013 The Black Forest Fire near Colorado Springs, Colorado, was the most destructive wildfire in the state's history, having burned over 14,000 acres and more than 500 homes. It was responsible for the deaths of two people and forced thousands more to leave their homes. The fire started June 11, 2013, and was considered fully contained on June 20, 2013. It began along the north side of Shoup Road, which forms the southern boundary of the burned area seen in the June 22 image. The northern portion of Colorado Springs is visible at the lower left. Images taken by the Enhanced Thematic Mapper Plus sensor onboard Landsat 7 and the Operational Land Imager onboard Landsat 8. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery "Black Forest Fire," U.S. Department of the Interior / USGS and NASA. Images taken by the Enhanced Thematic Mapper Plus sensor onboard Landsat 7 and the Operational Land Imager onboard Landsat 8. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery "Black Forest Fire," U.S. Department of the Interior / USGS and NASA. Lake shrinkage, Iraq

1995, 2003, and 2013 Bahr al Milh (also called Lake Razazah) is a salt sea in Iraq, fed by the Euphrates River via canal. Water levels of this shallow lake vary with the seasons, but levels have been drastically low year-round in the past decade. Images taken by Landsat 5, the Enhanced Thematic Mapper Plus instrument onboard Landsat 7, and the Operational Land Imager onboard Landsat 8. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery "Bahr al Milh," U.S. Department of the Interior / USGS and NASA. Images taken by Landsat 5, the Enhanced Thematic Mapper Plus instrument onboard Landsat 7, and the Operational Land Imager onboard Landsat 8. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery "Bahr al Milh," U.S. Department of the Interior / USGS and NASA. River evolution, Louisiana

1973, 1989, and 2003 These pictures show three decades of change in the birdsfoot delta where the Mississippi River meets the Gulf of Mexico in Louisiana. The Mississippi-Missouri River system collects eroded debris from the entire central half of the United States. Upon reaching the Gulf, the river's velocity slows abruptly, reducing its ability to carry suspended mud and sand, which is then deposited in an alluvial fan pattern. The delta has changed form many times over the past 10,000 years and has varied in location along a 200-mile (322-kilometer) stretch of coastline. The birdsfoot delta has occupied its current location for only about 600 years. 1973 image taken by the Multispectral Scanner sensor onboard Landsat 1. 1989 image taken by the Thematic Mapper sensor onboard Landsat 5. 2003 image taken by the Enhanced Thematic Mapper Plus sensor onboard Landsat 7. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery, “Mississippi Delta, USA,” U.S. Department of the Interior / U.S. Geological Survey. Lake shrinkage, Argentina

July 10, 1998 to September 27, 2011 Mar Chiquita, the largest of the naturally-occurring saline lakes in Argentina, has been shrinking and getting saltier. Its water comes primarily from the Dulce River, and increasing use of the river’s water for irrigation, coupled with long periods of drought, have diminished the lake’s water level and increased its salinity. Environmental studies continue to measure the regional impact of the changes in lake size and quality. Images taken by the Thematic Mapper sensor onboard Landsat 5. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery, "Mar Chiquita change over time," U.S. Department of the Interior / USGS and NASA. Lake growth, China

1992, 2003, and 2012 Lake Ayakkum, which is near the northern boundary of the Tibetan Plateau in central China, has been growing. This stands in contrast to many closed-basin saline lakes in Central Asia, which have been shrinking because of the construction of dams and aqueducts as well as human expansion into previously uninhabitable desert areas. Small streams fed by glaciers and snowmelt are increasing their flow to the lake. The development of a delta can be seen in the lower right portion. Images taken by the Thematic Mapper sensor onboard Landsat 5 and the Enhanced Thematic Mapper Plus onboard Landsat 7. Source:U.S. Geological Survey (USGS) Landsat Missions Gallery, "Lake Ayakkum," U.S. Department of the Interior / USGS and NASA. River flow, Russia

May 1, 2007 to May 17, 2007 From the time they thaw in early May, the Ob River and its tributary, the Irtysh, flow from the Altay Mountains of northern China to the Arctic Ocean. The northern reaches of the Ob flow over a flat permafrost plain past the cities of Ozernyy and Nefteyvgansk in northern Russia. Because the river cannot cut deep channels into the frozen land, it spreads out over the surrounding plain during the spring melt, as shown in the image on the right. Images taken by the Thematic Mapper sensor onboard Landsat 5. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery, "Ob River Flooding in Northern Russia," U.S. Department of the Interior / USGS and NASA. Bear Glacier melt, Alaska

1980, 1989, 2011 This series of images shows the shrinkage of Bear Glacier from 1980 to 2011. Warming in the region has caused less buildup of snow and therefore less material for glacial growth. As the glacier has receded, ice at the end of the glacier has broken off the main body, forming icebergs in the open water. The 2011 image shows considerable retreat of the glacier's "tongue." Also see this image pair of the same glacier. Left image taken by the Multispectral Scanner onboard Landsat 3. Center image taken by the Thematic Mapper sensor onboard Landsat 4. Right image taken by the Enhanced Thematic Mapper Plus sensor onboard Landsat 7. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery, "Bear Glacier, Alaska," U.S. Department of the Interior / USGS and NASA. Drought, Kansas

2010, 2011, 2012 The Cheyenne Bottoms Wildlife Wetlands area in central Kansas, the largest interior marsh in the United States, was dramatically impacted by the drought besetting large areas of the western U.S. in 2012. There was sufficient water in the wetland area as recently as 2010, but the levels began to diminish in 2011. By mid-July, 2012, virtually all the water had evaporated. The area has provided a resting place for millions of migrating birds every fall, and wildlife officials are using satellite images like these to help them determine what actions to take to sustain a habitat for the nesting waterfowl. Images taken by the Thematic Mapper sensor onboard Landsat 5 and by the Enhanced Thematic Mapper Plus onboard Landsat 7. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery, "Effects of Drought," U.S. Department of the Interior / USGS and NASA. Urban growth, Philippines

January 25, 2989 to April 14, 2012 The Philippine capital of Manila is the most densely populated city in the world, with more than 1.6 million inhabitants in 14.8 square miles (38.5 square kilometers). The greater metro area covers 246 square miles (638 square kilometers) and hosts a population of over 11 million. These satellite images illustrate how much the city has expanded in little more than two decades, bringing significant infrastructure and environmental problems. The Pasig River, which cuts through the urban area, is one of the most polluted rivers in the world. Images taken by the Thematic Mapper sensor onboard Landsat 4 and the Enhanced Thematic Mapper Plus sensor onboard Landsat 7. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery, "Manila, Philippines," U.S. Department of the Interior / USGS and NASA. Glacier calving, Greenland

July 16 and 17, 2012 The Petermann Glacier grinds and slides toward the sea along the northwestern coast of Greenland, ending in a giant floating tongue of ice. An iceberg about twice the size of Manhattan broke free of that tongue in July, 2012. Two years prior, Petermann calved an iceberg twice as big as this one. A glacier is essentially a slow-moving river of ice. When a glacier protrudes into the ocean, as the Petermann Glacier does, ice occasionally breaks off the end, creating new icebergs. The frequency depends on how fast the glacier grows because of new snow, how quickly it flows into the ocean, and how fast it melts. Petermann Glacier's floating ice tongue is the largest in the Northern Hemisphere. Images taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument onboard NASA's Aqua satellite. Source: NASA Earth Observatory Land change, Florida

May 14, 1984 to May 25, 2011 As the U.S. population has aged, more older people have been moving from northern states to southern communities. Sumpter County in central Florida grew 75 percent since 2000, largely due to expansion of The Villages, a master-planned retirement community with a strong emphasis on golf. Started as a mobile home park in the early 1980s, The Villages was the fastest growing micro-population area in the United States by 2008. These images illustrate the changes that have accompanied this growth. Agricultural land has turned into more than 40 golf courses, and small bodies of water (shown as black) have been converted to water hazards. Lakes have been drained to provide irrigation and residential communities (very light tones) have popped up around the golf courses. Images taken by the Thematic Mapper sensor onboard Landsat 5. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery, "The Villages, Florida," U.S. Department of the Interior / USGS and NASA. Urban growth, China

July 30, 1992 to April 8, 2012 The Binhai New Area — once home to salt farms, reed marshes and wasteland — has grown into one of China's key economic hubs. Since development began in the 1990s, it has become the home of numerous aerospace, oil, chemical and other manufacturing industries. Plans for coming years include an international airport. The changes over 20 years can be seen in these images acquired in 1992 and 2012. The Binhai New Area is located on the coast of the Bohai Sea Region southeast of China's capital city, Beijing. 1992 image taken by the Thematic Mapper sensor onboard Landsat 5. 2012 image taken by the Enhanced Thematic Mapper Plus sensor onboard Landsat 7. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery, "Binhai New Area, China," U.S. Department of the Interior / USGS.

January 25, 2011 to January 28, 2012 Pine Island Glacier calving, AntarcticaJanuary 25, 2011 to January 28, 2012 Left: January 25, 2011. Right: January 28, 2012. Pine Island is one of the largest and fastest-moving glaciers in Antarctica. The Pine Island Glacier Basin contributes more ice to the sea than any other ice-drainage basin in the world, and this has increased due to recent acceleration of the ice stream caused by thinning of the glacier. Scientists are concerned about the impact Pine Island's continued thinning will have on sea level. The 2011 image shows a series of splits along the western edge of the glacier. The same area in 2012 reveals a major break that will eventually extend all the way across the glacier and calve a giant iceberg expected to cover about 350 square miles (900 square kilometers). Images taken by the Enhanced Thematic Mapper Plus sensor onboard Landsat 7. Source: U.S. Geological Survey (USGS) Landsat Missions Gallery, "Pine Island Glacier," U.S. Department of the Interior / USGS. Fire, Idaho

July 24, 2010 to August 25, 2010 Left: July 24, 2010. Right: August 25, 2010. A series of wildfires, triggered by lightning strikes during the weekend of August 21 and 22, 2010, burned more than 300,000 acres of sage and grasses in the south-central region of Idaho. On August 23, the fire burned over 200,000 acres in a single day. Smoke from the fires dramatically impacted air quality in a number of local communities. The July 24 image shows burn marks from earlier, smaller fires, while the August 25 image shows the dark brown tone of the large fire scar. Fire and regional vegetation-management teams used the imagery to track the fire and to plan rehabilitation of the affected areas. Images taken by the Thematic Mapper sensor onboard Landsat 5. Source: USGS Landsat Missions Gallery, "Long Butte, Idaho Fire," U.S. Department of the Interior / U.S. Geological Survey. Fire, Georgia, United States

April 30, 2011 to July 3, 2011 Lightning sparked wildfires near the Okefenokee National Wildlife refuge in the Honey Prairie region of Georgia, US, on April 30, 2011, after the left-hand image was taken. Dry conditions helped fuel the fires and continued lightning strikes started new ones. By July 7, over 290,000 acres had burned. The red tones of the July 3 image represent recovering vegetation in previously burned areas. Light tones are the smoke of active fires. Images taken by the Thematic Mapper sensor aboard Landsat 5. Source: USGS Landsat Missions Gallery, "Honey Prairie Fires," U.S. Department of the Interior / U.S. Geological Survey. Water diversion, Dead Sea

November 9, 1984 to November 28, 2011 The Dead Sea lies in the Jordan Rift Valley, bordering Jordan, Israel and the West Bank. It is one of the world's saltiest bodies of water, too salty to harbor any life other than bacteria. Minerals from the sea, however, are extracted for various industrial purposes. Mineral evaporation ponds have replaced open water in the southern part of the sea, as can be seen in the 2011 image. In recent decades, the Dead Sea has shrunk as water has been diverted from the Jordan River, the sea's main tributary. A plan has been announced to replenish the Dead Sea by building a canal from the Red Sea, providing fresh (desalinated) water to Jordan en route. 1984 image taken by the Thematic Mapper sensor onboard Landsat 5. 2011 image taken by the Enhanced Thematic Mapper Plus sensor onboard Landsat 7. Source: USGS Landsat Missions Gallery, "The Dead Sea," U.S. Department of the Interior / U.S. Geological Survey. Lake shrinkage, Utah

August 1985 to September 2010 Dramatic change in the area of the Great Salt Lake over the past 25 years. Left: August 1985. Right: September 2010. The lake was filled to near capacity in 1985 because feeder streams were charged with snowmelt and heavy rainfall. In contrast, the 2010 image shows the lake shriveled by drought. The Promontory Peninsula (protruding into the lake from the top) is surrounded by water on three sides in the first image, but is landlocked on its eastern side in the second. Similarly, Antelope Island was encircled by water in 1985, but was connected to marshy areas in 2010. Mosaics of four satellite images were used to illustrate the changes over the full lake area. Images taken by the Thematic Mapper sensor aboard Landsat 5. Source: USGS Landsat Missions Gallery, "Great Salt Lake—1985-2010," U.S. Department of the Interior / U.S. Geological Survey. Coastal change, Mexico

August 7, 1993 to July 8, 2011 These images show changes to the western coastline of Sonora, Mexico due to the construction of shrimp farms over the past two decades. While the shrimp industry has generated profits and jobs, there have been concerns about its effect on the ecosystems of the region, and disputes have arisen about property rights to the communal coastal lands. Images taken by the Thematic Mapper sensor onboard Landsat 5. Source: USGS Landsat Missions Gallery, "Aquaculture Changes Mexican Shoreline," U.S. Department of the Interior / U.S. Geological Survey. Lake shrinkage, central Asia

1977, 1989, 2006, 2009 The Aral Sea, located in Kazakhstan and Uzbekistan in central Asia. Left: June 4, 1977. Center left: September 17, 1989. Center right: May 27, 2006. Right: June 3, 2009. Once one of the largest inland bodies of salty water in the world and the second largest sea in Asia — 70,000 square kilometers or 27,000 square miles in area — the Aral Sea has shrunk dramatically over the last 30 years. One of the main reasons is crop irrigation: water has been drawn off from the rivers that kept the Aral Sea filled. As the sea has shrunk, the local climate has become harsher, there have been contaminated dust storms, and drinking water and the local fishing industry have been lost. By the late 2000s, the Aral Sea had lost four fifths of its water volume. Images taken by the Multispectral Scanner onboard Landsat 1, the Thematic Mapper sensor onboard Landsat 5, and the Enhanced Thematic Mapper Plus onboard Landsat 7. Source: USGS Landsat Missions Gallery, "The Vanishing Aral Sea," U.S. Department of the Interior / U.S. Geological Survey and Encyclopaedia Britannica Online. New island appears, Red Sea

October 2007 to December 2011 A volcano erupted in the Red Sea in December 2011, apparently creating a new island. According to news reports, fishermen witnessed lava fountains reaching up to 30 meters (nearly 100 feet) high on December 19. By December 23, what looked like a new island had appeared. A thick plume can be seen in the 2011 image, dark near the bottom and light near the top, perhaps a mixture of volcanic ash and water vapor. The activity occurred along the Zubair Group, a collection of small islands off the west coast of Yemen. Running in a roughly northwest-southeast line, the islands poke above the sea surface, rising from a shield volcano. This region is part of the Red Sea Rift, where the African and Arabian tectonic plates pull apart and new ocean crust regularly forms. Images taken by the Advanced Land Imager onboard NASA's Earth Observing-1 satellite. Source: NASA Earth Observatory. Lake degradation, California

September 1985 to September 2010 Owens Lake lies in the Owens Valley between the Sierra Nevada and Inyo Mountains, about 130 miles north of Los Angeles, California. For thousands of years, it was one of the most important stopover sites in the western U.S. for migrating waterfowl and shore birds. However, in the early 20th century, the lower Owens River, which fed the lake, was largely diverted to the Los Angeles aqueduct. Water from springs and artesian wells kept some of the lake alive, but toxic chemicals and dust impinged on the regional environment and disturbed the bird habitat. Beginning in 1999, a plan was put in place to restore the lake region and alleviate the dust build-up, using ponds, native grasses, gravel deposits and limited shallow flooding. Images taken by the Thematic Mapper sensor onboard Landsat 5. Source: USGS Landsat Missions Gallery, "Owens Lake restoration," U.S. Department of the Interior / U.S. Geological Survey. Lake shrinkage, Texas Left: June 18, 1990. Right: June 12, 2011. Lake Meredith is a reservoir formed by the Sanford Dam on the Canadian River in the Texas panhandle. Continuous drought has diminished water levels significantly in the past few years, leading to a record low in 2011. In each image, the lake is the black feature near the center. Light tones at the lower end of the lake indicate dry land and former shores. Bright green indicates healthy vegetation along the river beds and irrigated fields in the upper center of each image. The nearby industrial area (a petroleum plant and a carbon-processing plant) appears as a dark spot. The light blue tone further east is Borger, Texas. Images taken by the Thematic Mapper sensor aboard Landsat 5. Source: USGS Landsat Missions Gallery, "Shrinking Lake Meredith, Texas," U.S. Department of the Interior / U.S. Geological Survey. Fire, New Mexico

June 24, 2011 to July 2, 2011 Las Conchas, New Mexico. Left: June 24, 2011. Right: July 2, 2011. A major fire ripped through New Mexico, destroying sites considered sacred by American Indian tribes and threatening the Los Alamos National Nuclear Laboratory. The blaze, thought to have been started by a downed power line, burned more than 125,000 acres of the Santa Fe National Forest. In the July 2 image, burned areas are reddish brown and bright tones at the edge of the forest indicate active fires. June image taken by the Thematic Mapper sensor aboard Landsat 5. July image taken by the Enhanced Thematic Mapper Plus sensor aboard Landsat 7. Main source: USGS Landsat Missions Gallery, U.S. Department of the Interior / U.S. Geological Survey. Lake shrinkage, Africa

1972, 1987, 2002 Lake Chad, Africa. Left: December 8, 1972. Middle: December 14, 1987. Right: December 18, 2002. Persistent drought has shrunk Lake Chad, once the world's sixth largest lake, to about one-twentieth of the size it was in the 1960s. Only 16 to 26 feet (5 to 8 meters) deep in "normal" times, small changes in depth have resulted in large changes in area. As the lake has receded, large wetland areas (shown in red) have replaced open water. 1972 image from Landsat 1. 1987 image from Landsat 4. 2002 image from Landsat 7. Courtesy of the U.S. Department of the Interior / U.S. Geological Survey. Taken from the USGS Landsat Missions Gallery. Water changes, Caspian Sea

1972, 1987, 2010 The Kara-Bogaz-Gol basin on the eastern edge of the Caspian Sea. Left: December 4, 1972. Middle: September 25, 1987. Right: October 10, 2010. The basin's water level has periodically undergone dramatic changes, and damming of its feeder inlets increased the magnitude of those changes. In 1980, a severe drop left a "salt bowl," with windborne salt reportedly poisoning soil and causing health problems hundreds of kilometers to the east. In 1984, the basin dried up completely. In 1992, after the barrier was breached, sea level rose, remaining fairly stable from 2000 to 2010. 1972 image taken by the Multispectral Scanner aboard Landsat 1. 1987 and 2010 images taken by the Thematic Mapper sensor aboard Landsat 5. Source: USGS Landsat Missions Gallery, U.S. Department of the Interior / U.S. Geological Survey. Deforestation, Bolivia

1989 to 2001 Near Santa Cruz de la Sierra, Bolivia. Left: August 4, 1986. Right: August 11, 2001. Most of the tropical dry forest visible in the 1986 image (dark red) has been replaced in the 2001 image by resettlement of people from the Altiplano (the Andean high plains) and by soybean production. The radial patterns are part of the San Javier resettlement plan. At the center of each unit is a small community that includes a church, bar/cafe, school and soccer field. The rectangular, light-colored areas are fields of soybeans cultivated for export. The dark strips running through the fields are windbreaks to protect the soil, which is prone to wind erosion 1986 image taken by Landsat. 2001 image taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). Reproduced from JPL's ASTER website. Courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and the U.S./Japan ASTER Science Team. River changes, China

2001 to 2009 The Yellow River Delta in China. Left: 2001. Right: 2009. The Yellow River is the second-longest river in China, and the sixth-longest in the world. It has been the cradle of Chinese civilization; but frequent devastating floods have also earned it the name of "China's Sorrow." Historical maps tell us that the river has undergone many dramatic changes in its course. Currently, the Yellow River ends in the Bohai Sea, yet its eastern terminus continues to oscillate from points north and south of the Shandong Peninsula. These images show the changes. Images taken by NASA's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument. Caption adapted from the ASTER gallery. Courtesy of NASA/GSFC/METI/ERSDAC/JAROS and the U.S./Japan ASTER Science Team. Urban growth, Saudi Arabia

1972 to 2000 The Saudi Arabian capital. Left: 1972. Middle: 1990. Right: 2000. During this time, its population soared from about half a million to more than two million. In the early 1970s, three times as many Saudi Arabians lived in rural areas as in cities. By 1990, the ratio had reversed — cities held three times as many as the rural regions. Images taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument. Courtesy of NASA/GSFC/METI/ERSDAC/JAROS and the U.S./Japan ASTER Science Team. Flood, Pakistan

2009 to 2010 Southern Pakistan. Left: August 8, 2009. Right: August 11, 2010. Twenty percent of the country is currently underwater as a result of floods caused by heavy monsoon rains that began in late July 2010. According to reports, six million Pakistanis are now homeless and around 17 million people have been affected in some way. This false-color image pair of the affected region was acquired by the Multi-angle Imaging SpectroRadiometer (MISR) instrument onboard NASA's Terra spacecraft. The Indus River can be seen snaking across the image from lower left to upper right. In the image from 2009, the Indus is about 1 kilometer (0.6 mile) wide. In the 2010 image, the river is 23 kilometers (14 miles) wide or more in parts. Images taken by the Multi-angle Imaging SpectroRadiometer onboard NASA's Terra spacecraft. Credit: NASA/GSFC/LaRC/JPL, MISR Team. Caption adapted from JPL's Photojournal. Ice melt, Tanzania

February 1993 to February 2000 Mount Kilimanjaro in Africa. Left: February 17, 1993. Right: February 21, 2000. Kilimanjaro is the tallest freestanding mountain in the world and is made up of three volcanic cones. These before and after images show the dramatic decline in Kilimanjaro's icecap over recent decades. Images taken by the NASA/USGS Landsat satellite. Credit: Jim Williams, NASA GSFC Scientific Visualization Studio, and the Landsat 7 Science Team. Lake degradation, Tunisia

2001 to 2005 Ichkeul Lake, northern Tunisia. Left: November 14, 2001. Right: July 29, 2005; the water level is higher, but a large part of the lake appears red due to the presence of aquatic plants. Ichkeul Lake and wetlands are a major stopover point for hundreds of thousands of migrating birds who come to feed and nest. It is the last remaining lake in a chain that once extended across North Africa, and has badly deteriorated as a result of the construction of three dams on rivers supplying it and its marshes, which have cut off almost all inflow of freshwater. The Tunisian government plans to undertake various measures to retain freshwater in the lake on a year-round basis and reduce the salinity of the lake. Images taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) onboard NASA's Terra satellite. Credit: NASA/GSFC/METI/ERSDAC/JAROS and the U.S./Japan ASTER Science Team. Source: the ASTER gallery.

May 2004 to December 2004 Tsunami / Earthquake, SumatraMay 2004 to December 2004 The city of Banda Aceh, on the island of Sumatra, before and after the 2004 Indian Ocean earthquake and resulting tsunami. Top: May 14, 2004. Bottom: December 29, 2004, days after the massive wave struck the coastline. Images taken by the Landsat-7 satellite. Source: NASA/USGS. Dust storm, China

March 2002 to April 2002 Dust obscuring most of the Liaoning region of China and parts of northern and western Korea. Left: March 23, 2002, a relatively clear day. Right: April 8, 2002, a day of extremely dusty skies. Storms transport mineral dust from the deserts of China and Mongolia over great distances, as well as pollution from agriculture, industry and power generation. Asian dust has been detected as far away as Colorado. Thick clouds of dust block substantial amounts of incoming sunlight, which in turn can influence marine phytoplankton production and have a cooling effect on regional climates. Images taken by NASA's Multi-angle Imaging Spectroradiometer (MISR). Credit: NASA/GSFC/LaRC/JPL, MISR Team. Urban growth, Nevada

1984 to 2007 Growth in the desert. Left: 1984. Right: 2007. These images show the increasing urban sprawl of Las Vegas, Nevada, and the shrinking of Lake Mead on the border of Nevada and Arizona. Rapid growth in Las Vegas has led to increased demand for water resources, while below-average rainfall has decreased the water levels in Lake Mead, which is the source of 90 percent of southern Nevada's water. Images taken by the Landsat-5 satellite. Credit: NASA/USGS. Up Next See Gallery Discover More Like This HIDE CAPTION SHOW CAPTION of SEE ALL BACK TO SLIDE

About the time they have to select a (vice presidential) candidate, one of them will say, "Well, I thought about it, and it might be a real issue."

"Earth day was started on account of pollution, but now it has taking on an even bigger and much more important role in climate change," said Nye.

The issue of climate change has already proved to be a contentious topic in the 2016 U.S. presidential election. And as November nears, the debate over climate change has emerged as a one of the defining and most polarizing issues of the election. Both sides of the isle have already selected their respective corners on the issue. "Everybody on the conservative side is a climate change denier," said Nye, weighing in on the current political landscape.

Republican front-runner Donald Trump has stated, "I am not a believer in climate change," calling it a "hoax." While both Democratic candidates, former Secretary of State Hillary Clinton and Vermont Senator Bernie Sanders, have made a point to express not only their belief in climate change, but also their plans for combating its impact.

Nye said he would not be taken aback if Trump, or whomever the GOP presidential nominee is come November, begins to backpedal on their denial of climate change as the general election draws closer.

National parks and Earth Day go hand and hand; they raise awareness of our place on this planet.

"About the time they have to select a (vice presidential) candidate, one of them will say, "Well, I thought about it, and it might be a real issue," Nye explained. And for him the reasoning behind such a pivot is rather obvious: "millennials."

"There aren't quite enough votes without people in the 20s and 30s."

It's true, the younger you are the more likely you are to be believe in climate change. According to the Pew Research Center, 60% of people between the ages of 18-29 believe in man made climate change, while only 48% of 50-64 year-olds do.



Ultimately the significance of Earth Day may be even bigger than the 2016 election, for Nye the day is the perfect time to reflect on humanity's place in the universe. "National Parks and Earth Day go hand and hand; they raise awareness of our place on this planet," said Nye.

Find Your Park - National park service happy 100th:

BY: WILLIAM STEAKIN