Are Sea Levels Really Rising?
According to the National Oceanic and Atmospheric Administration (NOAA) and the U.N. IPCC, sea levels are rising. Scientists project that sea levels could rise between 9" and 24" by 2060 and one to four feet over the next 100 years. This poses many challenges for coastal areas, such as saltwater intrusion into underground aquifers, the main source of fresh drinking water for much of South Florida.
Greenland Increases in temperature have caused significant portions of Greenland’s ice sheet to melt, resulting in a loss of 150 to 250 cubic kilometers (36 to 60 cubic miles) of ice per year between 2002 and 2006. Scientists also believe that meltwater from above and seawater from below is seeping beneath Greenland’s ice sheets, creating fissures that cause chunks to weaken and break off. As Greenland melts, sea levels rise. Sea levels have risen by more than one inch in the last decade, almost twice as fast as average during the 20th century.
Antarctica’s ice sheet has seven times more ice than Greenland. While there are no signs of ice melt in the high, cold desert of East Antarctica, where ice sits on dry land, West Antarctica is another situation entirely. West Antarctica is a series of islands covered by ice that sit on the floor of the Southern Ocean, and scientists have measured increased rates of glacier retreat and ice shelf collapse which contribute to sea level rise. Click here to learn more.
Glaciers are large sheets of snow and ice that are found on land all year long. Research shows significant glacier loss around the world in the last 50 years. In 1850, Glacier National Park had 150 glaciers. Today, only 25 remain large enough to be considered as functional glaciers. Melting glaciers decrease potable water and water for irrigation, threaten wildlife and contribute towards sea level rise.
Arctic Ice Caps
Arctic ice is similar to ice cubes in a glass, and as it melts, does not directly cause sea level rise. However it amplifies the warming of the planet which does cause sea level rise. The brightness of the ice helps to reflect the sun's rays back into space, and less ice sheets result in less reflection and more absorption of heat. Images from NASA satellites show a decline of permanent ice cover in the arctic at a rate of 15% each decade, accelerating over time. Arctic ice is anticipated to be completely melted during summers by the year 2050.
See what the City is doing to mitigate the effects of Sea Level Rise.