Ocean level rise - West Hemisphere - Earth's Western hemisphere with sea level+100m - Artist's...

Ocean level rise - West Hemisphere - Earth's Western hemisphere with sea level+100m - Artist's view showing North and South America as they would appear if ocean levels increased by 100 metres. This would happen if all glaciers on Earth melt. This is how the Earth's Western hemisphere may appear with mean sea level about 100 meters (330 feet) above today's. Such a dramatic rise in sea level could occur if all of the Earth's glaciers were to melt. In this image the Gulf of Mexico and Atlantic ocean have inundated almost all of southeastern United State including the entire state of Florida, almost all of Louisiana, and significant portions of the other southeastern states and the District of Columbia. Major US cities submerged include New York City, Boston, and Houston, and on the west coast Los Angeles, San Francisco, and much of San Diego. In addition to land claimed from the United States this 100 meter rise in sea level has also claimed much of Central America including the Yucatan Peninsula and further south almost all of the Amazon basin. A likely cause of a catastrophic melting of the Earth ice stores would be a change in climate, a sudden rise in the global temperature accelerated by a runaway greenhouse effect. While the amount of water held by the Earth's glaciers can be calculated with some accuracy, the exact mechanism that would set those glaciers to melting, and how long it would take for them to melt, is poorly understood. Some models suggest that several millennia of higher temperatures would be required to melt all the world's glaciers, while others predict much faster processes on the scale of centuries, or even decades