Each year humans move around 7 gigatons of earth. Some projects result in vast improvements for human living; others, not so much.

The Panama Canal

The idea of cutting a canal from the Atlantic to the Pacific through Panama was first proposed in 1524, with plans drawn up by 1529. Various nations considered the idea, but for reasons of war, international politics, or the huge expense, the project was postponed for nearly four centuries. A French company worked on the canal from 1881 to 188, and the Americans finished it between 1904 and 1914. The French had excavated 30 million cubic yards of earth, and the Americans dug another 238 million. The total amount of earth moved was four times the original estimate. However, using the canal saved thousands of miles and months of travel time by ship for voyages between the east and west coasts of North America.

The Three Gorges Dam

The Three Gorges Dam on the Yangtze River in China is slated to be the largest hydroelectric project on earth when it becomes fully operational in 2011. Plans were first offered in 1914, but revolution, wars, and political instability delayed construction until 1994. The massive project has been criticized internationally for the displacement of 1.5 million people who lived where the new lake is, and for the environmental disruption which is believed to have already led to the extinction of at least one species, the Baiji or Yangtze River Dolphin. The construction of the Three Gorges Dam moved about 13,400,000 cubicÂ yards of earth.

New York City Subway System

The first section of the New York City subway opened in 1904. Construction has continued ever since, with new lines, repairs, and replacement lines under constant construction. On most lines, the street is torn up to dig the tunnel, then the road is replaced. Tunnel-boring technology is necessary for the deeper lines, lines through rock, and those that cross under the East River. The system is now 722 miles long. It's difficult to estimate the volume of the underground sections, but in 1904 when the very first lines were opened, 3.5 million cubic yards of earth and rock had been removed.

Mountaintop Removal

The latest innovation in coal mining in the Appalachians is mountaintop removal, a method that exposes coal seams faster and more cheaply than deep mining or strip mining. Mountaintops are blasted away, and up to 250 million cubic yards of earth and rock are leveled into the surrounding valleys. The effects on the local environment can be devastating.

Boston's Big Dig

The Big Dig is officially named the Central Artery/Tunnel Project in Boston. It's a 3.5 mile tunnel to route vehicle traffic underneath the city. Construction began in 1991 and sections of the tunnel were opened between 2003 and 2006. The initial cost of the project was estimated to be $2.8 billion, but the final cost was close to $15 billion. Charges of corruption, inadequate materials, and a fatal collapse accompanied the project. The completed tunnel saw the excavation of 16 million cubic yards of earth.

The Delta Works

The Dutch have been building dikes to hold back the ocean for over 2,000 years. Today, 27% of The Netherlands is below sea level. When the sea encroaches, water is pumped back out, traditionally with windmill power, and in modern times with diesel and electric pumps. The Delta project was launched as a reaction to the North Sea Flood of 1953 that killed 1,836 people. It consisted of raising the height of 10,250 miles of dikes to levels that would protect the country from unexpectedly high sea floods. Construction of the original plan was completed in 1997. Statistics are hard to pin down because the Delta Works are seen as a series of projects, but it's been said that millions and millions of cubic feet of earth have been moved, with more added every year as land reclamation and improvement projects continue.