Overview

• A Harvard-led study in Geophysical Research Letters found that about 7,000 dams built from 1835 to 2011 shifted Earth’s rotational axis by roughly one meter.
• These dams trapped enough water to lower global sea levels by 21 mm, an amount comparable to twice filling the Grand Canyon.
• Dams in North America and Europe from 1835 to 1954 drove a 20.5 cm eastward shift of the North Pole.
• From 1954 to 2011, reservoir construction in East Africa and Asia caused a 57 cm westward pole movement.
• Researchers estimate that without dam-induced water storage, 20th-century sea-level rise would have been about 25% greater.