Climate change and the rise and fall of sea level over the millennium



Average rates of relative sea level rise (RSLR) along the coast of the eastern United States were 1–2 mm/yr over the last 2,000 years. Higher rates have occurred in recent centuries, and their onset seems to have preceded the period of modern global warming. A modest rate increase started in the 17th century, well before the modern global warming of this century, but the highest rates have occurred during the last 200 years, with a major acceleration around 1800 A.D. No significant acceleration is apparently associated with the rapidly rising temperatures of the last 100 years.

How does one establish possible relationships between rates of sea level rise and climate fluctuations? Tide-gauge records are too short and noisy to derive a quantitative, empirical relationship between relative sea level rise rates and climate change [Douglas, 1992], and predictions of future rates of sea level rise are largely based on theory. The recent geological record can provide empirical insights, which can be applied toward the assessment of current rates and those predicted for the next century.