An honest view of sea level change?

Writing for the National Parks Traveller, ecologist  Daniel Botkin claims

the sea level has been rising since the end of the last Ice Age, starting about 14,000 years ago as the continental and mountain glaciers have melted and sea water has expanded with the overall warming. The average rate has been about a foot or two a century (about 23-46 cm per century). Data suggest that the rate was much greater until about 8,000 years ago.

Time to look at the evidence, conveniently published by Lambeck et al a couple of weeks ago.

Solution for the ice-volume Equivalent Sea Level (esl) function and change in ice volume. (A) Individual esl estimates (blue) and the objective estimate of the denoised time series (red line). Inset gives an expanded scale for the last 9,000 y. (B) The same esl estimate and its 95% probability limiting values. Also shown are the major climate events in the interval [the Last Glacial Maximum (LGM), Heinrich events H1 to H3, the Bølling-Allerød warm period (B-A), and the Younger Dryas cold period (Y-D)] as well as the timing of MWP-1A, 1B, and the 8.2 ka BP cooling event. (C) The 95% probability estimates of the esl estimates. (D) Estimates of sea-level rate of change.

Solution for the ice-volume Equivalent Sea Level (esl) function and change in ice volume. (A) Individual esl estimates (blue) and the objective estimate of the denoised time series (red line). Inset gives an expanded scale for the last 9,000 y. (B) The same esl estimate and its 95% probability limiting values. Also shown are the major climate events in the interval [the Last Glacial Maximum (LGM), Heinrich events H1 to H3, the Bølling-Allerød warm period (B-A), and the Younger Dryas cold period (Y-D)] as well as the timing of MWP-1A, 1B, and the 8.2 ka BP cooling event. (C) The 95% probability estimates of the esl estimates. (D) Estimates of sea-level rate of change.

At no time during the last 14 kBP has the sea level rise been 23-46 cm/century. Before 7 kBP, the sea level rose much faster than this. Since 7 kBP, the rate is much lower than this. In the last 3 kBP, the period of most relevance for comparing the modern rise, there was only minor (<20 cm) variability is sea level. Botkin’s numbers are without foundation, designed to distract from the anthropogenic contribution to sea-level rise.

Botkin goes on to cite Ross McKitrick paper approvingly

An important scientific paper published September 1 this year states that Earth’s surface temperature has not changed for the past 19 years, and 16-26 years for the lower atmosphere.

Well at least he gets the publication date correct.

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About richard telford

Ecologist with interests in quantitative methods and palaeoenvironments
This entry was posted in climate, Fake climate sceptics, Silliness and tagged . Bookmark the permalink.

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