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Research & Commentary: Heartland Brief Shows No Evidence of Accelerated Sea-Level Rise

June 4, 2019

No Evidence Of Acceleration In Rise Of Global Sea Levels Since 1920s

A new Policy Brief from The Heartland Institute shows there is no evidence of acceleration in the rise of global sea levels since the 1920s and concludes the U.N. Intergovernmental Panel on Climate Change’s (IPCC) concerns over this issue is “without merit.”

The Policy Brief, titled “Global Sea Level Rise: An Evaluation of the Data,” authored by Dr. Craig Idso, chairman of the Center for the Study of Carbon Dioxide and Global Change, Dr. David Legates, professor of climatology in the Department of Geography at the University of Delaware, and Dr. S. Fred Singer, is taken from a chapter of Climate Change Reconsidered II: Fossil Fuels, a report from the Nongovernmental International Panel on Climate Change (NIPCC).

According to IPCC’s Fifth Assessment Report, “it is very likely that the rate of global mean sea level rise during the 21st century will exceed the rate observed during 1971–2010 for all Representative Concentration Pathway (RCP) scenarios due to increases in ocean warming and loss of mass from glaciers and ice sheets.”

However, Idso, Legates, and Singer argue “sea-level rise is a research area that has recently come to be dominated by computer models. Whereas researchers working with datasets built from long-term coastal tide gauges typically report a slow linear rate of sea-level rise, computer modelers assume a significant anthropogenic forcing and tune their models to find or predict an acceleration of the rate of rise.”

They note local sea-level trends “vary considerably because they depend not only on the average global trend, but also on tectonic movements of adjacent land. In many places vertical land motion, either up or down, exceeds the very slow global sea-level trend. Consequently, at some locations sea level is rising much faster than the global rate, and at other locations sea level is falling.”

For example, in Stockholm, Sweden, sea-level rise is “negative due to regional vertical land motion.” The water intrusion problems around the Chesapeake Bay in Virginia and Maryland are also not due to sea-level rise, but instead to land subsidence (the sinking of the land surface) from human activity such as groundwater depletion.

Instead of accelerated sea-level rises, the authors find “the best available data” shows “evidence is lacking for any recent changes in global sea level that lie outside natural variation.” They point out that if the negative effects of the claimed accelerated rise in sea level, such as a loss of surface area, were to be visible anywhere, it would most likely be in the small islands and coral atolls in the Pacific Ocean. However, research indicates many of these islands and atolls are actually increasing in size. Simply, they are “not being inundated by rising seas due to anthropogenic climate change.”

Fears of an accelerated rise in sea levels caused by anthropogenic climate change are misplaced and overblown. Further, this fearmongering should not be used by policymakers in coastal states and cities to advocate for policies that would seek to limit or eliminate carbon dioxide emissions.   

The following documents provide more information about land subsidence, sea-level rise, and climate change.

Global Sea-Level Rise: An Evaluation of the Data
This Heartland Policy Brief authored by Dr. Craig Idso, chairman of the Center for the Study of Carbon Dioxide and Global Change, Dr. David Legates, professor of climatology in the Department of Geography at the University of Delaware, and Dr. S. Fred Singer reviews recent research to determine if there is any evidence of such an acceleration and then examines claims that islands and coral atolls are being inundated by rising seas.

Will Global Warming Overflow the Chesapeake Bay?
This NIPCC Policy Brief finds flooding problems in the Chesapeake Bay region – Maryland and Virginia, in particular – are due not to sea-level rise, but to land subsidence. Author Roger H. Bezdek explains land subsidence and relative sea-level rise; discusses the causes of land subsidence in the Chesapeake Bay region; and points out the links between groundwater withdrawals and land subsidence.

Data versus Hype: How Ten Cities Show Sea Level Rise Is a False Crisis
Dennis E. Hedke, a geophysicist and past president of the Geophysical Society of Kansas and the Kansas Geological Society, reports and analyzes real data collected from 10 coastal cities with long and reliable sea-level records in this NIPCC Policy Brief. Those cities are Ceuta, Spain; Honolulu, Hawaii; Atlantic City, New Jersey; Sitka, Alaska; Port Isabel, Texas; St. Petersburg, Florida; Fernandina Beach, Florida; Mumbai/Bombay, India; Sydney, Australia; and Slipshavn, Denmark. He concludes the fear of rising sea levels is not a justification for reducing carbon-dioxide emissions or adopting policies that would have that effect.

Climate Change Reconsidered II: Fossil Fuels
In this fifth volume of the Climate Change Reconsidered series, 117 scientists, economists, and other experts assess the costs and benefits of the use of fossil fuels by reviewing scientific and economic literature on organic chemistry, climate science, public health, economic history, human security, and theoretical studies based on integrated assessment models (IAMs) and cost-benefit analysis (CBA). (Also see the Climate Change Reconsidered II: Fossil Fuels “Summary for Policymakers”:

10,000 To 5,000 Years Ago, Global Sea Levels Were 3 Meters Higher, Temperatures 4–6° C Warmer
Climate alarmists persistently claim human-caused climate change is causing sea levels to rise to an unnatural degree. In response, No Tricks Zone has compiled a list of studies examining sea levels from around the world. Those studies show sea levels have varied radically since the end of the most recent ice age, often being several feet higher than at present. Studies show historic sea levels at locations around the globe have been much higher in recent history than now.

Why Scientists Disagree About Global Warming
In this book published by The Heartland Institute, authors Craig Idso, Robert M. Carter, and S. Fred Singer say the most important fact about climate science, which they say is often overlooked, is scientists disagree about the environmental impacts of the combustion of fossil fuels on the global climate. There is no survey or study showing “consensus” on the most important scientific issues, despite frequent claims by advocates to the contrary. Scientists disagree about the causes and consequences of climate for several reasons. The authors say the only “consensus” among climate scientists is human activities can have an effect on local climate and the sum of such local effects could hypothetically rise to the level of an observable global signal. The key questions to be answered, they say, are whether the human global signal is large enough to be measured, and if it is, does it represent or is likely to become a dangerous change outside the range of natural variability? On these questions, an energetic scientific debate is taking place on the pages of peer-reviewed science journals, say the authors.

Climate Change Reconsidered II: Physical Science
Climate Change Reconsidered II: Physical Science is an independent, comprehensive, and authoritative report on the current state of climate science, published in October 2013. It is the fourth in a series of scholarly reports produced by the Nongovernmental International Panel on Climate Change, an international network of climate scientists sponsored by three nonprofit organizations: the Center for the Study of Carbon Dioxide and Global Change, the Science and Environmental Policy Project, and The Heartland Institute. (Also see the executive summary of Climate Change Reconsidered II: Physical Science

Climate Change Reconsidered II: Biological Impacts
Released on April 9, 2014, Climate Change Reconsidered II: Biological Impacts is an independent, comprehensive, and authoritative report on the impacts of climate change on plants, terrestrial animals, aquatic life, and human well-being. (Also see the Climate Change Reconsidered II: Biological Impacts “Summary for Policymakers”:


Nothing in this Research & Commentary is intended to influence the passage of legislation, and it does not necessarily represent the views of The Heartland Institute. For further information on this subject, visit Environment & Climate News, The Heartland Institute’s website, and PolicyBot, Heartland’s free online research database.

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