Those who argue human greenhouse gas emissions are causing dangerous climate change regularly point to rising sea levels as one of the most certain and devastating impacts on human communities.
Environmental activists, mainstream media outlets, and many scientists routinely claim unless governments take drastic action to transform the world’s economic system, including ending the use of fossil fuels, island nations will disappear beneath the seas and low-lying coastal cities will be swamped, forcing a great migration of populations inland.
The most recent fairy tale was published in Nature. Its author’s assert, without any evidence to back their claim up, that sea levels could rise up to four feet by the year 2100. EcoWatch’s story about the report is typical of much of the fawning alarmist media’s coverage.
Without asking questions any respectable investigative journalist would have raised, EcoWatch pronounces, “If nations fail to act, and current emissions lead to warming of 4.5 degrees, then sea levels are predicted to rise between 0.6 and 1.3 meters by 2100 and between 1.7 and 5.6 meters by 2300. The predictions are based on a survey of 106 of the world’s leading sea level researchers ….”
Note the report is based on a survey of so-called experts, not real world evidence. By contrast to “expert opinion,” hard data show ocean levels are not rising at an unusually rapid rate in historical terms. Sea level is currently rising at a pace of approximately 1 foot per century. This means, in the words of my colleague at The Heartland Institute, award winning meteorologist Anthony Watts, “sea level rise would have to—immediately, starting today—quadruple its pace and sustain that quadrupled pace without interruption for all of the next 80 years.”
Key to the prediction made in the Nature paper is the assertion that many massive Antarctic ice sheets will imminently collapse into the sea. Yet Dan Martin, a computational scientist at Lawrence Berkeley National Lab, explained to The Atlantic his and his colleagues’ work indicates recent claims that massive ice sheets in Antarctica were becoming unstable and prone to collapse might “simply be a product of running a computer model of ice physics at a too-low resolution.”
In fact, the best evidence indicates ice and snow is accumulating in Antarctica, not declining. Research from NASA indicates Antarctic snow accumulation that began 10,000 years ago, produced a net gain of 112 billion tons of ice a year from 1992 to 2001, falling to 82 billion tons of ice per year from 2003 to 2008, swamping the isolated losses at the edge of the continent’s thinning glaciers. Thus, Antarctica has been modestly reducing net rising sea levels for decades.
Beyond whatever is happening in Antarctica, another 2019 report by Drs. Craig Idso, David Legates, and the late, S. Fred Singer, confirms sea levels have not been rising at an unusual rate in recent years. After examining long-term data from tidal gauges and other sources, the scientists concluded the amount of sea level increase Earth has experienced over the past century is not unusual historically, nor has the rate of rise increased significantly over the past few decades. As Idso, Legates, and Singer put it, “the highest quality coastal tide gauges from around the world show no evidence of acceleration since the 1920s.”
The disconnect between data recorded by the global tidal gauge system and projections made by various purported climate authorities is due to the fact that “[l]ike ice melting, sea-level rise is a research area that has recently come to be dominated by computer models,” write the authors. “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.”
Global sea levels have risen by approximately 400 feet since the beginning of the end of the most recent ice age—approximately 20,000 years ago—with the rate of sea level slowing and increasing on the order of tens, hundreds, and thousands of years over the past 20,000 years, having nothing whatsoever to do with human activities.
Human actions, such as the construction of barriers, the channelization of rivers, the conversion of coastal wetlands to densely-populated metropolitan areas, and the draining of coastal aquifers for human consumption have undoubtedly made some coastal regions and populations more vulnerable to rising seas. However, there is little evidence increased greenhouse gas emissions are contributing to rising oceans.
In short, despite the media furor this new Nature study has generated, its predictions of sea level rise are preposterous, not supported by facts, and should be treated as we treat other popular delusions: exposed, explained, and dismissed.
Our knowledge of previous interglacial cycles indicates seas will continue rising unless and until the next ice age comes, notwithstanding any efforts humanity makes to stem the rising tides. Like the efforts of the apocryphal story of King Canute, they are bound to fail.
Although it makes sense to prepare for rising seas by hardening coastal areas, discouraging poorly designed coastal development, and making people living along coasts aware investments made there could be swallowed by rising water, ending the use of fossil fuels, and giving ever larger government increasing power over peoples’ lives will not stop seas from rising, but instead will only serve to make the world’s people poorer and less free.
H. Sterling Burnett, Ph.D. ([email protected]) is a senior fellow on energy and the environment at The Heartland Institute, a nonpartisan, nonprofit research center headquartered in Arlington Heights, Illinois.