A new peer-reviewed study published in the Journal of Marine Science and Engineering challenges a key claim of climate science: that global sea level rise is accelerating. An analysis of more than 200 long-term tide gauge records shows no evidence of such acceleration, while IPCC models systematically overestimate local sea level rise.

An analysis of more than 200 tide stations around the world shows that there is no evidence of a global acceleration in sea level rise.

That is the surprising conclusion of the paper A Global Perspective on Local Sea Level Changes, published this week in the Journal of Marine Science and Engineering. It is a unique study by two Dutch researchers, Hessel Voortman and Rob de Vos. Clintel has the story.

The paper also shows that IPCC models significantly overestimate local sea level rise in 2020.

This new publication is a follow-up to an earlier paper from 2023 in which first author Hessel Voortman demonstrated that sea level rise along the Dutch coast was not accelerating.

These two paragraphs are the opening of a press release sent out on August 29 by engineer Hessel Voortman. Voortman spoke about his sea level research at the Clintel conference last year. Together with Rob de Vos (blogger at klimaatgek.nl), he has now published a scientific paper in which they demonstrate that sea levels are not rising at an accelerated rate worldwide.

This is a spectacular result because climate scientists have been crying wolf about accelerating sea level rise in recent years. We will see whether this paper will receive as much media attention as the University of Utrecht modelling work earlier this week, which was used to make claims about the stagnation of the Atlantic Meridional Overturning Circulation (AMOC).

The climate is a sensitive subject. Since the IPCC appropriated the subject of ‘climate change’, what was once a hypothesis now seems to be an unshakeable ‘fact’: the climate is changing, CO2 is the culprit, and humans are to blame. The fact that it is all a bit more complicated and that consensus (if it even exists) in science is meaningless are slowly gaining ground. This is difficult, because the opposing forces (one-sided scientific research, political pressure, constant one-sided reporting, etc.) are strong.

One of the ‘crown jewels’ of what I call the IPCC narrative, is rising sea levels. Now, rising sea levels are nothing unusual. Since the end of the last ice age (about 15,000 years ago), sea levels have risen by about 120 meters. It was not so long ago that ‘we’ could reach England on foot (across what is now the bottom of the North Sea). A thick coat was desirable, because at the end of the most recent ice age, the Weichselian glaciation, our region had a tundra climate.

Rising temperatures from around 15,000 years ago caused ocean water levels to rise, initially rapidly and then more slowly, as shown in Figure 2. The graph is based on data from three publications by Fleming et al. 1998 and Milne et al. 2005. The main causes of this sea level rise were the melting of two ice caps in Scandinavia and North America and the expansion of ocean water as a result of warming.

In the modern era, sea levels are still rising, at an average rate of 1.7 ± 0.4 mm/year between 1901 and 2022 (Deltares). In recent years, there have been reports of an acceleration in sea level rise due to the enhanced greenhouse effect. In its latest report from 2021, the Intergovernmental Panel on Climate Change (IPCC) stated that sea levels have been rising at an increasing rate since 1900, in other words, that there has been a global acceleration in sea level rise.

Based on this, sea level models were developed that predicted fairly extreme sea levels for 2100.

Figure 3 shows the forecast of KNMI for sea levels on the Dutch coast up to 2100. According to KNMI, these could rise with more than 120 cm by 2100 (relative to the 1995-2014 average).

In an article from 2024, I calculated for the five Dutch coastal stations, that the relative sea level rise from 1900 to 2022 was 1.92 mm/year. If you subtract the average land subsidence along the coast from this, you arrive at an absolute sea level rise on the Dutch coast of 1.45 mm/year.

Read the full story here.