Global warming’s asserted impact on the oceans – and especially sea level rise – took center stage in last week’s House climate hearings. Democrats repeatedly hammered the message that global warming is causing sea level rise to accelerate, with catastrophic results this century if we don’t act immediately to reduce greenhouse gas emissions. The hearings called to mind a sea level rise paper climate scientist Judith Curry published in November 2018. The paper shows there has been no acceleration in sea level rise in recent decades, eviscerating the claims of alarmists.
Among Curry’s key findings:
• The pace of sea level rise between 1920 and 1950 – when carbon dioxide emissions were relatively minimal – was similar to the pace of sea level rise today. “The emergence of fossil fuel emissions prior to 1950 did not contribute significantly to 19th and early 20th century sea level rise,” writes Curry. As such, the pace of sea level rise in recent decades is indistinguishable from the pace of natural internal variability.
• Some coastal regions experience more sea level rise than others, but “in many of the most vulnerable coastal locations, the dominant causes of local sea level rise problems are natural oceanic and geologic processes and land use practices.”
• Land practices that influence local sea level rise “include sediment compaction from building loads, reduced sediment delivery to the coast, and extraction of subsurface resources such as groundwater, gas and petroleum.”
• To the extent sea level rises in coastal marsh regions, “Marshes naturally keep pace with sea level rise by trapping sediment and growing plants.”
• The melting of ice from land masses adds water to the oceans, but the loss of the ice’s weight triggers a rise in the land mass. While more water is added to the oceans, the rising of land masses increases the volume of the ocean basins, allowing the oceans to hold more water without raising sea level as much as would otherwise be expected relative to the land mass.
• Perhaps the most important finding is that satellite instrument measurements of global sea level show absolutely no recent acceleration. Although government-funded scientists who handle the satellite data report a modest recent acceleration, the entirety of the reported acceleration is fictitious. The government gatekeepers of satellite sea level measurements add a fictitious 3.1 mm per year to the observed sea level rise to ‘compensate’ for the rising land masses and measure the volume of water in the ocean basins. However, an increase in the volume of the ocean basin is irrelevant to global warming policy discussions; all that matters is the sea level relative to the coasts. Remove the fictitious 3.1 mm of fictitious ocean rise and there has been no recent increase in the pace of sea level rise.