Sea Level Rise Is Accelerating: 4 Inches Per Decade (or More) by 2100

Sea Level Rise Is Accelerating: 4 Inches Per Decade (or More) by 2100

SOURCE: Inside Climate News DATE: February 12, 2018 SNIP: The rate of sea level rise is accelerating so fast that some coastal communities could confront an additional 4 inches per decade by the end of the century—a growing concern now confirmed by thorough measurements from space. At that rapid pace of change, vulnerable communities might not be able to keep up. Storm surges will increase erosion and damage homes, businesses and transportation infrastructure in some areas. In other places, seawater will intrude on freshwater aquifers. In South Asia and the islands, people will lose the land where they live and farm. And the changes will arrive much faster than they do today. Some scientists also warn that a rapid disintegration of Antarctica’s ice sheets could push sea level up much faster and higher, by as much as 4 to 10 feet by...
Unstable East Antarctic Ice Sheet Could Spell Catastrophe

Unstable East Antarctic Ice Sheet Could Spell Catastrophe

SOURCE: Truthdig DATE: January 14, 2018 SNIP: New research has confirmed one of the worst nightmares of climate science: the instability of the East Antarctic ice sheet. [R]esearchers have confirmed that one stretch of the southern polar coastline has melted many times in the past: by enough to raise sea levels by three to five metres. US scientists report in the journal Nature that they went to what they called the Sabrina Coast of eastern Antarctica to look for geological and geophysical evidence of change. Although the western region, and the Antarctic peninsula, is warming swiftly, for decades scientists have assumed that the great mass of ice in the eastern Antarctic was stable. But last year a research team looked more closely at meltwater flow from one of the region’s glaciers and concluded that it was not stable, and that any melting could result in a dramatic rise in sea levels. The latest study confirms that suspicion. “It turns out that for much of the East Antarctic Ice Sheet’s history, it was not the commonly perceived large stable ice sheet with only minor changes in size over millions of years,” said Sean Gulick, of the University of Texas Institute for Geophysics, one of those who led the study. “Rather, we have evidence for a very dynamic ice sheet that grew and shrank significantly between glacial and interglacial periods. There were also often long intervals of open water along the Sabrina Coast, with limited glacial influence.” And his co-author Amelia Shevenell from the University of South Florida said: “As ice melts, global sea levels rise. Most of Florida is at...
Floods seen as warning of Boston’s future

Floods seen as warning of Boston’s future

SOURCE: Boston Globe DATE: January 6, 2018 SNIP: With its gradually sinking, low-lying lands, and development right up to the water’s edge, Boston has long been considered uncommonly vulnerable to rising sea levels. But that long-term climate forecast became bracingly immediate on Thursday when a powerful winter storm, of a type known to meteorologists as the bomb cyclone, whipped up a record tide that sent waves surging through the streets of downtown Boston. City officials have begun planning for the worst in recent years, driven by projections that as much as 30 percent of city land could be submerged by the end of the century. Still, many were stunned by the sight of water inundating large swaths of the city’s waterfront Thursday, even as they warned that it could become all too familiar in the years to come. A 2016 study by scientists at the University of Massachusetts and other local universities found that consequences of climate change could prove more calamitous to Boston than previous studies have suggested. That study found that sea levels could rise 10 feet by the end of the century and 37 feet by 2200 — nearly double what had been previously predicted. That projection was based in part on new research that suggests the accelerating melt of the ice sheets covering Antarctica will have a disproportionate impact on cities along the East...
The Bottom of the Ocean Is Sinking

The Bottom of the Ocean Is Sinking

SOURCE: LiveScience DATE: January 4, 2018 SNIP: The bottom of the ocean is more of a “sunken place” than it used to be. In recent decades, melting ice sheets and glaciers driven by climate change are swelling Earth’s oceans. And along with all that water comes an unexpected consequence — the weight of the additional liquid is pressing down on the seafloor, causing it to sink. Consequently, measurements and predictions of sea-level rise may have been incorrect since 1993, underestimating the growing volume of water in the oceans due to the receding bottom, according to a new study. [Scientists] found that around the world for two decades, ocean basins deformed an average of 0.004 inches (0.1 millimeter) per year, with a total deformation of 0.08 inches (2 mm). However, there were distinct regional patterns to the seafloor’s bending and stretching, and the amount of sag in certain parts of the ocean bottom could be significantly higher — as much as 0.04 inches (1 mm) per year in the Arctic Ocean, for a total of 0.8 inches (20 mm), the study authors reported. As a result, satellite assessments of sea-level change — which don’t account for a sinking ocean bottom — could be underestimating the amount that seas are rising by 8 percent, according to the...
Antarctic Modeling Pushes Up Sea-Level Rise Projections

Antarctic Modeling Pushes Up Sea-Level Rise Projections

SOURCE: Climate Central DATE: December 13, 2017 SOURCE: Antarctic ice sheet models double the sea-level rise expected this century if global emissions of heat-trapping pollution remain high, according to a new study led by Dr. Robert Kopp of Rutgers University and co-authored by scientists at Climate Central. The new study, “Evolving understanding of Antarctic ice-sheet physics and ambiguity in probabilistic sea-level projections,” projects a range of potential levels of sea rise under different greenhouse gas emissions scenarios. Even the lowest levels of projected sea-level rise would require heavy investments in adaptation efforts and could require residents and businesses to relocate. Greater levels of sea-level rise increase economic and social impacts. The median projection for sea-level rise from 2000 to 2050 in the study was roughly 30 cm (one foot) under RCP8.5. The research indicated that sea levels in 2050 will be affected little by the amount of greenhouse gas pollution that’s released during the coming years. The new projections warn of runaway risks during the second half of the century, with those risks substantially higher if current levels of greenhouse gas emissions...