NASA: Rising Sea Levels More Dangerous Than Thought. The consequences of global sea level rise could be even scarier than the worst-case scenarios predicted by the dominant climate models, which don't fully account for the fast breakup of ice sheets and glaciers, NASA scientists said today (Aug. 26) at a press briefing.
What's more, sea level rise is already occurring. The open question, NASA scientists say, is just how quickly the seas will rise in the future. Rising seas The current warming of the seas and the associated expansion of their waters account for about one-third of sea level rise around the world. "When heat goes under the ocean, it expands just like mercury in a thermometer," Steve Nerem, lead scientist for NASA's Sea Level Change Team at the University of Colorado in Boulder, said in the press briefing. The remaining two-thirds of sea level rise is occurring as a result of melting from ice sheets in Greenland and Antarctica and mountain glaciers, Nerem said.
Unpredictable pace American impact. Seas Are Rising at Fastest Rate in Last 28 Centuries. Western Illinois University Libraries -- Remote User Authentication. Sea Level. Study Reveals Stunning Acceleration of Sea Level Rise. The oceans have heaved up and down as world temperatures have waxed and waned, but as new research tracking the past 2,800 years shows, never during that time did the seas rise as sharply or as suddenly as has been the case during the last century. The new study, the culmination of a decade of work by three teams of farflung scientists, has charted what they called an “acceleration” in sea level rise that’s triggering and worsening flooding in coastlines around the world.
The findings also warn of much worse to come. The scientists reported in a paper published Monday in Proceedings of the National Academy of Sciences that they have greater than 95 percent certainty that at least half of more than 5 inches of sea level rise they detected during the 20th century was directly caused by global warming. By trapping heat, rising concentrations of atmospheric pollution are causing glaciers and ice sheets to melt into seas, lifting high tides ever higher. Climate Change and Impacts of Sea Level Rise. Global mean sea levels are rising and are predicted to continue to rise for the foreseeable future.
Because the projected rates of global mean sea-level rise (SLR) over the next century far exceed those observed in the past several thousand years, the potential exists for historically unprecedented impacts to the natural and built infrastructure occurring along coastlines. Plausible, risk-based scenarios estimate that global sea level could increase by roughly up to 2 meters by 2100 if Greenland ice sheet melt accelerates with regional and local effects adding to or subtracting from the global mean. SLR has the potential to affect existing coastal infrastructure critical to the Department of Defense (DoD). Potential local effects projected by changes in sea level also must account for associated coastal storms, tides, and inland precipitation and runoff. Environmental effects induced by SLR are far reaching and will differ based on the geophysical setting.
Images Show Impact of Sea Level Rise on Global Icons. Long-term sea level rise set in motion by near-term carbon emissions threatens major coastal cities across the world. Here we present paired images showing how iconic locations — in London, Shanghai, Mumbai, Sydney, Rio de Janeiro, Durban and New York — could fare under scenarios of business as usual vs. a sharp transition to clean energy. In the first image for each pair, we show projections of post-2100 sea level rise that could be locked in following 4°C (7.2°F) of warming from carbon pollution in the coming decades. This pathway corresponds roughly to business as usual. In the second image, we show projections based on 2°C (3.6°F) of warming from carbon pollution.
This degree of warming corresponds to the target limit widely discussed today as the threshold to avoid catastrophic climate change — and officially designated as part of the Cancun Agreement, signed in 2010 by international delegates gathered under the umbrella of the United Nations. Global Warming Effects on Sea Level. Higher seas endanger coastal communities—where 40 percent of the world's population lives—and threaten groundwater supplies. Two major mechanisms are causing sea level to rise. First, shrinking land ice, such as mountain glaciers and polar ice sheets, is releasing water into the oceans. Second, as ocean temperatures rise, the warmer water expands. Trapped within a basin bounded by the continents, the water has nowhere to go but up. In some parts of the world, especially low-lying river deltas, local land is sinking (known as subsidence)—making sea levels that much higher. The consequences of sea level rise include: Threats to coastal communities.
See references. Sea Level Rise -- National Geographic. Core samples, tide gauge readings, and, most recently, satellite measurements tell us that over the past century, the Global Mean Sea Level (GMSL) has risen by 4 to 8 inches (10 to 20 centimeters). However, the annual rate of rise over the past 20 years has been 0.13 inches (3.2 millimeters) a year, roughly twice the average speed of the preceding 80 years. Over the past century, the burning of fossil fuels and other human and natural activities has released enormous amounts of heat-trapping gases into the atmosphere. These emissions have caused the Earth's surface temperature to rise, and the oceans absorb about 80 percent of this additional heat. The rise in sea levels is linked to three primary factors, all induced by this ongoing global climate change: Thermal expansion: When water heats up, it expands. About half of the past century's rise in sea level is attributable to warmer oceans simply occupying more space.
Consequences How High Will It Go? Rivers of meltwater on Greenland’s ice sheet contribute to rising sea levels. Learning Zone Class Clips - Coastlines affected by sea level change - isostasy - Geography Video. Case Study the effect of sea level rise on East Anglia. Climate change could leave sharks unable to hunt. The dogfish isn't happy about ocean acidification. (Danielle Dixson) As more and more carbon dioxide enters the atmosphere, the ocean is acidifying too quickly for sharks to keep up. For at least one species, the cost could be the vital sense of smell. Without its ability to detect the odors of prey, the smooth dogfish could be left high and dry. And chances are that the smooth dogfish isn't the only marine life that will see this effect. The finding, in a study published last month in the journal Global Change Biology, continues lead author Danielle Dixson's work in clownfish. The experiment in progress, with a shark being exposed to plumes of squid stink.
In the experiment, the sharks were exposed to the smell of squid — a dogfish delicacy — in pools with different levels of carbon dioxide, which makes the water more acidic. In clownfish, this effect was caused by the fish's natural defense mechanisms. 5 Scary Effects Of Climate Change That Could Happen In Your Lifetime. Sea level rise will swallow Miami, New Orleans, study finds. Say goodbye to Miami and New Orleans. No matter what we do to curb global warming, these and other beloved US cities will sink below rising seas, according to a study Monday. But making extreme carbon cuts and moving to renewable energy could save millions of people living in iconic coastal areas of the United States, said the findings in the October 12 edition of the Proceedings of the National Academy of Sciences, a peer-reviewed US journal. Scientists have already established that if we do nothing to reduce our burning of fossil fuel up to the year 2100, the planet will face sea level rise of 14-32 feet (4.3–9.9 meters), said lead author Ben Strauss, vice president for sea level and climate impacts at Climate Central.
The big uncertainty is the issue of when. "Some of this could happen as early as next century," Strauss told AFP. "But it might also take many centuries," he added. "Just think of a pile of ice in a warm room. Too late? "New Orleans is a really sad story," Strauss said. What the Earth would look like if all the ice melted. What causes sea levels to change. Earth Under Water - Worldwide Flooding | Sea Level Rise (SLR)
Antarctic ice is melting so fast the whole continent may be at risk by 2100 | Environment. Antarctic ice is melting so fast that the stability of the whole continent could be at risk by 2100, scientists have warned. Widespread collapse of Antarctic ice shelves – floating extensions of land ice projecting into the sea – could pave the way for dramatic rises in sea level. The new research predicts a doubling of surface melting of the ice shelves by 2050. By the end of the century, the melting rate could surpass the point associated with ice shelf collapse, it is claimed. If that happened a natural barrier to the flow of ice from glaciers and land-covering ice sheets into the oceans would be removed.
Lead scientist, Dr Luke Trusel, Woods Hole Oceanographic Institution in Massachusetts, US, said: “Our results illustrate just how rapidly melting in Antarctica can intensify in a warming climate. “This has already occurred in places like the Antarctic Peninsula where we’ve observed warming and abrupt ice shelf collapses in the last few decades. Melting ice in west Antarctica could raise seas by three metres, warns study | Environment. A key area of ice in west Antarctica may already be unstable enough to cause global sea levels to rise by three metres of ocean rise, scientists said on Monday. The study follows research published last year, led by Nasa glaciologist Eric Rignot, warning that ice in the Antarctic had gone into a state of irreversible retreat, that the melting was considered “unstoppable” and could raise sea level by 1.2 metres.
This time, researchers at Germany’s Potsdam Institute for Climate Impact Research pointed to the long-term impacts of the crucial Amundsen Sea sector of west Antarctica, which they said “has most likely been destabilized”. While previous studies “examined the short-term future evolution of this region, here we take the next step and simulate the long-term evolution of the whole west Antarctic ice sheet,” the authors said in the Proceedings of the National Academy of Sciences.
They used computer models to project the effects of 60 more years of melting at the current rate. Arctic Glacier collapses . Too close for comfort. 5 terrifying impacts of rising sea levels. Sign up, Online Whiteboard | RealtimeBoard.