Satellites show warming is accelerating sea level rise

February 13, 2018 by  
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Melting ice sheets in Greenland and Antarctica are speeding up the already fast pace of sea level rise, new satellite research shows.

At the current rate, the world’s oceans on average will be at least 2 feet (61 centimeters) higher by the end of the century compared to today, according to researchers who published in Monday’s Proceedings of the National Academies of Sciences.

Sea level rise is caused by warming of the ocean and melting from glaciers and ice sheets. The research, based on 25 years of satellite data, shows that pace has quickened, mainly from the melting of massive ice sheets. It confirms scientists’ computer simulations and is in line with predictions from the United Nations, which releases regular climate change reports.

“It’s a big deal” because the projected sea level rise is a conservative estimate and it is likely to be higher, said lead author Steve Nerem of the University of Colorado.

Outside scientists said even small changes in sea levels can lead to flooding and erosion.

“Any flooding concerns that coastal communities have for 2100 may occur over the next few decades,” Oregon State University coastal flooding expert Katy Serafin said in an email.

Of the 3 inches (7.5 centimeters) of sea level rise in the past quarter century, about 55 percent is from warmer water expanding, and the rest is from melting ice.

But the process is accelerating, and more than three-quarters of that acceleration since 1993 is due to melting ice sheets in Greenland and Antarctica, the study shows.

Like weather and climate, there are two factors in sea level rise: year-to-year small rises and falls that are caused by natural events and larger long-term rising trends that are linked to man-made climate change. Nerem’s team removed the natural effects of the 1991 Mt. Pinatubo eruption that temporarily chilled Earth and the climate phenomena El Nino and La Nina, and found the accelerating trend.

Sea level rise, more than temperature, is a better gauge of climate change in action, said Anny Cazenave, director of Earth science at the International Space Science Institute in France, who edited the study. Cazenave is one of the pioneers of space-based sea level research.

Global sea levels were stable for about 3,000 years until the 20th century when they rose and then accelerated due to global warming caused by the burning of coal, oil and natural gas, said climate scientist Stefan Rahmstorf of the Potsdam Institute in Germany, who wasn’t part of the study.

Two feet of sea level rise by the end of the century “would have big effects on places like Miami and New Orleans, but I don’t still view that as catastrophic” because those cities can survive — at great expense — that amount of rising seas under normal situations, Nerem said.

But when a storm hits like 2012’s Superstorm Sandy, sea level rise on top of storm surge can lead to record-setting damages, researchers said.

Some scientists at the American Geophysical Union meeting last year said Antarctica may be melting faster than predicted by Monday’s study.

Greenland has caused three times more sea level rise than Antarctica so far, but ice melt on the southern continent is responsible for more of the acceleration.

“Antarctica seems less stable than we thought a few years ago,” Rutgers climate scientist Robert Kopp said.

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Follow Seth Borenstein on Twitter at @borenbears . His work can be found here .

Volvo Ocean Race Research Finds Microplastics In Remote Areas

February 13, 2018 by  
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Research

Published on February 12th, 2018
by Steve Hanley

 

February 12th, 2018 by


The Volvo Ocean Race is one of the most grueling sporting contests in the world. The teams race a total of 46,000 miles over a period of 9 months. Each leg is roughly 6,000 miles long and takes up to 3 weeks to complete — three weeks in which the sailors often get by on a few hours of sleep a day and eat reconstituted freeze dried food for breakfast, lunch, and dinner. For a brief introduction to what they experience out on the water, where wind speeds can exceed 50 miles per hour, check out the video below.

 

The theme of this year’s race is raising awareness of about the massive amounts of plastic debris that is floating in the ocean’s of the world. Leaving Hong Kong last week, one team got its keel tangled up with some plastic sheeting and had to sail backward briefly to get rid of it. One of the seven teams in the competition is called Turn The Tide On Plastic and is sponsored by the Mirpuri Foundation, a nonprofit foundation based in Portugal that is deeply involved in ocean plastic research.

Microplastics Found In Remote Areas

The course this year included a stopover in Cape Town, South Africa before heading across the South Indian Ocean to Melbourne, Australia. Turn The Tide On Plastic used special equipment along the way to take samples of the ocean water it was travelling through. When it reached Melbourne, those samples were flown to the Geomar Helmholtz Center for Ocean Research located in Kiel, Germany. There they were analyzed.

Researcher Sören Gutekunst reports the samples taken from the South Indian Ocean — an area of the world that is devoid of most human activity, showed 42 particles of plastic per cubic meter — an unexpectedly high number given the remoteness of the area.

“Data on microplastics has not been taken from this extremely remote area before and what we found was relatively high levels,” Gutekunst tells The Guardian. “There are places in the ocean which are not being observed and that is why it is so special for us to be doing this. It is amazing that we have the opportunity and this could lead to much further knowledge about what is happening with microplastics in the ocean.”

Other samples collected during the race showed the highest microplastic levels around Europe’s north Atlantic and Mediterranean coasts, ranging from 180 to 307 particles per cubic meter. High levels were also recorded off the coast of Cape Town — 152 per cubic meter — and the Australian coast — 115 particles per cubic meter.

Plastics Found 6 Miles Down In The Marianas Trench

Perhaps the most startling news about contamination in the ocean was reported a year ago by researchers at the University of Newcastle in the UK. Small crustaceans that live at the bottom of the Marianas Trench in the Pacific Ocean — the deepest part of the ocean known —  were harvested by a robotic underwater research vessel. They were found to have 50 times more toxic chemicals in their bodies than crabs that live in polluted waterways in China..

“We still think of the deep ocean as being this remote and pristine realm, safe from human impact, but our research shows that, sadly, this could not be further from the truth,” said Alan Jamieson, who led the research. “The fact that we found such extraordinary levels of these pollutants really brings home the long term, devastating impact that mankind is having on the planet.”

Some people, many of whom are now employed in the Trump administration, pooh pooh such concerns. They believe the earth, the atmosphere, and the oceans are so enormous that no amount of human activity could possible have an effect on them. They are wrong. Using the planet we live on as a communal cesspool is simply arrogant and unbelievably stupid. The fact that corporations have been doing so for so long in the pursuit of profits is criminally negligent. Cleaning up the mess humanity has made will take centuries and hundreds of trillions of dollars. But the implications of not doing so are simply unthinkable.

 


 

 

About the Author

Steve writes about the interface between technology and sustainability from his home in Rhode Island. You can follow him on Google + and on Twitter.