tagged w/ thermal expansion
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From site: "Since we have such an active community of armchair oceanographers and spreadsheet Glaciologists here, I thought it would be useful to speak to the real thing, the people who actually spend time on the ocean, on the ice sheets, do the measurements, and come back to share that knowledge with us. I had just that opportunity at the American Geophysical conference in December.
I spoke to Josh Willis, Oceanographer with NASA at the Jet Propulsion Lab – Josh is one of best known young ocean scientists on the planet. He pointed me to the recent Kemp et al study of tidal marshes on the US East coast, which has produced a long record of sea level over the last 2000 years, complete with a very Hockey-stickish uptick during the last 200 or so.
Jason Box of the Byrd Polar Center at Ohio State was there, presenting evidence of acceleration in Greenland ice loss over the last 200 years. His bottom line – “If we talk 10 years from now, my expectation is that Greenland will be losing roughly double what it is now.”
I round out the video with takes from old pros lead NASA scientist Jim Hansen and Admiral David Titley, the US Navy’s Chief Oceanographer.
More at the link
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And you can time it to the second how long it will take for the usual suspects who follow me to appear...They actually think they are converting people to believing their denier "religion" over actual scientists who are measuring the oceans and glaciers and what is right in front of our eyes. Laughable.From site: "Since we have such an active community of armchair oceanographers and... more
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"The year 2010 was one the worst years in world history for high-impact floods. But just three weeks into the new year, 2011 has already had an entire year's worth of mega-floods. “ -- Meteorologist Jeff Masters
I spend hours a day researching what New York Times columnist Thomas Friedman calls “global weirding”: the destabilization of our weather system fueled by the three million tonnes of fossil fuel pollution we inject into it each hour. So it is a rare day when something shocks me as much as a recent U.S. National Aeronautics and Space Administration (NASA) report on last year’s extreme rainfall.
As most locals know from soggy personal experience, our corner of planet Earth since last spring has been a bit wetter and greyer than normal. And next door, our Washington neighbours donned their gum boots and slogged through their fourth wettest year since 1895.
Still, we got off lucky. Very lucky it turns out.
According to this jaw-dropping NASA report, worldwide rainfall and snowfall were so extreme, in so many places last year, that sea levels fell dramatically.
Sea levels have been rising steadily for over a century as the ever warmer ocean water expands and the world’s remaining glaciers and ice sheets melt. In fact sea levels are rising twice as fast now as they were a few decades ago. As the NASA chart above shows there have been some ups and downs but nothing in the modern satellite record comes close to the 6 mm drop worldwide last year.
While 6 mm might not sound like a lot, when collected from the surface of all our planet’s oceans it adds up to 26,000 gallons of water per human.
So just where did all this missing water go?
The ringleader of the great water heist was one of the strongest La Nina cycles of recent times. La Nina shifted and altered weather patterns causing extreme precipitation to funnel into places like India, Pakistan, Australia, and northern tiers of both South and North America.
In the map below, produced from NASA’s GRACE satellite data, blue indicates areas that gained water last year. The darkest blue areas gained as much as 50 mm in one year.
These dark blue spots are also the sources of the world’s epic floods of the last couple years which not only left tens of millions homeless and destroyed agriculture and infrastructure, but also left behind so much water that global oceans were depleted by 6 mm.
A YEAR OF RECORD FLOODING
Last year 182 floods affected 180 million people, almost double the annual average for the last decade. Here are a few:
snip
NOW WHAT?
Well in the short term the seas will start rising again. As the NASA report states:
“water flows downhill, and the extra rain will eventually find its way back to the sea. When it does, global sea level will rise again. ‘We're heating up the planet, and in the end that means more sea level rise’".
What happens in the medium and long term depends on us. We humans really have only one question to answer: To burn or not to burn?
OPTION A: Leave most fossil fuels in the ground -- forever.
OPTION B: Keep doing what we are doing and dig up every last crumb of carbon and burn it.
The climate science is clear that we cannot burn most of the fossil fuels we already know about and also have a stable enough weather system that we can continue to prosper.
As local Nobel laureate and world famous climate scientist, Andrew Weaver, explained in a talk at UBC the other night, just reducing the rate at which we burn fossil fuels won’t prevent dangerous levels of climate change beyond 2C warming. Instead we must totally eliminate fossil fuel emissions.
Weaver showed that even if humanity cut 90% of our fossil fuel use by 2050 but kept burning that last 10% into the future, then we would still heat the climate by more than 2C. That sends us into the realm of dangerous and dramatic climate changes that Canada, USA and every major nation has stated clearly we must avoid.
As Weaver summed it up:
"At some point we just have to say stop.”
More at the link"The year 2010 was one the worst years in world history for high-impact floods.... more
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We’re at a record low Arctic sea ice extent and volume:
The area of the Arctic ocean at least 15% covered in ice is … lower than the previous record low set in 2007 – according to satellite monitoring by the US National Snow and Ice Data Centre (NSIDC) in Boulder, Colorado. In addition, new data from the University of Washington Polar Science Centre, shows that the thickness of Arctic ice this year is also the lowest on record.
In the past 10 days, the Arctic ocean has been losing as much as 150,000 square kilometres of sea a day, said Mark Serreze, director of the NSIDC.
“The extent [of the ice cover] is going down, but it is also thinning. So a weather pattern that formerly would melt some ice, now gets rid of much more. There will be ups and downs, but we are on track to see an ice-free summer by 2030. It is an overall downward spiral.“
The trend is painfully obvious to all who aren’t blinded by ideology. Indeed, many, including me, believe we’ll see virtually ice-free summers within a decade.
What do the experts — and deniers — predict for the September sea ice extent minimum? The Study of Environmental Arctic Change (SEARCH) has released its second Sea Ice Outlook report for July. Just about all the cryo-scientists think the Arctic will easily beat last year’s minimum:
More at the linkWe’re at a record low Arctic sea ice extent and volume:
The area of the... more
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The rate of sea level rise along the U.S. Atlantic coast is greater now than at any time in the past 2,000 years--and has shown a consistent link between changes in global mean surface temperature and sea level.
The findings are published this week in the journal Proceedings of the National Academy of Sciences (PNAS).
The research, funded by the National Science Foundation (NSF), was conducted by Andrew Kemp, Yale University; Benjamin Horton, University of Pennsylvania; Jeffrey Donnelly, Woods Hole Oceanographic Institution; Michael Mann, Pennsylvania State University; Martin Vermeer, Aalto University School of Engineering, Finland; and Stefan Rahmstorf, Potsdam Institute for Climate Impact Research, Germany.
"Having a detailed picture of rates of sea level change over the past two millennia provides an important context for understanding current and potential future changes," says Paul Cutler, program director in NSF's Division of Earth Sciences.
"It's especially valuable for anticipating the evolution of coastal systems," he says, "in which more than half the world's population now lives."
Adds Kemp, "Scenarios of future rise are dependent on understanding the response of sea level to climate changes. Accurate estimates of past sea-level variability provide a context for such projections."
Kemp and colleagues developed the first continuous sea-level reconstruction for the past 2,000 years, and compared variations in global temperature to changes in sea level over that time period.
The team found that sea level was relatively stable from 200 BC to 1,000 AD.
Then in the 11th century, sea level rose by about half a millimeter each year for 400 years, linked with a warm climate period known as the Medieval Climate Anomaly.
Then there was a second period of stable sea level during a cooler period called the Little Ice Age. It persisted until the late 19th century.
Since the late 19th century, sea level has risen by more than 2 millimeters per year on average, the steepest rate for more than 2,100 years.
"Sea-level rise is a potentially disastrous outcome of climate change," says Horton, "as rising temperatures melt land-based ice, and warm ocean waters."
To reconstruct sea level, the scientists used microfossils called foraminifera preserved in sediment cores extracted from coastal salt marshes in North Carolina. The age of the cores was estimated using radiocarbon dating and other techniques.
To test the validity of their approach, the team compared its reconstructions with tide-gauge measurements from North Carolina for the past 80 years, and global tide-gauge records for the past 300 years.
A second reconstruction from Massachusetts confirmed their findings.
more at the link.
__________The rate of sea level rise along the U.S. Atlantic coast is greater now than at any... more
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Could our coastlines disappear underwater much sooner than we think? The controversial view that sea levels could rise at a rate of more than 1 metre per century has found support from a new study of a long-melted ice sheet.
In reconstructing the events at the end of the last ice age, Anders Carlson of the University of Wisconsin-Madison and colleagues found that the Laurentide ice sheet, which covered most of North America between 95,000 and 7000 years ago, rapidly disintegrated.
The researchers began by studying beryllium isotopes in rocks to determine how the outer edges of the two final chunks of the Laurentide ice sheet retreated. They found that the ice retreated rapidly between 9000 and 8500 years ago, stabilised, and then made its final rapid retreat between 7600 and 6800 years ago.
The team calculated the volume of water that would have been released in each of these melting stages, and the rate at which it must have raised sea levels. They concluded that levels would have climbed 1.3 metres per century in the earlier period, and 0.7 metres per century in the final melt.
Carlson then used a sophisticated computer model – one that is used to forecast future climate change – to check the results. The model predicted an average sea level rise of 1.3 metres per century.
Different times
"The forces that led to the demise of the Laurentide ice sheet in a very rapid way are comparable to the forces the same computer models predict we will experience this century if we do not rapidly curb greenhouse gas emissions," says Gavin Schmidt of the NASA Goddard Institute for Space Studies, who collaborated with Carlson on the study.
For Mark Siddall of the University of Bristol, UK, and Michael Kaplan of the Lamont Doherty Earth Observatory in New York, however, there remain many differences between what happened nearly 10,000 years ago and the climate change Earth is currently experiencing.
"To what extent this dynamic response of the Laurentide ice sheet to past temperature change can be considered analogous to present and future reduction of the Greenland ice sheet remains unresolved," they say in an associated commentary. "But their work suggests that future reductions of the Greenland ice sheet on the order of one metre per century are not out of the question."
If Carlson's estimates are correct, they show that 2007 predictions made by the Intergovernmental Panel on Climate Change – a sea-level rise of between 18 centimetres and 59 cm by 2100 – are very conservative, as the IPCC acknowledged at the time.
Millions at risk
Sea-level rises of at least a metre per century were also predicted by the head of the NASA Goddard Institute for Space Studies, James Hansen. Hansen believes that our climate will soon hit tipping points – points of no return – beyond which the ice sheets will rapidly disintegrate.
Carlson says his team's findings are proof that large ice sheets can disintegrate very rapidly. What's more, he says the forces that caused the Laurentide ice sheet to disintegrate are equivalent to the ones that threaten the Greenland ice sheet today.
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Will the US and other industrialized nations then step up to the plate in Copenhagen next year? Will the US Congress do so as well? The way I feel today I would say it would have to take Greenland falling into the ocean before that happens. How irresponsible of them to not be making this the priority issue it must be.Could our coastlines disappear underwater much sooner than we think? The controversial... more
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