Of course winter is coming. This has nothing to do with climate change. Making such statements is typical RW lunacy to get the ignorant to agree with those who are brainwashing them.
Lectro was RIGHT--post1626--(climate related)
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Of course winter is coming. This has nothing to do with climate change. Making such statements is typical RW lunacy to get the ignorant to agree with those who are brainwashing them.
Having broken the all-time record for extent twice in September, Antarctic sea ice continues to run at record levels. According to NSIDC, the extent for the end of the month has set a new record at 19.505 million sq km, beating the previous record in 2005 by 293,000 sq km.
This year’s figure is also 978,000 sq km above the 1981-2010 mean.
Brrrrrrrrrrr
This year’s figure is also 978,000 sq km above the 1981-2010 mean.
Brrrrrrrrrrr
WFFaithful
Well-known member
In third grade, more sea ice might be a result of cooler temperatures, however the science speaks otherwise.
"While the interior of East Antarctica is gaining land ice, overall Antarctica has been losing land ice at an accelerating rate. Antarctic sea ice is growing despite a strongly warming Southern Ocean.
Climate Myth...
Antarctica is gaining ice
"[Ice] is expanding in much of Antarctica, contrary to the widespread public belief that global warming is melting the continental ice cap." (Greg Roberts, The Australian)
Antarctica is a continent with 98% of the land covered by ice, and is surrounded by ocean that has much of its surface covered by seasonal sea ice. Reporting on Antarctic ice often fails to recognise the fundamental difference between sea ice and land ice. Antarctic land ice is the ice which has accumulated over thousands of years on the Antarctica landmass through snowfall. This land ice therefore is actually stored ocean water that once evaporated and then fell as precipitation on the land. Antarctic sea ice is entirely different as it is ice which forms in salt water during the winter and almost entirely melts again in the summer.
Importantly, when land ice melts and flows into the oceans global sea levels rise on average; when sea ice melts sea levels do not change measurably but other parts of the climate system are affected, like increased absorbtion of solar energy by the darker oceans.
To summarize the situation with Antarctic ice trends:
Antarctic land ice is decreasing at an accelerating rate
Antarctic sea ice is increasing despite the warming Southern Ocean
Antarctic Land Ice is decreasing
Measuring changes in Antarctic land ice mass has been a difficult process due to the ice sheet's massive size and complexity. However, since the 1990s satellites have been launched that allow us to measure those changes. There are three entirely different approaches, and they all agree within their measurement uncertainties. The most recent estimate of land ice change that combines estimates from these three approaches reported (Shepherd and others, 2012) that between 1992 and 2011, the Antarctic Ice Sheets overall lost 1350 giga-tonnes (Gt) or 1,350,000,000,000 tonnes into the oceans, at an average rate of 70 Gt per year (Gt/yr). Because a reduction in mass of 360 Gt/year represents an annual global-average sea level rise of 1 mm, these estimates equate to an increase in global-average sea levels by 0.19 mm/yr, or 1.9 mm per decade. Together with the land ice loss from Greenland, this represents about 30% of the observed global-average sea level rise over this period.
Examining how this change is spread over time (Figure 1) reveals that the ice sheet as a whole was not losing or gaining ice in the early 1990s. Since then ice loss has begun, and is clearly seen to have accelerated during that time:
Figure 1: Estimates of total Antarctic land ice changes (bottom) and regions within it (top) and approximate sea level contributions using a combination of several different measurement techniques (Shepherd and others, 2012). Shaded areas represent the estimate uncertainty (1-sigma).
The satellite mission that is best suited to measuring land ice mass change is the Gravity Recovery and Climate Experiment (GRACE). The GRACE satellites measure changes in Earth's gravity and these can be directly related to surface mass variations such as the Antarctic ice sheet. Recent GRACE estimates of mass change show the dramatic mass loss in West Antarctica and mass gain in East Antarctica (King and others, 2012):
Figure 2: a, GRACE estimate of ice-mass change (2002-2012), with ice drainage basins numbered (boldface italics where trends are statistically different to zero with 95% confidence). b, c, Basin-specific lower and upper bounds on ice-mass change, respectively, reflecting the potential systematic error in the basin estimates (King and others, 2012).
The East Antarctic Ice Sheet is growing slightly over satellite period (Figures 1&2) but not enough to offset the other losses. It is not yet clear if the increase in mass in Antarctica is a short-term phenomena due to a particularly snowy period (Boening and others, 2012) or if it is a long-term trend. Increased snowfall in East Antarctica has long been predicted in a warming climate, so this is an important region to continue monitoring.
The land ice loss from the West Antarctic Ice Sheet is not due to surface melting, as the summer temperatures in Antarctica are generally always below freezing, and measured changes in precipitation cannot explain it either. Instead, the melting is occuring due to warm ocean water melting the land ice around its edges, resulting in a spreading of this ice loss inland:
Figure 3: Rates of lowering of land ice and its floating extensions in West Antarctica, 2003–2008 (Pritchard and others, 2012). Floating extensions of the land ice (ice shelves) that are labelled are Venable (V), Abbott (A), Cosgrove (C), Pine Island (PI), Thwaites (TH), Crosson (CR), Dotson (D), Getz (G), De Vicq (DV), Land (L), Nickerson (N) and Sulzberger (SZ). Arrows highlight areas of slow-flowing, grounded ice. Bathymetry landward of the continental-shelf break is in greyscale. The divide between floating and grounded ice is shown in white. The inset shows the location of the figure (green box) overlaid on the outline of Antarctica.
The influx in warm water onto the continental shelf in this region is not entirely understood but is probably at least partly linked to increased westerly winds that have occured as a result of reduced stratospheric ozone levels since the mid-20th Century (Gillet 2003, Thompson 2002, Turner 2009).
The Antarctic ice sheet plays an important role in the total contribution to sea level. That contribution is continuously and rapidly growing.
Antarctic Sea Ice is increasing
Antarctic sea ice has shown long term growth since satellites began measurements in 1979. This is an observation that has been often cited as proof against global warming. However, rarely is the question raised: why is Antarctic sea ice increasing? The implicit assumption is it must be cooling around Antarctica. This is decidedly not the case. In fact, the Southern Ocean has been warming faster than the rest of the world's oceans. Globally from 1955 to 1995, oceans have been warming at 0.1°C per decade. In contrast, the Southern Ocean has been warming at 0.17°C per decade. Not only is the Southern Ocean warming, it is warming faster than the global trend.
Figure 3: Surface air temperature over the ice-covered areas of the Southern Ocean (top). Sea ice extent, observed by satellite (bottom). (Zhang 2007)
If the Southern Ocean is warming, why is Antarctic sea ice increasing? There are several contributing factors. One is the drop in ozone levels over Antarctica. The hole in the ozone layer above the South Pole has caused cooling in the stratosphere (Gillet 2003). This strengthens the cyclonic winds that circle the Antarctic continent (Thompson 2002). The wind pushes sea ice around, creating areas of open water known as polynyas. More polynyas lead to increased sea ice production (Turner 2009).
Another contributor is changes in ocean circulation. The Southern Ocean consists of a layer of cold water near the surface and a layer of warmer water below. Water from the warmer layer rises up to the surface, melting sea ice. However, as air temperatures warm, the amount of rain and snowfall also increases. This freshens the surface waters, leading to a surface layer less dense than the saltier, warmer water below. The layers become more stratified and mix less. Less heat is transported upwards from the deeper, warmer layer. Hence less sea ice is melted (Zhang 2007). An increase in melting of Antarctic land ice will also contribute to the increased sea ice production (Bintanga et al. 2013).
In summary, Antarctic sea ice is a complex and unique phenomenon. The simplistic interpretation that it must be cooling around Antarctica is decidedly not the case. Warming is happening - how it affects specific regions is complicated."
link
Well Wf, that certainly looks official...what is the actual increase and how does it compare to historical trends?
That data shows an increase of 1.7 mm in sea level per year...big deal ? Let's have some history, eh?
http://judithcurry.com/2011/07/12/h...ea-levels-part-1-from-the-holocene-to-romans/
The IPCC AR4 projected sea level rise in 2100 to range from 18-59 cm, depending on the emission scenario. More recent projections are for a 1 m sea level rise in 2100 [here and here]. Apart from the issue of uncertainty and reliability of these future sea level projections, how do these magnitudes of sea level rise compare with historic variations in sea level rise?
Historic variations in sea levels is in three parts. Part 1 covers the Holocene to Roman times. Part 2 traces sea level changes to the Medieval Warm Period. Part 3-the modern age from 1700 to today.
This post is an abridged version of a longer document (Part 1), replete with references and additional diagrams and pictures.
The IPCC on historic sea level rise
The IPCC AR4 statement on historic sea level rise from AD0 is cited below:
“Yes, there is strong evidence that global sea level gradually rose in the 20th century and is currently rising at an increased rate, after a period of little change between AD 0 and AD 1900. Sea level is projected to rise at an even greater rate in this century.
The two major causes of global sea level rise are thermal expansion of the oceans (water expands as it warms) and the loss of land-based ice due to increased melting…
Global sea level rose by about 120 m during the several millennia that followed the end of the last ice age (approximately 21,000 years ago), and stabilised between 3,000 and 2,000 years ago. Sea level indicators suggest that global sea level did not change significantly from then until the late 19th century. The instrumental record of modern sea level change shows evidence for onset of sea level rise during the 19th century. Estimates for the 20th century show that global average sea level rose at a rate of about 1.7 mm yr–1.”
The IPCC provides no references for this FAQ on “Is sea level rising?”
The Figure below from the Wikimedia Commons shows sea level rise since the end of the last glacial episode. Because of the large magnitude of the change, the scale on the y-axis makes it impossible to resolve the magnitude of changes for the last 8,000 years. An expansion of this diagram for the past 9000 years enables examination of the sea level rise on the scale of meters. The uncertainty of the estimates at individual locations plus the range across different locations at any particular time can be associated with an uncertainty of several meters, which is larger than the magnitude of projected sea level rise that is under consideration.
Challenges in reconstructing and interpreting historical sea levels
Apart from the uncertainties in actually determining sea level change, the physical interpretation of sea level change needs to take into account deposition and erosion, land movement-often through post glacial rebound- and tectonic activity, in addition to climate change.
These historic changes in land level-dramatic or gradual- will have been taken into account in academic studies (although there is not unanimity over the rate of change). However all these factors demonstrate that accurate sea level reconstruction is problematic.
In private email correspondence that he has given me permission to reproduce, Dr Simon Holgate of Proudman Oceanographic Observatory refers to sea level reconstructions back to 200AD-which covers several warm periods such as the Roman Optimum and MWP- and remarks:
That data shows an increase of 1.7 mm in sea level per year...big deal ? Let's have some history, eh?
http://judithcurry.com/2011/07/12/h...ea-levels-part-1-from-the-holocene-to-romans/
The IPCC AR4 projected sea level rise in 2100 to range from 18-59 cm, depending on the emission scenario. More recent projections are for a 1 m sea level rise in 2100 [here and here]. Apart from the issue of uncertainty and reliability of these future sea level projections, how do these magnitudes of sea level rise compare with historic variations in sea level rise?
Historic variations in sea levels is in three parts. Part 1 covers the Holocene to Roman times. Part 2 traces sea level changes to the Medieval Warm Period. Part 3-the modern age from 1700 to today.
This post is an abridged version of a longer document (Part 1), replete with references and additional diagrams and pictures.
The IPCC on historic sea level rise
The IPCC AR4 statement on historic sea level rise from AD0 is cited below:
“Yes, there is strong evidence that global sea level gradually rose in the 20th century and is currently rising at an increased rate, after a period of little change between AD 0 and AD 1900. Sea level is projected to rise at an even greater rate in this century.
The two major causes of global sea level rise are thermal expansion of the oceans (water expands as it warms) and the loss of land-based ice due to increased melting…
Global sea level rose by about 120 m during the several millennia that followed the end of the last ice age (approximately 21,000 years ago), and stabilised between 3,000 and 2,000 years ago. Sea level indicators suggest that global sea level did not change significantly from then until the late 19th century. The instrumental record of modern sea level change shows evidence for onset of sea level rise during the 19th century. Estimates for the 20th century show that global average sea level rose at a rate of about 1.7 mm yr–1.”
The IPCC provides no references for this FAQ on “Is sea level rising?”
The Figure below from the Wikimedia Commons shows sea level rise since the end of the last glacial episode. Because of the large magnitude of the change, the scale on the y-axis makes it impossible to resolve the magnitude of changes for the last 8,000 years. An expansion of this diagram for the past 9000 years enables examination of the sea level rise on the scale of meters. The uncertainty of the estimates at individual locations plus the range across different locations at any particular time can be associated with an uncertainty of several meters, which is larger than the magnitude of projected sea level rise that is under consideration.
Challenges in reconstructing and interpreting historical sea levels
Apart from the uncertainties in actually determining sea level change, the physical interpretation of sea level change needs to take into account deposition and erosion, land movement-often through post glacial rebound- and tectonic activity, in addition to climate change.
These historic changes in land level-dramatic or gradual- will have been taken into account in academic studies (although there is not unanimity over the rate of change). However all these factors demonstrate that accurate sea level reconstruction is problematic.
In private email correspondence that he has given me permission to reproduce, Dr Simon Holgate of Proudman Oceanographic Observatory refers to sea level reconstructions back to 200AD-which covers several warm periods such as the Roman Optimum and MWP- and remarks:
More from the same link...for the chap to lazy to look for himself...to be capable of some degree of healthy scepticism in the face of this 17 year failure in computer modeling.
It's not Hard!
In private email correspondence that he has given me permission to reproduce, Dr Simon Holgate of Proudman Oceanographic Observatory refers to sea level reconstructions back to 200AD-which covers several warm periods such as the Roman Optimum and MWP- and remarks:
“It seems plausible that sea level would be higher in a warmer period (how warm and how much of the Earth was actually affected by the warm period is debated) but it isn’t clear how sea level would respond. So maybe it was higher than today, or maybe it wasn’t. We have no observations and we just don’t know. For me, there is far too much uncertainty in the ‘reconstructions’ of sea level for them to be very useful…Overall I would say that the evidence from the (Roman) fish tanks etc suggests that there has been no real change in the average height of sea level over the last c. 2000 years prior to the mid to late 1800s.”
It is important to fix in our minds therefore that sea level change is not necessarily as a result of their being less or more water (through glacier melt and thermal expansion) but that much of what we might observe is as a result of changes in the height of the land relative to the sea.
It's not Hard!
In private email correspondence that he has given me permission to reproduce, Dr Simon Holgate of Proudman Oceanographic Observatory refers to sea level reconstructions back to 200AD-which covers several warm periods such as the Roman Optimum and MWP- and remarks:
“It seems plausible that sea level would be higher in a warmer period (how warm and how much of the Earth was actually affected by the warm period is debated) but it isn’t clear how sea level would respond. So maybe it was higher than today, or maybe it wasn’t. We have no observations and we just don’t know. For me, there is far too much uncertainty in the ‘reconstructions’ of sea level for them to be very useful…Overall I would say that the evidence from the (Roman) fish tanks etc suggests that there has been no real change in the average height of sea level over the last c. 2000 years prior to the mid to late 1800s.”
It is important to fix in our minds therefore that sea level change is not necessarily as a result of their being less or more water (through glacier melt and thermal expansion) but that much of what we might observe is as a result of changes in the height of the land relative to the sea.
Same link^
More history...because it matters. Here is some boots on ground Science
We commence our watery journey with this short excerpt from the book ‘The Little Ice Age’ by Brian Fagan, Professor of Archaeology at the University of California.
“Ten thousand years ago the southern North Sea was a marshy plain where elk and deer wandered…England was part of the continent until as recently as 6000 BC when rising sea levels caused by post ice age warming filled the North sea.”
“Prof. Bryony Coles has been examining the archaeology of “Doggerland”, which now lies under the North Sea. Its highest point is the submerged Dogger Bank where prehistoric artefacts are occasionally found by fishermen and geologists. At the height of the last Ice Age, Doggerland was dry and stretched from the present east coast of Britain and the present coasts of The Netherlands, Denmark and North Germany. Thus, the so-called land-bridge, was a place where people settled as the ice-sheets wasted and north Western Europe became habitable once more. But, as the ice-sheets retreated further and sea levels rose, the North Sea encroached on the land, eventually separating the British Peninsula from the mainland.”
It is a sobering thought that where once our ancestors hunted, fish now take their place, and graphically illustrates that sea level rise is by no means a modern phenomenon in the context of human history.
Great thread on the history of Great Britian.
Here is the University of Haifa's Dr. Sivan discussing historical sea records for Israel:
Over the past century, we have witnessed the sea level in Israel fluctuating with almost 19 centimeters between the highest and lowest levels. Over the past 50 years Israel’s mean sea level rise is 5.5 centimeters, but there have also been periods when it rose by 10 centimeters over 10 years. That said, even acute ups and downs over short periods do not testify to long-term trends. An observation of the sea levels over hundreds and thousands of years shows that what seems a phenomenon today is as a matter of fact “nothing new under the sun,” Dr. Sivan concludes.
Over the past century, we have witnessed the sea level in Israel fluctuating with almost 19 centimeters between the highest and lowest levels. Over the past 50 years Israel’s mean sea level rise is 5.5 centimeters, but there have also been periods when it rose by 10 centimeters over 10 years. That said, even acute ups and downs over short periods do not testify to long-term trends. An observation of the sea levels over hundreds and thousands of years shows that what seems a phenomenon today is as a matter of fact “nothing new under the sun,” Dr. Sivan concludes.
More history...because it matters. Here is some boots on ground Science
We commence our watery journey with this short excerpt from the book ‘The Little Ice Age’ by Brian Fagan, Professor of Archaeology at the University of California.
“Ten thousand years ago the southern North Sea was a marshy plain where elk and deer wandered…England was part of the continent until as recently as 6000 BC when rising sea levels caused by post ice age warming filled the North sea.”
“Prof. Bryony Coles has been examining the archaeology of “Doggerland”, which now lies under the North Sea. Its highest point is the submerged Dogger Bank where prehistoric artefacts are occasionally found by fishermen and geologists. At the height of the last Ice Age, Doggerland was dry and stretched from the present east coast of Britain and the present coasts of The Netherlands, Denmark and North Germany. Thus, the so-called land-bridge, was a place where people settled as the ice-sheets wasted and north Western Europe became habitable once more. But, as the ice-sheets retreated further and sea levels rose, the North Sea encroached on the land, eventually separating the British Peninsula from the mainland.”
It is a sobering thought that where once our ancestors hunted, fish now take their place, and graphically illustrates that sea level rise is by no means a modern phenomenon in the context of human history.
Great thread on the history of Great Britian.
Here is the University of Haifa's Dr. Sivan discussing historical sea records for Israel:
Over the past century, we have witnessed the sea level in Israel fluctuating with almost 19 centimeters between the highest and lowest levels. Over the past 50 years Israel’s mean sea level rise is 5.5 centimeters, but there have also been periods when it rose by 10 centimeters over 10 years. That said, even acute ups and downs over short periods do not testify to long-term trends. An observation of the sea levels over hundreds and thousands of years shows that what seems a phenomenon today is as a matter of fact “nothing new under the sun,” Dr. Sivan concludes.
Over the past century, we have witnessed the sea level in Israel fluctuating with almost 19 centimeters between the highest and lowest levels. Over the past 50 years Israel’s mean sea level rise is 5.5 centimeters, but there have also been periods when it rose by 10 centimeters over 10 years. That said, even acute ups and downs over short periods do not testify to long-term trends. An observation of the sea levels over hundreds and thousands of years shows that what seems a phenomenon today is as a matter of fact “nothing new under the sun,” Dr. Sivan concludes.
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ONW
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Judith Curry's blog...seriously...
http://www.youtube.com/watch?v=MPnj9eR7t0g&feature=player_embedded
Don't watch this video Lectro. Your world will implode.
http://www.youtube.com/watch?v=MPnj9eR7t0g&feature=player_embedded
Don't watch this video Lectro. Your world will implode.
Another academic study showing the latest research from Antartica...
A string of volcanoes are behind the heating of the Western shelf.
https://news.wustl.edu/news/Pages/25611.aspx
Read and learn
A string of volcanoes are behind the heating of the Western shelf.
https://news.wustl.edu/news/Pages/25611.aspx
Read and learn
Another academic study showing the latest research from Antartica...
A string of volcanoes are behind the heating of the Western shelf.
https://news.wustl.edu/news/Pages/25611.aspx
Volcano discovered smoldering under a kilometer of ice in West Antarctica
Its heat may increase the rate of ice loss from one of the continent’s major ice streams
Read and learn
A string of volcanoes are behind the heating of the Western shelf.
https://news.wustl.edu/news/Pages/25611.aspx
Volcano discovered smoldering under a kilometer of ice in West Antarctica
Its heat may increase the rate of ice loss from one of the continent’s major ice streams
Read and learn
WFFaithful
Well-known member
Lectro, do you acknowledge now that sea ice expansion in Antarctica is not evidence of global cooling?
Yes. I believe the sun is going through a cooling phase. I consider the sun to be,by far, the driver of climate. The correlations shown by Henrik Svensmark and Fris Christiansen are undeniable.
The antarctic (western) melt... https://news.wustl.edu/news/Pages/25611.aspx
On the other hand, a subglacial eruption and the accompanying heat flow will melt a lot of ice. “The volcano will create millions of gallons of water beneath the ice — many lakes full,” Wiens said.
This water will rush beneath the ice toward the sea and feed into the hydrological catchment of the MacAyeal Ice Stream, one of several major ice streams draining ice from Marie Byrd Land into the Ross Ice Shelf.
By lubricating the bedrock, it will speed the flow of the overlying ice, perhaps increasing the rate of ice-mass loss in West Antarctica.
“We weren’t expecting to find anything like this,” Wiens said.
The research was funded by the National Science Foundation, Division of Polar Programs.
The antarctic (western) melt... https://news.wustl.edu/news/Pages/25611.aspx
On the other hand, a subglacial eruption and the accompanying heat flow will melt a lot of ice. “The volcano will create millions of gallons of water beneath the ice — many lakes full,” Wiens said.
This water will rush beneath the ice toward the sea and feed into the hydrological catchment of the MacAyeal Ice Stream, one of several major ice streams draining ice from Marie Byrd Land into the Ross Ice Shelf.
By lubricating the bedrock, it will speed the flow of the overlying ice, perhaps increasing the rate of ice-mass loss in West Antarctica.
“We weren’t expecting to find anything like this,” Wiens said.
The research was funded by the National Science Foundation, Division of Polar Programs.
ONW
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HOLY FUCK!!! Lava melts ice! Groundbreaking development.
ONW
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What myth?