Earthwatch Issue 3 Sunspots, and more

Earthwatch Issue 3 Sunspots, and more


Global Rockhound Community Environmental News

Issue 03: March 2007: Editor Sally Taylor:

RHS1 Global Rockhound Community Environmental News,Monitoring, earthquakes, global warming, climate change, hurricanes and tornados, bio-diversity, keeping an eye on our fast changing planet. Climate change,global warming,earthquake, earthwatch,Chandler wobble, Chandler’s wobble,rockhound world center,


Our Climate; Our Future; Our Options; Synthesis;

Scary Monsters: The eye of Ra…Part 2

During the past month I have been researching the the subject of global warming and climate change and I have to tell you that finding some hard facts is about as easy as juggling soot in the dark…

I mean… “Have a look at this”

The measurements of the Altimeter Radar Satellite indicate that the Eastern Antarctic ice shield is increasing its mass in by approx; 48 billion metric tons per year since 1992. The increase in mass is associated with an increase in the snowfalls.

The new study in east Antarctica used direct measurement of snowfall and more than 50 ice cores to reconstruct annual snowfall over the past 50 years. The new study shows that since 1991, the amount of snow falling in that area has decreased.

The sources of the above information are both rock solid…”TILT?“….Groan!

A paper published in Science in June this year detailed the results of a similar analysis of the Antarctic Ice Sheet based on ERS radar altimeter data, carried out by a team led by Professor Curt Davis of the University of Missouri-Columbia. The results showed thickening in East Antarctica on the order of 1.8 cm per year, but thinning across a substantial part of West Antarctica.

The measurements of the Altimeter Radar Satellite indicate that the Eastern Antarctic ice shield is increasing its mass in by approx; 48 billion metric tons per year since 1992. The increase in mass is associated with an increase in the snowfalls.

(View Earthwatch article about the Altimeter Radar Satellite below)

East Antarctic and Circum-Antarctic climate History from ITASE ice coring in Eastern Wilkes Land. A six person ice-coring team was deployed for two weeks at a remote location in Wilkes Land some 750 km east of Casey. The aim of this project was to recover ice cores to provide records of past climate in this region. This was a cooperative project, between the Environmental Geoscience Group at the University of Newcastle and the AAD Glaciology Program

The new study in east Antarctica used direct measurement of snowfall and more than 50 ice cores to reconstruct annual snowfall over the past 50 years. The new study shows that since 1991, the amount of snow falling in that area has decreased.

Forgive me for being perplexed here; because apparently we have a prima facia contradiction.
  • Yes it has snowed more in the eastern Antarctic since the beginning of the the 90s.
  • No it has not snowed more in the eastern Antarctic since the beginning of the 90s.
Or a least that the way I am reading the conclusion of the two reports, of course I haven’t studied the data because I am not qualified to study it, nor would I want to even if I was qualified.

It would have saved millions if the scientists had just simply flipped a coin in the air and called- “More snow in the Antarctic…Heads its yes…Tails its no.”

Now this situation is a classic of “Science in action” and with it I rest my case as to No 3 on the list below…

  • 1…On a global scale…The temperature has risen/ is rising…
  • 2…On a global scale…Climate patterns are changing…
  • 3…We cannot be 100% certain of the validity of information, received, regarding 1&2 in this list…

Earth’s atmosphere is producing a “greenhouse effect” reflecting heat back to the planets surface…

CO2 : Carbon Dioxide :
Culprit or red herring?


Carbon Dioxide
.”The era of procrastination, of half measures, of soothing and baffling expedients of delay are coming to a close.
In its place, we are entering a period of consequences.”
Winston Churchill

CO2 aka Carbon Dioxide
Click the image above to discover more
“Governments, businesses and individual members of the public need to take that warning very seriously. If I write this check for $25 million, it will be the best check I’ve ever written.”
Richard Branson
Now Sheriff Branson and Marshal Al Gore Have put a bounty on the CO2 problem. This is a positive guesture…However with all respects gentlemen a billion tons at $25,000000 is 2.5 cents a ton quite frankly you could not process water over a cliff at this price…Maybe wise to up the ante a wee bit -O)

The Carbon Dioxide Hoax

“Within the atmospheric conditions that exist on the Earth, carbon dioxide is not a greenhouse gas. This statement is supported by scientific observations and the chemical properties of the gas.

The Earth’s atmosphere contains 3.3 percent carbon dioxide. By contrast, the atmosphere of Mars contains more than 95.0 percent carbon dioxide. There is more than ten times as much carbon dioxide in a cubic meter of atmosphere at ground level on Mars than in the same volume of atmosphere at ground level on Earth. There is no greenhouse on Mars. NASA engineers had hoped for some small greenhouse effect on Mars when they began their surface explorations of the Red planet but, found none. When the Sun sets on Mars the temperature plummets.

A greenhouse gas works by absorbing energy and reemitting it. It does not work by acting as a blanket and trapping heated air inside. Nor does it work by reflecting energy back to the planet’s surface. Where is the experimental or observational evidence that proves that carbon dioxide is a greenhouse gas? You can put any gas (even monatomic helium) in a closed container and get a greenhouse effect. However, this is due to the effect of the container, not the gas.”

 Now are the above statements correct? Sounds reasonable enough.

Here is the other side of the coin.

Electric Cars and the Goldilocks Planet

Open Access Article Originally Published: February 24, 2007 on
The climate involves many facets of complex science and those wishing to mislead for blood moneys are more than happy to make it even more technical if it supports their uncaring, greedy and biased objectives. The objective of this article is to find the unbiased truth in a format that most can understand.

No one knows every minuscule aspect of what produces our climate, but the major reactants are known. Almost all of the references are from studies that are unrelated to Earth’s industrial global warming and are almost universally accepted.

While researching our solar systems three CO2 planets’ atmospheres and temperatures, Johnson’s “Goldilocks and the Three Planets” popped up. This short, entertaining, and informative article is highly recommended for a brief overall view of the climates of Venus, Earth, and Mars, the Greenhouse effect, and the CO2 cycle (including volcanic action for the “no SUVs” history majors). It’s amusing title seemed unique until it was Googled and 73 other references popped up. One of which was an informative 10 minute video with a slightly different perspective.

It is extremely important to note that the Greenhouse Effect of CO2 on Venus and Mars are virtually undisputed. The CO2 molecule is a greenhouse gas because of its dipolar characteristics which absorb and radiate the infrared energy (1/3 the wavelength of a microwave). The effects of infrared energy on dipolar molecules are also virtually undisputed. Apparently, no ‘scientist’ was able to gain personal blood or grant money for disputing these facts.

The current atmosphere of Venus is about 96% CO2 at 90 times the density of Earth’s (93 million miles from the sun) atmosphere which is about 100 times the density of Mars’ atmosphere. Venus (67 million miles from the sun) has an average temperature of 855 F, while Mercury’s (36 million miles from the sun with virtually no atmosphere) temperature ranges from -300 F to 870 F. Venus is hotter than Mercury in spite of being almost twice the distance from the sun which should make Venus (if it had no atmosphere) about 200 F cooler than Mercury.

The current thin atmosphere of Mars (142 million miles from the sun) contains 95% CO2 with less than 1% of the atmospheric pressure of Earth. The temperature range is from a high of 98 F to a low of -190 F. This sparse compaction of the greenhouse gas CO2 by Mars’ weak gravitational force is only enough to raise the surface temperature by 9 F.


PHOTO CAPTION: Of the four innermost terrestial planets, only Earth has the ideal concentration of carbon dioxide to assure a temperate climate suitable for the widest spectrum of life.
“The Discovery of the Greenhouse Effect” (1820) on Earth (93 million miles from the sun) is also virtually undisputed. Without the greenhouse effect of the gases of our current atmosphere, Earth would be a very inhospitable planet and about 90 F cooler (also a good article for basic climate information). CO2 is a proven planet warmer. CO2 has increased from less than .03% (280 ppm) to .04% (390 ppm) in the last two decades without any signs of decreasing. Earth is rapidly approaching the CO2 effects of Mars which is responsible for at least 9 F without the effects of other greenhouse gases – water vapor, methane, N2O, various hydrocarbons – all of which add their warming effects. Once, like Venus, these compounds reach a concentration where more heat is retained than removed, as is the current situation, a runaway greenhouse effect is started. There is one proven way this effect has stopped of its own accord – the melting of all of the ice on the planet. Will it be enough to prevent the formation of another Venus? The facts say that Earth will start finding out by the year 2040.

While it is believed that Venus and Earth started as very similar planets, Venus suffered a “runaway” greenhouse effect. This event occurred sometime between four billion years ago when the sun was 30 to 40% cooler (this process continues daily at an imperceptible level – to such a small degree that it might take a century to notice a measurable change in the massive amounts of energy released) and now. The slightly smaller gravitational force and closer proximity to the sun explains why Venus would runaway prior to Earth. An average surface temperature of 80 F is believed to be the temperature range at which the runaway effect would start on Earth.

The basic properties of the gaseous components of the atmosphere are fairly standard science and are further illustrated by the current temperatures/climates/atmospheres of Venus and Mars. The blanket analogy for greenhouse effect is an excellent one. If one compares the amounts/density of greenhouse gases to the thread count of a blanket/sheet, the effects are very similar and more easily understood. Mars’ blanket has a thread count of one with minimal greenhouse effect, while the Venus’ blanket has a thread count 9,ooo and retains 99.9% of the heat that reaches its surface. Currently, Earth is in between those two climates. One day, hopefully millions of years from now as the sun continues its normal star progression, Earth will become Venus long before the sun reaches a red giant phase. However, basic chemistry and physics clearly show that mankind’s actions may drastically shorten the length of time for that to happen.

In the billions of years it took for life to develop on Earth, complete/incomplete meltdowns of Earth’s ice sheets has happened several times, without a runaway greenhouse occurring. So far, the article has only dealt with the ‘positive feedback’ loops of global warming. There are many ‘negative feedback’ loops that exist in nature to cool the earth, but history has shown that the negative feedback loops will not be significant enough to stop the complete meltdown of all natural ice sheets on Earth under the circumstances that existed in the past or in the present.

Second verse, same as the first… but a little different. So far the article has not included is the destruction of rain forests by the shifting of weather patterns, the acidity of the oceans decreasing the removal of CO2 in our normal carbon cycle, and the 900 billion tons of CO2 (90 times the amount of yearly CO2 production – as well as tons of methane) awaiting dispersal from it’s resting place in the ice that is melting.

There is nothing we can do to control the solar cycle, animal production of methane, and the physics of water vapor. But, there are existing easy methods of dealing with CO2 production and more difficult methods for dealing with methane production from refuse.

Complete melting of all natural ice on the planet will result in 200 to 300 feet of sea level rise based on previous occurrences. When this happens (some have evidence of its occurrence prior to 2040 and being beyond the point of no return – the most accurate assessment of our current situation, although it is slightly optimistic in this reporter’s opinion), there will certainly be some ‘negative feedback’ loops placed on global warming. The surface area of more reflective water will be dramatically increased – although this will be counteracted by the loss of more reflective ice sheets. Millions of coastal area inhabitants will be displaced or killed like the residents of New Orleans that were murdered by covering up the rising sea levels of global warming. Fertile farmlands will be drastically reduced by rising tides. Starvation will assure that there are far fewer sapiens to worry about or to pollute the environment. Salt water will contaminate many of our water sources that are not already drained, polluted by radiation or toxic chemicals. We will not have to drive nearly as far to get to the beach. Hydro power sources will be much more available and there will be far fewer people requiring energy by the time they can be built.

There is no doubt that some on the global warming issue have finances influencing their actions. There is no doubt that most of the global warming ‘debunkers’ have financial reasons for their actions. However, there is a vast difference between supporting science facts for the continuance of all of mankind, and ignoring/hiding/distraction of science facts for the destruction of mankind for the sake of blood money. Just as there is a vast difference between creating a study to evaluate the facts and come to a conclusion, creating a conclusion for the cherry picking of any evidence to support that conclusion or deliberately censoring all information in scientific articles contrary to amassing huge profits.

Anyone in the past that has denied greenhouse effects, or the fact this planet is warming – the solar cycle still accounts for about the temperature rise since 1900, it fails to explain a rise of 0.4 C since 1980 (It’s the heat being retained that is causing the temperature rise), or has taken money to prove a conclusion with some facts rather than taking all the facts to form a conclusion, should at the very least be read with skepticism of their motives.

The Kyoto pact – A Slight Division of NWO Agendas for Cash and Power. While the Bush Administration denies and classifies (at least until very recently denying, but probably still classifying the real facts) global warming for expansion of corporate and personal greed in his NWO agenda of the ineffectual buying and selling of pollution credits. The UN uses global warming for its NWO agenda of ‘savior’ for gaining control of countries with its trivial reductions of CO2 decades from now. Both of these scenarios promote the continuance of the problem rather than a complete shift from the problem – an oil driven economy with corporate and government control.

Current hydrocarbon conversion to electricity wastes between 30 and 60% of the potential energy with the majority wasting as much as the process converts. Transfer of electricity over a great distance further degrades the conversion effectiveness. Even without further development of alternate energy sources there are currently more than adequate ways to completely change our delivery of needed energy without ‘living in a cave’ as the debunkers like promote. These current technologies are not cost effective because this government has supported the creation of massive profit corporations, instead of supplementing self sustaining individual energy creation and usage and alternate existing transportation.

Personnel solar, wind and water energy converters and vehicles get no subsidies, credits, or adoption by this government. Instead, the government prefers to subsidize the corporations and let alternate energy die on the vine. Tesla Motors already has an impressive electric performance roadster with plans to produce a vehicle more along the lines of a transportation car. GM and Toyota had electric cars and NiMh- Lithium batteries that were allowed to die on the vine. If any of these already existing technologies had been given a chance to compete with the destructive forms of hydrocarbon energy usage by subsidy, incentives, or taxing, they would have the volumes of production required to lower the manufacturing costs to where they would be directly competitive with our existing vehicles – similar to the reduced costs of computers and calculators. The technologies are already here. They just need to be granted the opportunity to compete instead of insuring the current corporation-government symbiosis – all without losing any of our energy requirements.

Billions of dollars have been spent on nuclear reactors which currently already have millions of tons of radioactive waste contaminating water, air and earth without any way of getting rid of them. Our current cancer rate may be as high as 10 times the pre-1950 rates. Billions of dollars have been spent on harvesting a hot fusion reaction – because it’s a way to get funding for nuclear weapons’ advancements without the pesky truth. Virtually nothing has been spent on zero point energy, Aquygen, or cold fusion, except to denounce it by this government, despite continued advancements and partial technology working models.

Article by Ed Ward.

“We are all complicit in the process of global warming, unfortunately, my generation
has been somewhat careless in looking after our only planet.”
U.N. Secretary General Ban Ki Moon
As you can undoubtedly appreciate CO2 is not a straight forward situation as usual…
It is pointless to bat the CO2 ball over the ping pong net…
We need a direction.

Now 3.3 percent of CO2 in the Earth’s atmosphere does not seem a lot compared to the total volume; Were as it not helping the situation to keep on shoveling CO2 into the air and certainly we need to clean up our act, the rate at which the Arctic and Greenland are thawing seems out of proportion, The effect is bigger than the cause. If CO2 is a culprit then maybe its not working alone. So stay tuned folks for part 3 of…

Scary Monsters: The eye of Ra…

Part 3 of this article: See next months…RHS1 Earthwatch Page

The Carteret Islands.

“This year 2006 will go down as the year that the vast majority of people woke up to climate change. People are now seeing the reality of climate change.”
Duncan McLaren, the chief executive of Friends of the Earth Scotland
The Carteret Islands (also known as Carteret Atoll, Tulun or Kilinailau Islands/Atoll), Han, Jangain, Yesila, Yolasa and Piul are part of Papua New Guinea located 86 kilometres north-east of Bougainville in the South Pacific at 4 degrees 45’S, 155 degrees 24’E. The atoll is a scattering of low lying islands in a horseshoe shape stretching around 30 kilometers in north-south direction, with a total land area of 0.6 square kilometers and a maximum elevation of 1.5 meters above sea level.

The islands were named after the British navigator Philip Carteret who discovered them in the sloop Swallow in 1767. As of 2005 about one thousand people live on the islands. Han is the most significant island with partial (but rapidly dieing due to saltwater introgression) tree cover, the others being small islets in the lagoon.

It was widely reported in November 2005 that the islands have progressively become uninhabitable, with an estimate of their total submersion by 2015. The islanders have fought a more than twenty years battle against the rising ocean, building sea walls and planting mangroves. However, storm surges and high tides continue to wash away homes, destroy vegetable gardens and contaminate fresh water supplies. On November 24, 2005, the Papua New Guinean government authorised the government-funded total evacuation of the islands, 10 families at a time; the evacuation is expected to be completed by 2007. It has been said that the islanders are the first climate refugees due to sea level rise attributed to global warming and climate change.

Disagreement over causes of flooding

Paul Tobasi, the atolls’ District Manager with Papua New Guinea’s Bougainville Province, denied that reefs were being destroyed by dynamite Tobasi and regional environmentalist groups have stated that the flooding is tied to global warming.

It has also been suggested that the movement of tectonic plates could be responsible. The islands lie in one of the most complex tectonic areas of the earth. They sit next to a plate convergence zone at the boundary of the Pacific Plate, Indo-Australian Plate, and South Bismark Plate on a subduction zone next to the New Hebrides Trench (Bougainville Trench), where the earth’s crust is disappearing. There is an active volcano on Bougainville Island, 86km away


NEW YORK, Feb. 15 -E-Wire:

Tuvalu, formerly known as the Ellice Islands, is a Polynesian island nation
located in the Pacific Ocean midway between Hawaii and Australia.
The old saying “Out of sight out of mind” is, without a doubt, true in many cases. It is particularly applicable to “Global Warming”, “The Kyoto Protocol” and the Tuvalu Islands.

The fate of the Tuvalu Islands has been publicized worldwide in all the media. The encroaching sea is being attributed to Global Warming. Many documentaries have been made of the situation at Tuvalu and the plight of the inhabitants there. Their Islands are being swamped by the rising ocean.

The Global Warming proponents are adamant that Carbon Emissions and the burning of fossil fuels are the cause of rising seas. The debate espouses that all the C02 produced from these emissions is causing the icecaps to melt. The conclusion of the argument is that the melting icecaps are causing the sea levels to rise.

Tuvalu has been used as an example of what is going to happen to low lying countries around the world as the ice caps melt. Tuvalu is, therefore, being used to keep our minds on rising sea levels supposedly caused by Global Warming? Tuvalu is a prima facie case in the Global Warming debate. But is the evidence conclusive? Just how conclusive it is we will see? The Carteret Islands are a part of Papua New Guinea.

The Atoll is horseshoe shaped scattered along a 24 mile chain of low lying islands. The Islands run in a north-south direction with a maximum elevation of 5 feet and a total land area of less than a square mile. The Carteret Islands have much in common with Tuvalu. The media has, however chosen to ignore their dilemma. Why has the media spotlighted rising seas at Tuvalu and ignored the tragedy of the Carteret Islands. The only logical conclusion one can draw is that the Carteret Islands are being kept ‘out of sight by the media in order to add support to the rising sea level arguments of the Global Warming lobby. In other words it is and inconvenient truth.

If the situation at the Carteret Islands is exposed it will most definitely weaken the “Global Warming” hypothesis. This explanation seems plausible because the Carteret Islands are also sinking into the Pacific. “Global Warming” is already under grave suspicion i.e. as far as sea level rise is concerned. As I said before “Global Warming” is a fact of life, and the heat has been increasing over many years. Global Warming is not however, causing sea levels to rise. On the contrary sea levels are falling.

The melting of the icecaps and their fresh water contribution to the seas will not make any difference to sea levels. Sea levels are falling constantly and will continue to do so even if all the ice caps melt. So the real moot point is…….What causes “Global Warming”? In my article ‘TUVALU STATE OF FEAR” I suggested that the Tuvalu Islands were sinking because of tectonic activity on the Pacific Ocean Floor.

Richard Guy

Greenland’s flag

ERS altimeter survey shows growth
of Greenland Ice Sheet interior

“The ice sheet covering Earth’s largest island of Greenland has an area of 1 833 900 square kilometres and an average thickness of 2.3 kilometres. It is the second largest concentration of frozen freshwater on Earth and if it were to melt completely global sea level would increase by up to seven metres.”


Seasonal results from the survey
Click here for a high resolution image.

Researchers have utilised more than a decade’s worth of data from radar altimeters on ESA’s ERS satellites to produce the most detailed picture yet of thickness changes in the Greenland Ice Sheet.

A Norwegian-led team used the ERS data to measure elevation changes in the Greenland Ice Sheet from 1992 to 2003, finding recent growth in the interior sections estimated at around six centimetres per year during the study period. The research is due to be published by Science Magazine in November, having been published in the online Science Express on 20 October.



Overall elevation changes over 11 years
Click here for a high resolution image.

ERS radar altimeters work by sending 1800 separate radar pulses down to Earth per second then recording how long their echoes take to bounce back 800 kilometres to the satellite platform. The sensor times its pulses’ journey down to under a nanosecond to calculate the distance to the planet below to a maximum accuracy of two centimetres.

ESA has had at least one working radar altimeter in polar orbit since July 1991, when ERS-1 was launched. ESA’s first Earth Observation spacecraft was joined by ERS-2 in April 1995, then the ten-instrument Envisat satellite in March 2002.

The result is a scientifically valuable long-term dataset covering Earth’s oceans and land as well as ice fields – which can be used to reduce uncertainty about whether land ice sheets are growing or shrinking as concern grows about the effects of global warming.

The ice sheet covering Earth’s largest island of Greenland has an area of 1 833 900 square kilometres and an average thickness of 2.3 kilometres. It is the second largest concentration of frozen freshwater on Earth and if it were to melt completely global sea level would increase by up to seven metres.

The influx of freshwater into the North Atlantic from any increase in melting from the Greenland Ice Sheet could also weaken the Gulf Stream, potentially seriously impacting the climate of northern Europe and the wider world.

Efforts to measure changes in the Greenland Ice Sheet using field observations, aircraft and satellites have improved scientific knowledge during the last decade, but there is still no consensus assessment of the ice sheet’s overall mass balance. There is however evidence of melting and thinning in the coastal marginal areas in recent years, as well as indications that large Greenland outlet glaciers can surge, possibly in response to climate variations.

Much less known are changes occurring in the vast elevated interior area of the ice sheet. Therefore an international team of scientists – from Norway’s Nansen Environmental and Remote Sensing Center (NERSC), Mohn-Sverdrup Center for Global Ocean Studies and Operational Oceanography and the Bjerknes Centre for Climate Research, Russia’s Nansen International Environmental and Remote Sensing Center and the United States’ Environmental Systems Analysis Research Center – were compelled to derive and analyse the longest continuous dataset of satellite altimeter observations of Greenland Ice Sheet elevations.



Greenland’s east coast seen by Envisat
Click here for a high resolution image.

By combining tens of millions of data points from ERS-1 and ERS-2, the team determined spatial patterns of surface elevation variations and changes over an 11-year period.

The result is a mixed picture, with a net increase of 6.4 centimetres per year in the interior area above 1500 metres elevation. Below that altitude, the elevation-change rate is minus 2.0 cm per year, broadly matching reported thinning in the ice-sheet margins. The trend below 1500 metres however does not include the steeply-sloping marginal areas where current altimeter data are unusable.

The spatially averaged increase is 5.4 cm per year over the study area, when corrected for post-Ice Age uplift of the bedrock beneath the ice sheet. These results are remarkable because they are in contrast to previous scientific findings of balance in Greenland’s high-elevation ice.

The team, led by Professor Ola M. Johannessen of NERSC, ascribe this interior growth of the Greenland Ice Sheet to increased snowfall linked to variability in regional atmospheric circulation known as the North Atlantic Oscillation (NAO). First discovered in the 1920s, the NAO acts in a similar way to the El Nino phenomenon in the Pacific, contributing to climate fluctuations across the North Atlantic and Europe.

Comparing their data to an index of the NAO, the researchers established a direct relationship between Greenland Ice Sheet elevation change and strong positive and negative phases of the NAO during winter, which largely control temperature and precipitation patterns over Greenland.

Professor Johannessen commented: “This strong negative correlation between winter elevation changes and the NAO index, suggests an underappreciated role of the winter season and the NAO for elevation changes – a wildcard in Greenland Ice Sheet mass balance scenarios under global warming.”

He cautioned that the recent growth found by the radar altimetry survey does not necessarily reflect a long-term or future trend. With natural variability in the high-latitude climate cycle that includes the NAO being very large, even an 11-year long dataset remains short.

“There is clearly a need for continued monitoring using new satellite altimeters and other observations, together with numerical models to calculate the Greenland Ice Sheet mass budget,” Johannessen added.

Modelling studies of the Greenland Ice Sheet mass balance under greenhouse global warming have shown that temperature increases up to about 3 degrees C lead to positive mass balance changes at high elevations – due to snow accumulation – and negative at low elevations – due to snow melt exceeding accumulation.

Such models agree with the new observational results. However after that threshold is reached, potentially within the next hundred years, losses from melting would exceed accumulation from increases in snowfall – then the meltdown of the Greenland Ice Sheet would be on.

A paper published in Science in June this year detailed the results of a similar analysis of the Antarctic Ice Sheet based on ERS radar altimeter data, carried out by a team led by Professor Curt Davis of the University of Missouri-Columbia.

The results showed thickening in East Antarctica on the order of 1.8 cm per year, but thinning across a substantial part of West Antarctica. Data were unavailable for much of the Antarctic Peninsula, subject to recent ice sheet thinning due to regional climate warming, again because of limitations in current radar altimeter performance.

ESA’s CryoSat mission, lost during launch on 8 October, carried the world’s first radar altimeter purpose-built for use over both land and sea ice. In the context of land ice sheets, CryoSat would have been capable of acquiring data over steeply-sloping ice margins which remain invisible to current radar altimeters – these being the very regions where the greatest loss is taking place.

Efforts are currently underway to investigate the possibility of building and flying a CryoSat-2, with a decision to be taken by the end of the year. In the meantime, the valuable climatological record of ice sheet change established by ERS and Envisat will continue to be extended.

ESA: European Space Agency