The role of Latent Heat of Fusion in Global Warming
by Anthony Marr
The following is a thought experiment in geophysics performed by Anthony Marr in regards to climate change and how it will unfold over the next few decades. It may or may not be the same as any modeling being conducted by anyone else, past or present. If so, it is a mutual confirmation. If not, it will shed light on how the climate will change not yet been seen.
The crucial item in this consideration is called Latent Heat, or Enthalpy. "Latent" means "hidden". The following will explain.
On a hot and dry day, sweating will cool the body, because when the sweat evaporates, it absorbs "latent heat of evaporation" from it's surroundings, mostly your skin. So, in a real sense, heat is removed from your skin to change the sweat from liquid to vapor. Conversely, if steam hits your skin and condenses into water, it would release the latent heat, thus heating your skin even more than boiling water. Simply, latent heat is absorbed when a substance changes from solid to liquid and from liquid to vapor, and it is released when the vapor condenses into liquid, and when the liquid freezes into solid. The latent heat involved in melting and solidification is called the Latent Heat of Fusion (LHF), and that involved in boiling and condensation is called the Latent Heat of Evaporation (LHE). For water, the LHF is 40 calories or 334 jules per gram, and the LHE (at the boiling point) is 280 calories or 2260 jules per gram.
The thing to note about LHF and LHE is this. When heat is applied to water above freezing, say, +10C/+48F, the more heat applied, the higher the temperature of the water becomes, which is common sense. But if heat is applied to a bucket of ice at, say, -10C/+16F, the content of the bucket would warm up to 0C/32F, but no higher, no matter how much more heat is applied. More heat will raise the melting rate, but not the temperature. But once all the ice had melted, the temperature of the result water will rise as more heat is applied. That amount of heat needed to melt all the ice without raising the temperature from the melting point is the Latent Heat of Fusion (LHF). And likewise for the LHE for boiling water.
The Latent Heat of Fusion (LHF) in regards to Arctic, Antarctic, Greenland and glacial ice will play a huge role in determining how future climate change will unfold. Here in a nutshell is what and how and when and why.
The temperature of the sea ice is of course 0C/32F, whereas the water of the Arctic Ocean in the summer is around 5C/40F. Thus, it melts the ice from below. When the ice melts, it abosrbs LHF from both the water below, and the air above. Thus, it cools the air as well as the water.
At the same time, since the sea ice meltdown has exposed the northern shoreline of Europe and Siberia to the warmer water, the water will warm up the air above the land to as far as 1,000 km /600 miles inland, thus melting the permafrost. The melting of the permafrost also absorbs LHF, this time from the land and from the air, thus cooling both, temporarily.
Meanwhile, the melting of the terrestrial and marine permafrost deposits release trapped methane, a powerful green house gas, which in sufficient volume will generate its own positive feedback loop to melt even more permafrost and further warm the ocean and release even more methane.
It is now apparent that as long as there is ice in the Arctic to melt, thus absorbing LHF, global warming will be relatively. The melting of ice is to an extent self-retarding, since LHF cools the surroundings of the substance being melted, thus slowing the rate of melting.
Conversely, in the winter, when the ice refreezes, it release its Latent Heat of Fusion, thus warming the water and slowing the refreezing. And the refreezing of the Arctic has been slowing over the last 5 years.
This implies something of paramount importance. The melting of Arctic ice in global warming tends to cool the summers by absorbing LHF through melting, and warms the winters by releasing LHF through refreezing. The latter, however, may end up being a cooling of the northern winter, because of the net loss of sea ice in that year, resulting in a net loss of LHF to the northern regions, including, for example, Vancouver, BC, which did experience a cooler winter in 2008/2009. The problem we face in the immediate future is that, as mentioned, the summer melting rate is increasing and the winter refreezing rate is decreasing, resulting in a net loss of ice and a net increase of LHF in the climatic system.
Unfortunately, no matter how fast the ice melts, the LHF absorption rate by ice-melting will decline with the decline of the total amount of ice to be melted. Since 2000, the Arctic has suffered a net-loss of about 2 trillion tons of sea ice. This means that while the planet is warming due to direct solar radiation and greenhouse-gas-heat-entrapment, it is cooled by the LHF removed from the climatic system due to the ice melt. This gives the Arctic ice the well deserved title of the "air conditioner of the planet". But the capacity of this air conditioner diminishes the less there is left of the sea ice.
To quantify this somewhat, the LHF of water is 334 jules to melt one gram of ice or about 40 calories, which is about 160X the amount of heat needed to raise the same amount of water by 1C/1.6F(!) Since 2000, the Arctic has suffered a 2-trillion-tonne net loss of sea ice. One tonne = 1,000 kg = 1,000,000 g. 2-trillion-tonnes = 2,000,000,000,000,000 grams. At 40 caleries per gram, the total amount of LHF absorbed from the planet by the net ice-loss since 2000 is in the order of 80,000,000,000,000,000 caleries, which is a huge amount of heat removed from global warming. If the ice has completely melted off, this same amount of heat will remain in the system and contribute to global heating.
In fact, the faster the ice melts, the greater the cooling effect in the northern lands, and cold fronts could be more powerful for a few years, inciting comments again of, "Global warming? What global warming?" In this context, a more reasonable approach would be to see that a colder winter could mean faster Arctic ice-melt due to intensified warming of the Arctic Ocean by the Albedo effect.
But of course, the faster the ice melts, the less there will be left to melt, and the less LHF will be absorbed. The air-conditioner will wind down, and eventuall shut down. "Eventually" of course means the time when all the ice in the world has melted, including the Arctic sea ice, the Greenland ice sheet, the mountain glaciers and the Antarctic ice cover. But we don't have to go that far to begin suffering major calamities all over the world. The Arctic Ocean will be 100% sea-ice-free in the summer of 2013, and it's being 100% sea-ice-free in the winter will soon follow, meaning, within decades.
By now, any reader still with me will have concluded that this cooling will be short-lived, and we are currently enjoying the maximum of its cooling effect. Although the ice will continue to melt faster and faster, it's total amount will continue to dwindle, and the amount of LHF absorbed will decline, eventually to zero when there is no ice left. At that point, because there is nothing left to absorb the quintillions of calories in LHFs, global warming speed will take a quantum leap, as if someone had cranked the tial to 10.
Since the Arctic sea ice is now half-gone, the cooling effect of the rest melting will decline. As I wrote earlier, we are currently enjoying the maximum cooling effect of the Arctic sea-ice meltdown. But it won't last. Long before the Arctic becomes ice-free in the winter, perhaps as early as 2012, the global temperature may have begun an inexorable skyrocketing we may not be able to slow down, much less bring to a halt.
There might be some truth in the December 21, 2012 Doomsday prophesy after all. But if the end of the world is going to happen, the means would not be an asteroid strike or nuclear war or alien invasion. It will be the detonation of the M-Bomb, known otherwise as the Methane Time-Bomb. While the A-Bomb is in terms of kilotons, and the H-Bomb is in terms megatons, the M-Bomb is in terms of gigatons. It is truly the Doomsday Machine. But it won't go off in a flash as the A and H bombs do. The M-Bomb is a slow bomb, which will taken decades to spend, by which time there will be little left to live for.
The time to save the planet is - IMMEDIATELY OR SOONER!
Anthony Marr, founder and president
Heal Our Planet Earth (HOPE)
www.HOPE-CARE.org
www.MySpace.com/AnthonyMarr
www.YouTube.com/AnthonyMarr
www.HomoSapiensSaveYourEarth.blogspot.com
www.ARConference.org
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In short...
Referring to the Huffington article [World Nearing Tipping Point For Disastrous Breakdown, Study Finds], someone asked me, "If the world is on the brink, why don't I feel it?"
The answer is three-fold:
- Earth's atmosphere and hydrosphere are both immense. Any cause-input will take 2-3 decades to produce the effect-output. This said, the cause-input began becoming significant as of about mid-last-century, and it has been continuous and increasing. So, in spite of the time lag, we've had measurable results, chief amongst which is the 0.9C mean global temperature rise from the baseline of 1880 when the Industrial Revolution began. Also more than obvious are the melting glaciers around the world, including those in the Himalayas, Greenland and the Antarctic, and the Arctic sea ice. Of course none of these is in anyone's backyard, so, for those with no or little awareness beyond their own physical or event horizons, "nothing is happening".
- Carbon dioxide is a stable gas and is therefore cumulative in the atmosphere to continue warming the planet for centuries to come. Even if we stopped burning fossil fuels yesterday, what we have already pumped into the atmosphere will be enough to trigger the deadly Methane Time Bomb. But, for now, nothing seems to be happening, and we carry on business as usual.
- Least known is the mechanism of latent (hidden) heat. Anyone who does not know what Latent Heat is will have a false sense of security. It is not hard to understand if I do not use physics jargon. Place on a hot stove a pot of cold water containing 1 kg of ice cubes. Stir the ice water with a long thermometer and take temperature readings. My question is: When will the thermometer begin to show a rise in temperature? Answer: After all the ice has melted. In other words, all the heat from the stove would first all go into melting the ice, without raising the water temperature. The amount of heat entering a system without raising the temperature of the system is called Latent Heat. It takes 80 calories of heat to melt one gram of ice. So in this case, the first 80,000 calories of heat from the stove went into melting the 1 kg of ice first. Only when the ice is all gone will the water temperature rise, and it will do so until it reaches 100C, when the water will begin to boil. Once again, Latent Heat comes into play, and the water temperature will stabilize at the boiling point - until all the water have changed from liquid to vapour, at which point the temperature of the dry pot will rise to the temperature of the flame itself. So how does this apply to Earth's climate? Consider the Arctic Ocean to be a gigantic pot of ice water, and the sun as the stove. For as long as there is still sea ice to melt, the Arctic Ocean will remain relatively cool, in spite of the ever increasing solar heat entering the Arctic ocean due to ever decreasing ice cover. When the sea ice is gone in the summer, as early as the latter part of this decade, the Arctic Ocean's temperature will steeply rise, and when it does, so will the global mean temperature, and all hell will break lose.
So, enjoy the "Arctic Air Conditioner" while it lasts, and be prepared to sweat after it quits. And when it happens, believe me, you will feel the heat!
Anthony Marr, founder and president
Heal Our Planet Earth (HOPE)
The Great Meltdown - Antartica
May 2007
Of all the places affected by global warming, Antarctica seems to be experiencing the most dramatic climate change.
The landscape has been transformed, leaving animals struggling to adapt. "On really hot days, penguins are gasping for air", states Antarctic historian Dave Burkitt. Nearly 90% of glaciers here are retreating and ice shelves are collapsing at an alarming rate. With less ice available, seals have moved inland, where they disrupt nesting birds and damage plants. "The continent warming opens up the door to the introduction of many species", explains biologist Gary Miller. "That's our immediate concern."
In 1914, the explorer Ernest Shackleton set out to explore Antarctica on foot. Comparing pictures of his voyage with the situation there now reveals the scale of changes.
Produced by SBS/Dateline - Distributed by Journeyman Pictures
Of all the places affected by global warming, Antarctica seems to be experiencing the most dramatic climate change.
The landscape has been transformed, leaving animals struggling to adapt. "On really hot days, penguins are gasping for air", states Antarctic historian Dave Burkitt. Nearly 90% of glaciers here are retreating and ice shelves are collapsing at an alarming rate. With less ice available, seals have moved inland, where they disrupt nesting birds and damage plants. "The continent warming opens up the door to the introduction of many species", explains biologist Gary Miller. "That's our immediate concern."
In 1914, the explorer Ernest Shackleton set out to explore Antarctica on foot. Comparing pictures of his voyage with the situation there now reveals the scale of changes.
Produced by SBS/Dateline - Distributed by Journeyman Pictures
2008 - New pictures of melting ice caps cause alarm
March 2008
Environmentalists are warning of the possibility of irreversible changes to sea levels as new satellite images show alarming evidence of the ice caps melting. The pictures show a chunk four times the size of Paris breaking off from Antarctica.
It belongs to the Wilkins Ice Shelf, a broad sheet of permanent floating ice located on the southwest Antarctic peninsula, some 1,600 kilometres from South America.
Speaking to the EU's environment committee in Brussels, Rajendra Pachauri, the head of the UN Intergovernmental Panel on Climate Change, voiced concern:
"We have (...) clearly mentioned the possibility of irreversible and abrupt changes, which could be essentially a collapse of these large bodies of ice that would result in several metres of increase in sea level. I hope that doesn't happen but it's a possibility that we have to be aware of."
Experts believe warm air and exposure to ocean waves are triggering the breakup.
With the summer melting season coming to an end, the disintegration is expected to cease, but scientists will be watching to see if it continues to fall apart next year.
Environmentalists are warning of the possibility of irreversible changes to sea levels as new satellite images show alarming evidence of the ice caps melting. The pictures show a chunk four times the size of Paris breaking off from Antarctica.
It belongs to the Wilkins Ice Shelf, a broad sheet of permanent floating ice located on the southwest Antarctic peninsula, some 1,600 kilometres from South America.
Speaking to the EU's environment committee in Brussels, Rajendra Pachauri, the head of the UN Intergovernmental Panel on Climate Change, voiced concern:
"We have (...) clearly mentioned the possibility of irreversible and abrupt changes, which could be essentially a collapse of these large bodies of ice that would result in several metres of increase in sea level. I hope that doesn't happen but it's a possibility that we have to be aware of."
Experts believe warm air and exposure to ocean waves are triggering the breakup.
With the summer melting season coming to an end, the disintegration is expected to cease, but scientists will be watching to see if it continues to fall apart next year.
NASA maps Earth's polar ice caps
December 2011
A NASA airborne laboratory, flying out of Punta Arenas in southern Chile, is conducting the largest airborne survey of Earth's polar ice caps.
With plans to map three-dimensional views of the Antarctic region and armed with sophisticated radar and altimeter lasers, "Operation Ice Bridge" will enable scientists ble to compare ice sheets' thickness from one year to the next which will help determining how quickly the ocean may rise.
The study will produce similar data on the Arctic region.
The effects of melting ice caps are one of the issues being highlighted at the 2011 United Nations Climate Change Conference under way in South Africa.
Al Jazeera's Lucia Newman reports from over the Antarctic Peninsula.
NOAA: Arctic sea ice 3rd lowest on record
Sea ice in the Arctic Ocean melts to its lowest extents around the 15th of September each year.
Since 1979, satellites have been used to closely monitor these dynamics of ice growth and retreat - since not only is sea ice important in determining global climate and weather patterns, but also for commerce, transportation, and national security.
With these careful satellite measurements, scientists have documented an almost 9% decrease in ice extent per decade. And though some years experience ice extent levels greater than the previous year, in general there has been a dramatic annual decline in Arctic ice.
In 2010, these trends continued making this year the third lowest sea ice extent ever measured by satellite. Only 2007 and 2008 had a lesser amount during the September minimum. In 2010, ice extent around the September 15th minimum was 22% below the average minimum of the past 30 years. To put it in perspective, a loss of 22% of the contiguous U.S. would be equivalent to losing all of the land area in the New England, Mid-Atlantic, Southeast, and Appalachian states. Not only is area of sea ice at near record low levels, but also the thickness and concentrations are equally low.
Video Credit :National Oceanic and Atmospheric Administration (NOAA)
Since 1979, satellites have been used to closely monitor these dynamics of ice growth and retreat - since not only is sea ice important in determining global climate and weather patterns, but also for commerce, transportation, and national security.
With these careful satellite measurements, scientists have documented an almost 9% decrease in ice extent per decade. And though some years experience ice extent levels greater than the previous year, in general there has been a dramatic annual decline in Arctic ice.
In 2010, these trends continued making this year the third lowest sea ice extent ever measured by satellite. Only 2007 and 2008 had a lesser amount during the September minimum. In 2010, ice extent around the September 15th minimum was 22% below the average minimum of the past 30 years. To put it in perspective, a loss of 22% of the contiguous U.S. would be equivalent to losing all of the land area in the New England, Mid-Atlantic, Southeast, and Appalachian states. Not only is area of sea ice at near record low levels, but also the thickness and concentrations are equally low.
Video Credit :National Oceanic and Atmospheric Administration (NOAA)
Catastrophic melting of Arctic ice, the 1980-2012
The heating of the planet for 127 years
A serious warning by Supreme Master Ching Hai
March 2008
The following video highlights the critical point of the environment in regards to global warming. Shows information on the methane gas hydrates being released from the Arctic lakes and permafrost and also shows NASA Report on global warming with quote from Jay Zwally.
The following video highlights the critical point of the environment in regards to global warming. Shows information on the methane gas hydrates being released from the Arctic lakes and permafrost and also shows NASA Report on global warming with quote from Jay Zwally.
The vast area of Siberian permafrost is thawing
and emitting methane
September 2011
Russian scientists discovers huge methane reserves bubbling from Artic ice
December 2011
According to Igor Semiletov of the Russian Academy of Sciences, methane gas is 20 times more harmful than carbon dioxide. Semiletov has studied these methane plumes for years but most of that time they were only about 30 meters in diameter. Semiletov said, "We carried out checks at about 115 stationary points and discovered methane fields of a fantastic scale — I think on a scale not seen before."
But with these methane bubbling holes having expanded to nearly one mile wide with no end to their expansion in sight , he is more than just a little bit concerned.
According to Igor Semiletov of the Russian Academy of Sciences, methane gas is 20 times more harmful than carbon dioxide. Semiletov has studied these methane plumes for years but most of that time they were only about 30 meters in diameter. Semiletov said, "We carried out checks at about 115 stationary points and discovered methane fields of a fantastic scale — I think on a scale not seen before."
But with these methane bubbling holes having expanded to nearly one mile wide with no end to their expansion in sight , he is more than just a little bit concerned.
Please read also: The Methane time bomb
Arctic ice shrinks to all-time low; half 1980 size
September 2012
WASHINGTON (AP) — In a critical climate indicator showing an ever warming world, the amount of ice in the Arctic Ocean shrank to an all-time low this year, obliterating old records.
The ice cap at the North Pole measured 1.32 million square miles on Sunday. That's 18 percent smaller than the previous record of 1.61 million square miles set in 2007, according to the National Snow and Ice Data Center in Boulder, Colo. Records go back to 1979 based on satellite tracking.
"On top of that, we're smashing a record that smashed a record," said data center scientist Walt Meier. Sea ice shrank in 2007 to levels 22 percent below the previous record of 2005.
Ice in the Arctic melts in summer and grows in winter, and it started growing again on Monday. In the 1980s, Meier said, summer sea ice would cover an area slightly smaller than the Lower 48 states. Now it is about half that.
Man-made global warming has melted more sea ice and made it thinner over the last couple decades with it getting much more extreme this year, surprisingly so, said snow and ice data center director Mark Serreze.
"Recently the loss of summer ice has accelerated and the six lowest September ice extents have all been in the past six years," Serreze said. "I think that's quite remarkable."
Serreze said except for one strong storm that contributed to the ice loss, this summer melt was more from the steady effects of day-to-day global warming. But he and others say the polar regions are where the globe first sees the signs of climate change.
"Arctic sea ice is one of the most sensitive of nature's thermometers," said Jason Box, an Ohio State University polar researcher.
What happens in the Arctic changes climate all over the rest of the world, scientists have reported in studies.
The ice in the Arctic "essentially acts like an air conditioner by keeping things cooler," Meier said. And when sea ice melts more, it's like the air conditioner isn't running efficiently, he said.
Sea ice reflects more than 90 percent of the sun's heat off the Earth, but when it is replaced by the darker open ocean, more than half of the heat is absorbed into the water, Meier said.
Scientists at the snow and ice data center said their computer models show an Arctic that would be essentially free of ice in the summer by 2050, but they add that current trends show ice melting faster than the computers are predicting.
On the Net:
The National Snow and Ice Data Center: http://nsidc.org/
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