Methane, Atmospheric Warming, & Changes in Ice and Sea Level
Deep Ocean Methane Hydrates as an energy resource:
"The 'relative greenhouse effect' of methane is estimated at about 17 times that of carbon dioxide. In cold climate, the ratio may be as high as 40 times that of CO2." http://the-greenhouse-effect.blogspot.com/ (Some say the multiplier is 60.) But that is unconverted methane - converting it to water and CO2 in an engine or fuel cell would reduce its the greenhouse effect. Environmental emissions of methane, whether from natural sources - coal mining, peat bogs, release from methane hydrates in the ocean - or anthropogenic - livestock production, natural gas fuel systems, ethanol and methanol (biogas) fuel systems, etc.) are much more significant to the acceleration of the greenhouse effect than is CO2.
Yes. The use of biogas is perverse, in this context, and the only way to make it less so is to prevent methane emissions from fuel systems. Have a look at the posting at the link for more on this. Although using biomass to produce biogas, instead of feeding it to livestock, will make meat (and grains and soy) more expensive, the effect on total methane emissions is offset by the fact that cattle are themselves a major source of methane emissions. It's that ruminant stomach, you know. That's how they digest the cellulose, and the methane is a byproduct.
Well, the ecologists have been telliing us that everything is tied to everything else.
A ringer of sorts in the debate over the "Peak Oil" hypothesis is the possibility that the peaking and subsequent fall-off of petroleum and natural gas hydrocarbon energy sources (aka "fossil fuels) could be irrelevant to - detached from - related speculations about an end to the era of plentiful and relatively cheap energy, due to potential substitution of deep ocean methane hydrates for the missing oil and gas.
There is no credible argument that we have an unlimited supply of oil and gas on this earth - all of the argument is, or at least should be - about the nature of the impact on societies and the world economy when the supply of that resource is recognized to be decreasing relative to demand/ At the margin, that is, where all the economic action occurs. This resolves to arguments, or discussions, and rarely perhaps even thought about the nature of the the substitutions for oil and gas that will occur as those become relatively more expensive, and whether these substitutions will permit "life as we know it" to continue.
It's pretty plain that a shortage of energy, in the particular form of oil and gas, is not the primary threat to "life as we know it". Substitutions for those resources will occur, and may be dislocating and painful, but are nowhere near the significance of other issues - atmospheric warming, over population, and the prospect of drowning in our own waste products among them.
Methane hydrates obtained from truly immense deposits in the deep ocean are one possible substitution for fossil fuels. The stability of methane hydrate at depth is dependant on a two factor homeostatic regime, pressure and temperature or P-T. The P-T boundary is the depth in the ocean below which the hydrate is stable at a given (the ambient) temperature. Deepening of the oceans through rising sea levels will stabilize deep ocean methane hydrates, and possibly reduce natural release of the gas into the atmosphere from that source. But warming of the ocean waters will have the opposite effect, increasing the release into the atmosphere. If caused by a sudden dive of a warm current into a formerly cold deep area, the effects could be dramatic, even catastrophic.
Industrial accidents in mining methane hydrates from the ocean, even minor ones if frequent, might have very significant adverse effects on greenhouse warming of the atmosphere - as leakage from methane distribution and fueling systems might also. Deep ocean sequestration of methane hydrate is possible, but has its dangers, long term. And burying a fuel this useful on the ocean floor is an unlikely strategy.
Atmospheric Warming and Changes in Ice and Sea Level Balance
Homeostatic Balance and Positive and Negative Reinforcement Cycles
Amidst all the arguments and assertions about "Global Warming" there are occasional discussions of the positive and negative reinforcement effects of observed changes in average temperature. Positive reinforcement is a condition where a variation from a given state (or average temperature in this case) results in other changes that reinforce, or increase the initial variation. A temperature increase changes something else which in turn causes additional temperature increase. Or a change in CO2 levels causes something else to change which in turn causes CO2 levels to increase.
In negative reinforcement, the opposite occurs - the change causes a change in another factor which dampens, or reduces the initial change, and the system tends to return to its initial state.
Every possible combination of positive and negative reinforcement that can be imagined, it seems, has at one time or another been a part of an argument about the eventual end state of the current warming cycle. Will the warming observed be amplified or dampened by its effects on hundreds of different natural systems that it is impacting as it occurs?
Currently the consensus is that these changes will result in a net positive reinforcement - that warming begets warming, resulting in a relatively long term increase in average temperatures - perhaps until they increase to such an extreme point that they finally trigger changes that cause cooling.
I am persuaded by the consensus thinking. I see no serious evidence of cooling effects taking hold, or likely to take hold under current conditions. A major increase in reflective dust in the atmosphere is one possibility, but I suspect warming will get much greater before that becomes a significant cooling factor.
One example of a positive reinforcement is methane which has been locked in permafrost being released into the atmosphere as the permafrost melts. That melting has reached a rate and extent in Siberia which is astonishing professional climatologists and geologists. They are seeing changes in Siberia that they expected to see in a global warming regime - but at a rate far faster than they projected.
Phase State Changes are Typically Abrupt
In fact, this will turn out to be the case with most changes resulting from global warming - they will occur suddenly, that is with a rapidity that shocks the professional community. They are after all phase state changes, and phase state changes are extremely sensitive "at the margin". The system looks like it is not affected by external changes - until it finally shifts states, and moves into a new stable state. At the atomic level these are known as quantum state changes, named for the amount of energy that causes an electron to change from one orbital (energy) level with respect to the nucleus to another.
We must not expect the changes from global warming to occur slowly and smoothly over time as the warming progresses. Each natural system affected by the global change in temperature will occur relatively rapidly - and not necessarily at the same time as other systems change. Some of these changes, such as methane released from permafrost, or the reduced reflectivity of the arctic as ice melts, will result in positive reinforcement of the warming trend. Others, such as increased reflective dust in the atmosphere from dsertification, will dampen the effect of the warming. Careless and biased people will select such individual trends to argue with others about the direction and eventual end state of the changes being observed. Only diligent study and self education can help the average individual to sort all of this out, and make sense of the noise we get from MSM and WWW sources. MGHUA.
Melting of Ice is a Phase State Change
To me, anyone who has watched ice melt when moved from a subfreezing to a thawing environment must have noted that there is virtually no change apparent while the entire mass warms to the melting point, which can be a good long time.
Once melting begins change is noticeable and rapid. But why? It takes only .5 calories to raise the temperature of a gram of ice one degree until the ice is at 0 degrees Centigrade. It takes 80 calories for the phase change which converts one gram of ice to water at 0 degrees Centigrade. Once the ice has changed phase to become water it takes 1 calorie to raise the temperature of a gram of water 1 degree. ( http://www.chemtutor.com/sta.htm has excellent background on phase states. )
If you have ever driven on snow or ice when the temperature was at freezing, you should have noticed that the pressure of the tires on the ice melted it, and the tires wanted to slip - very nasty conditions, far worse than driving when well below freezing. If you take an ice cube from the refrigerator at -20 Centigrade and put it under pressure, but not enough to shatter it, it will retain its shape or deform very slowly. but as it warms to near the melting point it will deform much more rapidly. Try it. (This works with your teeth too, but you might break them - if you believe your mother.) A warm piece of ice becomes almost pliable under pressure, right before it melts.
So the odd thing is not that glaciers on Antarctica are moving faster, even before melting, or getting especially near the melting point. It is that the people studying them are surprised by that fact. Ice crystals have, at their boundaries, interface layers that are easily converted to water under pressure. That particular phase change is governed by a relation of temperature and pressure, as it is under your car's tires or the soles of your shoes. As the temperature of the frozen mass of ice increases, more and more of the interface between crystals converts to a state where it can easily shift to a molecule thick layer of water - even while the mass of ice is still below freezing temperature. Once again - as temperature increases, at any given point in time the proportion of the interface which is fluid is increasing. All this happens before melting, and before the 80 calorie input needed to convert the ice to water is available. The glacier, as the ice cube, becomes pliable, and flows. Surprise! ... Not really.
The Ice Cube Demonstration: When a floating ice cube melts the water in the glass does not rise. When an ice cube is added to the water, the water runs over.
Global warming deniers occasionally have fun with the unfortunate fact that many people concerned with the melting of the Arctic ice, or of Antarctic ice shelves think that those events will raise sea levels. That will not happen, since the volume of ice floating in the sea is already reflected in the sea level. But every bit if ice and water lost from the continental glaciers, no matter where they are, will raise the sea level. The ice does not even have to melt, it has only to reach the sea. Watch those glaciers, people. Watch them very closely.
"The 'relative greenhouse effect' of methane is estimated at about 17 times that of carbon dioxide. In cold climate, the ratio may be as high as 40 times that of CO2." http://the-greenhouse-effect.blogspot.com/ (Some say the multiplier is 60.) But that is unconverted methane - converting it to water and CO2 in an engine or fuel cell would reduce its the greenhouse effect. Environmental emissions of methane, whether from natural sources - coal mining, peat bogs, release from methane hydrates in the ocean - or anthropogenic - livestock production, natural gas fuel systems, ethanol and methanol (biogas) fuel systems, etc.) are much more significant to the acceleration of the greenhouse effect than is CO2.
Yes. The use of biogas is perverse, in this context, and the only way to make it less so is to prevent methane emissions from fuel systems. Have a look at the posting at the link for more on this. Although using biomass to produce biogas, instead of feeding it to livestock, will make meat (and grains and soy) more expensive, the effect on total methane emissions is offset by the fact that cattle are themselves a major source of methane emissions. It's that ruminant stomach, you know. That's how they digest the cellulose, and the methane is a byproduct.
Well, the ecologists have been telliing us that everything is tied to everything else.
A ringer of sorts in the debate over the "Peak Oil" hypothesis is the possibility that the peaking and subsequent fall-off of petroleum and natural gas hydrocarbon energy sources (aka "fossil fuels) could be irrelevant to - detached from - related speculations about an end to the era of plentiful and relatively cheap energy, due to potential substitution of deep ocean methane hydrates for the missing oil and gas.
There is no credible argument that we have an unlimited supply of oil and gas on this earth - all of the argument is, or at least should be - about the nature of the impact on societies and the world economy when the supply of that resource is recognized to be decreasing relative to demand/ At the margin, that is, where all the economic action occurs. This resolves to arguments, or discussions, and rarely perhaps even thought about the nature of the the substitutions for oil and gas that will occur as those become relatively more expensive, and whether these substitutions will permit "life as we know it" to continue.
It's pretty plain that a shortage of energy, in the particular form of oil and gas, is not the primary threat to "life as we know it". Substitutions for those resources will occur, and may be dislocating and painful, but are nowhere near the significance of other issues - atmospheric warming, over population, and the prospect of drowning in our own waste products among them.
Methane hydrates obtained from truly immense deposits in the deep ocean are one possible substitution for fossil fuels. The stability of methane hydrate at depth is dependant on a two factor homeostatic regime, pressure and temperature or P-T. The P-T boundary is the depth in the ocean below which the hydrate is stable at a given (the ambient) temperature. Deepening of the oceans through rising sea levels will stabilize deep ocean methane hydrates, and possibly reduce natural release of the gas into the atmosphere from that source. But warming of the ocean waters will have the opposite effect, increasing the release into the atmosphere. If caused by a sudden dive of a warm current into a formerly cold deep area, the effects could be dramatic, even catastrophic.
Industrial accidents in mining methane hydrates from the ocean, even minor ones if frequent, might have very significant adverse effects on greenhouse warming of the atmosphere - as leakage from methane distribution and fueling systems might also. Deep ocean sequestration of methane hydrate is possible, but has its dangers, long term. And burying a fuel this useful on the ocean floor is an unlikely strategy.
Atmospheric Warming and Changes in Ice and Sea Level Balance
Homeostatic Balance and Positive and Negative Reinforcement Cycles
Amidst all the arguments and assertions about "Global Warming" there are occasional discussions of the positive and negative reinforcement effects of observed changes in average temperature. Positive reinforcement is a condition where a variation from a given state (or average temperature in this case) results in other changes that reinforce, or increase the initial variation. A temperature increase changes something else which in turn causes additional temperature increase. Or a change in CO2 levels causes something else to change which in turn causes CO2 levels to increase.
In negative reinforcement, the opposite occurs - the change causes a change in another factor which dampens, or reduces the initial change, and the system tends to return to its initial state.
Every possible combination of positive and negative reinforcement that can be imagined, it seems, has at one time or another been a part of an argument about the eventual end state of the current warming cycle. Will the warming observed be amplified or dampened by its effects on hundreds of different natural systems that it is impacting as it occurs?
Currently the consensus is that these changes will result in a net positive reinforcement - that warming begets warming, resulting in a relatively long term increase in average temperatures - perhaps until they increase to such an extreme point that they finally trigger changes that cause cooling.
I am persuaded by the consensus thinking. I see no serious evidence of cooling effects taking hold, or likely to take hold under current conditions. A major increase in reflective dust in the atmosphere is one possibility, but I suspect warming will get much greater before that becomes a significant cooling factor.
One example of a positive reinforcement is methane which has been locked in permafrost being released into the atmosphere as the permafrost melts. That melting has reached a rate and extent in Siberia which is astonishing professional climatologists and geologists. They are seeing changes in Siberia that they expected to see in a global warming regime - but at a rate far faster than they projected.
Phase State Changes are Typically Abrupt
In fact, this will turn out to be the case with most changes resulting from global warming - they will occur suddenly, that is with a rapidity that shocks the professional community. They are after all phase state changes, and phase state changes are extremely sensitive "at the margin". The system looks like it is not affected by external changes - until it finally shifts states, and moves into a new stable state. At the atomic level these are known as quantum state changes, named for the amount of energy that causes an electron to change from one orbital (energy) level with respect to the nucleus to another.
We must not expect the changes from global warming to occur slowly and smoothly over time as the warming progresses. Each natural system affected by the global change in temperature will occur relatively rapidly - and not necessarily at the same time as other systems change. Some of these changes, such as methane released from permafrost, or the reduced reflectivity of the arctic as ice melts, will result in positive reinforcement of the warming trend. Others, such as increased reflective dust in the atmosphere from dsertification, will dampen the effect of the warming. Careless and biased people will select such individual trends to argue with others about the direction and eventual end state of the changes being observed. Only diligent study and self education can help the average individual to sort all of this out, and make sense of the noise we get from MSM and WWW sources. MGHUA.
Melting of Ice is a Phase State Change
To me, anyone who has watched ice melt when moved from a subfreezing to a thawing environment must have noted that there is virtually no change apparent while the entire mass warms to the melting point, which can be a good long time.
Once melting begins change is noticeable and rapid. But why? It takes only .5 calories to raise the temperature of a gram of ice one degree until the ice is at 0 degrees Centigrade. It takes 80 calories for the phase change which converts one gram of ice to water at 0 degrees Centigrade. Once the ice has changed phase to become water it takes 1 calorie to raise the temperature of a gram of water 1 degree. ( http://www.chemtutor.com/sta.htm has excellent background on phase states. )
If you have ever driven on snow or ice when the temperature was at freezing, you should have noticed that the pressure of the tires on the ice melted it, and the tires wanted to slip - very nasty conditions, far worse than driving when well below freezing. If you take an ice cube from the refrigerator at -20 Centigrade and put it under pressure, but not enough to shatter it, it will retain its shape or deform very slowly. but as it warms to near the melting point it will deform much more rapidly. Try it. (This works with your teeth too, but you might break them - if you believe your mother.) A warm piece of ice becomes almost pliable under pressure, right before it melts.
So the odd thing is not that glaciers on Antarctica are moving faster, even before melting, or getting especially near the melting point. It is that the people studying them are surprised by that fact. Ice crystals have, at their boundaries, interface layers that are easily converted to water under pressure. That particular phase change is governed by a relation of temperature and pressure, as it is under your car's tires or the soles of your shoes. As the temperature of the frozen mass of ice increases, more and more of the interface between crystals converts to a state where it can easily shift to a molecule thick layer of water - even while the mass of ice is still below freezing temperature. Once again - as temperature increases, at any given point in time the proportion of the interface which is fluid is increasing. All this happens before melting, and before the 80 calorie input needed to convert the ice to water is available. The glacier, as the ice cube, becomes pliable, and flows. Surprise! ... Not really.
The Ice Cube Demonstration: When a floating ice cube melts the water in the glass does not rise. When an ice cube is added to the water, the water runs over.
Global warming deniers occasionally have fun with the unfortunate fact that many people concerned with the melting of the Arctic ice, or of Antarctic ice shelves think that those events will raise sea levels. That will not happen, since the volume of ice floating in the sea is already reflected in the sea level. But every bit if ice and water lost from the continental glaciers, no matter where they are, will raise the sea level. The ice does not even have to melt, it has only to reach the sea. Watch those glaciers, people. Watch them very closely.
Labels: Atmosphere, Glaciers, Methane, Ocean, Peak Oil, Sea Level