"The greatest challenge of man's future is to provide the energy needed to lift the world's population out of poverty without imposing a cost on the planet that neither humans nor the rest of its inhabitants can bear. The answer to the challenge is in part political and in part technological, but none of the possible technologies are ready. Over the next twenty years, say, we need a massive research program to get them ready - we need to be investing heavily in research into solar energy as well as carbon capture."
Wallace Broecker and Robert Kunzig, "CO2 - Fixing Climate", chapter "Fixing climate".
Showing posts with label energy. Show all posts
Showing posts with label energy. Show all posts
Thursday, October 22, 2009
Tuesday, October 13, 2009
The biggest problem
"The biggest problem confronting the world, Lackner was deciding at that time, is not whether quarks could exist in a free, unconfined state outside the atomic nucleus - the question that had exercised his brain as a theoretical physicist, and that he pursues these days as a hobby, the way other men might go bowling. The biggest problem was environmental. Malthus and his followers were right: we are headed for a brick wall. But the wall our growing population would soon crash into was not, as the Malthusians thought, the limited resources of the planet. It was the limited ability of the planet's thin biosphere to sustain the environmental impact our growing population and spreading industry are inflicting on it.
Ultimately that problem came down to energy. "If we had cheap, clean, and copious energy, we could solve our problems about being sustainable," Lackner says. Unlike other energy sources, fossil fuels are cheap and copious right now. If we could just make them clean, they would be perfect."
Wallace Broecker and Robert Kunzig, "CO2 - Fixing Climate", chapter "Scrubbing the air".
As the title of this chapter suggests, Klaus Lackner thinks there is a solution: capturing CO2 out of the ambient air, and storing it as carbonates, the way nature does it with the weathering process, albeit at much too slow a rate to keep up with our emissions. As crazy as it may sound, some people have thought about it seriously, and are beginning to show it could be feasible. I'll make another post about it later, but I just would like to add here an excerpt from Lackner's 2003 Science paper ("A guide to CO2 sequestration"):
"CO2 is three times as heavy as fuel and therefore cannot be stored in cars or airplanes. CO2 from these sources will have to be released into the atmosphere and recaptured later. Currently, photosynthesis is the only practical form of air capture. Capture from air flowing over chemical sorbents - such as strong alkali solutions or activated carbon substrates - appears feasible but needs to be demonstrated. [...]
Because the atmosphere mixes rapidly, extraction at any site, however remote, could compensate for emissions from anywhere else. By decoupling power generation from sequestration, air capture would allow the existing fossil fuel-based energy infrastructure to live out its useful life; it would open remote disposal sites and even allow for the eventual reduction of atmospheric CO2 concentration."
Ultimately that problem came down to energy. "If we had cheap, clean, and copious energy, we could solve our problems about being sustainable," Lackner says. Unlike other energy sources, fossil fuels are cheap and copious right now. If we could just make them clean, they would be perfect."
Wallace Broecker and Robert Kunzig, "CO2 - Fixing Climate", chapter "Scrubbing the air".
As the title of this chapter suggests, Klaus Lackner thinks there is a solution: capturing CO2 out of the ambient air, and storing it as carbonates, the way nature does it with the weathering process, albeit at much too slow a rate to keep up with our emissions. As crazy as it may sound, some people have thought about it seriously, and are beginning to show it could be feasible. I'll make another post about it later, but I just would like to add here an excerpt from Lackner's 2003 Science paper ("A guide to CO2 sequestration"):
"CO2 is three times as heavy as fuel and therefore cannot be stored in cars or airplanes. CO2 from these sources will have to be released into the atmosphere and recaptured later. Currently, photosynthesis is the only practical form of air capture. Capture from air flowing over chemical sorbents - such as strong alkali solutions or activated carbon substrates - appears feasible but needs to be demonstrated. [...]
Because the atmosphere mixes rapidly, extraction at any site, however remote, could compensate for emissions from anywhere else. By decoupling power generation from sequestration, air capture would allow the existing fossil fuel-based energy infrastructure to live out its useful life; it would open remote disposal sites and even allow for the eventual reduction of atmospheric CO2 concentration."
Thursday, October 8, 2009
Is nuclear the energy solution?
A rational critic of nuclear energy as a practical solution to our energy and global warming problem:
"It's a measure of how urgent the CO2 problem has become that some antinuclear environmentalists have lately been willing to reconsider their long-standing opposition. Nuclear power, as its proponents frequently remind us, has killed far fewer people than coal mining, not to mention pollution from coal-fired power plants. But that doesn't mean there aren't rational reasons to be skeptical of it. There is still no permanent disposal site anywhere on Earth for waste that will remain dangerously radioactive for thousands of years. And the fear that a proliferation of civilian power plants could promote the proliferation of nuclear weapons has only grown more acute since September 11, 2001. The huge expansion of nuclear power that would be necessary for it to contribute significantly to resolving the CO2 problem is, in our opinion, just not going to happen."
Wallace Broecker and Robert Kunzig, "CO2 - Fixing Climate", chapter "Green is not enough".
"It's a measure of how urgent the CO2 problem has become that some antinuclear environmentalists have lately been willing to reconsider their long-standing opposition. Nuclear power, as its proponents frequently remind us, has killed far fewer people than coal mining, not to mention pollution from coal-fired power plants. But that doesn't mean there aren't rational reasons to be skeptical of it. There is still no permanent disposal site anywhere on Earth for waste that will remain dangerously radioactive for thousands of years. And the fear that a proliferation of civilian power plants could promote the proliferation of nuclear weapons has only grown more acute since September 11, 2001. The huge expansion of nuclear power that would be necessary for it to contribute significantly to resolving the CO2 problem is, in our opinion, just not going to happen."
Wallace Broecker and Robert Kunzig, "CO2 - Fixing Climate", chapter "Green is not enough".
Saturday, September 26, 2009
The carbon pie
A good explanation and discussion of the concept of carbon pie:
"Yet any realistic solution to the climate problem will have to resolve that conflict between the powerful drive to use fossil fuels and the real threat CO2 poses. One way to get an idea of both the scale of the problem and of what an equitable solution might look like is to think in terms of a "carbon pie". The pie represents the amount of CO2 we could still put into the atmosphere without disastrous effects. Its size is not easy to specify. We don't really know at what level the CO2 concentration will become truly dangerous - at what threshold the climate might shift so that rapid melting of the ice sheets becomes unavoidable, say, or the intensity of the drought in the American West is incompatible with the civilization we have built there. James Hansen, director of the NASA Goddard Institute for Space Studies in New York, puts the threshold at 450 parts per million. The Goddard climate model predicts a one-degree-Celsius warming from that concentration, and Hansen thinks a global average temperature one degree warmer than today is enough to threaten the long-term stability of the ice sheets.[...]
The drawback to setting that as a goal, however, is that it is probably not attainable.[...]
A more realistic goal would be 560 ppm - a doubling of pre-industrial CO2 - for which the middle-of-the-range climate-model forecast is a warming of three degrees Celsius. That would give us a carbon pie of 720 gigatons. How should the pie be sliced? The most equitable way would be for each country to get a slice proportional in size to its population. The industrialized countries as a group would then get around 20 percent of the pie, or 144 gigatons. At present they are emitting nearly 5 gigatons a year; at that rate, they will have eaten their pie in less than thirty years. Three decades to reduce their CO2 emissions to zero: that gives an idea of the challenge those countries face, if they want to take full responsibility for the consequences of their prosperity and do as much as possible - though much less than some researchers advocate - to protect the planet from dangerous climate change.
Clearly, the industrialized countries are not going to reduce their carbon emissions to zero in thirty years. Most of them are not even going to meet their much less challenging obligations under the Kyoto Protocol, which calls on them to reduce their emissions by 2012 to below the 1990 levels - on average 5 percent below. The United States, which signed but never ratified the 1997 protocol, has not even tried to reduce its CO2 emissions [...]. At the same time, one of the great shortcomings of the Kyoto Protocol, which conservative climate skeptics have stressed and which has become starkly evident in recent years, is that it placed no obligations on developing countries.
The carbon pie suggests a conceptual way out of this dilemma. It dramatizes the reality that any solution to the climate problem is going to require an overarching deal between industrialized and developing countries. In essence, the former will have to buy extra pieces of pie from the latter, to avoid the choice between protecting climate and torpedoing their economies. In return, the developing countries will get some kind of help with developing - ideally, in a way that helps alleviate rather than aggravate the CO2 problem. The bigger slices of pie that an equitable division would allot them would also allow them to use more fossil fuels for longer - which will in itself be an essential component of their development."
Wallace Broecker and Robert Kunzig, "CO2 - Fixing Climate", chapter "Green is not enough".
I think if such an agreement were reached at the Copenhagen Climate Conference in December, it would be a very good thing both for reducing the threats of global warming (although one can argue that if we choose a limit above the threshold at which climate change becomes dangerous for our civilization, then our efforts will be vain) and for helping the developing countries to get most of its people out of poverty, by transferring some of the riches the industrialized countries have gathered thanks to fossil fuels to those who have not yet enjoyed their benefits. But let's hope that these people don't follow our bad example and pollute as much as we did as they are developing. We therefore also need to develop cleaner energy production systems and to transfer these technologies to the developing countries as soon as possible!
"Yet any realistic solution to the climate problem will have to resolve that conflict between the powerful drive to use fossil fuels and the real threat CO2 poses. One way to get an idea of both the scale of the problem and of what an equitable solution might look like is to think in terms of a "carbon pie". The pie represents the amount of CO2 we could still put into the atmosphere without disastrous effects. Its size is not easy to specify. We don't really know at what level the CO2 concentration will become truly dangerous - at what threshold the climate might shift so that rapid melting of the ice sheets becomes unavoidable, say, or the intensity of the drought in the American West is incompatible with the civilization we have built there. James Hansen, director of the NASA Goddard Institute for Space Studies in New York, puts the threshold at 450 parts per million. The Goddard climate model predicts a one-degree-Celsius warming from that concentration, and Hansen thinks a global average temperature one degree warmer than today is enough to threaten the long-term stability of the ice sheets.[...]
The drawback to setting that as a goal, however, is that it is probably not attainable.[...]
A more realistic goal would be 560 ppm - a doubling of pre-industrial CO2 - for which the middle-of-the-range climate-model forecast is a warming of three degrees Celsius. That would give us a carbon pie of 720 gigatons. How should the pie be sliced? The most equitable way would be for each country to get a slice proportional in size to its population. The industrialized countries as a group would then get around 20 percent of the pie, or 144 gigatons. At present they are emitting nearly 5 gigatons a year; at that rate, they will have eaten their pie in less than thirty years. Three decades to reduce their CO2 emissions to zero: that gives an idea of the challenge those countries face, if they want to take full responsibility for the consequences of their prosperity and do as much as possible - though much less than some researchers advocate - to protect the planet from dangerous climate change.
Clearly, the industrialized countries are not going to reduce their carbon emissions to zero in thirty years. Most of them are not even going to meet their much less challenging obligations under the Kyoto Protocol, which calls on them to reduce their emissions by 2012 to below the 1990 levels - on average 5 percent below. The United States, which signed but never ratified the 1997 protocol, has not even tried to reduce its CO2 emissions [...]. At the same time, one of the great shortcomings of the Kyoto Protocol, which conservative climate skeptics have stressed and which has become starkly evident in recent years, is that it placed no obligations on developing countries.
The carbon pie suggests a conceptual way out of this dilemma. It dramatizes the reality that any solution to the climate problem is going to require an overarching deal between industrialized and developing countries. In essence, the former will have to buy extra pieces of pie from the latter, to avoid the choice between protecting climate and torpedoing their economies. In return, the developing countries will get some kind of help with developing - ideally, in a way that helps alleviate rather than aggravate the CO2 problem. The bigger slices of pie that an equitable division would allot them would also allow them to use more fossil fuels for longer - which will in itself be an essential component of their development."
Wallace Broecker and Robert Kunzig, "CO2 - Fixing Climate", chapter "Green is not enough".
I think if such an agreement were reached at the Copenhagen Climate Conference in December, it would be a very good thing both for reducing the threats of global warming (although one can argue that if we choose a limit above the threshold at which climate change becomes dangerous for our civilization, then our efforts will be vain) and for helping the developing countries to get most of its people out of poverty, by transferring some of the riches the industrialized countries have gathered thanks to fossil fuels to those who have not yet enjoyed their benefits. But let's hope that these people don't follow our bad example and pollute as much as we did as they are developing. We therefore also need to develop cleaner energy production systems and to transfer these technologies to the developing countries as soon as possible!
Monday, September 8, 2008
Electromagnetic fields at home
For once, this post is not going to be a quotation, but I am going to relate an experiment which I have done tonight, and which left me baffled !
I am reading in parallel to other books the book by B. Blake Levitt, Electromanetic fields, a consumer's guide to the issues and how to protect ourselves. After a first part on the fundamentals of electromagnetism and standards historic, a second part on the medical issues potentially related to electromagnetic fields (EMFs), I have finally reached the last part on how to measure our exposure and how to mitigate it. Levitt proposes a simple experiment, which I recommend everybody to perform : take a portable radio, tune it in between radio stations so as to listen to the background noise (the results are more spectacular on the AM band than on the FM band, and I chose the lowest AM frequency on my radio, around 500 KHz). Then get the radio close to any electric appliance in your home or office, and listen how the noise increases next to them. The strongest noise came from my laptop, desktop, TV, and microwave oven. Even when these devices were turned off, they still emitted strong EM noise. Only when I unplugged them from the wall socket did the noise disappear. So, simply by laziness to unplug our electrical devices when we don't use them, we waste energy and expose ourselves to potentially harmful EMFs ! To remedy the laziness issue, one solution is to buy power strips with switches, and plug your applicances on them, so that you only need to push the switch off to "unplug" everything.
About the harmfulness of EMFs, there are thousands of studies that show statistically significant relationships between various illnesses, including cancers, and high exposure to EMFs in lab animals as well as in humans. There are also hypotheses being refined to explain such relationships. For example, a possible link would be through the secretion of melatonin by the pineal gland, located in the middle of the brain. Melatonin destroys free radicals in the body and has anticancer properties, among other things. Melatonin production is elevated at night, but has been found to be suppressed by EMFs "at frequencies not far above those of earth's natural magnetic background and within the scope of the common household ranges of 50 to 60 Hz. If melatonin's production is suppressed at night, due to particular EMF exposures from electric blankets, waterbed heaters, or ambiant background exposures, health repercussions may be especially severe." (Chapter "The body's electrical system").
So after this experiment, I barely dare sitting in front of my laptop (well, I am sitting in front of it right now, writing this post, and during most of the day, 5-7 days a week !). What can I do about that ? This is my main work tool !...
But for sure now I am going to unplug most of my electric appliances before going to bed. I'll save energy, and perhaps some years of life before getting cancers or Alzheimer's or God knows what...
I am reading in parallel to other books the book by B. Blake Levitt, Electromanetic fields, a consumer's guide to the issues and how to protect ourselves. After a first part on the fundamentals of electromagnetism and standards historic, a second part on the medical issues potentially related to electromagnetic fields (EMFs), I have finally reached the last part on how to measure our exposure and how to mitigate it. Levitt proposes a simple experiment, which I recommend everybody to perform : take a portable radio, tune it in between radio stations so as to listen to the background noise (the results are more spectacular on the AM band than on the FM band, and I chose the lowest AM frequency on my radio, around 500 KHz). Then get the radio close to any electric appliance in your home or office, and listen how the noise increases next to them. The strongest noise came from my laptop, desktop, TV, and microwave oven. Even when these devices were turned off, they still emitted strong EM noise. Only when I unplugged them from the wall socket did the noise disappear. So, simply by laziness to unplug our electrical devices when we don't use them, we waste energy and expose ourselves to potentially harmful EMFs ! To remedy the laziness issue, one solution is to buy power strips with switches, and plug your applicances on them, so that you only need to push the switch off to "unplug" everything.
About the harmfulness of EMFs, there are thousands of studies that show statistically significant relationships between various illnesses, including cancers, and high exposure to EMFs in lab animals as well as in humans. There are also hypotheses being refined to explain such relationships. For example, a possible link would be through the secretion of melatonin by the pineal gland, located in the middle of the brain. Melatonin destroys free radicals in the body and has anticancer properties, among other things. Melatonin production is elevated at night, but has been found to be suppressed by EMFs "at frequencies not far above those of earth's natural magnetic background and within the scope of the common household ranges of 50 to 60 Hz. If melatonin's production is suppressed at night, due to particular EMF exposures from electric blankets, waterbed heaters, or ambiant background exposures, health repercussions may be especially severe." (Chapter "The body's electrical system").
So after this experiment, I barely dare sitting in front of my laptop (well, I am sitting in front of it right now, writing this post, and during most of the day, 5-7 days a week !). What can I do about that ? This is my main work tool !...
But for sure now I am going to unplug most of my electric appliances before going to bed. I'll save energy, and perhaps some years of life before getting cancers or Alzheimer's or God knows what...
Monday, September 1, 2008
Nucléaire : la solution miraculeuse ?
À la question de Frédéric Lenoir:
"Tout bien considéré, le nucléaire n'apparaît-il pas comme la meilleure solution présente, dans la mesure où il ne participe pas au réchauffement de la planète ?"
Hubert Reeves répond:
"Effectivement, le nucléaire semble à première vue le moyen idéal pour résoudre à la fois le problème de l'énergie et celui du réchauffement. J'ai d'ailleurs été naguère un ardent défenseur de ce mode d'énergie. Pourtant je vais expliciter mes réticences et essayer de montrer qu'à mon avis c'est une mauvaise solution, dont il faudrait se passer le plus vite possible. [...]
Pendant des années j'ai continué à penser que l'énergie nucléaire civile était vraiment l'énergie de l'avenir et que les problèmes techniques seraient rapidement résolus (la « fuite en avant » : une attitude qui a joué et qui continue à jouer un grand rôle chez les protagonistes du nucléaire). [...] Car les problèmes posés par ce mode d'extraction de l'énergie se sont révélés beaucoup plus coriaces que prévu. Je me suis peu à peu rendu compte que l'humanité se lançait dans une technologie que personne ne maîtrisait : ni le problème des déchets ni les conséquences d'un accident majeur.
Mais ce qui me paraît le plus préoccupant, c'est l'hypothèque qu'il fait peser sur nos enfants et petits-enfants. Entre la construction des centrales, leur démantèlement et la désactivation des déchets nucléaires, il peut se passer de nombreuses décennies, voire plusieurs siècles.
Or, aucun pays aujourd'hui ne peut être assuré d'une stabilité économique à l'échelle de siècles ou même de décennies. Les empires finissent toujours par s'effondrer. Prenons comme exemple le cas de l'Argentine, prospère jusqu'aux années 1930 et aujourd'hui en pleine débâcle économique. Qui dans ce pays pourrait aujourd'hui payer pour le démantèlement des installations nucléaires et la gestion des noyaux radioactifs à longue vie ? Le krash de 1929 a montré la fragilité des économies mondiales à l'échelle de quelques mois. Et imaginons qu'à la place des pyramides les Égyptiens aient bâti des réacteurs et que dans les souterrains de Gizéh et de Carnac soient stockées d'immenses quantités de matériaux radioactifs. Qui s'en serait occupé après l'écroulement de l'Empire égyptien ?
Le nucléaire, c'est « après nous le déluge ! » ou, si vous préférez, « profitons-en maintenant et laissons nos descendants payer la note s'ils en sont encore capables ». Et l'idée que d'autres industries en font autant n'est guère une excuse acceptable."
Hubert Reeves, Mal de Terre, chapitre "Quelles énergies pour demain ?".
"Tout bien considéré, le nucléaire n'apparaît-il pas comme la meilleure solution présente, dans la mesure où il ne participe pas au réchauffement de la planète ?"
Hubert Reeves répond:
"Effectivement, le nucléaire semble à première vue le moyen idéal pour résoudre à la fois le problème de l'énergie et celui du réchauffement. J'ai d'ailleurs été naguère un ardent défenseur de ce mode d'énergie. Pourtant je vais expliciter mes réticences et essayer de montrer qu'à mon avis c'est une mauvaise solution, dont il faudrait se passer le plus vite possible. [...]
Pendant des années j'ai continué à penser que l'énergie nucléaire civile était vraiment l'énergie de l'avenir et que les problèmes techniques seraient rapidement résolus (la « fuite en avant » : une attitude qui a joué et qui continue à jouer un grand rôle chez les protagonistes du nucléaire). [...] Car les problèmes posés par ce mode d'extraction de l'énergie se sont révélés beaucoup plus coriaces que prévu. Je me suis peu à peu rendu compte que l'humanité se lançait dans une technologie que personne ne maîtrisait : ni le problème des déchets ni les conséquences d'un accident majeur.
Mais ce qui me paraît le plus préoccupant, c'est l'hypothèque qu'il fait peser sur nos enfants et petits-enfants. Entre la construction des centrales, leur démantèlement et la désactivation des déchets nucléaires, il peut se passer de nombreuses décennies, voire plusieurs siècles.
Or, aucun pays aujourd'hui ne peut être assuré d'une stabilité économique à l'échelle de siècles ou même de décennies. Les empires finissent toujours par s'effondrer. Prenons comme exemple le cas de l'Argentine, prospère jusqu'aux années 1930 et aujourd'hui en pleine débâcle économique. Qui dans ce pays pourrait aujourd'hui payer pour le démantèlement des installations nucléaires et la gestion des noyaux radioactifs à longue vie ? Le krash de 1929 a montré la fragilité des économies mondiales à l'échelle de quelques mois. Et imaginons qu'à la place des pyramides les Égyptiens aient bâti des réacteurs et que dans les souterrains de Gizéh et de Carnac soient stockées d'immenses quantités de matériaux radioactifs. Qui s'en serait occupé après l'écroulement de l'Empire égyptien ?
Le nucléaire, c'est « après nous le déluge ! » ou, si vous préférez, « profitons-en maintenant et laissons nos descendants payer la note s'ils en sont encore capables ». Et l'idée que d'autres industries en font autant n'est guère une excuse acceptable."
Hubert Reeves, Mal de Terre, chapitre "Quelles énergies pour demain ?".
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