6pm: Following broadcast news reports of Mr Cameron's speech declaring Britain "a land of opportunity", 26 million employees immediately resign to become self-employed and plan to pay no tax for the next two years as they make the usual losses while creating their multinational businesses.
6.15 pm: Speaking from a television studio temporarily manned by police and Army personnel, the Prime Minster issues a correction, saying "We didn't mean you. Any of you. Now get back to work."
All original material is copyright of its author. Fair use permitted. Contact via comment. Unless indicated otherwise, all internet links accessed at time of writing. Nothing here should be taken as personal advice, financial or otherwise. No liability is accepted for third-party content, whether incorporated in or linked to this blog; or for unintentional error and inaccuracy. The blog author may have, or intend to change, a personal position in any stock or other kind of investment mentioned.
Wednesday, October 02, 2013
John Cook's Climate Change Mythbusters 15
This is part of a series reposting material from John Cook's Skeptical Science website. Although he is a physicist rather than a specialist in climate science, he is a convinced "global warmist" and tries to rebut frequently-raised objections to the theory. However, it is always possible to question the data (e.g. this valuable note about measuring temperature) and the line of argument. Please help advance the debate - with facts and logic.
_______________________________________________________
Not all of the CO2 emitted by human industrial activities remains in the atmosphere. Between 25% and 50% of these emissions over the industrial period have been absorbed by the world’s oceans, preventing atmospheric CO2 buildup from being much, much worse.
But this atmospheric benefit comes at a considerable price.
As ocean waters absorb CO2 they become more acidic. This does not mean the oceans will become acid. Ocean life can be sensitive to slight changes in pH levels, and any drop in pH is an increase in acidity, even in an alkaline environment.
The acidity of global surface waters has increased by 30% in just the last 200 years. This rate of acidification is projected through the end of the century to accelerate even further with potentially catastrophic impacts to marine ecosystems.
Endorsed by seventy academies of science from around the world, a June 2009 statement from the InterAcademy Panel on International Issues (IAP) stated the following.
"The current rate of change is much more rapid than during any event over the last 65 million years. These changes in ocean chemistry are irreversible for many thousands of years, and the biological consequences could last much longer."
- The InterAcademy Panel, June 1, 2009
As surface waters become more acidic, it becomes more difficult for marine life like corals and shellfish to form the hard shells necessary for their survival, and coral reefs provide a home for more than 25% of all oceanic species. Tiny creatures called pteropods located at the base of many oceanic food chains can also be seriously impacted. The degradation of these species at the foundation of marine ecosystems could lead to the collapse of these environments with devastating implications to millions of people in the human populations that rely on them.
The IAP also stated that, if atmospheric CO2 were to reach 550 parts per million (ppm) along its current rapid ascent from its pre-industrial level of 280 ppm, coral reefs around the globe could be dissolving.
All original material is copyright of its author. Fair use permitted. Contact via comment. Unless indicated otherwise, all internet links accessed at time of writing. Nothing here should be taken as personal advice, financial or otherwise. No liability is accepted for third-party content, whether incorporated in or linked to this blog; or for unintentional error and inaccuracy. The blog author may have, or intend to change, a personal position in any stock or other kind of investment mentioned.
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Ocean acidification: global warming's evil twin
What The Science Says:
Ocean acidification threatens entire marine food chains.
Ocean acidification threatens entire marine food chains.
Climate Myth: Ocean acidification isn't serious
'Our harmless emissions of trifling quantities of carbon dioxide cannot possibly acidify the oceans. Paper after paper after learned paper in the peer-reviewed literature makes that quite plain. Idso cites some 150 scientific sources, nearly all of them providing hard evidence, by measurement and experiment, that there is no basis for imagining that we can acidify the oceans to any extent large enough to be measured even by the most sensitive instruments.' (Christopher Monckton)
'Our harmless emissions of trifling quantities of carbon dioxide cannot possibly acidify the oceans. Paper after paper after learned paper in the peer-reviewed literature makes that quite plain. Idso cites some 150 scientific sources, nearly all of them providing hard evidence, by measurement and experiment, that there is no basis for imagining that we can acidify the oceans to any extent large enough to be measured even by the most sensitive instruments.' (Christopher Monckton)
But this atmospheric benefit comes at a considerable price.
As ocean waters absorb CO2 they become more acidic. This does not mean the oceans will become acid. Ocean life can be sensitive to slight changes in pH levels, and any drop in pH is an increase in acidity, even in an alkaline environment.
The acidity of global surface waters has increased by 30% in just the last 200 years. This rate of acidification is projected through the end of the century to accelerate even further with potentially catastrophic impacts to marine ecosystems.
Endorsed by seventy academies of science from around the world, a June 2009 statement from the InterAcademy Panel on International Issues (IAP) stated the following.
"The current rate of change is much more rapid than during any event over the last 65 million years. These changes in ocean chemistry are irreversible for many thousands of years, and the biological consequences could last much longer."
- The InterAcademy Panel, June 1, 2009
As surface waters become more acidic, it becomes more difficult for marine life like corals and shellfish to form the hard shells necessary for their survival, and coral reefs provide a home for more than 25% of all oceanic species. Tiny creatures called pteropods located at the base of many oceanic food chains can also be seriously impacted. The degradation of these species at the foundation of marine ecosystems could lead to the collapse of these environments with devastating implications to millions of people in the human populations that rely on them.
The IAP also stated that, if atmospheric CO2 were to reach 550 parts per million (ppm) along its current rapid ascent from its pre-industrial level of 280 ppm, coral reefs around the globe could be dissolving.
All original material is copyright of its author. Fair use permitted. Contact via comment. Unless indicated otherwise, all internet links accessed at time of writing. Nothing here should be taken as personal advice, financial or otherwise. No liability is accepted for third-party content, whether incorporated in or linked to this blog; or for unintentional error and inaccuracy. The blog author may have, or intend to change, a personal position in any stock or other kind of investment mentioned.
Can we escape?
Michael Snyder has written a good piece on waste ("About 40 Percent Of All Food In The United States Is Thrown In The Garbage", 1 October). But as one of his sources makes clear, something like that percentage starts as garbage:
The food I sell is not healthy, by any stretch. I sell potato chips, candy bars, bread, canned food, ice cream, soda, packaged meat, cigarettes and alcohol. I noticed quickly that a common ingredient of most of the foods is sugar and grains. Sugar and grains are easy to grow and produce cheaply and are used as fillers in processed food to cut cost and mask the taste of other questionable ingredients. Grains work in conjunction with sugars to inflame the body and compromise the immune system. Grains and sugars also have no nutritional value besides calories, so on top of inflaming the body; they do not provide the sustenance the body needs to survive. As the functions of the body require these nutrients the diet lacks, the body sucks these minerals from the bones, teeth and brain. Bone loss, and tooth decay and decreased brain function are the unfortunate symptoms of malnutrition. The poorest of the customers I serve are also the sickest. I have witnessed toothless mouths in the young and old. Mental retardation is also a common trait among many of them. I have even witnessed one unfortunate woman whose skin was a pale green color. These people are dying a slow starvation and they don’t even know it.
I think all this is connected to what Marxists call "reification", the process whereby a need or function becomes institutionalised and then the agenda is driven by that institution's instinct to survive and thrive. In this case, the manufacturer's need to widen profit margins by using cheap ingredients, and the supermarket's need to have products with a long shelf life, so skewing them towards sugar, salt and other preservatives.
Food, health, education, crime prevention, entertainment, government - almost all of it comes in somebody else's box.
The case for freedom is sometimes overstated. We give up a lot of freedom for an easy, comfortable life. But when the institutions become toxic, we begin to think like Huck Finn:
I reckon I got to light out for the territory ahead of the rest, because Aunt Sally she's going to adopt me and sivilize me, and I can't stand it. I been there before.
All original material is copyright of its author. Fair use permitted. Contact via comment. Unless indicated otherwise, all internet links accessed at time of writing. Nothing here should be taken as personal advice, financial or otherwise. No liability is accepted for third-party content, whether incorporated in or linked to this blog; or for unintentional error and inaccuracy. The blog author may have, or intend to change, a personal position in any stock or other kind of investment mentioned.
The food I sell is not healthy, by any stretch. I sell potato chips, candy bars, bread, canned food, ice cream, soda, packaged meat, cigarettes and alcohol. I noticed quickly that a common ingredient of most of the foods is sugar and grains. Sugar and grains are easy to grow and produce cheaply and are used as fillers in processed food to cut cost and mask the taste of other questionable ingredients. Grains work in conjunction with sugars to inflame the body and compromise the immune system. Grains and sugars also have no nutritional value besides calories, so on top of inflaming the body; they do not provide the sustenance the body needs to survive. As the functions of the body require these nutrients the diet lacks, the body sucks these minerals from the bones, teeth and brain. Bone loss, and tooth decay and decreased brain function are the unfortunate symptoms of malnutrition. The poorest of the customers I serve are also the sickest. I have witnessed toothless mouths in the young and old. Mental retardation is also a common trait among many of them. I have even witnessed one unfortunate woman whose skin was a pale green color. These people are dying a slow starvation and they don’t even know it.
I think all this is connected to what Marxists call "reification", the process whereby a need or function becomes institutionalised and then the agenda is driven by that institution's instinct to survive and thrive. In this case, the manufacturer's need to widen profit margins by using cheap ingredients, and the supermarket's need to have products with a long shelf life, so skewing them towards sugar, salt and other preservatives.
Food, health, education, crime prevention, entertainment, government - almost all of it comes in somebody else's box.
The case for freedom is sometimes overstated. We give up a lot of freedom for an easy, comfortable life. But when the institutions become toxic, we begin to think like Huck Finn:
I reckon I got to light out for the territory ahead of the rest, because Aunt Sally she's going to adopt me and sivilize me, and I can't stand it. I been there before.
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| Even the wrapper is useful. Pic source. |
All original material is copyright of its author. Fair use permitted. Contact via comment. Unless indicated otherwise, all internet links accessed at time of writing. Nothing here should be taken as personal advice, financial or otherwise. No liability is accepted for third-party content, whether incorporated in or linked to this blog; or for unintentional error and inaccuracy. The blog author may have, or intend to change, a personal position in any stock or other kind of investment mentioned.
Tuesday, October 01, 2013
Sunday in London
£2 to park all day at Solihull station, 102 minutes to Marylebone, then half an hour to South Kensington Tube station, where there's a feast of museums, and, like a trip through Gringotts' vaults, you go straight from the ticket barrier into the tiled tunnel that connects them.
The Victoria & Albert's tea room is a sensual, secular temple - more stained glass, ceramic workman's mottos and erotic goddess-like sculpture than you can take in at one go. Someday we'll do lunch there - the hot food looks top quality - but this time coffee and a scone were enough. Then up to Level 6, passing some absorbing interactive displays in the wood furniture section and a richly ornamented virginal, to arrive at the ceramics rooms. Some things were familiar - De Morgan tiles, Wedgwood, the 1957 design Homemaker plates (we have a well-used couple), some deceptively modern - a tiny, vigorous vase in the shape of a ram's head that looked postwar but was classical Greek (400 - 300 BC), and the one that astonished me this time was a huge blue alien - an ancient Egyptian "was-sceptre" seven feet high and 3,500 years old:
You can't read a library, so we broke off and went to the Natural History Museum. Sunday being sprog day, the place was packed with children seeking dinosaurs, and they were rewarded from the off:
The architecture alone is worth a visit, built as though it takes a delight in itself and the staircases could move about as in Hogwarts. Sit by the loos and look through an archway into the main hall, catching the slant of a stair and a brick-pilastered gallery hinting at more space beyond, in the way great buildings have that make them seem bigger than the open air.
The mammal collection was full of things that were safely stuffed, as I suppose we are these days. Standing by hippos and polar bears, I thought if it's them or me there's no question. And the blue whale made the neighbouring elephant look undersized and vulnerable: just a good mouthful.
Undraped, the walls echo so that on a busy day you can't really follow the talking displays, and for a venue so attractive to the young there doesn't seem to be enough to engage them actively - unlike at Bristol Zoo, which has put a great deal of thought and imagination into making things for children to poke their heads or fold their bodies in, clamber on, push, turn, squirt (there's a telltale puddle by the lion's-backside board, but kids don't anticipate) and so on. Still, they'll have enjoyed their dinos. We shoved a fiver into the perspex donation box and left.
And on up the Brompton Road, past the gloriously-interiored Oratory to turn right into Beauchamp Place for the Maroush Bakehouse, one of a chain of Lebanese restaurants.
Baker Street, the Edgware Road, Knightsbridge, the Temple area - Lebanese is popping up everywhere. Delicate spicing, deliciously fresh salads, mint tea, Mediterranean-style coffee and shisha pipes in many places, the odd piece of hot charcoal falling off the tinfoil and scorching the tablecloth as the girls suck and giggle. Organic-shaped pots, jugs and lamps, arabesque music, modern Dubai-style consumerist TV, all good for an hour's worth of playing the Oriental.
This Maroush didn't play up to the hokum smokum, but the food was excellent. We went for the set meal for two and could have fed at least another person, while an Australian couple in sports gear ("size matters" said the stripe on his sweatpants) talked business strategy on the next table and their neighbours examined kid pictures on granny's boasting-iPhone. Anyway, stuffed again, but in a good way this time. They do breakfast too, and the bakery section does takeaway; we like.
And so to walk it off, passing Harrod's (open till 6 on Sunday and the Food Hall is another place of worship, packed with Arabs and Japanese) and Knightsbridge Tube Station (which may well have been built specifically to exit smack by the store). We cut left a couple of times to enter Hyde Park and head north across its expanse, crossing an earthen ride and skirting the Serpentine (where Shelley's wife drowned herself) to pause at Speaker's Corner. There, a black man in a police sergeant's jacket and jackboots was using an England flag as a pointer as he listed races that he alleged "they don't like"; his patter palled with repetition, so we walked on past various Christian evangelists and the horse's head sculpture that I thought was a reference to the 1982 bombings, but not necessarily so, through Marble Arch and across the road island - where banner-holding Egyptians were protesting to the traffic against the military government - to Marylebone, and home.
All original material is copyright of its author. Fair use permitted. Contact via comment. Unless indicated otherwise, all internet links accessed at time of writing. Nothing here should be taken as personal advice, financial or otherwise. No liability is accepted for third-party content, whether incorporated in or linked to this blog; or for unintentional error and inaccuracy. The blog author may have, or intend to change, a personal position in any stock or other kind of investment mentioned.
The Victoria & Albert's tea room is a sensual, secular temple - more stained glass, ceramic workman's mottos and erotic goddess-like sculpture than you can take in at one go. Someday we'll do lunch there - the hot food looks top quality - but this time coffee and a scone were enough. Then up to Level 6, passing some absorbing interactive displays in the wood furniture section and a richly ornamented virginal, to arrive at the ceramics rooms. Some things were familiar - De Morgan tiles, Wedgwood, the 1957 design Homemaker plates (we have a well-used couple), some deceptively modern - a tiny, vigorous vase in the shape of a ram's head that looked postwar but was classical Greek (400 - 300 BC), and the one that astonished me this time was a huge blue alien - an ancient Egyptian "was-sceptre" seven feet high and 3,500 years old:
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| V&A link |
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| Pic source |
The mammal collection was full of things that were safely stuffed, as I suppose we are these days. Standing by hippos and polar bears, I thought if it's them or me there's no question. And the blue whale made the neighbouring elephant look undersized and vulnerable: just a good mouthful.
Undraped, the walls echo so that on a busy day you can't really follow the talking displays, and for a venue so attractive to the young there doesn't seem to be enough to engage them actively - unlike at Bristol Zoo, which has put a great deal of thought and imagination into making things for children to poke their heads or fold their bodies in, clamber on, push, turn, squirt (there's a telltale puddle by the lion's-backside board, but kids don't anticipate) and so on. Still, they'll have enjoyed their dinos. We shoved a fiver into the perspex donation box and left.
And on up the Brompton Road, past the gloriously-interiored Oratory to turn right into Beauchamp Place for the Maroush Bakehouse, one of a chain of Lebanese restaurants.
Baker Street, the Edgware Road, Knightsbridge, the Temple area - Lebanese is popping up everywhere. Delicate spicing, deliciously fresh salads, mint tea, Mediterranean-style coffee and shisha pipes in many places, the odd piece of hot charcoal falling off the tinfoil and scorching the tablecloth as the girls suck and giggle. Organic-shaped pots, jugs and lamps, arabesque music, modern Dubai-style consumerist TV, all good for an hour's worth of playing the Oriental.
This Maroush didn't play up to the hokum smokum, but the food was excellent. We went for the set meal for two and could have fed at least another person, while an Australian couple in sports gear ("size matters" said the stripe on his sweatpants) talked business strategy on the next table and their neighbours examined kid pictures on granny's boasting-iPhone. Anyway, stuffed again, but in a good way this time. They do breakfast too, and the bakery section does takeaway; we like.
And so to walk it off, passing Harrod's (open till 6 on Sunday and the Food Hall is another place of worship, packed with Arabs and Japanese) and Knightsbridge Tube Station (which may well have been built specifically to exit smack by the store). We cut left a couple of times to enter Hyde Park and head north across its expanse, crossing an earthen ride and skirting the Serpentine (where Shelley's wife drowned herself) to pause at Speaker's Corner. There, a black man in a police sergeant's jacket and jackboots was using an England flag as a pointer as he listed races that he alleged "they don't like"; his patter palled with repetition, so we walked on past various Christian evangelists and the horse's head sculpture that I thought was a reference to the 1982 bombings, but not necessarily so, through Marble Arch and across the road island - where banner-holding Egyptians were protesting to the traffic against the military government - to Marylebone, and home.
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| Pic source |
John Cook's Climate Change Mythbusters 14
This is part of a series reposting material from John Cook's Skeptical Science website. Although he is a physicist rather than a specialist in climate science, he is a convinced "global warmist" and tries to rebut frequently-raised objections to the theory. However, it is always possible to question the data (e.g. this valuable note about measuring temperature) and the line of argument. Please help advance the debate - with facts and logic.
_______________________________________________________
According to ice cores from Antarctica, the past 400,000 years have been dominated by glacials, also known as ice ages, that last about 100,000. These glacials have been punctuated by interglacials, short warm periods which typically last 11,500 years. Figure 1 below shows how temperatures in Antarctica changed over this period. Because our current interglacial (the Holocene) has already lasted approximately 12,000 years, it has led some to claim that a new ice age is imminent. Is this a valid claim?
Figure 1: Temperature change at Vostok, Antarctica (Petit 2000). The timing of warmer interglacials is highlighted in green; our current interglacial, the Holocene, is the one on the far right of the graph.
To answer this question, it is necessary to understand what has caused the shifts between ice ages and interglacials during this period. The cycle appears to be a response to changes in the Earth’s orbit and tilt, which affect the amount of summer sunlight reaching the northern hemisphere. When this amount declines, the rate of summer melt declines and the ice sheets begin to grow. In turn, this increases the amount of sunlight reflected back into space, increasing (or amplifying) the cooling trend. Eventually a new ice age emerges and lasts for about 100,000 years.
So what are today’s conditions like? Changes in both the orbit and tilt of the Earth do indeed indicate that the Earth should be cooling. However, two reasons explain why an ice age is unlikely:
All original material is copyright of its author. Fair use permitted. Contact via comment. Unless indicated otherwise, all internet links accessed at time of writing. Nothing here should be taken as personal advice, financial or otherwise. No liability is accepted for third-party content, whether incorporated in or linked to this blog; or for unintentional error and inaccuracy. The blog author may have, or intend to change, a personal position in any stock or other kind of investment mentioned.
_______________________________________________________
Are we heading into a new Ice Age?
What The Science Says:
Worry about global warming impacts in the next 100 years, not an ice age in over 10,000 years.
Worry about global warming impacts in the next 100 years, not an ice age in over 10,000 years.
Climate Myth: We're heading into an ice age
"One day you'll wake up - or you won't wake up, rather - buried beneath nine stories of snow. It's all part of a dependable, predictable cycle, a natural cycle that returns like clockwork every 11,500 years. And since the last ice age ended almost exactly 11,500 years ago…" (Ice Age Now)
"One day you'll wake up - or you won't wake up, rather - buried beneath nine stories of snow. It's all part of a dependable, predictable cycle, a natural cycle that returns like clockwork every 11,500 years. And since the last ice age ended almost exactly 11,500 years ago…" (Ice Age Now)
To answer this question, it is necessary to understand what has caused the shifts between ice ages and interglacials during this period. The cycle appears to be a response to changes in the Earth’s orbit and tilt, which affect the amount of summer sunlight reaching the northern hemisphere. When this amount declines, the rate of summer melt declines and the ice sheets begin to grow. In turn, this increases the amount of sunlight reflected back into space, increasing (or amplifying) the cooling trend. Eventually a new ice age emerges and lasts for about 100,000 years.
So what are today’s conditions like? Changes in both the orbit and tilt of the Earth do indeed indicate that the Earth should be cooling. However, two reasons explain why an ice age is unlikely:
- These two factors, orbit and tilt, are weak and are not acting within the same timescale – they are out of phase by about 10,000 years. This means that their combined effect would probably be too weak to trigger an ice age. You have to go back 430,000 years to find an interglacial with similar conditions, and this interglacial lasted about 30,000 years.
- The warming effect from CO2 and other greenhouse gases is greater than the cooling effect expected from natural factors. Without human interference, the Earth’s orbit and tilt, a slight decline in solar output since the 1950s and volcanic activity would have led to global cooling. Yet global temperatures are definitely on the rise.
All original material is copyright of its author. Fair use permitted. Contact via comment. Unless indicated otherwise, all internet links accessed at time of writing. Nothing here should be taken as personal advice, financial or otherwise. No liability is accepted for third-party content, whether incorporated in or linked to this blog; or for unintentional error and inaccuracy. The blog author may have, or intend to change, a personal position in any stock or other kind of investment mentioned.
Monday, September 30, 2013
John Cook's Climate Change Mythbusters 13
This is part of a series reposting material from John Cook's Skeptical Science website. Although he is a physicist rather than a specialist in climate science, he is a convinced "global warmist" and tries to rebut frequently-raised objections to the theory. However, it is always possible to question the data (e.g. this valuable note about measuring temperature) and the line of argument. Please help advance the debate - with facts and logic.
_______________________________________________________
Climate sensitivity is the estimate of how much the earth's climate will warm in response to the increased greenhouse effect if we double the amount of carbon dioxide in the atmosphere. This includes feedbacks which can either amplify or dampen that warming. This is very important because if it is low, as some climate 'skeptics' argue, then the planet will warm slowly and we will have more time to react and adapt. If sensitivity is high, then we could be in for a very bad time indeed.
There are two ways of working out what climate sensitivity is. The first method is by modelling:
Basic rebuttal written by GPWayne.
All original material is copyright of its author. Fair use permitted. Contact via comment. Unless indicated otherwise, all internet links accessed at time of writing. Nothing here should be taken as personal advice, financial or otherwise. No liability is accepted for third-party content, whether incorporated in or linked to this blog; or for unintentional error and inaccuracy. The blog author may have, or intend to change, a personal position in any stock or other kind of investment mentioned.
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How sensitive is our climate?
What The Science Says:
Net positive feedback is confirmed by many different lines of evidence.
Net positive feedback is confirmed by many different lines of evidence.
Climate Myth: Climate sensitivity is low
"His [Dr Spencer's] latest research demonstrates that – in the short term, at any rate – the temperature feedbacks that the IPCC imagines will greatly amplify any initial warming caused by CO2 are net-negative, attenuating the warming they are supposed to enhance. His best estimate is that the warming in response to a doubling of CO2 concentration, which may happen this century unless the usual suspects get away with shutting down the economies of the West, will be a harmless 1 Fahrenheit degree, not the 6 F predicted by the IPCC." (Christopher Monckton)
"His [Dr Spencer's] latest research demonstrates that – in the short term, at any rate – the temperature feedbacks that the IPCC imagines will greatly amplify any initial warming caused by CO2 are net-negative, attenuating the warming they are supposed to enhance. His best estimate is that the warming in response to a doubling of CO2 concentration, which may happen this century unless the usual suspects get away with shutting down the economies of the West, will be a harmless 1 Fahrenheit degree, not the 6 F predicted by the IPCC." (Christopher Monckton)
There are two ways of working out what climate sensitivity is. The first method is by modelling:
Climate models have predicted the least temperature rise would be on average 1.65°C (2.97°F) , but upper estimates vary a lot, averaging 5.2°C (9.36°F). Current best estimates are for a rise of around 3°C (5.4°F), with a likely maximum of 4.5°C (8.1°F).
The second method calculates climate sensitivity directly from physical evidence, by looking at climate changes in the distant past:
Various paleoclimate-based equilibrium climate sensitivity estimates from a range of geologic eras. Adapted from PALEOSENS (2012) Figure 3a by John Cook.
These calculations use data from sources like ice cores to work out how much additional heat the doubling of greenhouse gases will produce. These estimates are very consistent, finding between 2 and 4.5°C global surface warming in response to doubled carbon dioxide.
It’s all a matter of degree
All the models and evidence confirm a minimum warming close to 2°C for a doubling of atmospheric CO2 with a most likely value of 3°C and the potential to warm 4.5°C or even more. Even such a small rise would signal many damaging and highly disruptive changes to the environment. In this light, the arguments against reducing greenhouse gas emissions because of climate sensitivity are a form of gambling. A minority claim the climate is less sensitive than we think, the implication being we don’t need to do anything much about it. Others suggest that because we can't tell for sure, we should wait and see.
In truth, nobody knows for sure quite how much the temperature will rise, but rise it will. Inaction or complacency heightens risk, gambling with the entire ecology of the planet, and the welfare of everyone on it.
All original material is copyright of its author. Fair use permitted. Contact via comment. Unless indicated otherwise, all internet links accessed at time of writing. Nothing here should be taken as personal advice, financial or otherwise. No liability is accepted for third-party content, whether incorporated in or linked to this blog; or for unintentional error and inaccuracy. The blog author may have, or intend to change, a personal position in any stock or other kind of investment mentioned.
Sunday, September 29, 2013
John Cook's Climate Change Mythbusters 12
This is part of a series reposting material from John Cook's Skeptical Science website. Although he is a physicist rather than a specialist in climate science, he is a convinced "global warmist" and tries to rebut frequently-raised objections to the theory. However, it is always possible to question the data (e.g. this valuable note about measuring temperature) and the line of argument. Please help advance the debate - with facts and logic.
_______________________________________________________
Figure 2: Average global temperature (blue), Antarctic temperature (red), and atmospheric CO2 concentration (yellow dots). Source.
All original material is copyright of its author. Fair use permitted. Contact via comment. Unless indicated otherwise, all internet links accessed at time of writing. Nothing here should be taken as personal advice, financial or otherwise. No liability is accepted for third-party content, whether incorporated in or linked to this blog; or for unintentional error and inaccuracy. The blog author may have, or intend to change, a personal position in any stock or other kind of investment mentioned.
_______________________________________________________
CO2 lags temperature - what does it mean?
What The Science Says:
CO2 didn't initiate warming from past ice ages but it did amplify the warming. In fact, about 90% of the global warming followed the CO2 increase.
CO2 didn't initiate warming from past ice ages but it did amplify the warming. In fact, about 90% of the global warming followed the CO2 increase.
Climate Myth: CO2 lags temperature
"An article in Science magazine illustrated that a rise in carbon dioxide did not precede a rise in temperatures, but actually lagged behind temperature rises by 200 to 1000 years. A rise in carbon dioxide levels could not have caused a rise in temperature if it followed the temperature." (Joe Barton)
"An article in Science magazine illustrated that a rise in carbon dioxide did not precede a rise in temperatures, but actually lagged behind temperature rises by 200 to 1000 years. A rise in carbon dioxide levels could not have caused a rise in temperature if it followed the temperature." (Joe Barton)
Earth’s climate has varied widely over its history, from ice ages characterised by large ice sheets covering many land areas, to warm periods with no ice at the poles. Several factors have affected past climate change, including solar variability, volcanic activity and changes in the composition of the atmosphere. Data from Antarctic ice cores reveals an interesting story for the past 400,000 years. During this period, CO2 and temperatures are closely correlated, which means they rise and fall together. However, based on Antarctic ice core data, changes in CO2 follow changes in temperatures by about 600 to 1000 years, as illustrated in Figure 1 below. This has led some to conclude that CO2 simply cannot be responsible for current global warming.
Figure 1: Vostok ice core records for carbon dioxide concentration and temperature change.
This statement does not tell the whole story. The initial changes in temperature during this period are explained by changes in the Earth’s orbit around the sun, which affects the amount of seasonal sunlight reaching the Earth’s surface. In the case of warming, the lag between temperature and CO2 is explained as follows: as ocean temperatures rise, oceans release CO2 into the atmosphere. In turn, this release amplifies the warming trend, leading to yet more CO2 being released. In other words, increasing CO2 levels become both the cause and effect of further warming. This positive feedback is necessary to trigger the shifts between glacials and interglacials as the effect of orbital changes is too weak to cause such variation. Additional positive feedbacks which play an important role in this process include other greenhouse gases, and changes in ice sheet cover and vegetation patterns.
A 2012 study by Shakun et al. looked at temperature changes 20,000 years ago (the last glacial-interglacial transition) from around the world and added more detail to our understanding of the CO2-temperature change relationship. They found that:
- The Earth's orbital cycles trigger the initial warming (starting approximately 19,000 years ago), which is first reflected in the the Arctic.
- This Arctic warming caused large amounts of ice to melt, causing large amounts of fresh water to flood into the oceans.
- This influx of fresh water then disrupted the Atlantic Ocean circulation, in turn causing a seesawing of heat between the hemispheres. The Southern Hemisphere and its oceans warmed first, starting about 18,000 years ago.
- The warming Southern Ocean then released CO2 into the atmosphere starting around 17,500 years ago, which in turn caused the entire planet to warm via the increased greenhouse effect.
Overall, about 90% of the global warming occurred after the CO2 increase (Figure 2).
Figure 2: Average global temperature (blue), Antarctic temperature (red), and atmospheric CO2 concentration (yellow dots). Source.
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