As I understand it the increase in sea ice in Antarctica is partially caused by the ozone hole that develops every winter over the continent. Ozone is not usually connected to global warming but it is a greenhouse gas contributing around 5% of the total greenhouse effect. With an ozone hole you have more energy escaping to space and the subsequent stratospheric cooling strengthens the circumpolar winds (don't ask me to explain how that works). Apparently that stronger winds blow the existing sea ice around causing more polynyas (open water between ice floes) that subsequently freezes expanding sea ice area.
At the same time the GRACE satellites have been showing a net loss of ice from the ice sheets (the ice that's sitting on land), particularly in Western Antarctica. In the 7 years after GRACE was launched it showed a net loss of over 800 Gt (Gigatonnes) of land ice and the loss rate is accelerating by 26 Gt a year. But it only amounts to a millimeter or so of sea level rise per year for the time being.
What 15 years of cooling? Oh, you mean the one where when you start with 1995 the statistical certainty is only 93% that the warming observed during that period is not solely natural, not the 95% certainty level required to be called statistically significant.
2009 was in a virtual tie with a couple of other years for the 2nd warmest year on record globally (according to GISSTEMP records).
Ok, throw all of that unaccessible data out. It's a small enough area of the world that it doesn't make that much difference to the ultimate results. You would still see the warming trend in the data.
In the middle 1980s when that data was being processed the cost of enough hard disk to store what you can on a 10 GB thumb drive would have been over $1,000,000.
And yet for 150 years before 1960 tree ring data did match up pretty well with thermometer observations and tree ring data going back further matches up pretty well with other proxies. So all that says is something happened around the 1960s that broke the relationship, not that the data is totally useless.
In 1980 the cost of disk storage was well over $100,000/GB. In 2010 the price is somewhere in the $0.25/GB range. It didn't drop under $1,000/GB until 1994. Look here. Backups on the kinds of computers that scientists would have been using in the 1980s would have been to 10.5 inch reels of 9 track tape which have their own storage issues. At my place of work we didn't get our first tape cartridge backup system until around 1989. The raw temperature data is from thousands of weather stations around the world, many with multiple daily measurements and many with records going back well over 100 years. If you printed the data as 60 lines per page with each line being the record of one day it would take a little over 6 pages for a years worth of data for a single station. Multiply that by thousands of stations and you're talking about multiple truckloads of paper.
You young guys just don't appreciate how expensive storage was back then.
Yes! Arctic and Antarctic ice is melting faster than the IPCC predicted. Sea level is rising faster than they predicted. I could go on. Most predictions the IPCC has made have been on the conservative side.
Real Climate has allowed many comments critical of them to be published on their site. They just don't like wasting their time on unscientific bullshit.
No, they "unceremoniously dumped these tree ring data from their data sets" because they didn't match up with actual observations from thermometers. It has nothing to do with preconceived notions.
No climate scientist has said the Sun is meaningless. But we have been observing it rather closely since at least the 1950s and with continuous satellite observation since the 1980s and there have been on observed changes large enough to account for the observed climate changes. It is possible to distinguish the signal of the 22 year solar cycle in climate observations. What the Sun does in the future may be unpredictable but what can you do other than to assume it will be similar to what has happened in the recent past and make adjustments when you find that to be wrong?
The editorial said 1/3 of the references were to non-peer reviewed papers. But I'd bet if you examined it more closely you'd find most of those were in the WG III report, the one about what we can do about global warming. It had input from industrial interests and NGO's because in the end our response to it is a political issue.
I you checked the WG 1, the one about the physical science basis of global warming you will find very few if any non-peer reviewed references.
If you're wondering the WG II was about the impacts and vulnerability to global warming.
I think a good definition of pollution is too much of something where you don't want it. If the atmosphere suddenly jumped from 20% O2 to 40% I doubt we'd enjoy it much.
The confusion about global warming is in the general public, not the climate science community. There is lots of misinformation published about it because of the high stakes involved.
The last estimate I heard about the start of the next glaciation is about 20,000 years based on an analysis of the Milankovich Cycles. That is a short time in geologic terms but twice as long as our current civilizations existence.
The core of climate science is physics, specifically radiative transfer. Anyone who trains in that area is going to get a shitload of statistics before they get their degree.
I never said we knew everything however most of the work being done now is on details, not the big things. In the absence of evidence that we are missing something big, and no global warming is not that evidence, you go with what you know.
I believe the dip in temperature in the 1950s-1970s was at least partially human caused.
Aerosols such as SO2 are relatively shortlived in the atmosphere so you have to keep pumping them in to keep the levels up. Also they can be somewhat localized. That makes it a difficult field of study. But we're learning more all the time.
Earth's normal state varies depending on what epoch you're talking about but since before the genus Homo evolved around 2 million years ago the CO2 level has been below 300 ppm so we have a condition now that humans have never faced. Large volcanic eruptions can have a short term effect (a few years) but it takes a supervolcano such as Toba or Yellowstone to have much long term effect.
The Wikipedia article on the instrumental temperature record has a section on calculating global temperatures but it's not very specific.
I think the thing to remember here is that we care less about the absolute global temperature and more about how the temperature changes over time. If the methodology they use to calculate a global temperature is consistently applied we should get an accurate measurement of how it has changed.
You obviously believe climate scientists are driven by political ideology rather than science so there's no point in arguing with you. My personal opinion is that climate scientists do all they can to get it right and the political question is what do we do about it.
Who says the system isn't knowable? If it wasn't would we even be able to predict the weather tomorrow? The fact is that it's been an area of pretty intense study since at least the 1950's and we know more about it now than we did then but not as much as we will in the future. In science if reality is at odds with the current understanding that understanding moves to encompass the current reality. You obviously don't believe it has but I see no reason to seriously doubt climate scientists.
What evidence do you have that it will cost more to respond to it now than to wait until we're desperate? Most economic estimates I've seen project a cost of 1-2% of GDP for moving hard toward renewable energy sources. If the science is right we could incur far greater costs by waiting.
Don't you think solar astronomers put a lot of effort into knowing everything possible about the Sun? Anyone who comes up with something significant about it that we haven't measured yet will probably win a Nobel Prize. It would have to be something we don't have a clue about now. Until such a thing is discovered the simplest answer is to assume it doesn't exist. To say there's something about the Sun we don't know about that's causing global warming is putting the cart before the horse.
The plateau is accounted for by natural variability just like in other similar dips in the record.
Industrial aerosols being partially responsible for the cooling after WWII is something I first heard about 10 or 15 years ago. I don't know of any SO2 proxies and I'm not sure they are available. A reasonable place to start learning about the subject would be the Wikipedia article on global dimming.
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As I understand it the increase in sea ice in Antarctica is partially caused by the ozone hole that develops every winter over the continent. Ozone is not usually connected to global warming but it is a greenhouse gas contributing around 5% of the total greenhouse effect. With an ozone hole you have more energy escaping to space and the subsequent stratospheric cooling strengthens the circumpolar winds (don't ask me to explain how that works). Apparently that stronger winds blow the existing sea ice around causing more polynyas (open water between ice floes) that subsequently freezes expanding sea ice area.
At the same time the GRACE satellites have been showing a net loss of ice from the ice sheets (the ice that's sitting on land), particularly in Western Antarctica. In the 7 years after GRACE was launched it showed a net loss of over 800 Gt (Gigatonnes) of land ice and the loss rate is accelerating by 26 Gt a year. But it only amounts to a millimeter or so of sea level rise per year for the time being.
What 15 years of cooling? Oh, you mean the one where when you start with 1995 the statistical certainty is only 93% that the warming observed during that period is not solely natural, not the 95% certainty level required to be called statistically significant.
2009 was in a virtual tie with a couple of other years for the 2nd warmest year on record globally (according to GISSTEMP records).
Ok, throw all of that unaccessible data out. It's a small enough area of the world that it doesn't make that much difference to the ultimate results. You would still see the warming trend in the data.
In the middle 1980s when that data was being processed the cost of enough hard disk to store what you can on a 10 GB thumb drive would have been over $1,000,000.
And yet for 150 years before 1960 tree ring data did match up pretty well with thermometer observations and tree ring data going back further matches up pretty well with other proxies. So all that says is something happened around the 1960s that broke the relationship, not that the data is totally useless.
That's only if you believe Time and Newsweek are better sources of science than peer reviewed journals.
In 1980 the cost of disk storage was well over $100,000/GB. In 2010 the price is somewhere in the $0.25/GB range. It didn't drop under $1,000/GB until 1994. Look here. Backups on the kinds of computers that scientists would have been using in the 1980s would have been to 10.5 inch reels of 9 track tape which have their own storage issues. At my place of work we didn't get our first tape cartridge backup system until around 1989. The raw temperature data is from thousands of weather stations around the world, many with multiple daily measurements and many with records going back well over 100 years. If you printed the data as 60 lines per page with each line being the record of one day it would take a little over 6 pages for a years worth of data for a single station. Multiply that by thousands of stations and you're talking about multiple truckloads of paper.
You young guys just don't appreciate how expensive storage was back then.
Yes! Arctic and Antarctic ice is melting faster than the IPCC predicted. Sea level is rising faster than they predicted. I could go on. Most predictions the IPCC has made have been on the conservative side.
Real Climate has allowed many comments critical of them to be published on their site. They just don't like wasting their time on unscientific bullshit.
No, they "unceremoniously dumped these tree ring data from their data sets" because they didn't match up with actual observations from thermometers. It has nothing to do with preconceived notions.
No climate scientist has said the Sun is meaningless. But we have been observing it rather closely since at least the 1950s and with continuous satellite observation since the 1980s and there have been on observed changes large enough to account for the observed climate changes. It is possible to distinguish the signal of the 22 year solar cycle in climate observations. What the Sun does in the future may be unpredictable but what can you do other than to assume it will be similar to what has happened in the recent past and make adjustments when you find that to be wrong?
My first reaction to the headline is that's going to be one hell of a projector.
Most wars are fought over economic issues such as access to resources. Religious reasons may be used to justify it to the citizens.
The editorial said 1/3 of the references were to non-peer reviewed papers. But I'd bet if you examined it more closely you'd find most of those were in the WG III report, the one about what we can do about global warming. It had input from industrial interests and NGO's because in the end our response to it is a political issue.
I you checked the WG 1, the one about the physical science basis of global warming you will find very few if any non-peer reviewed references.
If you're wondering the WG II was about the impacts and vulnerability to global warming.
I think a good definition of pollution is too much of something where you don't want it. If the atmosphere suddenly jumped from 20% O2 to 40% I doubt we'd enjoy it much.
The confusion about global warming is in the general public, not the climate science community. There is lots of misinformation published about it because of the high stakes involved.
The last estimate I heard about the start of the next glaciation is about 20,000 years based on an analysis of the Milankovich Cycles. That is a short time in geologic terms but twice as long as our current civilizations existence.
The core of climate science is physics, specifically radiative transfer. Anyone who trains in that area is going to get a shitload of statistics before they get their degree.
I never said we knew everything however most of the work being done now is on details, not the big things. In the absence of evidence that we are missing something big, and no global warming is not that evidence, you go with what you know.
I believe the dip in temperature in the 1950s-1970s was at least partially human caused.
Aerosols such as SO2 are relatively shortlived in the atmosphere so you have to keep pumping them in to keep the levels up. Also they can be somewhat localized. That makes it a difficult field of study. But we're learning more all the time.
Earth's normal state varies depending on what epoch you're talking about but since before the genus Homo evolved around 2 million years ago the CO2 level has been below 300 ppm so we have a condition now that humans have never faced. Large volcanic eruptions can have a short term effect (a few years) but it takes a supervolcano such as Toba or Yellowstone to have much long term effect.
The Wikipedia article on the instrumental temperature record has a section on calculating global temperatures but it's not very specific.
I think the thing to remember here is that we care less about the absolute global temperature and more about how the temperature changes over time. If the methodology they use to calculate a global temperature is consistently applied we should get an accurate measurement of how it has changed.
AC is right.
You obviously believe climate scientists are driven by political ideology rather than science so there's no point in arguing with you. My personal opinion is that climate scientists do all they can to get it right and the political question is what do we do about it.
I'm not very happy with either party myself.
Who says the system isn't knowable? If it wasn't would we even be able to predict the weather tomorrow? The fact is that it's been an area of pretty intense study since at least the 1950's and we know more about it now than we did then but not as much as we will in the future. In science if reality is at odds with the current understanding that understanding moves to encompass the current reality. You obviously don't believe it has but I see no reason to seriously doubt climate scientists.
What evidence do you have that it will cost more to respond to it now than to wait until we're desperate? Most economic estimates I've seen project a cost of 1-2% of GDP for moving hard toward renewable energy sources. If the science is right we could incur far greater costs by waiting.
Don't you think solar astronomers put a lot of effort into knowing everything possible about the Sun? Anyone who comes up with something significant about it that we haven't measured yet will probably win a Nobel Prize. It would have to be something we don't have a clue about now. Until such a thing is discovered the simplest answer is to assume it doesn't exist. To say there's something about the Sun we don't know about that's causing global warming is putting the cart before the horse.
The plateau is accounted for by natural variability just like in other similar dips in the record.
Industrial aerosols being partially responsible for the cooling after WWII is something I first heard about 10 or 15 years ago. I don't know of any SO2 proxies and I'm not sure they are available. A reasonable place to start learning about the subject would be the Wikipedia article on global dimming.
Ok, but you have to admit it's a pretty generic term in the first place.