Arctic warming not natural

[Old Rocks]

Climate warming 'highly unusual' says new study



A major U.S. government report on Arctic climate, prepared with information from eight Canadian scientists, has concluded that the recent rapid warming of polar temperatures and shrinking of multi-year Arctic sea ice are "highly unusual compared to events from previous thousands of years."

The findings, released Friday, counter suggestions from skeptics that such recent events as the opening of the Northwest Passage and collapse of ice shelves in the Canadian Arctic are predictable phenomena that can be explained as part of a natural climate cycle rather than being driven by elevated carbon emissions from human activity.

A summary of the report -- described as "the first comprehensive analysis of the real data we have on past climate conditions in the Arctic," by U.S. Geological Survey director Mark Myers -- warns that "sustained warming of at least a few degrees" is probably enough "to cause the nearly complete, eventual disappearance of the Greenland ice sheet, which would raise sea level by several metres."

The study also sounds the alarm that "temperature change in the Arctic is happening at a greater rate than other places in the Northern Hemisphere, and this is expected to continue in the future. As a result, glacier and ice-sheet melting, sea-ice retreat, coastal erosion and sea-level rise can be expected to continue."

Ice cover in the Canadian Arctic and throughout the polar world has experienced record-setting melts in the past few years. The summer of 2007 saw polar ice cover shrink to its lowest extent in recorded history. Last summer's melt came close to matching that record, and recent research indicates that overall ice volume -- because of the continual replacement of thicker, multi-year ice with thinner new ice -- was lower in 2008 than 2007.

This past summer also saw further dramatic evidence of the unusual warming of the Canadian Arctic, including record-setting high temperatures in Iqaluit, Nunavut, rapid erosion and flooding of a glacial landscape on Baffin Island, the re-opening of the Northwest Passage, an unprecedented clearing of ice from the Beaufort Sea and the collapse of hundreds of square kilometres of ancient ice shelves on Ellesmere Island.

Research for the U.S. Congress-commissioned report was conducted by 37 scientists from the U.S., Germany, Canada, Britain and Denmark.

"The current rate of human-influenced Arctic warming is comparable to peak natural rates documented by reconstructions of past climates. However, some projections of future human-induced change exceed documented natural variability," the scientists conclude. "The past tells us that when thresholds in the climate system are crossed, climate change can be very large and very fast. We cannot rule out that human-induced climate change will trigger such events in the future."

© Copyright (c) The Vancouver Sun

 

[dilloduck]

Climate warming 'highly unusual' says new study



A major U.S. government report on Arctic climate, prepared with information from eight Canadian scientists, has concluded that the recent rapid warming of polar temperatures and shrinking of multi-year Arctic sea ice are "highly unusual compared to events from previous thousands of years."

The findings, released Friday, counter suggestions from skeptics that such recent events as the opening of the Northwest Passage and collapse of ice shelves in the Canadian Arctic are predictable phenomena that can be explained as part of a natural climate cycle rather than being driven by elevated carbon emissions from human activity.

A summary of the report -- described as "the first comprehensive analysis of the real data we have on past climate conditions in the Arctic," by U.S. Geological Survey director Mark Myers -- warns that "sustained warming of at least a few degrees" is probably enough "to cause the nearly complete, eventual disappearance of the Greenland ice sheet, which would raise sea level by several metres."

The study also sounds the alarm that "temperature change in the Arctic is happening at a greater rate than other places in the Northern Hemisphere, and this is expected to continue in the future. As a result, glacier and ice-sheet melting, sea-ice retreat, coastal erosion and sea-level rise can be expected to continue."

Ice cover in the Canadian Arctic and throughout the polar world has experienced record-setting melts in the past few years. The summer of 2007 saw polar ice cover shrink to its lowest extent in recorded history. Last summer's melt came close to matching that record, and recent research indicates that overall ice volume -- because of the continual replacement of thicker, multi-year ice with thinner new ice -- was lower in 2008 than 2007.

This past summer also saw further dramatic evidence of the unusual warming of the Canadian Arctic, including record-setting high temperatures in Iqaluit, Nunavut, rapid erosion and flooding of a glacial landscape on Baffin Island, the re-opening of the Northwest Passage, an unprecedented clearing of ice from the Beaufort Sea and the collapse of hundreds of square kilometres of ancient ice shelves on Ellesmere Island.

Research for the U.S. Congress-commissioned report was conducted by 37 scientists from the U.S., Germany, Canada, Britain and Denmark.

"The current rate of human-influenced Arctic warming is comparable to peak natural rates documented by reconstructions of past climates. However, some projections of future human-induced change exceed documented natural variability," the scientists conclude. "The past tells us that when thresholds in the climate system are crossed, climate change can be very large and very fast. We cannot rule out that human-induced climate change will trigger such events in the future."

© Copyright (c) The Vancouver Sun

who cares ?

 

[Old Rocks]

Climate warming 'highly unusual' says new study



A major U.S. government report on Arctic climate, prepared with information from eight Canadian scientists, has concluded that the recent rapid warming of polar temperatures and shrinking of multi-year Arctic sea ice are "highly unusual compared to events from previous thousands of years."

The findings, released Friday, counter suggestions from skeptics that such recent events as the opening of the Northwest Passage and collapse of ice shelves in the Canadian Arctic are predictable phenomena that can be explained as part of a natural climate cycle rather than being driven by elevated carbon emissions from human activity.

A summary of the report -- described as "the first comprehensive analysis of the real data we have on past climate conditions in the Arctic," by U.S. Geological Survey director Mark Myers -- warns that "sustained warming of at least a few degrees" is probably enough "to cause the nearly complete, eventual disappearance of the Greenland ice sheet, which would raise sea level by several metres."

The study also sounds the alarm that "temperature change in the Arctic is happening at a greater rate than other places in the Northern Hemisphere, and this is expected to continue in the future. As a result, glacier and ice-sheet melting, sea-ice retreat, coastal erosion and sea-level rise can be expected to continue."

Ice cover in the Canadian Arctic and throughout the polar world has experienced record-setting melts in the past few years. The summer of 2007 saw polar ice cover shrink to its lowest extent in recorded history. Last summer's melt came close to matching that record, and recent research indicates that overall ice volume -- because of the continual replacement of thicker, multi-year ice with thinner new ice -- was lower in 2008 than 2007.

This past summer also saw further dramatic evidence of the unusual warming of the Canadian Arctic, including record-setting high temperatures in Iqaluit, Nunavut, rapid erosion and flooding of a glacial landscape on Baffin Island, the re-opening of the Northwest Passage, an unprecedented clearing of ice from the Beaufort Sea and the collapse of hundreds of square kilometres of ancient ice shelves on Ellesmere Island.

Research for the U.S. Congress-commissioned report was conducted by 37 scientists from the U.S., Germany, Canada, Britain and Denmark.

"The current rate of human-influenced Arctic warming is comparable to peak natural rates documented by reconstructions of past climates. However, some projections of future human-induced change exceed documented natural variability," the scientists conclude. "The past tells us that when thresholds in the climate system are crossed, climate change can be very large and very fast. We cannot rule out that human-induced climate change will trigger such events in the future."

© Copyright (c) The Vancouver Sun

who cares ?

People with more than two digit IQs.

 

[dilloduck]

Climate warming 'highly unusual' says new study



A major U.S. government report on Arctic climate, prepared with information from eight Canadian scientists, has concluded that the recent rapid warming of polar temperatures and shrinking of multi-year Arctic sea ice are "highly unusual compared to events from previous thousands of years."

The findings, released Friday, counter suggestions from skeptics that such recent events as the opening of the Northwest Passage and collapse of ice shelves in the Canadian Arctic are predictable phenomena that can be explained as part of a natural climate cycle rather than being driven by elevated carbon emissions from human activity.

A summary of the report -- described as "the first comprehensive analysis of the real data we have on past climate conditions in the Arctic," by U.S. Geological Survey director Mark Myers -- warns that "sustained warming of at least a few degrees" is probably enough "to cause the nearly complete, eventual disappearance of the Greenland ice sheet, which would raise sea level by several metres."

The study also sounds the alarm that "temperature change in the Arctic is happening at a greater rate than other places in the Northern Hemisphere, and this is expected to continue in the future. As a result, glacier and ice-sheet melting, sea-ice retreat, coastal erosion and sea-level rise can be expected to continue."

Ice cover in the Canadian Arctic and throughout the polar world has experienced record-setting melts in the past few years. The summer of 2007 saw polar ice cover shrink to its lowest extent in recorded history. Last summer's melt came close to matching that record, and recent research indicates that overall ice volume -- because of the continual replacement of thicker, multi-year ice with thinner new ice -- was lower in 2008 than 2007.

This past summer also saw further dramatic evidence of the unusual warming of the Canadian Arctic, including record-setting high temperatures in Iqaluit, Nunavut, rapid erosion and flooding of a glacial landscape on Baffin Island, the re-opening of the Northwest Passage, an unprecedented clearing of ice from the Beaufort Sea and the collapse of hundreds of square kilometres of ancient ice shelves on Ellesmere Island.

Research for the U.S. Congress-commissioned report was conducted by 37 scientists from the U.S., Germany, Canada, Britain and Denmark.

"The current rate of human-influenced Arctic warming is comparable to peak natural rates documented by reconstructions of past climates. However, some projections of future human-induced change exceed documented natural variability," the scientists conclude. "The past tells us that when thresholds in the climate system are crossed, climate change can be very large and very fast. We cannot rule out that human-induced climate change will trigger such events in the future."

© Copyright (c) The Vancouver Sun

who cares ?

People with more than two digit IQs.

oh my--you have the wrong forum then

 

[DavidS]

Climate warming 'highly unusual' says new study



A major U.S. government report on Arctic climate, prepared with information from eight Canadian scientists, has concluded that the recent rapid warming of polar temperatures and shrinking of multi-year Arctic sea ice are "highly unusual compared to events from previous thousands of years."

The findings, released Friday, counter suggestions from skeptics that such recent events as the opening of the Northwest Passage and collapse of ice shelves in the Canadian Arctic are predictable phenomena that can be explained as part of a natural climate cycle rather than being driven by elevated carbon emissions from human activity.

A summary of the report -- described as "the first comprehensive analysis of the real data we have on past climate conditions in the Arctic," by U.S. Geological Survey director Mark Myers -- warns that "sustained warming of at least a few degrees" is probably enough "to cause the nearly complete, eventual disappearance of the Greenland ice sheet, which would raise sea level by several metres."

The study also sounds the alarm that "temperature change in the Arctic is happening at a greater rate than other places in the Northern Hemisphere, and this is expected to continue in the future. As a result, glacier and ice-sheet melting, sea-ice retreat, coastal erosion and sea-level rise can be expected to continue."

Ice cover in the Canadian Arctic and throughout the polar world has experienced record-setting melts in the past few years. The summer of 2007 saw polar ice cover shrink to its lowest extent in recorded history. Last summer's melt came close to matching that record, and recent research indicates that overall ice volume -- because of the continual replacement of thicker, multi-year ice with thinner new ice -- was lower in 2008 than 2007.

This past summer also saw further dramatic evidence of the unusual warming of the Canadian Arctic, including record-setting high temperatures in Iqaluit, Nunavut, rapid erosion and flooding of a glacial landscape on Baffin Island, the re-opening of the Northwest Passage, an unprecedented clearing of ice from the Beaufort Sea and the collapse of hundreds of square kilometres of ancient ice shelves on Ellesmere Island.

Research for the U.S. Congress-commissioned report was conducted by 37 scientists from the U.S., Germany, Canada, Britain and Denmark.

"The current rate of human-influenced Arctic warming is comparable to peak natural rates documented by reconstructions of past climates. However, some projections of future human-induced change exceed documented natural variability," the scientists conclude. "The past tells us that when thresholds in the climate system are crossed, climate change can be very large and very fast. We cannot rule out that human-induced climate change will trigger such events in the future."

© Copyright (c) The Vancouver Sun

who cares ?

People with more than two digit IQs.

The arctic is warming because of methane that is slowly being released from underneath the sea. This is a natural event.

 

[JohnStOnge]

How come you guys don't kind of cut up the quoted portions to shorten things?

 

[Old Rocks]

No, David, that release in not a natural event. It is only happening because of the warming caused by the adding of GHGs to the atmosphere.

ScienceDaily (Dec. 18, 2008) — A team led by International Arctic Research Center scientist Igor Semiletov has found data to suggest that the carbon pool beneath the Arctic Ocean is leaking.


--------------------------------------------------------------------------------

Methane
The results of more than 1,000 measurements of dissolved methane in the surface water from the East Siberian Arctic Shelf this summer as part of the International Siberian Shelf Study show an increased level of methane in the area. Geophysical measurements showed methane bubbles coming out of chimneys on the seafloor.

“The concentrations of the methane were the highest ever measured in the summertime in the Arctic Ocean,” Semiletov said. “We have found methane bubble clouds above the gas-charged sediment and above the chimneys going through the sediment.”

The new data indicates the underwater permafrost is thawing and therefore releasing methane. Permafrost can affect methane release in two ways. Both underwater and on land, it contains frozen organic material such as dead plants and animals. When permafrost thaws, that organic material decomposes, releasing gases like methane and carbon dioxide. In addition, methane, either in gas form or in ice-like methane hydrates, is trapped underneath the permafrost. When the permafrost thaws, the trapped methane can seep out through the thawed soil. Methane, a greenhouse gas 20 times more powerful than carbon dioxide, is thought to be an important factor in global climate change
Scientists Find Increased Methane Levels In Arctic Ocean

 

[JohnStOnge]

"'The current rate of human-influenced Arctic warming is comparable to peak natural rates documented by reconstructions of past climates. However, some projections of future human-induced change exceed documented natural variability,' the scientists conclude."'

Study that statement and think about it.

 

[JohnStOnge]

In general I discourage ad hominem argument. However, I've noticed that those who advocate taking drastic action to save the planet from human-induced climate change spend a pretty good bit of time attacking things like who those who disagree with their position are funded by. So, like, if there is a study funded by oil companies they say, "You can't believe that because it was funded by oil companies."

Well, this study was commissioned by a Democrat controlled US Congress under circumstances where it's clear that Democrats want to impose certain controls and requirements. I think it's pretty reasonable to assume that when they commissioned this study they were wanting a certain result.

So I'm wondering: Are the people that have been saying people like, say, Richard Lindzen can't be taken seriously because of some of his funding sources now going to say this study can't be taken seriously because it was comissioned by a Democrat controlled US Congress?

 

[alan1]

Global climate change is as natural as homosexuality.
Get used to it.

 

[JohnStOnge]

There's another thing involved in this kind of discussion. The article refers to thousands of years as though that's a long time. It's a long time to us, but it's not a long time to this planet. If you go with the estimate that life began here about 3.8 million years ago, even a million years to that tenure is like a couple of hours is to a year.

If I said, "It's the hottest it's been in over 2 hours," would that make a big impression on you? Below is one depiction of what's believed about what temperatures have been over some of the long term history of this planet. It's a figure entitled "Temperatures over the last 4.6 billion years" from a discussion at temperature. I think you'll find the same basic picture regardless of where you look for what's believed about the past.

Look at it and think about it when people say that what's going on now or what is likely to go on in, say, the next 100 years is something "unprecedented" in terms of global temperatures.

 

[Chris]

Increasing the amount of CO2 in the atmosphere by 40% in 200 years is not a natural event.

CO2 in the atmosphere is now at its highest level in 600,000 years, which is as far as the Antarctic ice core record goes back.

 

[alan1]

Increasing the amount of CO2 in the atmosphere by 40% in 200 years is not a natural event.

CO2 in the atmosphere is now at its highest level in 600,000 years, which is as far as the Antarctic ice core record goes back.

Homosexuality is also at it's highest recorded level in 600,000 years.
Gee, it must be the homosexuals causing it.

 

[Old Rocks]

Look at it and think about it when people say that what's going on now or what is likely to go on in, say, the next 100 years is something "unprecedented" in terms of global temperatures.

OK, since you point it out, we, as a species, have been on earth less than 200,000 years. In that time, we have been through at least two adrupt climate changes. The beginning and end of the Younger Dryas. Although the Clovis Culture had very low numbers, was spread out over the whole of the North American continent, it ceased to exist.

Today, with over 7 billion of us on this planet, a similiar adrupt climate change, matters little in which direction, would mean the starvation of a good portion of that number. And, by historical precedent in geological history, we are approaching an adrupt climate change again, as we continue to add GHGs to the atmosphere. Even were we to cease adding GHGs right now, what is already in the atmosphere is going to cause us trouble for centuries.

 

[dilloduck]

Look at it and think about it when people say that what's going on now or what is likely to go on in, say, the next 100 years is something "unprecedented" in terms of global temperatures.

OK, since you point it out, we, as a species, have been on earth less than 200,000 years. In that time, we have been through at least two adrupt climate changes. The beginning and end of the Younger Dryas. Although the Clovis Culture had very low numbers, was spread out over the whole of the North American continent, it ceased to exist.

Today, with over 7 billion of us on this planet, a similiar adrupt climate change, matters little in which direction, would mean the starvation of a good portion of that number. And, by historical precedent in geological history, we are approaching an adrupt climate change again, as we continue to add GHGs to the atmosphere. Even were we to cease adding GHGs right now, what is already in the atmosphere is going to cause us trouble for centuries.

We can adapt

 

[JohnStOnge]

Increasing the amount of CO2 in the atmosphere by 40% in 200 years is not a natural event.

CO2 in the atmosphere is now at its highest level in 600,000 years, which is as far as the Antarctic ice core record goes back.

I don't think we can assume that they have an unbiased estimate of what the average global CO2 concentration was 600,000 years ago based on ice core data. They know what CO2 concentrations were at the point at which the ice core was taken. I think that most people have way too much faith in what scientists say they know about the distant past.

Do you think that, today, you could provide an unbiased estimate of global average atmospheric CO2 concentration by making a CO2 measurement at one point on the surface of an ice sheet near one of the poles? Could you do it by taking measurements from all of the spots at which they've taken ice cores? The answer is "no."

I'm not saying that it's not reasonable to believe the CO2 level is higher now than it was 600,000 years ago. Nobody doubts that we produce a lot of CO2 and we were not doing that all those eons ago. But I think people really need to think about what the limitations might be when people make confident statements about the entire atmopsheric composition or average temperature of the planet based on gas trapped in an ice core. Don't just suck it up without critical thought because it comes from people we've been taught to believe. I'm sure they'd say they have some understanding of what spaitial variation in CO2 was like but anything they "know" is going to be based at some point on assumpmtions that can't be verified.

 

[JohnStOnge]

Look at it and think about it when people say that what's going on now or what is likely to go on in, say, the next 100 years is something "unprecedented" in terms of global temperatures.

OK, since you point it out, we, as a species, have been on earth less than 200,000 years. In that time, we have been through at least two adrupt climate changes. The beginning and end of the Younger Dryas. Although the Clovis Culture had very low numbers, was spread out over the whole of the North American continent, it ceased to exist.

Today, with over 7 billion of us on this planet, a similiar adrupt climate change, matters little in which direction, would mean the starvation of a good portion of that number. And, by historical precedent in geological history, we are approaching an adrupt climate change again, as we continue to add GHGs to the atmosphere. Even were we to cease adding GHGs right now, what is already in the atmosphere is going to cause us trouble for centuries.

I think you're touching on another level of the climate change issue in that you're getting into IPCC predictions about how horrible it's going to be if climate changes in a certain way. I do not think they can legitimately predict that a change in temperature like they're talking about will, on balance, be a net deteriment to our population. People are starving now. We don't know that a larger number would be starving if they're generally right about the temperature increase. We know that the IPCC says that will be the case.

This whole thing goes beyond the question of whether or not human activity means the planet is warmer now than it would be if we weren't here. It also goes into the idea that people can predict that if we do or don't do X then Y or Z will happen. At every stage there is tremendous uncertainty due to the nature of the beast (a highly complex set of questions about a highly complex system with all sorts of interactions and feedbacks; questions that can't be addressed through controlled experimentation). I think that the scientists in this case are creating the impression that there is a whole lot more certainty about things they believe than there actually is.

 

[Old Rocks]

Increasing the amount of CO2 in the atmosphere by 40% in 200 years is not a natural event.

CO2 in the atmosphere is now at its highest level in 600,000 years, which is as far as the Antarctic ice core record goes back.

I don't think we can assume that they have an unbiased estimate of what the average global CO2 concentration was 600,000 years ago based on ice core data. They know what CO2 concentrations were at the point at which the ice core was taken. I think that most people have way too much faith in what scientists say they know about the distant past.

Do you think that, today, you could provide an unbiased estimate of global average atmospheric CO2 concentration by making a CO2 measurement at one point on the surface of an ice sheet near one of the poles? Could you do it by taking measurements from all of the spots at which they've taken ice cores? The answer is "no."I'm not saying that it's not reasonable to believe the CO2 level is higher now than it was 600,000 years ago. Nobody doubts that we produce a lot of CO2 and we were not doing that all those eons ago. But I think people really need to think about what the limitations might be when people make confident statements about the entire atmopsheric composition or average temperature of the planet based on gas trapped in an ice core. Don't just suck it up without critical thought because it comes from people we've been taught to believe. I'm sure they'd say they have some understanding of what spaitial variation in CO2 was like but anything they "know" is going to be based at some point on assumpmtions that can't be verified.

Quite on the contrary, the answer is yes. In fact, on some of the more recent ice cores, they have specifically tracked the last centuries CO2 levels as a comparison. They track nicely, with little differance.
RealClimate

 

[Old Rocks]

Here's another source on the methods;

EESC V2100 - Vostok Ice Core

 

[JohnStOnge]

Quite on the contrary, the answer is yes. In fact, on some of the more recent ice cores, they have specifically tracked the last centuries CO2 levels as a comparison. They track nicely, with little differance.
RealClimate

I'm going to need for you to provide a more specific link. When I click on the link in your post I go to an article about how ratios of CO2 isotopes are used to infer things about the proportion of CO2 due to human activity. I admit I didn't read all the comments but I read the main article and didn't see anything about comparing some other estimates of average global CO2 concentration to estimates based on ice core data.

When I get to the article I'm going to be interested in seeing how they say they've derived unbiased estimates of average CO2 concentrations at any point. To get an unbiased estimate, they'd have to define some population then obtain a probability sample of that population. For example: They could define the population as the average of all CO2 levels that occur at all of the points in the atmosphere over the year 2010. Then they could collect a random sample. They would need to randomly generate a set of space and time points (1 foot above the surface at latitude 30.7678, longitude 90.1111 at 10:36:00.01 am GMT on January 23 is an example of a space/time point). That is their sampling list. They then would have to go out and be at each point in the atmosphere at the appointed time to take a reading. When done, they'd take the average of all the readings. Then they'd have an unbiased estimate.

That's the kind of thing I'm talking about. I think most people take the the idea that when scientists talk about levels of certain things they are correct for granted. But they shouldn't. The only way you could, for instance, know that there's either no bias or not enough bias to worry about associated with a method to estimate a mean CO2 estimate that wasn't derived through probability sampling is to have estimates derived through probability sampling to compare it to. And if you had estimated derived through probability sampling you wouldn't need the other method you've had to resort to to begin with.

A lot of time it doesn't matter from a pracitcal standpoint. Like if you're talking about a doubling of atmospheric CO2 level by whatever method of estimation they're using, given that they're dealing with gases that can mix, it's pretty safe to assume there's been a substantial increase. But they don't have assurance that they have an ubiased estimate unless it was derived through a probability sample and they don't have that.