For a Lack of Better Words.... W.T.F?

[skierinvermont]

Nothing he says in the paragraph following that statement supports your interpretation. You are hearing what you want to hear and putting words in his mouth.

Yes it does.. he says in the same paragraph:

It is not a well posed question to ask "Is it caused by global warming" or "Is it caused by natural variability" because it is always both.

He says the correct question to ask is how have the odds of such an event changed. IE the loaded dice approach I have always advocated.

[tacoman25]

He is going beyond the "loaded dice"...Trenberth is taking it to a new level. He is taking specific weather events (the drought/heatwave in Russia, the floods in Pakistan and China) and saying "it is unlikely they would have occurred without AGW". THAT IS ATTRIBUTION. He is saying that specific weather events can be linked to climate change.

Enough with the silly semantics.

[skierinvermont]

He is going beyond the "loaded dice"...Trenberth is taking it to a new level. He is taking specific weather events (the drought/heatwave in Russia, the floods in Pakistan and China) and saying "it is unlikely they would have occurred without AGW". THAT IS ATTRIBUTION. He is saying that specific weather events can be linked to climate change.

Enough with the silly semantics.

No that is not attribution. It is a probablistic statement that refers to how the odds have changed.

I suppose when the odds change enough, such that an event which used to be essentially impossible, can now occur, then in one sense you could call this "attribution." Although we must always bear in mind that the proximate "cause" of specific events is weather not climate.

[tacoman25]

Yes it does.. he says in the same paragraph:

It is not a well posed question to ask "Is it caused by global warming" or "Is it caused by natural variability" because it is always both.

He says the correct question to ask is how have the odds of such an event changed. IE the loaded dice approach I have always advocated.

"It is always both"? Ok...but that's complete nonsense. Why? Because it is completely unprovable.

I can look outside then and say: "It's a warm, sunny day - thanks to natural variability and global warming". But that's ridiculous. It's a warm, sunny day because the atmosphere has high pressure over Colorado right now. GLOBAL warming has nothing to do with it - just like climate change had nothing to do with Seattle having its coldest April since 1955 last month. We can say with certainty that that was almost 100% natural variability - or what part did global warming play in that?

[tacoman25]

No that is not attribution. It is a probablistic statement that refers to how the odds have changed.

I suppose when the odds change enough, such that an event which used to be essentially impossible, can now occur, then in one sense you could call this "attribution." Although we must always bear in mind that the proximate "cause" of specific events is weather not climate.

Except that we don't know what those odds really are! That statement implies a knowledge that we simply don't possess. Given that extreme events like heatwaves, floods, and hurricanes have always happened on a fairly regular basis, what is the evidence that a particular event is caused by the "loaded dice"?

[skierinvermont]

"It is always both"? Ok...but that's complete nonsense. Why? Because it is completely unprovable.

I can look outside then and say: "It's a warm, sunny day - thanks to natural variability and global warming". But that's ridiculous. It's a warm, sunny day because the atmosphere has high pressure over Colorado right now. GLOBAL warming has nothing to do with it - just like climate change had nothing to do with Seattle having its coldest April since 1955 last month. We can say with certainty that that was almost 100% natural variability - or what part did global warming play in that?

Yes AGW does have something to do with it... the specific cold spell that occurred would have been different without AGW. AGW affects all aspects of weather. When you have more moisture and heat in the air, it is simply not possible for the weather to be the same as without that extra heat or water. It's an academic point. It's a "truism" as Schmidt said.

[skierinvermont]

Except that we don't know what those odds really are! That statement implies a knowledge that we simply don't possess. Given that extreme events like heatwaves, floods, and hurricanes have always happened on a fairly regular basis, what is the evidence that a particular event is caused by the "loaded dice"?

It's not "caused" by the loaded dice.. the loaded dice just allow for X event to be more likely to occur.

We don't know exactly what the odds were on the old dice or what they are on the new dice... but we try to estimate what the were and what they are now. Simulations of climate will tell you that the Russian heatwave was extremely unlikely 100 years ago but now it is only very unlikely. It's gone from a 1 in 1000 year event to a 1 in 50 year or something. I'm just making up numbers but the idea is the same.

[tacoman25]

Why do I care so much about this issue? Because of the ignorant assumptions that are made once we start attributing everything "bad" to AGW, because AGW is "bad". It's circular reasoning at its worst, and is a very good example of positive feedbacks in real life.

Think about it: why did journalists start asking questions about climate change immediately after the tornadic outbreak? Because they've been trained to think that way...look what happened after 2005 and Hurricane Katrina. Suddenly, AGW causing hurricanes was all the rage.

I believe that part of the reason for this is people like to have something to blame after a severe event or tragedy. Climate change makes an easy and convenient culprit. But that simply is not a balanced or scientific viewpoint.

[skierinvermont]

Why do I care so much about this issue? Because of the ignorant assumptions that are made once we start attributing everything "bad" to AGW, because AGW is "bad". It's circular reasoning at its worst, and is a very good example of positive feedbacks in real life.

Think about it: why did journalists start asking questions about climate change immediately after the tornadic outbreak? Because they've been trained to think that way...look what happened after 2005 and Hurricane Katrina. Suddenly, AGW causing hurricanes was all the rage.

I believe that part of the reason for this is people like to have something to blame after a severe event or tragedy. Climate change makes an easy and convenient culprit. But that simply is not a balanced or scientific viewpoint.

I think it is quite clear that in this case they were making an academic point that AGW affects all aspects of weather but we don't know how. It's almost like chaos theory (except cause and effect are not quite that far removed). The bolded type 7 statements which you didn't respond to make that make that as clear as day.

[tacoman25]

Yes AGW does have something to do with it... the specific cold spell that occurred would have been different without AGW. AGW affects all aspects of weather. When you have more moisture and heat in the air, it is simply not possible for the weather to be the same as without that extra heat or water. It's an academic point. It's a "truism" as Schmidt said.

Actually, you don't know that. Most of the time, natural variability vastly overpowers AGW, especially for smaller regions over smaller time periods. I could build a much stronger argument that the -PDO phase, La Nina, and natural weather patterns led to the near record cold April in the PNW. Any role that AGW played was miniscule at best. And that goes for most things weather-related.

[tacoman25]

It's not "caused" by the loaded dice.. the loaded dice just allow for X event to be more likely to occur.

We don't know exactly what the odds were on the old dice or what they are on the new dice... but we try to estimate what the were and what they are now. Simulations of climate will tell you that the Russian heatwave was extremely unlikely 100 years ago but now it is only very unlikely. It's gone from a 1 in 1000 year event to a 1 in 50 year or something. I'm just making up numbers but the idea is the same.

Exactly my point. We don't have an accurate enough point of reference to say "AGW was probably to blame".

And I really don't like how only these big, negative events have AGW connected to them. It paints an inaccurate and unscientific picture, but a lot of AGW proponents don't care, because it gets across the message they want: AGW is bad, it's here, and it's something to be scared of.

[skierinvermont]

Actually, you don't know that. Most of the time, natural variability vastly overpowers AGW, especially for smaller regions over smaller time periods. I could build a much stronger argument that the -PDO phase, La Nina, and natural weather patterns led to the near record cold April in the PNW. Any role that AGW played was miniscule at best. And that goes for most things weather-related.

Of course those are the proximate causes... but there is simply no way that an atmosphere with much more heat and water vapor in it will behave the EXACTLY the SAME as one without.

[skierinvermont]

Exactly my point. We don't have an accurate enough point of reference to say "AGW was probably to blame".

And I really don't like how only these big, negative events have AGW connected to them. It paints an inaccurate and unscientific picture, but a lot of AGW proponents don't care, because it gets across the message they want: AGW is bad, it's here, and it's something to be scared of.

We have enough evidence to believe that the European and Russian heatwaves are becoming much more likely over time. Heatwaves of that intensity were much less likely previously. We have seen an increase in moderate heatwaves, and we have seen the number of unprecedented heatwaves grow.

[tacoman25]

I think it is quite clear that in this case they were making an academic point that AGW affects all aspects of weather but we don't know how. It's almost like chaos theory (except cause and effect are not quite that far removed). The bolded type 7 statements which you didn't respond to make that make that as clear as day.

But it's not merely an "academic point" when it's always used as a potential scapegoat when weather-related tragedies occur. Don't be naive and think it just happens to be brought up then by chance.

[skierinvermont]

But it's not merely an "academic point" when it's always used as a potential scapegoat when weather-related tragedies occur. Don't be naive and think it just happens to be brought up then by chance.

It was brought up because a reporter called them. They have been saying the same thing for years prior to the outbreak. And they were VERY CLEAR that it is not known how AGW will affect tornadoes.. only that we know it will affect it somehow. Schmidt even said it was simply a "truism" IE an academic point with little practical meaning.

[tacoman25]

Of course those are the proximate causes... but there is simply no way that an atmosphere with much more heat and water vapor in it will behave the SAME as one without.

Who knows exactly. But your definition of "much more" heat/water vapor is subjective, and there is little evidence at this point that the atmosphere is behaving much different than it has in the past.

[tacoman25]

It was brought up because a reporter called them. They have been saying the same thing for years prior to the outbreak. And they were VERY CLEAR that it is not known how AGW will affect tornadoes.. only that we know it will affect it somehow. Schmidt even said it was simply a "truism."

But it's never implied that AGW could actually make the tornado situation better. The worst is always assumed. That is the built in assumption with AGW. Don't even try to deny that.

[tacoman25]

We have enough evidence to believe that the European and Russian heatwaves are becoming much more likely over time. Heatwaves of that intensity were much less likely previously. We have seen an increase in moderate heatwaves, and we have seen the number of unprecedented heatwaves grow.

Stats?

What about the fact that many of the all-time heat records in the U.S. and the world happened a long time ago?

[skierinvermont]

But it's never implied that AGW could actually make the tornado situation better. The worst is always assumed. That is the built in assumption with AGW. Don't even try to deny that.

So for example the evidence that scientists have presented that hurricane frequency will decrease?

[skierinvermont]

Stats?

What about the fact that many of the all-time heat records in the U.S. and the world happened a long time ago?

The U.S. is clearly an exception (which is probably partly related to the poor farming practices). Globally the number of moderate, and unprecedented heatwaves, has increased.

Modelling also can tell give us reasonable estimates for how likely a heatwave like the Russian heatwave were without and with AGW.

[tacoman25]

So for example the evidence that scientists have presented that hurricane frequency will decrease?

As I said earlier, the evidence on hurricanes is still very debatable. I sure didn't see that research right after the record-breaking number of storms in 2004/2005. I did see many articles assuming a probable link between what happened in 2005 and global warming. The blame game!

[tacoman25]

The U.S. is clearly an exception (which is probably partly related to the poor farming practices). Globally the number of moderate, and unprecedented heatwaves, has increased.

Modelling also can tell give us reasonable estimates for how likely a heatwave like the Russian heatwave were without and with AGW.

Evidence?

And that type of modelling is nearly meaningless in determing the factors leading to a single event occurring. Do you know how many 100 or 500 year events I've seen in my lifetime?

[skierinvermont]

For example this study published in Nature estimated that AGW has increased the probability of the 2003 European by at least 2X (90% confidence).

They also say the same thing Trenberth does word for word 'it is an ill-posed question whether the 2003 heatwave was caused by [AGW]'

The summer of 2003 was probably the hottest in Europe since at latest ad1500^{1, 2, 3, 4}, and unusually large numbers of heat-related deaths were reported in France, Germany and Italy⁵. It is an ill-posed question whether the 2003 heatwave was caused, in a simple deterministic sense, by a modification of the external influences on climate—for example, increasing concentrations of greenhouse gases in the atmosphere—because almost any such weather event might have occurred by chance in an unmodified climate. However, it is possible to estimate by how much human activities may have increased the risk of the occurrence of such a heatwave^{6, 7, 8}. Here we use this conceptual framework to estimate the contribution of human-induced increases in atmospheric concentrations of greenhouse gases and other pollutants to the risk of the occurrence of unusually high mean summer temperatures throughout a large region of continental Europe. Using a threshold for mean summer temperature that was exceeded in 2003, but in no other year since the start of the instrumental record in 1851, we estimate it is very likely (confidence level >90%)⁹ that human influence has at least doubled the risk of a heatwave exceeding this threshold magnitude.

http://climatepredic...nature03089.pdf

[tacoman25]

Also, I love how it suddenly became popular after the last couple winters to say AGW will cause more/bigger east coast snowstorms. Where were those statements a few years ago?

It's these built-in assumptions about climate change that allow anything and everything weather/climate related to be linked to AGW...at our discretion.

[skierinvermont]

I'm just waiting for zucker to submit his definitive proof that tornadic activity will decrease to peer-reviewed journals. I'm sure the scientists who are trying to figure out how all of the complex interactions involved will affect tornadoes will be pleasantly surprised to know the answer to this mystery!

[tacoman25]

For example this study published in Nature estimated that AGW has increased the probability of the 2003 European by at least 2X (90% confidence).

They also say the same thing Trenberth does word for word 'it is an ill-posed question whether the 2003 heatwave was caused by [AGW]'

The summer of 2003 was probably the hottest in Europe since at latest ad1500^{1, 2, 3, 4}, and unusually large numbers of heat-related deaths were reported in France, Germany and Italy⁵. It is an ill-posed question whether the 2003 heatwave was caused, in a simple deterministic sense, by a modification of the external influences on climate—for example, increasing concentrations of greenhouse gases in the atmosphere—because almost any such weather event might have occurred by chance in an unmodified climate. However, it is possible to estimate by how much human activities may have increased the risk of the occurrence of such a heatwave^{6, 7, 8}. Here we use this conceptual framework to estimate the contribution of human-induced increases in atmospheric concentrations of greenhouse gases and other pollutants to the risk of the occurrence of unusually high mean summer temperatures throughout a large region of continental Europe. Using a threshold for mean summer temperature that was exceeded in 2003, but in no other year since the start of the instrumental record in 1851, we estimate it is very likely (confidence level >90%)⁹ that human influence has at least doubled the risk of a heatwave exceeding this threshold magnitude.

http://climatepredic...nature03089.pdf

It's still just a guess based on very limited evidence. And no, that is not the same thing Trenberth was saying - it was just your interpretation.

Even if their calculations were completely accurate, a mere doubling of the chance of that event still leaves a very high possibility that it could have occurred without AGW. Certainly, without AGW a severe heatwave would have occurred in summer 2003 in Europe. AGW may have made it a little worse than it otherwise would have been.

Flimsy as it is, the case for this particular event is actually much stronger than trying to link events such as hurricanes, floods, blizzards, etc. No matter what, a much stronger case can almost always be made for natural patterns/variability playing a much larger role in these events. And yet natural variability is often overlooked in favor of the much more flashy CLIMATE CHANGE.

[skierinvermont]

It's still just a guess based on very limited evidence. And no, that is not the same thing Trenberth was saying - it was just your interpretation.

Even if their calculations were completely accurate, a mere doubling of the chance of that event still leaves a very high possibility that it could have occurred without AGW. Certainly, without AGW a severe heatwave would have occurred in summer 2003 in Europe. AGW may have made it a little worse than it otherwise would have been.

Flimsy as it is, the case for this particular event is actually much stronger than trying to link events such as hurricanes, floods, blizzards, etc. No matter what, a much stronger case can almost always be made for natural patterns/variability playing a much larger role in these events. And yet natural variability is often overlooked in favor of the much more flashy CLIMATE CHANGE.

It IS the same thing Trenberth said almost word for word (which is probably not a coincidence):

"It is not a well posed question to ask "Is it caused by global warming"

-Trenberth

"It is an ill-posed question whether the 2003 heatwave was caused [by global warming]"

-Nature study

Of course natural patterns are ALWAYS the proximate cause of weather events. Nobody denies that. The question being asked and in some cases answered by these scientists is what is the expected change in frequency of these specific events. These are climate scientists studying how AGW changes climate. If you want to hear or learn about how weather patterns cause weather, talk to a meteorologist or read an interview of a meteorologist.

[tacoman25]

It IS the same thing Trenberth said almost word for word (which is probably not a coincidence):

"It is not a well posed question to ask "Is it caused by global warming"

-Trenberth

"It is an ill-posed question whether the 2003 heatwave was caused [by global warming]"

-Nature study

Of course natural patterns are ALWAYS the proximate cause of weather events. Nobody denies that. The question being asked and in some cases answered by these scientists is what is the expected change in frequency of these specific events. These are climate scientists studying how AGW changes climate. If you want to hear or learn about how weather patterns cause weather, talk to a meteorologist or read an interview of a meteorologist.

Then why are they making statements about specific weather events? If we can both acknowledge that specific weather events are primarily due to natural weather patterns/variability, why should these climate scientists be making statements about climate change being involved, as if that's a major factor?

[nzucker]

I'm just waiting for zucker to submit his definitive proof that tornadic activity will decrease to peer-reviewed journals. I'm sure the scientists who are trying to figure out how all of the complex interactions involved will affect tornadoes will be pleasantly surprised to know the answer to this mystery!

Roy Spencer, a NASA climatologist, says that global warming should decrease tornadoes. And hey he's an expert climatologist like Viner, so who am I to doubt the experts?

In all seriousness, though, decreasing lapse rates and contrast in airmasses should ameliorate severe weather outbreaks. When Trenberth says "It is irresponsible not to mention climate change," he is implying that climate change was partially responsible for these tornadoes. That is the impression 99% of people reading his words are going to get, and given his 2011 AMS presentation it is the impression he intends to convey; in that speech, he was particularly assertive that events such as the 2/5 Snowmaggedon and California floods would have been less likely without global warming. Ironically, it's actually climate change that is probably reducing severe weather outbreaks, but of course individual events can NEVER be assumed to be part of a "greater picture" unless there is a clear threshold at which warming dictates the formation of a certain weather phenomenon. Why is it irresponsible not to mention climate change when discussing a tornado outbreak if we don't know of any mechanism by which warming would actually increase tornadoes? Isn't it, on the other hand, actually irresponsible to mention AGW since we don't have any proof that it's involved, and given the media's tendency to go crazy with this stuff like Katrina 2005?

Then why are they making statements about specific weather events? If we can both acknowledge that specific weather events are primarily due to natural weather patterns/variability, why should these climate scientists be making statements about climate change being involved, as if that's a major factor?

Right. Global climate is a tiny contributor to most weather phenomena, so we need to talk more about the pattern. Dr. Trenberth clearly does not understand the difference between climate and weather; his lack of meteorological background means that he can't grasp that the DC snowstorms in 09-10 were due to a west-based El Nino, or that the 4/27/11 tornado outbreak was due to La Nina and the -PDO pattern. Moreover, it's interesting how any weather event is now molded to fit the AGW hypothesis: when it wasn't snowing a lot in London, Viner said it was because of global warming. We frequently heard the same refrain here in NYC during the low snowfall years of the 1990s. Then, when it started snowing a lot again, it was also because of global warming. You can't have it both ways. If something isn't definitively linked to climate change, then why mention it?

Also ironic is that AGW alarmists like Bill McKibben have derided skeptics for mentioning cold and snowstorms in support of their argument that the Earth isn't warming much. Yet McKibben is the first one to use the Summer 1988 heatwave in Glens Falls to prove how global warming is changing the weather. Viner is the first one to say that snowless winters are caused by global warming. Trenberth is quick to include climate change in the media dialog about the tornado outbreaks. How come these alarmists criticize skeptics for pointing to snow and cold as a sign of climate trends, and yet use the same tactic themselves in the other direction, even when none of these individual events has been connected with any certainty to global climate?

[skierinvermont]

Then why are they making statements about specific weather events? If we can both acknowledge that specific weather events are primarily due to natural weather patterns/variability, why should these climate scientists be making statements about climate change being involved, as if that's a major factor?

He isn't making statements about specific events.. he is making statements about the frequency and/or probability of specific events, IE climate.