Snow

[tacoman25]

The past month? How about the past year? Russian heat wave and fires, Pakistan floods, multiple flooding events in the US, Brazilian flood, Australian floods (western Pacific very warm), deep incursions of cold to the south and warmth to the north. Atlantic as warm as ever measured this past summer. If you isolate on the past month then maybe you have a point, I just don't think you can disregard the global warmth of the past year so quickly.

A complex system is at it's most unstable when it is in the act of change. These type events become more likely in a changing climate.

Perhaps...but again, I think there are stronger arguments that many of the changes/shifts we are seeing have happened before, due to natural causes. Global warming has been going on for decades. Why would it all of the sudden be causing way more extreme events? This would be more plausible if the last ten years had seen a sudden acceleration in global warming. But that has not been the case.

[skierinvermont]

I haven't seen any good studies documenting a statistically significant increase in extreme events. If I remember correctly, the one the IPCC used was unpublished and the published version actually concluded the opposte: no statistically significant increase in damaging weather events after adjusting for inflation, population growth and exchange rates.

I did read one study that concluded a statistically significant increase in extreme flooding events in the worlds largest river basins. (I think it was the largest 50 but I could be remembering wrong). But other studies seemed to dispute this and it was not a large trend.

If someone could point me to a study that does show a statistically significant trend in extreme events over the last 50+ years that would be great.

[Mencken_Fan]

There is no evidence of a relationship between -NAO/-AO and AGW. In fact, past history suggests that the most powerful blocking took place during COLD periods, not wam periods.

There have been many times in the Recent Holocene Era where temps reached about 2C higher than we are right now. Man Made Co2 is having no impact thus far.

Really?

[LocoAko]

I haven't seen any good studies documenting a statistically significant increase in extreme events. If I remember correctly, the one the IPCC used was unpublished and the published version actually concluded the opposte: no statistically significant increase in damaging weather events after adjusting for inflation, population growth and exchange rates.

I did read one study that concluded a statistically significant increase in extreme flooding events in the worlds largest river basins. (I think it was the largest 50 but I could be remembering wrong). But other studies seemed to dispute this and it was not a large trend.

If someone could point me to a study that does show a statistically significant trend in extreme events over the last 50+ years that would be great.

I haven't read this too in depth, so I'm not sure if this is exactly what you're looking for, but perhaps it is?

[skierinvermont]

Really?

No. He is basing this off his new favorite graph (after I showed that his old favorite graph of ISCCP cloud data is not regarded as accurate by the head of the ISCCP) which doesn't have the resolution or precision to show the temperatures of the last 10,000 years in detail.

[tacoman25]

I haven't seen any good studies documenting a statistically significant increase in extreme events. If I remember correctly, the one the IPCC used was unpublished and the published version actually concluded the opposte: no statistically significant increase in damaging weather events after adjusting for inflation, population growth and exchange rates.

I did read one study that concluded a statistically significant increase in extreme flooding events in the worlds largest river basins. (I think it was the largest 50 but I could be remembering wrong). But other studies seemed to dispute this and it was not a large trend.

If someone could point me to a study that does show a statistically significant trend in extreme events over the last 50+ years that would be great.

Exactly. Show me the evidence. Otherwise, this is just the same type of anecdotal speculation we have seen from both sides of the debate many times before.

[skierinvermont]

I haven't read this too in depth, so I'm not sure if this is exactly what you're looking for, but perhaps it is?

http://www.americanw...global-warming/

Could be, but see my response in that thread.

[Mencken_Fan]

Another thing: if you're going to use the "loaded dice" argument...well, a warming world would also "load the dice" for warmer winters. Which is exactly why many people in the US, Canada, the UK, etc, believed that the unusually warm stretch from 1997-2007 was due to global warming. But since then, we have seen markedly cooler winters. Are we rolling the same dice?

Oh come on y'all; cause and effect should be so simple!

Perhaps the warming reached a point where the climate now needs make an adjustment (one that's driving the PV crazy.)

Who the heck knows.

Climate Change and Instant Gratification of Knowledge simply don't mix.

Have patience....enjoy the show...and learn only what's learnable.

[WeatherRusty]

Exactly. Show me the evidence. Otherwise, this is just the same type of anecdotal speculation we have seen from both sides of the debate many times before.

We are forced to agree given the apparent lack of statistical confirmation that what we are discussing is anecdotal in nature. My points I think are based more on theoretical expectation devoid of rigorous cause and effect relationship than anything else. Such is the nature of any complex system, or expectations that are probability based.

[tacoman25]

We are forced to agree given the apparent lack of statistical confirmation that what we are discussing is anecdotal in nature. My points I think are based more on theoretical expectation devoid of rigorous cause and effect relationship than anything else. Such is the nature of any complex system, or expectations that are probability based.

Indeed. A good lesson for anyone trying to figure out what's going on with the climate.

[WeatherRusty]

Another thing: if you're going to use the "loaded dice" argument...well, a warming world would also "load the dice" for warmer winters. Which is exactly why many people in the US, Canada, the UK, etc, believed that the unusually warm stretch from 1997-2007 was due to global warming. But since then, we have seen markedly cooler winters. Are we rolling the same dice?

The winters have been cooler in some areas while not so in others. Globally, the climate the past few years has been as warm as at any time in the instrumental record. It may not have warmed significantly over the past decade, but neither has it cooled. Regionally colder winters are largely offset elsewhere by warmth. The dice are loaded as the climate warms within the oscillations produced by ENSO, PDO etc.

[Littleiceage]

I don't understand your point. I don't know that Hansen said that. I didn't set up the strawman!

BTW...I am one of the strongest arguers in support of the science underlying climate change on these boards.

I give you credit WeatherRusty, you do a great job distilling the foundational aspects of AGW, so that comment is clearly not justified.

Just for the record, I believe solar factors have a greater influence over long-term climate change, so my comments regarding WeatherRusty are not motivated by an AGW bias.

[nzucker]

There is no evidence of a relationship between -NAO/-AO and AGW. In fact, past history suggests that the most powerful blocking took place during COLD periods, not wam periods.

There have been many times in the Recent Holocene Era where temps reached about 2C higher than we are right now. Man Made Co2 is having no impact thus far.

During the 1990s and early 2000s, people were saying the sequence of mild +NAO/+AO winters was caused by global warming, attributable to warming Indian Ocean temperatures causing a lack of blocking over Greenland and the Arctic. This storyline fit perfectly, since the US and Europe were in the middle of a string of warm and snowless winters, which made sense according to climate change theory and common perceptions of what a warming world would look like.

Since the return to colder winters in Europe and the US in 08-09, we've been told that global warming is causing the -NAO/-AO that's making us experience all these wintry and bitter conditions. Even the New York Times floated this theory recently. So which are we to believe? You can't have it both ways.

[tacoman25]

The winters have been cooler in some areas while not so in others. Globally, the climate the past few years has been as warm as at any time in the instrumental record. It may not have warmed significantly over the past decade, but neither has it cooled. Regionally colder winters are largely offset elsewhere by warmth. The dice are loaded as the climate warms within the oscillations produced by ENSO, PDO etc.

Again, you're kind of missing the point here. The warm winters of the 1997-2007 period were linked to global warming in many people's minds. But since 2007, the same places that were warm 1997-2007 (large areas, I might add), have turned much cooler. Making the arguments for the loaded dice in this case much less convincing.

[tacoman25]

During the 1990s and early 2000s, people were saying the sequence of mild +NAO/+AO winters was caused by global warming, attributable to warming Indian Ocean temperatures causing a lack of blocking over Greenland and the Arctic. This storyline fit perfectly, since the US and Europe were in the middle of a string of warm and snowless winters, which made sense according to climate change theory and common perceptions of what a warming world would look like.

Since the return to colder winters in Europe and the US in 08-09, we've been told that global warming is causing the -NAO/-AO that's making us experience all these wintry and bitter conditions. Even the New York Times floated this theory recently. So which are we to believe? You can't have it both ways.

Excellent point. No matter what happens, someone always finds a way to point to AGW and run with it. Even if the exact opposite trend was attributed to AGW the previous decade!

It's like some people honestly believe that every climate fluctuation/weather trend is directly caused by humans. Mother nature has no control over herself anymore, apparently.

[tacoman25]

During the 1990s and early 2000s, people were saying the sequence of mild +NAO/+AO winters was caused by global warming, attributable to warming Indian Ocean temperatures causing a lack of blocking over Greenland and the Arctic. This storyline fit perfectly, since the US and Europe were in the middle of a string of warm and snowless winters, which made sense according to climate change theory and common perceptions of what a warming world would look like.

Since the return to colder winters in Europe and the US in 08-09, we've been told that global warming is causing the -NAO/-AO that's making us experience all these wintry and bitter conditions. Even the New York Times floated this theory recently. So which are we to believe? You can't have it both ways.

Just a reminder to those who aren't aware how significant the turn around has been since 2007, compared to the previous ten years. And 2010-11 will obviously continue this trend, making 4 much cooler winters nationally in a row.

[WeatherRusty]

Again, you're kind of missing the point here. The warm winters of the 1997-2007 period were linked to global warming in many people's minds. But since 2007, the same places that were warm 1997-2007 (large areas, I might add), have turned much cooler. Making the arguments for the loaded dice in this case much less convincing.

When we say loaded dice what do we mean? Does it mean that colder winters will not occur? Of course they will still occur, Global temps have only changed 0.7C since 1870. Natural variability is collectively a larger variable than 0.7C. However as the climate warms, and it is as warm as it has been in the record, we should expect these types of winter conditions to become less frequent, but they will still happen. With 4% greater water vapor in the atmosphere and when the patterns become amplified like the past two winters, you can expect cold incursion deep to the south and copious precipitation.

Add to everything else in the crazy weather of the past year an Australian Cyclone (Hurricane) of record intensity in that region. Cat5, 186mph sustained.

[superjames1992]

One year does not a climate make.

Could this be the beginning of a trend? Sure. But we don't know that.

[nzucker]

Could this be the beginning of a trend?

I hope so

[superjames1992]

I hope so

If this is what global warming is like, then bring it on!!!

[nzucker]

If this is what global warming is like, then bring it on!!!

Exactly. I don't care how many polar bears are dying, I want to be buried with an historical snowstorm every 2 weeks, interspersed with huge arctic outbreaks, as we've seen this winter here in NYC.

In all seriousness, though, global temperatures have actually been much lower for Winter 10-11, and that may be playing a slight role in the cold weather we've seen. It's probably not too much of a difference, but perhaps every airmass is 0.5F-1F colder given the drop-off in global temps.

[BethesdaWX]

Really?

Yes Our current warmth is nothing more than interglacial fluctuations....if you'll notice that peak at over +2C several thousand years ago................that appears to be the RWP

[skierinvermont]

Wrong, the peak on your graph occurs about 7,000-9,000 years ago during the Holocene Thermal Maximum, right after the end of the last ice age. You can't even interpret an x-axis.

[BethesdaWX]

Wrong, the peak on your graph occurs about 7,000-9,000 years ago during the Holocene Thermal Maximum, right after the end of the last ice age. You can't even interpret an x-axis.

Which spike are you referring to? The big one?

Either way, that doesn't change my argument.....our temperature is actually unprecedentedly COLD for an Interglacial.

[skierinvermont]

Which spike are you referring to? The big one?

Either way, that doesn't change my argument.....our temperature is actually unprecedentedly COLD for an Interglacial.

Indeed it is. Everybody knows this. You can find this information quite clearly explained in the iPCC report.

And thank goodness, since during past interglacials sea levels were 30+ meters higher.

[BethesdaWX]

Indeed it is. Everybody knows this. You can find this information quite clearly explained in the iPCC report.

And thank goodness, since during past interglacials sea levels were 30+ meters higher.

Whaaaaaaat?

This is an unrelated topic.

[wokeupthisam]

Indeed it is. Everybody knows this. You can find this information quite clearly explained in the iPCC report.

And thank goodness, since during past interglacials sea levels were 30+ meters higher.

Not so fast, I live 500+ ft above sea level and though I didn't live in a past interglacial I might have preferred that more temperate environment and enhanced food-growing opportunities, as a trade-off for the present-day coastline, thank you.

WIthin this tongue-in-cheek post is a larger point: Would a colder climate be preferable to a warmer one? Forget about keeping it status quo - there won't be status quo day to day, month to month, year to year, decade to decade, or century to century. So Yes, 'climate change' is inevitable. Which makes the nomenclature laughable - this politically-charged debate is about global warming! Please, let's all agree to call it that - it's about a planet warming 'artificially'; it's about catastrophic human consequences; and at its extreme, its about overheating beyond some 'tipping point' from which there is no recovery - all will be lost. Let's leave the double-speak euphemistic window-dressing PC phrase 'climate change' in the drawer and call it by its real name: global WARMING with its attendant dire consequences for the living things thereon.

I find it bizarre that while arguments rage back and forth about whether X additional molecules of CO2 yield Y units of higher temperatures on earth resulting in dire straits in Z years, the sides have conveniently skipped past a central question: is the earth a better, more habitable place, if it is globally COLDER than present; or WARMER than present? (Since both sides agree variability is built-in to our climate system, we can be assured that it is unlikely to remain the SAME). We're left with the question: are humans (the anthropogenic variable in the debate) better off in a globally COLDER climate, or a globally WARMER climate? And to what degree? FWIW, a cursory glance back through geologic time overwhelmingly shouts that on balance, the earth is a cold, inhospitable place. And in the span of human history (however brief comparatively), warmer times seem to be preferable. And wouldn't it be ironic, if the climate were to be entering a 30-odd year anomoly toward cold (as some New Dalton proponents have argued), if man-made warming were to serve as a buffer, however slight, against the more drastic consequences that could otherwise result from a New Dalton Minimum?

[skierinvermont]

Not so fast, I live 500+ ft above sea level and though I didn't live in a past interglacial I might have preferred that more temperate environment and enhanced food-growing opportunities, as a trade-off for the present-day coastline, thank you.

WIthin this tongue-in-cheek post is a larger point: Would a colder climate be preferable to a warmer one? Forget about keeping it status quo - there won't be status quo day to day, month to month, year to year, decade to decade, or century to century. So Yes, 'climate change' is inevitable. Which makes the nomenclature laughable - this politically-charged debate is about global warming! Please, let's all agree to call it that - it's about a planet warming 'artificially'; it's about catastrophic human consequences; and at its extreme, its about overheating beyond some 'tipping point' from which there is no recovery - all will be lost. Let's leave the double-speak euphemistic window-dressing PC phrase 'climate change' in the drawer and call it by its real name: global WARMING with its attendant dire consequences for the living things thereon.

I find it bizarre that while arguments rage back and forth about whether X additional molecules of CO2 yield Y units of higher temperatures on earth resulting in dire straits in Z years, the sides have conveniently skipped past a central question: is the earth a better, more habitable place, if it is globally COLDER than present; or WARMER than present? (Since both sides agree variability is built-in to our climate system, we can be assured that it is unlikely to remain the SAME). We're left with the question: are humans (the anthropogenic variable in the debate) better off in a globally COLDER climate, or a globally WARMER climate? And to what degree? FWIW, a cursory glance back through geologic time overwhelmingly shouts that on balance, the earth is a cold, inhospitable place. And in the span of human history (however brief comparatively), warmer times seem to be preferable. And wouldn't it be ironic, if the climate were to be entering a 30-odd year anomoly toward cold (as some New Dalton proponents have argued), if man-made warming were to serve as a buffer, however slight, against the more drastic consequences that could otherwise result from a New Dalton Minimum?

First of all, it is would be far more than a buffer even if we were heading into a Dalton, we would still warm dramatically.

Second of all, questions about what the ideal climate for humans have been answered. Something around the present. We can take some change, but not too much. It's probably best around our current temperature because that gives us some buffer from heading into a Dalton which would decrease arable land due to cold.

However, there's not much more room on the upside because we are quickly heading towards uncharted territories for our current interglacial. Another 1-2C of warming will cause the Greenland ice sheet to melt raising sea levels 25 feet.

[wokeupthisam]

First of all, it is would be far more than a buffer even if we were heading into a Dalton, we would still warm dramatically.

Second of all, questions about what the ideal climate for humans have been answered. Something around the present. We can take some change, but not too much. It's probably best around our current temperature because that gives us some buffer from heading into a Dalton which would decrease arable land due to cold.

However, there's not much more room on the upside because we are quickly heading towards uncharted territories for our current interglacial. Another 1-2C of warming will cause the Greenland ice sheet to melt raising sea levels 25 feet.

If we were heading into a Dalton, we should hope for far more than a buffer. It's not easy raising crops and feeding the world when summer weather in the richest agrigable lands on earth becomes unstable on the cooler side. The ideal climate may be something warmer than present. I don't think that question is settled. My understanding of the sea level rise is that it won't come in as a tsunami like in a Hollywood movie. Even the original post talked of a centuries-long process. I would think humans could make accomodation in that timeframe. Regardless, the question is still not settled - what is better - WARMER, or COLDER? I know you said "something around present" but that implies the past 10,000 years of stability is maintainable. Is it? There are other factors at play when taking the 10,000 year view of climate, vs. a few decades of warming or cooling.

[BethesdaWX]

First of all, it is would be far more than a buffer even if we were heading into a Dalton, we would still warm dramatically.

Second of all, questions about what the ideal climate for humans have been answered. Something around the present. We can take some change, but not too much. It's probably best around our current temperature because that gives us some buffer from heading into a Dalton which would decrease arable land due to cold.

However, there's not much more room on the upside because we are quickly heading towards uncharted territories for our current interglacial. Another 1-2C of warming will cause the Greenland ice sheet to melt raising sea levels 25 feet.

Since our warming is caused by the Sun and Not Co2, if we head into a Dalton, we would cool dramatially. We actually need to resume warming in the first place FYI....cooling since 2002, now that the JAN anomaly came out from UAH, and continues the trend of global cooling since the beginning of the Last Decade (the 2000's)

We just experienced the fastest 4 month drop in global temps in recorded history....0.5C in 4 months... only difference......don't expect us to bounce back up very far.