Leading Paleoclimatologist: Prepare for the Next Ice Age

[skierinvermont]

Except you quoted the 1998-2010 trends...which are not extremely ENSO negative. Remember, 1999-2001 was a multi-year Nina. You are thinking of the trend since 2002, which is more ENSO negative.

Right, but if we do the temperature trend since 2000 it will be more positive because the ENSO trend is less negative. The ENSO corrected trends don't change much and are pretty consistent at .12C/decade for GISS, regardless of start date.

[tacoman25]

Right, but if we do the temperature trend since 2000 it will be more positive because the ENSO trend is less negative. The ENSO corrected trends don't change much and are pretty consistent at .12C/decade for GISS, regardless of start date.

They are easily highest for GISS, moreso than any other source. As you pointed out, UAH is 33% lower...and that's the next closest.

[tacoman25]

Recent papers on climate sensitivity and transient climate response:

Climate sensitivity:

Assigns the most likely climate sensitivity of only 1.6C/doubling, much below the IPCC: http://journals.amet...1175/JCLI3611.1

Argues against higher climate sensitivities and assigns a best guess of 2.9C slightly lower than the IPCC:http://www.nature.co...ature04679.html

Argues against highest climate sensitivities: http://www.nature.co...ature04679.html

Assigns a mean climate sensitivity of 2.8C, slightly lower than the IPCC: http://journals.amet...1175/JCLI3611.1

There has been little change in the best estimate of climate sensitivity: http://www.nature.co...bs/ngeo337.html

Argues against the higher climate sensitivities: http://www.springerl...p5t35mq27p3q24/

Argues against the higher climate sensitivities: http://citeseerx.ist...p=rep1&type=pdf

Uses a climate sensitivity lower than the IPCC: http://books.google....esponse&f=false

Transient Climate Response:

Argues for a lower transient climate response: http://www.agu.org/j...7GL032904.shtml

Argues for a transient climate response similar to the IPCC: http://homepages.see...Forster2008.pdf

Exactly. That was my point. You can find reputable sources quoting a huge range, basically 1C-5C+ by 2100. Tons of uncertainty, not at all the neat little "standard" numbers Rusty likes to trot out.

[skierinvermont]

http://climateprogre...emissions-path/

Is the Hadley Center unaware of proper CO2 forcing? In 2008, they forecasted anywhere from 2.1C-7.1C rise in temperatures by 2100, depending on emissions between now and 2050.

I'm trying to find the original Hadley Center release instead of just that link that you posted which is all I can ever find.

The blogger's description of the Hadley Study is not really accurate.

The numbers in that chart are the worst case scenario. They represent the Hadley Center's 50th to 10th percentile warmest probablistic outcomes. This is noted in the double tiny asterisk at the bottom. They do not represent the full range of uncertainty, even in Hadley's opinion.

What was probably going on, I think, is that this was an effort by Hadley to represent "the worst case scenario" given our continued uncertainty in climate sensitivity. Since they published this, a number of studies have said that the highest sensitivities should be ruled out.

[skierinvermont]

Exactly. That was my point. You can find reputable sources quoting a huge range, basically 1C-5C+ by 2100. Tons of uncertainty, not at all the neat little "standard" numbers Rusty likes to trot out.

Well the Number's Rusty is posting I think are the 90% confidence interval. All of the studies I posted had mean estimates of between 1.6 and 3.0 (all but one were from 2.5-3). The 95% confidence intervals varied from 1.2 to 6.2. The 2-4.5C/doubling equilibrium response was and remains what most would consider the "likely" interval.

[skierinvermont]

The 2010 El Nino spike changes the entire picture.

No it does not, the ENSO trend remains strongly negative from 2002-2011.

ENSO corrected trends to present:

[tacoman25]

I'm trying to find the original Hadley Center release instead of just that link that you posted which is all I can ever find.

The blogger's description of the Hadley Study is not really accurate.

The numbers in that chart are the worst case scenario. They represent the Hadley Center's 50th to 10th percentile warmest probablistic outcomes. This is noted in the double tiny asterisk at the bottom. They do not represent the full range of uncertainty, even in Hadley's opinion.

What was probably going on, I think, is that this was an effort by Hadley to represent "the worst case scenario" given our continued uncertainty in climate sensitivity. Since they published this, a number of studies have said that the highest sensitivities should be ruled out.

No, the numbers are not all worst-case scenarios.

The "No Action Taken" worst case scenario leads to 5C+ warming.

A much more optimistic scenario, with emissions levels returning to 1990 levels by 2050, still results in roughly 3-4C rise!

The "best case" scenario, with emissions dropping 47% by 2050, results in 2.1C - 2.8C rise.

[skierinvermont]

No, the numbers are not all worst-case scenarios.

The "No Action Taken" worst case scenario leads to 5C+ warming.

A much more optimistic scenario, with emissions levels returning to 1990 levels by 2050, still results in roughly 3-4C rise!

The "best case" scenario, with emissions dropping 47% by 2050, results in 2.1C - 2.8C rise.

Yeah I know.. but even for a given emissions scenario X, these are still the worst case scenarios. The fine print (the double **) in the bottom left says that these represent the upper 50th to 10th percentiles of the uncertainty range.

This was basically Hadley's effort to say.. well if the climate sensitivity is on the high edge of what we think it could be, then this is what will happen given X emissions.

I remember reading this in the original release (which I can't find anymore) and remember being confused by it the first time and it also is indicated in the ** in the bottom left of the figure.

[Clifford]

Somehow I think this topic has gotten derailed a little bit.

The question is whether or not an Ice Age is imminent.

At this point, such a prediction is premature.

What we can count on is that the pressures that drive ice ages are likely to return... sometime.... and humanity is not at all prepared for such an event.

Whether or not accidental, or intentional efforts by man will counteract these pressures is anybody's guess.

We could say that there is a greater than 90% likelihood of ice age "forcing" to return within 10,000 years. But, breaking it down to a likelihood over the next decade or century is difficult.

[VAwxman]

ENSO, TSI, and volcanoes have by far the largest short-term effects in perturbing temperature. Removing those 3 variables gives us a much better estimate of the underlying trend. When we remove them, we find an underlying trend near to the expected .18C/decade in the 2000s.

This is where I get stuck. I do not see how you can accurately remove ENSO for a few reasons. First, every ENSO event is of different intensity. Second, ENSO events of the same intensity are not going to result in the same impact on temperatures, since of course a slew of other factors are in play. Third, AGW in theory would alter the global circulations themselves, thus impacting ENSO itself since the mean temeprature gradient / trade winds would be impacted. Fourth, everything is tied together so intricately that I don't see any way you can accurately remove anything with any degree of confidence, because without ENSO, some of the other factors would not be as they are, and vice versa.

And the other problem for me is that the predictions for warming made no mention about having to correct for ENSO anyway, at least that I have heard of.

[LakeEffectKing]

This is where I get stuck. I do not see how you can accurately remove ENSO for a few reasons. First, every ENSO event is of different intensity. Second, ENSO events of the same intensity are not going to result in the same impact on temperatures, since of course a slew of other factors are in play. Third, AGW in theory would alter the global circulations themselves, thus impacting ENSO itself since the mean temeprature gradient / trade winds would be impacted. Fourth, everything is tied together so intricately that I don't see any way you can accurately remove anything with any degree of confidence, because without ENSO, some of the other factors would not be as they are, and vice versa.

And the other problem for me is that the predictions for warming made no mention about having to correct for ENSO anyway, at least that I have heard of.

I'd get used to it! I imagine that we will get a lot of "if we remove the sun, volcanoes, watervapor, ENSO, PDO, Spencer, Christy, Soon, Skeptics....etc. we, in fact have catastrophic AGW" if the global temps don't respond as forecast. I also predict that the definition of "long term" will......ummm.....become longer.....

[WeatherRusty]

Exactly. That was my point. You can find reputable sources quoting a huge range, basically 1C-5C+ by 2100. Tons of uncertainty, not at all the neat little "standard" numbers Rusty likes to trot out.

The numbers I have trotted out ad nauseum refer to specific estimates given a forcing equal to 3.7W/m^2.

1.2C / 2X CO2 is the black body temperature response. This Planck Response is quite certain.

2.0C - 4.5C is the estimated range in total temperature response following full response including feedbacks.

These figures do not tell us what the temperature will be say in 2020, 2050 or 2100. They inform us how the climate will respond over time to a radiative forcing of 3.7W/m^2 whenever that occurs. If CO2 goes from pre-industrial concentration 280ppm to 560pmmp, there is one 3.7W/m^2 increment. If CO2 goes to 700ppm by 2060 the forcing will not be 3.7W/m^2, it will be somewhat greater and thus so will the temperature response.

If methane and other long lived greenhouse gases increase in concentration the Equivalent CO2 Radiative Forcing will be greater than in the isolated case of CO2 alone. Likewise, depending on the direction aerosols take, the radiative forcing will be added to or subtracted from.

When at some point along the increasing temperature trend the following kick in --- ie. tipping points:

• The defrosting of the permafrost
• The drying of the Northern peatlands (bogs, moors, and mires).
• The destruction of the tropical wetlands
• Decelerating growth in tropical forest trees — thanks to accelerating carbon dioxide
• Wildfires and Climate-Driven forest destruction by pests
• The desertification-global warming feedback
• The saturation of the ocean carbon sink

The carbon feedback process will gain momentum on its own. If these processes occur then all bets are off. They are NOT included in climate models because it is not understood when, to what degree or even if some of them might occur.

It is quit possible CO2 equivalent forcing could become 800-1000ppm even if anthropogenic induced CO2 itself is at 500ppm for instance. The great fear is that some of these carbon feedbacks will occur at some point. So, remember it is the total radiative forcing unleashed by human activity which will determine the outcome. If it happens CO2 equivalent forcing approaches two doublings then 5C - 9C is not out of the question.

When Hadley issues a high estimate for temp. response by late century they are including the carbon feedback process in their thinking, something the models have not dealt with. In addition, the models don't consider the long term effects on albedo due to reduced ice and snow coverage. Uncertainty is not our friend.

[LakeEffectKing]

The numbers I have trotted out ad nauseum refer to specific estimates given a forcing equal to 3.7W/m^2.

1.2C / 2X CO2 is the black body temperature response. This Planck Response is quite certain.

2.0C - 4.5C is the estimated range in total temperature response following full response including feedbacks.

These figures do not tell us what the temperature will be say in 2020, 2050 or 2100. They inform us how the climate will respond over time to a radiative forcing of 3.7W/m^2 whenever that occurs. If CO2 goes from pre-industrial concentration 280ppm to 560pmmp, there is one 3.7W/m^2 increment. If CO2 goes to 700ppm by 2060 the forcing will not be 3.7W/m^2, it will be somewhat greater and thus so will the temperature response.

If methane and other long lived greenhouse gases increase in concentration the Equivalent CO2 Radiative Forcing will be greater than in the isolated case of CO2 alone. Likewise, depending on the direction aerosols take, the radiative forcing will be added to or subtracted from.

When at some point along the increasing temperature trend the following kick in --- ie. tipping points:

• The defrosting of the permafrost
• The drying of the Northern peatlands (bogs, moors, and mires).
• The destruction of the tropical wetlands
• Decelerating growth in tropical forest trees — thanks to accelerating carbon dioxide
• Wildfires and Climate-Driven forest destruction by pests
• The desertification-global warming feedback
• The saturation of the ocean carbon sink

The carbon feedback process will gain momentum on its own. If these processes occur then all bets are off. They are NOT included in climate models because it is not understood when, to what degree or even if some of them might occur.

It is quit possible CO2 equivalent forcing could become 800-1000ppm even if anthropogenic induced CO2 itself is at 500ppm for instance. The great fear is that some of these carbon feedbacks will occur at some point. So, remember it is the total radiative forcing unleashed by human activity which will determine the outcome. If it happens CO2 equivalent forcing approaches two doublings then 5C - 9C is not out of the question.

When Hadley issues a high estimate for temp. response by late century they are including the carbon feedback process in their thinking, something the models have not dealt with. In addition, the models don't consider the long term effects on albedo due to reduced ice and snow coverage. Uncertainty is not our friend.

WTH is a "carbon feedback"???? If you are talking about "global temp. feedback" we have no history of such "feedbacks" getting out of control during "natural" temperature fluctuations over the last few millenia.....niether in a negative or positive role...

[BethesdaWX]

No it does not, the ENSO trend remains strongly negative from 2002-2011.

ENSO corrected trends to present:

1) Use UAH, Not GISS.

2 For the 3rd time now...

The effects of Cloud Cover (GCC), GLAAM in locations of HLB & strength, Global SST.........The BASIS of the ENSO events, the Strength of the PDO....ALL will have effects that will alter the trendline.

They will make or break the trend.

[BethesdaWX]

This is where I get stuck. I do not see how you can accurately remove ENSO for a few reasons. First, every ENSO event is of different intensity. Second, ENSO events of the same intensity are not going to result in the same impact on temperatures, since of course a slew of other factors are in play. Third, AGW in theory would alter the global circulations themselves, thus impacting ENSO itself since the mean temeprature gradient / trade winds would be impacted. Fourth, everything is tied together so intricately that I don't see any way you can accurately remove anything with any degree of confidence, because without ENSO, some of the other factors would not be as they are, and vice versa.

And the other problem for me is that the predictions for warming made no mention about having to correct for ENSO anyway, at least that I have heard of.

Thankyou so Much! This is what I cannot seem to convey well enough for his understanding, everyone trusts a red-Tagger

[LocoAko]

Get your head out of your ass dude

The effects of Cloud Cover (GCC), GLAAM in locations of HLB & strength, Global SST.........The BASIS of the ENSO events, the Strength of the PDO....ALL will have significant effects that will alter the trendline.

All of those together will make or break a trend, thus we cannot remove.

I have a quick question - is it possible for you to ever debate/discuss things without resorting to name calling and profanities? Just curious.

[BethesdaWX]

I have a quick question - is it possible for you to ever debate/discuss things without resorting to name calling and profanities? Just curious.

Yes...yes it is.

[skierinvermont]

This is where I get stuck. I do not see how you can accurately remove ENSO for a few reasons. First, every ENSO event is of different intensity. Second, ENSO events of the same intensity are not going to result in the same impact on temperatures, since of course a slew of other factors are in play. Third, AGW in theory would alter the global circulations themselves, thus impacting ENSO itself since the mean temeprature gradient / trade winds would be impacted. Fourth, everything is tied together so intricately that I don't see any way you can accurately remove anything with any degree of confidence, because without ENSO, some of the other factors would not be as they are, and vice versa.

And the other problem for me is that the predictions for warming made no mention about having to correct for ENSO anyway, at least that I have heard of.

Before removing ENSO we find large variation in the temperature trends to present. After removing ENSO we find that this variation is washed out and the trends to present are much smoother. This is an indication that we are adjusting for a real phenomenon. When we perform a correlation analysis we find that ENSO explains X% of the variation in temperature trends. We can then remove that X% and see what remains. What remains is a much smoother consistent temperature trend.. indicating that we have adjusted for a real phenomenon. It is not perfect because there are other factors at play, and because each ENSO event might act slightly differently.

Also you raise the concern that some ENSO events are stronger, but in my formula stronger ENSO events are adjusted more. The formula used is created based off the correlation analysis and adjusts GISS temperature by .105C for every 1C of ONI. This is also a method used in peer-reviewed studies. We see that trends to present from 1998-2001 are adjusted downwards because the ENSO trend to present is positive, whereas 2002-2005 is adjusted upwards because the ENSO trend to present is negative. The result is a much more consistent trend that gradually falls from .18C/decade to .1C/decade before being taken over by even shorter term variation. It's not perfect, but it removes much of the variation based on ENSO.

Basically, Bethesda doesn't like this method because he can no longer claim that temperatures have been dropping since 2002, because the ENSO trend from 2002-present is strongly negative. It also prevents AGWers, for example, selecting trends to present starting in 1999 and claiming that we have been warming .2C/decade.

remember, this is a graph of trends to present

[BethesdaWX]

Before removing ENSO we find large variation in the temperature trends to present. After removing ENSO we find that this variation is washed out and the trends to present are much smoother. This is an indication that we are adjusting for a real phenomenon. When we perform a correlation analysis we find that ENSO explains X% of the variation in temperature trends. We can then remove that X% and see what remains. What remains is a much smoother consistent temperature trend.. indicating that we have adjusted for a real phenomenon. It is not perfect because there are other factors at play, and because each ENSO event might act slightly differently.

Also you raise the concern that some ENSO events are stronger, but in my formula stronger ENSO events are adjusted more. The formula used is created based off the correlation analysis and adjusts GISS temperature by .105C for every 1C of ONI. This is also a method used in peer-reviewed studies.

1) But you Can't remove ENSO, as has been explained to you...the atmosphere will not respond to each event in the Same way! Other factors outside of ENSO through intercorrelation also impact the trend, and ENSO itself. It cannot be done. GCC, PDO strength/#, Global SST, HLB, etc.

2) Show some Evidence of HOW ENSO is removed, do it...Peer reviewd.

3) GISS? .

[skierinvermont]

1) Use UAH, Not GISS.

2 For the 3rd time now...

The effects of Cloud Cover (GCC), GLAAM in locations of HLB & strength, Global SST.........The BASIS of the ENSO events, the Strength of the PDO....ALL will have effects that will alter the trendline.

They will make or break the trend.

Fine Bethesda, if you want to claim cooling since 2002, I'm going to claim extremely rapid warming of .2C/decade since 1999.

Or we could just agree to remove ENSO, as I have done, and agree that the trends to present from 1999 or 2002 are around .11C/decade for GISS, and .08C/decade for UAH. But if you don't want to remove ENSO, I'm just going to use ENSO-positive periods, such as 1999-present, and claim that the trend to present is .2C/decade. Afterall, according to you, we can't remove ENSO!!!!

We have been warming rapidly at .2C/decade since 1999. This is even faster than the IPCC predicted.. they are busting too cold!!@11@! OMG

[BethesdaWX]

Fine Bethesda, if you want to claim cooling since 2002, I'm going to claim extremely rapid warming of .2C/decade since 1999.

Or we could just agree to remove ENSO, as I have done, and agree that the trends to present from 1999 or 2002 are around .11C/decade for GISS, and .08C/decade for UAH. But if you don't want to remove ENSO, I'm just going to use ENSO-positive periods, such as 1999-present, and claim that the trend to present is .2C/decade. Afterall, according to you, we can't remove ENSO!!!!

We have been warming rapidly at .2C/decade since 1999. This is even faster than the IPCC predicted.. they are busting too cold!!

Choosing 1999 for warming is like choosing 1998 for cooling. 2002 temperatures remained the same in 2003, 2004, 2005, and 2006, a flatline which represents the peak of the "warming" period.

And yea, you can't remove ENSO, which AGW is supposed to effect in a positive manner regardless. Thats like using UAH but removing the Mid Lattitudes and just measuring everything else for a global mean.

[tacoman25]

This is where I get stuck. I do not see how you can accurately remove ENSO for a few reasons. First, every ENSO event is of different intensity. Second, ENSO events of the same intensity are not going to result in the same impact on temperatures, since of course a slew of other factors are in play. Third, AGW in theory would alter the global circulations themselves, thus impacting ENSO itself since the mean temeprature gradient / trade winds would be impacted. Fourth, everything is tied together so intricately that I don't see any way you can accurately remove anything with any degree of confidence, because without ENSO, some of the other factors would not be as they are, and vice versa.

And the other problem for me is that the predictions for warming made no mention about having to correct for ENSO anyway, at least that I have heard of.

Bingo.

The nearly .2C/decade trend we are supposed to be seeing by now has no provisions for PDO cycles, ENSO trends, solar, etc.

[skierinvermont]

Choosing 1999 for warming is like choosing 1998 for cooling. 2002 temperatures remained the same in 2003, 2004, 2005, and 2006, a flatline which represents the peak of the "warming" period.

And yea, you can't remove ENSO, which AGW is supposed to effect in a positive manner regardless. Thats like using UAH but removing the Mid Lattitudes and just measuring everything else for a global mean.

Starting in 2002 is the worst starting point one can possibly pick because the ENSO trend to present is STRONGLY NEGATIVE. It's far worse than starting in 1998 or 1999.

If you're claiming we can't remove ENSO, I'm going to start all my trends in 1999 and claim we have been warming rapidly at .2C/decade.

[skierinvermont]

Bingo.

The nearly .2C/decade trend we are supposed to be seeing by now has no provisions for PDO cycles, ENSO trends, solar, etc.

Yes they do. "Natural variation" is factored into the confidence intervals.

This is why it takes 14 years to be 95% sure we will have a positive temperature trend.

[skierinvermont]

I also believe that if you look at the individual ensemble members, you will see that they simulate natural variation due to things like ENSO and many other variables. What is commonly reported is the ensemble mean and the multi-model mean (of ensemble means). One way in which the confidence intervals can be calculated is based off the ensemble member spread.

[tacoman25]

Starting in 2002 is the worst starting point one can possibly pick because the ENSO trend to present is STRONGLY NEGATIVE. It's far worse than starting in 1998 or 1999.

If you're claiming we can't remove ENSO, I'm going to start all my trends in 1999 and claim we have been warming rapidly at .2C/decade.

Actually, I don't believe 2002-2010 is a strongly negative ENSO trend. 2002 was an mostly an ENSO neutral influenced year (the Nino developed in the second half of the year, but given a 5 month satellite temp lag, the Nino effects weren't felt until late in the year). 2010 was primarily a Nino-influenced year.

[BethesdaWX]

Starting in 2002 is the worst starting point one can possibly pick because the ENSO trend to present is STRONGLY NEGATIVE. It's far worse than starting in 1998 or 1999.

If you're claiming we can't remove ENSO, I'm going to start all my trends in 1999 and claim we have been warming rapidly at .2C/decade.

The Temperature trend since 2003 is also negative. So is 2004...also 2005. The Problem is natural variability is part of the climactic feedback system, AGW is supposed to create more +ENSO....as to where negative feedbacks supposedyl do not exist in IPCC models................Global Cloud Cover could have been dropping the entire time. HLB swithced up, AMO/IOD were warming, its interconnected.

[tacoman25]

Yes they do. "Natural variation" is factored into the confidence intervals.

This is why it takes 14 years to be 95% sure we will have a positive temperature trend.

1998-2011 will be 14 years....

[skierinvermont]

Actually, I don't believe 2002-2010 is a strongly negative ENSO trend. 2002 was an mostly an ENSO neutral influenced year (the Nino developed in the second half of the year, but given a 5 month satellite temp lag, the Nino effects weren't felt until late in the year). 2010 was primarily a Nino-influenced year.

Even with a full 6 month lag, the trend is strongly negative. Without the 6 month lag it is even more negative.

[BethesdaWX]

1998-2011 will be 14 years....

I'm not a big fan of starting in 1998, itws kind of picky. 2002-2006 were very smililar in the flatline, representing the peak of the warming cycle, I'd assume.