...

[ORH_wxman]

I hate to do this, but warming hasn't stopped for 15 years, it's been 8-10 at most.

 

 

Actually its been 8-10 at least. Only UAH falls within the 8-10 year time frame. RSS is at 16.5 years, Hadcrut4 is at almost 13 years, and GISS is at 12.5 years.

[LakeEffectKing]

I hate to do this, but warming hasn't stopped for 15 years, it's been 8-10 at most.

Pretty flat, especially when averaging out the El Nino/La Nina couplet in the late 90's:

 

[nflwxman]

It looks like it warmed up to 2005 and dropped off a bit. Just eyeballing the GISS graph, qIt's quite clear. Thus claiming warming stopped (based on a linear trend from 1998-present) is slightly misleading. I think a more accurate statement is that it warmed to 2005 and then cooled a bit to present (with exception of 2010).

[nflwxman]

Pretty flat, especially when averaging out the El Nino/La Nina couplet in the late 90's:

[/quote

Use 12 month averages at least, that's hard on the eyes and nearly impossible to discern a short term trend.

[ORH_wxman]

It looks like it warmed up to 2005 and dropped off a bit. Just eyeballing the GISS graph, qIt's quite clear. Thus claiming warming stopped (based on a linear trend from 1998-present) is slightly misleading. I think a more accurate statement is that it warmed to 2005 and then cooled a bit to present (with exception of 2010).

 

 

Using linear regression is the way to go. If we have cooled from a certain point, then by definition we have not warmed from a certain point prior to that cooling point. Its easier to just say "we haven't warmed since 2000 or 2001" rather than say "we've had global cooling since 2005".

 

If we want to make exceptions like "cooled except 2010" or "warmed to 2005", then it becomes a jumbled mess because then you can claim we warmed until 1998 "except for 1991-1992" and then cooled to the present "except 2005 and 2010". Using linear regression smooths out the shorter intra-year spikes.

[LakeEffectKing]

Pretty flat, especially when averaging out the El Nino/La Nina couplet in the late 90's:

[/quote

Use 12 month averages at least, that's hard on the eyes and nearly impossible to discern a short term trend.

Come on!  It's hard on your eyes because it doesn't show the "blade" that you've been conditioned to see.  And, BTW, as Will pointed out, the only temp. series that (just barely) doesn't show a longer than 12yr. stall is UAH.  It is what it is.

[Cory]

It looks like it warmed up to 2005 and dropped off a bit. Just eyeballing the GISS graph, qIt's quite clear. Thus claiming warming stopped (based on a linear trend from 1998-present) is slightly misleading. I think a more accurate statement is that it warmed to 2005 and then cooled a bit to present (with exception of 2010).

 

The long pause been mentioned in scientific papers, such as this 2011 entry in PNAS: "...it has been unclear why global surface temperatures did not rise between 1998 and 2008." http://www.pnas.org/content/108/29/11790

[LakeEffectKing]

Pretty flat, especially when averaging out the El Nino/La Nina couplet in the late 90's:

[/quote

Use 12 month averages at least, that's hard on the eyes and nearly impossible to discern a short term trend.

Here nfl....I made it easier for your eyes....red line is for reference only:

[nflwxman]

Using linear regression is the way to go. If we have cooled from a certain point, then by definition we have not warmed from a certain point prior to that cooling point. Its easier to just say "we haven't warmed since 2000 or 2001" rather than say "we've had global cooling since 2005".

If we want to make exceptions like "cooled except 2010" or "warmed to 2005", then it becomes a jumbled mess because then you can claim we warmed until 1998 "except for 1991-1992" and then cooled to the present "except 2005 and 2010". Using linear regression smooths out the shorter intra-year spikes.

I gotta be honest. I don't believe this discussion will bear fruit. I think people should hold judgement on alarmists and deniers (etc) and who wins and losses. This last decade is certainly not enough data to make sweeping statements and change our models. For all we know, we could warm double the rate next time the PDO flips and surpass surface temp modeled projections

We are literally debating over 3 % of climate change's additional energy. We have not talked about how the PDO affects sea level rise (happening faster than "modeled," ocean heat content, sea ice (melting faster than "modeled"), and ice sheets.

[GaWx]

It looks like it warmed up to 2005 and dropped off a bit. Just eyeballing the GISS graph, qIt's quite clear. Thus claiming warming stopped (based on a linear trend from 1998-present) is slightly misleading. I think a more accurate statement is that it warmed to 2005 and then cooled a bit to present (with exception of 2010).

 

 If it has cooled since 2005 overall, then is it possible that the quieter sun has actually already induced cooling with no lag? I'm not saying that and haven't been thinking that (I've been thinking pretty steady global temp.'s overall since 1998), but I guess it would be a valid question if one were to assume cooling since 2005. Opinion? This is so tricky!

[nflwxman]

If it has cooled since 2005 overall, then is it possible that the quieter sun has actually already induced cooling with no lag? I'm not saying that and haven't been thinking that (I've been thinking pretty steady global temp.'s overall since 1998), but I guess it would be a valid question if one were to assume cooling since 2005. Opinion? This is so tricky!

The low sun activity certainly has contributed to depressed global temps since 2007 and 2008. I think someone (maybe skier) has a temp value based on a rough model he created. I'm not sure of the exact value.

[LakeEffectKing]

I gotta be honest. I don't believe this discussion will bear fruit. I think people should hold judgement on alarmists and deniers (etc) and who wins and losses. This last decade is certainly not enough data to make sweeping statements and change our models. For all we know, we could warm double the rate next time the PDO flips and surpass surface temp modeled projections

We are literally debating over 3 % of climate change's additional energy. We have not talked about how the PDO affects sea level rise (happening faster than "modeled," ocean heat content, sea ice (melting faster than "modeled"), and ice sheets.

Nobody is judging, we are discussing the results of a study that comes with a rather profound shift in the overall landscape of climate change discussions.

[ORH_wxman]

I gotta be honest. I don't believe this discussion will bear fruit. I think people should hold judgement on alarmists and deniers (etc) and who wins and losses. This last decade is certainly not enough data to make sweeping statements and change our models. For all we know, we could warm double the rate next time the PDO flips and surpass surface temp modeled projections

We are literally debating over 3 % of climate change's additional energy. We have not talked about how the PDO affects sea level rise (happening faster than "modeled," ocean heat content, sea ice (melting faster than "modeled"), and ice sheets.

 

 

That would be sad if that is the case. Counting on a warming of +0.4C (or more) per decade the next time the PDO goes positive is a silly way to address the question of why we aren't warming in the past decade plus versus why GCMs have predicted it to warm about 0.25C since 2000.

 

Yes, the timeframe is fairly short, but its long enough to start detecting that something may not quite be correct in our modeling. The central estimate for surface temperature increase in the IPCC models using a "business as usual" emmissions scenario is 2.8C of warming by 2100 from the year 2000.

 

Studies like this which might suggest that the anthropogenic contribution is less than many GCM assumptions can only be useful. Whether we found out that is correct or not...its important to study it.

[nflwxman]

Nobody is judging, we are discussing the results of a study that comes with a rather profound shift in the overall landscape of climate change discussions.

I really think climate scientists have know about this longer than many believe. There are several studies prior to this that show essentially the same thing (with quantifying it).

Do you think sea level rise will be faster since more of that energy is staying in the ocean for longer periods?

[nflwxman]

That would be sad if that is the case. Counting on a warming of +0.4C (or more) per decade the next time the PDO goes positive is a silly way to address the question of why we aren't warming in the past decade plus versus why GCMs have predicted it to warm about 0.25C since 2000.

Yes, the timeframe is fairly short, but its long enough to start detecting that something may not quite be correct in our modeling. The central estimate for surface temperature increase in the IPCC models using a "business as usual" emmissions scenario is 2.8C of warming by 2100 from the year 2000.

Studies like this which might suggest that the anthropogenic contribution is less than many GCM assumptions can only be useful. Whether we found out that is correct or not...its important to study it.

I don't disagree with what you are saying. It should be studied thoroughly. But as far as future projections are concerned, how do you model an oscillation that is fairly random? It's easier to hindcast these projections since we have ONI values since 1900.

[LakeEffectKing]

I really think climate scientists have know about this longer than many believe. There are several studies prior to this that show essentially the same thing (with quantifying it).

Do you think sea level rise will be faster since more of that energy is staying in the ocean for longer periods?

No.  IMO, the current sea level rise will slow over the next decade, maybe even level off. 

[nflwxman]

That would be sad if that is the case. Counting on a warming of +0.4C (or more) per decade the next time the PDO goes positive is a silly way to address the question of why we aren't warming in the past decade plus versus why GCMs have predicted it to warm about 0.25C since 2000.

Yes, the timeframe is fairly short, but its long enough to start detecting that something may not quite be correct in our modeling. The central estimate for surface temperature increase in the IPCC models using a "business as usual" emmissions scenario is 2.8C of warming by 2100 from the year 2000.

Studies like this which might suggest that the anthropogenic contribution is less than many GCM assumptions can only be useful. Whether we found out that is correct or not...its important to study it.

To be clear, this study does quantify the anthropogenic contribution to surface warming over the past 100 years. It does not downplay the overall energy imbalance though.

[f2tornado]

I gotta be honest. I don't believe this discussion will bear fruit. I think people should hold judgement on alarmists and deniers (etc) and who wins and losses. This last decade is certainly not enough data to make sweeping statements and change our models. For all we know, we could warm double the rate next time the PDO flips and surpass surface temp modeled projections

We are literally debating over 3 % of climate change's additional energy. We have not talked about how the PDO affects sea level rise (happening faster than "modeled," ocean heat content, sea ice (melting faster than "modeled"), and ice sheets.

 

There are no winners and losers. It's the scientific method, not a Presidential debate. The last decade has shown GCMs are not very effective incorporating natural climate variability and, therefore, we have not yet fully delineated the AGW signal from the natural signal and magnitude of climate sensitivity remains an open question.

[ORH_wxman]

I don't disagree with what you are saying. It should be studied thoroughly. But as far as future projections are concerned, how do you model an oscillation that is fairly random? It's easier to hindcast these projections since we have ONI values since 1900.

 

 

Hindcasting in a model like this helps us identify that the anthro trend was lower than many other studies believe it was (assuming the study is on the right track). Therefore, models that project going forward that assume in their hindcast that the 1970s-2000s warming was almost all anthropogenic, will give us results that are biased high.

 

We might not be able to predict exactly when the PDO flips will happen, but if these types of studies help us isolate the anthro trend from natural variation, then we can make more accurate long term predictions.

[nflwxman]

Hindcasting in a model like this helps us identify that the anthro trend was lower than many other studies believe it was (assuming the study is on the right track). Therefore, models that project going forward that assume in their hindcast that the 1970s-2000s warming was almost all anthropogenic, will give us results that are biased high.

We might not be able to predict exactly when the PDO flips will happen, but if these types of studies help us isolate the anthro trend from natural variation, then we can make more accurate long term predictions.

Right, but most hindcasts start at 1900, which allows us to model the PDO/ENSO long enough in that it should have very little impact on the global temp trend. In a vacuum, where 1975-2005 is modeled entirely anthropogenic, I could see the GCMs way overdoing the sensitivity. Generally in most papers with hindcasts, that is not the case.

[GaWx]

 I have criticized Joe Bastardi in the past in this forum for having shown deceiving global temperature anomaly maps as a result of misuse of the color codings though I suspect this was unintentional/careless rather than intentional. So, I'm not at all afraid to criticize him. Also, I used to criticize him for a cold bias in the E US in winter and a general bias toward forecasting extremes. However, in all fairness, he has been one who has been pushing the importance of the PDO and AMO cycles in global temp. cycles for at least several years. So, I think this latest report kind of makes him look favorable with regard to this topic. Any other opinions about this in particular? Agree or disagree?

[ORH_wxman]

Right, but most hindcasts start at 1900, which allows us to model the PDO/ENSO long enough in that it should have very little impact on the global temp trend. In a vacuum, where 1975-2005 is modeled entirely anthropogenic, I could see the GCMs way overdoing the sensitivity. Generally in most papers with hindcasts, that is not the case.

 

 

Hindcasts assume that most of the previous warming prior to 1950 was not anthropogenic (or certainly a minority) and then assume that the more recent warming period from 1970s-2000s was anthropogenic. It doesn't matter if you start in 1970 or 1900 if the model is making those assumptions anyway.

[nflwxman]

Hindcasts assume that most of the previous warming prior to 1950 was not anthropogenic (or certainly a minority) and then assume that the more recent warming period from 1970s-2000s was anthropogenic. It doesn't matter if you start in 1970 or 1900 if the model is making those assumptions anyway.

Well, it has a slow ramping up of anthropogenic components starting at 1880 when co2 was 280 ppm. Those hindcasts are reasonably accurate. I don't think it's quite as black and white as saying it didn't include a anthropogenic component before 1970, it just wasn't as strong and was in the midst of ramping up. I'd place the graph of forcings assumed in the IPCC report, but I'm on my phone.

[ORH_wxman]

Well, it has a slow ramping up of anthropogenic components starting at 1880 when co2 was 280 ppm. Those hindcasts are reasonably accurate. I don't think it's quite as black and white as saying it didn't include a anthropogenic component before 1970, it just wasn't as strong and was in the midst of ramping up. I'd place the graph of forcings assumed in the IPCC report, but I'm on my phone.

 

The IPCC models under-forecast the warming in the early 20th century and also the cooling in the mid-20th century. Then do quite well in the late 20th century until overshooting almost out of their range for error in the first 13 years of the 21st century. That would suggest they rely too much on the GHG component and not enough on internal variability.

 

Its certainly possible that its a fluke and they will do fine going forward, but there's enough skeptical scientists out there that we have studies explaining the lack of warming and also the potential natural variables that may have caused late 20th century warming.

[nflwxman]

The IPCC models under-forecast the warming in the early 20th century and also the cooling in the mid-20th century. Then do quite well in the late 20th century until overshooting almost out of their range for error in the first 13 years of the 21st century. That would suggest they rely too much on the GHG component and not enough on internal variability.

Its certainly possible that its a fluke and they will do fine going forward, but there's enough skeptical scientists out there that we have studies explaining the lack of warming and also the potential natural variables that may have caused late 20th century warming.

Even the hindcasts have a few

years they shoot our of their 95% confidence range. Hence why short term decadal temps are rarely used to judge performance of a model. But on a longer time scale they perform well.

What models are we almost out of the confidence range now? Skier posted a graph earlier the the IPCC model ensemble range from 2007 and it appears while we dropped below the mean, we are still within the bands of uncertainty defined.

[Jonger]

I gotta be honest. I don't believe this discussion will bear fruit. I think people should hold judgement on alarmists and deniers (etc) and who wins and losses. This last decade is certainly not enough data to make sweeping statements and change our models. For all we know, we could warm double the rate next time the PDO flips and surpass surface temp modeled projections

We are literally debating over 3 % of climate change's additional energy. We have not talked about how the PDO affects sea level rise (happening faster than "modeled," ocean heat content, sea ice (melting faster than "modeled"), and ice sheets.

 

The IPCC models under-forecast the warming in the early 20th century and also the cooling in the mid-20th century. Then do quite well in the late 20th century until overshooting almost out of their range for error in the first 13 years of the 21st century. That would suggest they rely too much on the GHG component and not enough on internal variability.

 

Its certainly possible that its a fluke and they will do fine going forward, but there's enough skeptical scientists out there that we have studies explaining the lack of warming and also the potential natural variables that may have caused late 20th century warming.

 

Cool the past to warm the present....

 

The GHG emissions were doing a good job warming the ocean and the land, now they suddenly aren't effective at warming the land anymore and the ocean warming slows WAY down after Argo went live(post-adjustment)... 

 

The planet has warmed, just not much.

[nflwxman]

Cool the past to warm the present....

The GHG emissions were doing a good job warming the ocean and the land, now they suddenly aren't effective at warming the land anymore and the ocean warming slows WAY down after Argo went live(post-adjustment)...

The planet has warmed, just not much.

Only in shallow waters. The deep water has warmed much quicker.

[ORH_wxman]

Even the hindcasts have a few

years they shoot our of their 95% confidence range. Hence why short term decadal temps are rarely used to judge performance of a model. But on a longer time scale they perform well.

What models are we almost out of the confidence range now? Skier posted a graph earlier the the IPCC model ensemble range from 2007 and it appears while we dropped below the mean, we are still within the bands of uncertainty defined.

 

 

The IPCC CMIP5 models...you can see how in addition to slightly under-forecasting the cooling through the mid 1970s and over-forecasting the warming through the early 21st century...they are also over-forecasting the cooling response to volcanic eruptions (Pinatubo, El Chicon, and Agung).

 

 

 

This could be evidence they are too sensitive to aerosols/GHGs.

[Jonger]

Only in shallow waters. The deep water has warmed much quicker.

 

I'm going to put a graphic up, but when you see how global sea temperatures were taken just 10 years ago and how sparse the data is, you might not feel so comfortable with that statement.

 

 

Pay attention to the last 10-15 years.

 

0 - 700M just goes FLAT after 2003, look at the buoy deployment starting in 2003 onward.

 

 

[nflwxman]

I'm going to put a graphic up, but when you see how global sea temperatures were taken just 10 years ago and how sparse the data is, you might not feel so comfortable with that statement.

Pay attention to the last 10-15 years.

0 - 700M just goes FLAT after 2003, look at the buoy deployment starting in 2003 onward.

You have seen the 0-2000m OHC graph from the OHC thread that friv started?