Climate Attribution Claims Questioned

[Jack Hays]

"Attribution science" has become fashionable among alarmists. Unfortunately it does not seem to have sound basis. A new paper in Nature, highlighted in Science, suggests the whole concept may need to be rethought.

Missed wind patterns are throwing off climate ... - Science

Climate scientists can confidently tie global warming to impacts such as sea-level rise and extreme heat. But ask how rising temperatures will affect rainfall and storms, and the answers get a lot shakier. For a long time, researchers chalked the problem up to natural variability in wind patterns—the inherently unpredictable fluctuations of a chaotic atmosphere.
Now, however, a new analysis has found that the problem is not with the climate, it’s with the massive computer models designed to forecast its behavior. “The climate is much more predictable than we previously thought,” says Doug Smith, a climate scientist at the United Kingdom’s Met Office who led the 39-person effort published this week in Nature. But models don’t capture that predictability, which means they are unlikely to correctly predict the long-term changes that are most influenced by large-scale wind patterns: rainfall, drought, flooding, and extreme storms. “Obviously we need to solve it,” Smith says.
The study, which includes authors from several leading modeling centers, casts doubt on many forecasts of regional climate change, which are crucial for policymaking. It also means efforts to attribute specific weather events to global warming, now much in vogue, are rife with errors. “The whole thing is concerning,” says Isla Simpson, an atmospheric dynamicist and modeler at the National Center for Atmospheric Research, who was not involved in the study. “It could mean we’re not getting future climate projections right.”. . .

North Atlantic climate far more predictable than ... - Nature

[url]www.nature.com › articles
[/URL]
by DM Smith - ‎2020
Jul 29, 2020 - This approach greatly improves decadal predictions of winter climate for Europe and eastern North America. Predictions of Atlantic multidecadal ...

 

[bubbabgone]

"Attribution science" has become fashionable among alarmists. Unfortunately it does not seem to have sound basis. A new paper in Nature, highlighted in Science, suggests the whole concept may need to be rethought.

Missed wind patterns are throwing off climate ... - Science

Climate scientists can confidently tie global warming to impacts such as sea-level rise and extreme heat. But ask how rising temperatures will affect rainfall and storms, and the answers get a lot shakier. For a long time, researchers chalked the problem up to natural variability in wind patterns—the inherently unpredictable fluctuations of a chaotic atmosphere.
Now, however, a new analysis has found that the problem is not with the climate, it’s with the massive computer models designed to forecast its behavior. “The climate is much more predictable than we previously thought,” says Doug Smith, a climate scientist at the United Kingdom’s Met Office who led the 39-person effort published this week in Nature. But models don’t capture that predictability, which means they are unlikely to correctly predict the long-term changes that are most influenced by large-scale wind patterns: rainfall, drought, flooding, and extreme storms. “Obviously we need to solve it,” Smith says.
The study, which includes authors from several leading modeling centers, casts doubt on many forecasts of regional climate change, which are crucial for policymaking. It also means efforts to attribute specific weather events to global warming, now much in vogue, are rife with errors. “The whole thing is concerning,” says Isla Simpson, an atmospheric dynamicist and modeler at the National Center for Atmospheric Research, who was not involved in the study. “It could mean we’re not getting future climate projections right.”. . .

North Atlantic climate far more predictable than ... - Nature

[url]www.nature.com › articles
[/URL]
by DM Smith - ‎2020
Jul 29, 2020 - This approach greatly improves decadal predictions of winter climate for Europe and eastern North America. Predictions of Atlantic multidecadal ...

"Now, however, a new analysis has found that the problem is not with the climate, it’s with the massive computer models designed to forecast its behavior."

Well ... yeah. Climate models don't work - but it ain't just the NAO effect they can't capture. And they start off with both feet in the ditch as well.

 

[Jack Hays]

"Now, however, a new analysis has found that the problem is not with the climate, it’s with the massive computer models designed to forecast its behavior."

Well ... yeah. Climate models don't work - but it ain't just the NAO effect they can't capture. And they start off with both feet in the ditch as well.

As Abraham Lincoln said, "One war at a time, gentlemen."

 

[istodolez]

"The study does not cast doubt on forecasts of overall global warming, which is driven by human emissions of greenhouse gases." (SOURCE)

 

[istodolez]

"Now, however, a new analysis has found that the problem is not with the climate, it’s with the massive computer models designed to forecast its behavior."

Well ... yeah. Climate models don't work - but it ain't just the NAO effect they can't capture. And they start off with both feet in the ditch as well.

Study Confirms Climate Models are Getting Future Warming Projections Right – Climate Change: Vital Signs of the Planet

Even 50-year-old climate models correctly predicted global warming | Science | AAAS

Climate Models Got It Right on Global Warming - Scientific American

Remember this article you all are jumping on apparently relates mostly to finer-scale events. AGW is on pretty solid ground. The warming we see is real.

 

[Jack Hays]

"The study does not cast doubt on forecasts of overall global warming, which is driven by human emissions of greenhouse gases." (SOURCE)

Filed under: "So what?"

Forecasts of overall global warming were not their subject.

 

[Jack Hays]

. . . AGW is on pretty solid ground. The warming we see is real.

The warming is real. The AGW attribution is in question.

New Study: The Post-Pause Global Warming After 2013 Was Not Caused By CO2, But Shortwave Radiation Forcing

By Kenneth Richard on 17. August 2020
Share this...


Echoing the determination of NASA scientists, a new study suggests the natural variability in cloud cover allowing more solar radiation to be absorbed by the Earth’s oceans drove the 2014-2020 global warming.

NASA scientists (Loeb et al., 2018) used satellite data to assess the 2014-2017 warming was driven by a +0.83 W/m² shortwave forcing due to the downward trend in cloud cover. . . .

A new study (Ollila, 2020) affirms this analysis and suggests the 2018-2020 temperature changes can also be explained by shortwave cloud forcing.
“…the pause was over at the end of 2014, and the major cause was not the anthropogenic forcing, but it was the SW [shortwave] radiation forcing”
“Decreases in low cloud cover were the primary driver of the decrease in reflected SW…” . . .

 

[Jack Hays]

Study Confirms Climate Models are Getting Future Warming Projections Right – Climate Change: Vital Signs of the Planet

Even 50-year-old climate models correctly predicted global warming | Science | AAAS

Climate Models Got It Right on Global Warming - Scientific American . . .

Climate models for lawyers

Posted on November 12, 2016 by curryja | 315 comments
by Judith Curry I have been asked to write an Expert Report on climate models. ***SEE UPDATE


Figure 4. Comparison of CMIP5 climate model simulations of global surface temperature anomalies with observations through 2014 (HadCRUT4). Figure 11.25 of the IPCC AR5


Figure 5. Comparison of CMIP5 climate model simulations of global surface temperature anomalies with observations through 2014 (HadCRUT4). Updated from Figure 11.25 of the IPCC AR5, to include observations through 2014. http://www.climate-lab-book.ac.uk/comparing-cmip5-observations/

 

[Surface Detail]

The warming is real. The AGW attribution is in question.

New Study: The Post-Pause Global Warming After 2013 Was Not Caused By CO2, But Shortwave Radiation Forcing

By Kenneth Richard on 17. August 2020
Share this...


Echoing the determination of NASA scientists, a new study suggests the natural variability in cloud cover allowing more solar radiation to be absorbed by the Earth’s oceans drove the 2014-2020 global warming.

NASA scientists (Loeb et al., 2018) used satellite data to assess the 2014-2017 warming was driven by a +0.83 W/m² shortwave forcing due to the downward trend in cloud cover. . . .

A new study (Ollila, 2020) affirms this analysis and suggests the 2018-2020 temperature changes can also be explained by shortwave cloud forcing.
“…the pause was over at the end of 2014, and the major cause was not the anthropogenic forcing, but it was the SW [shortwave] radiation forcing”
“Decreases in low cloud cover were the primary driver of the decrease in reflected SW…” . . .

Isn't this the exact opposite to what Svensmark was claiming? If I remember correctly, Svensmark reckoned that falling solar activity would result in an increase in cosmic radiation reaching Earth and hence greater cloud formation and resultant cooling. But this study says the Earth is warming because of reduced cloud cover and hence reduced shortwave reflection.

It this the final nail in the coffin for Svensmark's theory?

 

[bubbabgone]

Study Confirms Climate Models are Getting Future Warming Projections Right – Climate Change: Vital Signs of the Planet

Even 50-year-old climate models correctly predicted global warming | Science | AAAS

Climate Models Got It Right on Global Warming - Scientific American

Remember this article you all are jumping on apparently relates mostly to finer-scale events. AGW is on pretty solid ground. The warming we see is real.

Ya know what else? You could have predicted global warming 400 years ago without models. Why is that so?
There are many models. Why don't their results all look the same?

 

[Jack Hays]

Isn't this the exact opposite to what Svensmark was claiming? If I remember correctly, Svensmark reckoned that falling solar activity would result in an increase in cosmic radiation reaching Earth and hence greater cloud formation and resultant cooling. But this study says the Earth is warming because of reduced cloud cover and hence reduced shortwave reflection.

It this the final nail in the coffin for Svensmark's theory?

Ollila 2020 cites Svensmark often, and suggests atmospheric processes require further study. As for Svensmark, his explanation does not simply cite "solar activity" but is related to open magnetic field lines and the strength of the solar wind.

 

[istodolez]

Ya know what else? You could have predicted global warming 400 years ago without models.

And you base that on....what, exactly?

Why is that so?
There are many models. Why don't their results all look the same?

Any examples you'd like to share in specific?

 

[bubbabgone]

And you base that on....what, exactly?

what was it like 400 years ago?

Any examples you'd like to share in specific?

Lots of 'em ...

 

[istodolez]

These are RCP projections. RCP's are based on a variety of possible warming based on our emissions, land use changes, general human activities, etc. Since we don't know how much more GHG's we'll be emitting or how we might change land-use they took several different "scenarios".

SO OF COURSE they are going to look different!

The key difference being: how are WE going to alter our GHG emissions in the future?

 

[bubbabgone]

These are RCP projections. RCP's are based on a variety of possible warming based on our emissions, land use changes, general human activities, etc. Since we don't know how much more GHG's we'll be emitting or how we might change land-use they took several different "scenarios".

SO OF COURSE they are going to look different!

The key difference being: how are WE going to alter our GHG emissions in the future?

Projections are based on models which are the subject of the thread.
What do all the models have in common as their assumed main driver of climate i.e. temp change?

 

[istodolez]

what was it like 400 years ago?

You mean in Europe and North America? You are buying the standard "Little Ice Age" gambit from denialists.

First off: The Little Ice Age was not necessarily "global"...localized changes in climate are one thing, GLOBAL changes are quite another. AGW is a global phenomenon.

We have a good idea of what caused the LIA...part of it from the Sporer Minimum decrease in solar activity. Sadly for the denialists solar activity has not really increased in the latter part of the 20th century yet the earth continues to warm. Ooopsy!

Part of the LIA may have been due to increased volcanic activity. And since the 1950's the volcanic activity we've seen should have resulted in a net NEGATIVE forcing, yet the earth continues to warm. Oopsy!

Interestingly enough: the LIA may have been associated in part with a "slowdown" of the Thermohaline Circulation (which also makes sense from a "localized" approach). This is actually a concern for the future as Greenland's Ice Sheet melts and puts a lot of freshwater in right at the top arch of the THC. While the earth warms on average we could see a slowdown/shutdown/reorganization of the THC and a general cooling in Western Europe. (Many denialists on this forum who don't understand oceanography don't think this a real threat, despite the fact that REAL oceanographers do consider it). So today as the Greenland Ice Sheet melts and we DO see changes in the Meridional Overturning (part of the THC) the earth continues to warm.

 

[istodolez]

Projections are based on models which are the subject of the thread.

Not the same. the assumptions in the RCP's are related to the possible HUMAN activities. Those are things within our control. This is not the same as assumptions around forcings etc.

If we continue to burn fossil fuels as we are today that follows ONE of the RCP's. If we aggressively de-carbonize our energy infrastructure, that follows ANOTHER RCP.


"Socio-economic and emission scenarios are used in climate research to provide plausible descriptions of how the future may evolve with respect to a range of variables including socio-economic change, technological change, energy and land use, and emissions of greenhouse gases and air pollutants. They are used as input for climate model runs and as a basis for assessment of possible climate impacts and mitigation options and associated costs. For better comparisons between various studies as well as easier communication of model results, it is preferable to use a common set of scenarios across the scientific community. In the past, several sets of scenarios have performed such a role, including the IS92 scenarios (Leggett et al. 1992) and, more recently, the scenarios from the Special Report on Emission Scenarios (SRES) (Nakicenovic et al. 2000)." (SOURCE) (Emphasis added)


So it is telling us the most likely outcome based on A VARIETY OF HUMAN ACTIVITIES plugged into the models SO BY DEFINITION THEY SHOULD LOOK DIFFERENT.

 

[bubbabgone]

You mean in Europe and North America? You are buying the standard "Little Ice Age" gambit from denialists.

First off: The Little Ice Age was not necessarily "global"...localized changes in climate are one thing, GLOBAL changes are quite another. AGW is a global phenomenon.

We have a good idea of what caused the LIA...part of it from the Sporer Minimum decrease in solar activity. Sadly for the denialists solar activity has not really increased in the latter part of the 20th century yet the earth continues to warm. Ooopsy!

Part of the LIA may have been due to increased volcanic activity. And since the 1950's the volcanic activity we've seen should have resulted in a net NEGATIVE forcing, yet the earth continues to warm. Oopsy!

Interestingly enough: the LIA may have been associated in part with a "slowdown" of the Thermohaline Circulation (which also makes sense from a "localized" approach). This is actually a concern for the future as Greenland's Ice Sheet melts and puts a lot of freshwater in right at the top arch of the THC. While the earth warms on average we could see a slowdown/shutdown/reorganization of the THC and a general cooling in Western Europe. (Many denialists on this forum who don't understand oceanography don't think this a real threat, despite the fact that REAL oceanographers do consider it). So today as the Greenland Ice Sheet melts and we DO see changes in the Meridional Overturning (part of the THC) the earth continues to warm.

You mean there was no LIA? And no MWP either then? And no global climate temp swings throughout history? And we're not participating in one right now? Just what should be the normal global temp of earth anyway?

 

[bubbabgone]

Not the same. the assumptions in the RCP's are related to the possible HUMAN activities. Those are things within our control. This is not the same as assumptions around forcings etc.

If we continue to burn fossil fuels as we are today that follows ONE of the RCP's. If we aggressively de-carbonize our energy infrastructure, that follows ANOTHER RCP.


"Socio-economic and emission scenarios are used in climate research to provide plausible descriptions of how the future may evolve with respect to a range of variables including socio-economic change, technological change, energy and land use, and emissions of greenhouse gases and air pollutants. They are used as input for climate model runs and as a basis for assessment of possible climate impacts and mitigation options and associated costs. For better comparisons between various studies as well as easier communication of model results, it is preferable to use a common set of scenarios across the scientific community. In the past, several sets of scenarios have performed such a role, including the IS92 scenarios (Leggett et al. 1992) and, more recently, the scenarios from the Special Report on Emission Scenarios (SRES) (Nakicenovic et al. 2000)." (SOURCE) (Emphasis added)


So it is telling us the most likely outcome based on A VARIETY OF HUMAN ACTIVITIES plugged into the models SO BY DEFINITION THEY SHOULD LOOK DIFFERENT.

Again ... What do all the models have in common as their assumed main driver of climate i.e. temp change?

 

[istodolez]

Again ... What do all the models have in common as their assumed main driver of climate i.e. temp change?

You asked why they looked different.

The reason they look different is due in no small part by how WE CHOOSE TO ACT.

(You DID read the citations I provided, correct?)

 

[istodolez]

You mean there was no LIA? And no MWP either then?

Are you actually reading what I wrote. The LIA and MWP are both quite real. JUST NOT GLOBAL.

Wow. If you can't understand that you are way out of your depth on this overall conversation.

And no global climate temp swings throughout history? And we're not participating in one right now? Just what should be the normal global temp of earth anyway?

Yes the earth's climate has changed over time. In many cases we know why and in the CURRENT case the ONLY FACTORS that FULLY explain the warming are a combination of natural and HUMAN ACTIVITIES.

The warming we see in the last 60 years cannot be explained by natural forcings alone.

In fact the reason we have this insight is because we have paleoclimatological studies which help us understand what drives the climate.

 

[bubbabgone]

Not the same. the assumptions in the RCP's are related to the possible HUMAN activities. Those are things within our control. This is not the same as assumptions around forcings etc.

If we continue to burn fossil fuels as we are today that follows ONE of the RCP's. If we aggressively de-carbonize our energy infrastructure, that follows ANOTHER RCP.


"Socio-economic and emission scenarios are used in climate research to provide plausible descriptions of how the future may evolve with respect to a range of variables including socio-economic change, technological change, energy and land use, and emissions of greenhouse gases and air pollutants. They are used as input for climate model runs and as a basis for assessment of possible climate impacts and mitigation options and associated costs. For better comparisons between various studies as well as easier communication of model results, it is preferable to use a common set of scenarios across the scientific community. In the past, several sets of scenarios have performed such a role, including the IS92 scenarios (Leggett et al. 1992) and, more recently, the scenarios from the Special Report on Emission Scenarios (SRES) (Nakicenovic et al. 2000)." (SOURCE) (Emphasis added)


So it is telling us the most likely outcome based on A VARIETY OF HUMAN ACTIVITIES plugged into the models SO BY DEFINITION THEY SHOULD LOOK DIFFERENT.

It's preposterous to say that the projections from the models are not related to human activity that result in greenhouse gas concentration. Simply a unserious attempt to explain wildly different model outputs.

 

[bubbabgone]

You asked why they looked different.

The reason they look different is due in no small part by how WE CHOOSE TO ACT.

(You DID read the citations I provided, correct?)

I asked the question again because you didn't answer the first time.

 

[bubbabgone]

Are you actually reading what I wrote. The LIA and MWP are both quite real. JUST NOT GLOBAL.

Wow. If you can't understand that you are way out of your depth on this overall conversation.



Yes the earth's climate has changed over time. In many cases we know why and in the CURRENT case the ONLY FACTORS that FULLY explain the warming are a combination of natural and HUMAN ACTIVITIES.

The warming we see in the last 60 years cannot be explained by natural forcings alone.

In fact the reason we have this insight is because we have paleoclimatological studies which help us understand what drives the climate.

There's plenty of studies that show the MWP and LIA were global. You shouldn't force yourself to defend Mann by denying what everyone else has accepted.
Human activity supplements the effect of natural causes. Assuming the other way around is the height of human arrogance ... or more likely human politics.

 

[Drawdown]

"Attribution science" has become fashionable among alarmists. Unfortunately it does not seem to have sound basis. A new paper in Nature, highlighted in Science, suggests the whole concept may need to be rethought.

Missed wind patterns are throwing off climate ... - Science

Climate scientists can confidently tie global warming to impacts such as sea-level rise and extreme heat. But ask how rising temperatures will affect rainfall and storms, and the answers get a lot shakier. For a long time, researchers chalked the problem up to natural variability in wind patterns—the inherently unpredictable fluctuations of a chaotic atmosphere.
Now, however, a new analysis has found that the problem is not with the climate, it’s with the massive computer models designed to forecast its behavior. “The climate is much more predictable than we previously thought,” says Doug Smith, a climate scientist at the United Kingdom’s Met Office who led the 39-person effort published this week in Nature. But models don’t capture that predictability, which means they are unlikely to correctly predict the long-term changes that are most influenced by large-scale wind patterns: rainfall, drought, flooding, and extreme storms. “Obviously we need to solve it,” Smith says.
The study, which includes authors from several leading modeling centers, casts doubt on many forecasts of regional climate change, which are crucial for policymaking. It also means efforts to attribute specific weather events to global warming, now much in vogue, are rife with errors. “The whole thing is concerning,” says Isla Simpson, an atmospheric dynamicist and modeler at the National Center for Atmospheric Research, who was not involved in the study. “It could mean we’re not getting future climate projections right.”. . .

North Atlantic climate far more predictable than ... - Nature

[url]www.nature.com › articles
[/URL]
by DM Smith - ‎2020
Jul 29, 2020 - This approach greatly improves decadal predictions of winter climate for Europe and eastern North America. Predictions of Atlantic multidecadal ...

Lots of things need to be rethought about climate, and the models in particular, but that does not mean climate change is not occurring. Climate, however, is not our primary problem. Ecological degradation is and the democrats and ecomodernists want to accelerate in the damage in the name of "solving climate change".