Recent Comprehensive Studies

[bdgwx]

There have been a few comprehensive style studies that have been published recently which try to provide the best estimates of critical metrics related to climate change based on the large body of evidence available at the time of publication. I am but an amateur, but it is my belief that these publications are impactful and that they are of the type that may appear prominently in the forthcoming IPCC AR6 report. If anyone has noteworthy or impactful peer-reviewed publications then by all means please post them to this thread. If possible provide a link to an open access (non pay-walled) version of the manuscript. 

Temperature Reconstruction

Kaufman 2020: Holocene global mean surface temperature, a multi-method reconstruction approach

Kaufman 2020: A global database of Holocene paleotemperature records

Summary: The rate of warming during the contemporary era is likely unprecedented during the Holocene. The global mean temperature is very likely to be much higher than at any point in the last 2000 years and possibly even exceeding the Holocene Climate Optimum 6000+ years ago.

Climate Sensitivity

Sherwood 2020: An Assessment of Earth's Climate Sensitivity Using Multiple Lines of Evidence

Summary: For 2xCO2 they report 2.6 - 3.9C and 2.3 - 4.7C for 66% and 95% certainty respectively with a value of 3.1C being at the peak of the probability distribution curve. It is noted that the upper bound should be considered more cautiously. It is far easier to constrain the lower bound than the upper bound. Values <= 1.5C can now be confidently ruled out. Using the IPCC's standard 66% confidence window this study suggests a refinement of the "official" climate sensitivity to 2.6 - 3.9C as opposed to the current range of 1.5 - 4.5C. 

Earth Energy Imbalance

Schuckmann 2020: Heat stored in the Earth system: where does the energy go?

Summary: The EEI is +0.87 +- 0.12 W/m^2 and is increasing. 1% goes into the atmosphere. 4% goes into the cryosphere. 6% goes into the land. 89% goes into the oceans. To pull the EEI back to 0 would require a change in CO2 concentration from 410 ppm to 353 ppm. For those that don't know EEI is the amount of forcing still needing to be equilibriated via an increase in temperature. It should not be confused with effective radiative forcing (ERF) which is the cumulative forcing after fast feedbacks (like water vapor, etc.) have played out. EEI goes to zero after the climate system fully equilibrates to the ERF. This publication says the following of EEI.."This simple number, EEI, is the most fundamental metric that the scientific community and public must be aware of as the measure of how well the world is doing in the task of bringing climate change under control."

[blizzard1024]

9 hours ago, bdgwx said:

Kaufman 2020: Holocene global mean surface temperature, a multi-method reconstruction approach

I read this and it looks interesting. But, the adding of the 20th century data statistically is not convincing.  Low resolution proxy data vs better (although not perfect) data from the 20th century. This is the crux of this paper and it is weakest link. But thanks for the paper. 

[Bhs1975]

There have been a few comprehensive style studies that have been published recently which try to provide the best estimates of critical metrics related to climate change based on the large body of evidence available at the time of publication. I am but an amateur, but it is my belief that these publications are impactful and that they are of the type that may appear prominently in the forthcoming IPCC AR6 report. If anyone has noteworthy or impactful peer-reviewed publications then by all means please post them to this thread. If possible provide a link to an open access (non pay-walled) version of the manuscript. 

Temperature Reconstruction

Kaufman 2020: Holocene global mean surface temperature, a multi-method reconstruction approach

Kaufman 2020: A global database of Holocene paleotemperature records

Summary: The rate of warming during the contemporary era is likely unprecedented during the Holocene. The global mean temperature is very likely to be much higher than at any point in the last 2000 years and possibly even exceeding the Holocene Climate Optimum 6000+ years ago.

Climate Sensitivity

Sherwood 2020: An Assessment of Earth's Climate Sensitivity Using Multiple Lines of Evidence

Summary: For 2xCO2 they report 2.6 - 3.9C and 2.3 - 4.7C for 66% and 95% certainty respectively with a value of 3.1C being at the peak of the probability distribution curve. It is noted that the upper bound should be considered more cautiously. It is far easier to constrain the lower bound than the upper bound. Values Earth Energy Imbalance

Schuckmann 2020: Heat stored in the Earth system: where does the energy go?

Summary: The EEI is +0.87 +- 0.12 W/m^2 and is increasing. 1% goes into the atmosphere. 4% goes into the cryosphere. 6% goes into the land. 89% goes into the oceans. To pull the EEI back to 0 would require a change in CO2 concentration from 410 ppm to 353 ppm. For those that don't know EEI is the amount of forcing still needing to be equilibriated via an increase in temperature. It should not be confused with effective radiative forcing (ERF) which is the cumulative forcing after fast feedbacks (like water vapor, etc.) have played out. EEI goes to zero after the climate system fully equilibrates to the ERF. This publication says the following of EEI.."This simple number, EEI, is the most fundamental metric that the scientific community and public must be aware of as the measure of how well the world is doing in the task of bringing climate change under control."

This further confirms that 350ppm CO2 is the max safe limit.

[donsutherland1]

1 hour ago, blizzard1024 said:

I read this and it looks interesting. But, the adding of the 20th century data statistically is not convincing.  Low resolution proxy data vs better (although not perfect) data from the 20th century. This is the crux of this paper and it is weakest link. But thanks for the paper. 

If the use of proxy data is the “weakest link,” how would you go about trying to compare today’s temperatures with those during the rest of the Holocene?

[blizzard1024]

8 hours ago, donsutherland1 said:

If the use of proxy data is the “weakest link,” how would you go about trying to compare today’s temperatures with those during the rest of the Holocene?

Use the proxy data into the 21st century. You are comparing apples to oranges here. Why not look at the proxy data to the 21st century?   I think there is a divergence issue around 1960 though when proxy data shows a fall in temperature. That was Michael Mann's hide the decline "trick".  He wasn't hiding a real temperature decline as is often portrayed on other blogs. For some reason tree ring data diverge from temperatures around this time. I have seen this stitching of 20th century data to proxy data for over 20 years. I will research this by reading those papers again. I didn't get it before back 15-20 years ago. It looks fishy to me. But I will approach it with an open mind. Thanks. 

 

 

 

[donsutherland1]

@blizzard1024Tree rings at some locations had seemingly become a less reliable indicator of temperature. More recent research suggests that light (dimming) may have been responsible.

https://phys.org/news/2014-05-arctic-tree-ring-divergence-problem.html

 

[rclab]

1 hour ago, donsutherland1 said:

@blizzard1024Tree rings at some locations had seemingly become a less reliable indicator of temperature. More recent research suggests that light (dimming) may have been responsible.

https://phys.org/news/2014-05-arctic-tree-ring-divergence-problem.html

 

Thank you, Don. Excellent article for a common persons ease of understanding. Considering the, as described, human initiated fix, the article could have easily been subtitled, Damned if you do/Damned if you don’t. The natural balancing, to right the global problem, when it comes, will be out of our hands. As always ....

[blizzard1024]

12 hours ago, donsutherland1 said:

@blizzard1024Tree rings at some locations had seemingly become a less reliable indicator of temperature. More recent research suggests that light (dimming) may have been responsible.

https://phys.org/news/2014-05-arctic-tree-ring-divergence-problem.html

 

interesting. thanks. 

[blizzard1024]

On 9/25/2020 at 11:09 AM, bdgwx said:

Temperature Reconstruction

Kaufman 2020: Holocene global mean surface temperature, a multi-method reconstruction approach

Kaufman 2020: A global database of Holocene paleotemperature records

Summary: The rate of warming during the contemporary era is likely unprecedented during the Holocene. The global mean temperature is very likely to be much higher than at any point in the last 2000 years and possibly even exceeding the Holocene Climate Optimum 6000+ years ago.

Thank you for the papers. I read both of them. The first paper does show a Holocene warm period in the higher latitudes of the NH of between 2 and 4C which I have read about before. It is also consistent with pollen samples in the northeast U.S which showed a more Oak, hickory, sweet gum like forest north into NY state the lower elevations of New England. The climate in these northern areas was more like Virginia or even north Carolina somewhere 6-8 thousand year ago. Tree line was farther north at least in Canada too. Spruce and fir retreated northward and up the slopes of the Appalachians and New England all based on pollen samples.  But I find it very confusing that the global  temperature anomaly only reached only +.7C globally during this time with such dramatic local climate changes.  Plus neither paper described how they stitched the ERA20C measured data which is much better and higher resolution to this proxy data(it is not perfect due to the various adjustments as discussed before). Apples are being compared to oranges here. These Hockey Stick looking graphs go back to MBH 98. Also they even admit that their proxy data showed  ":This cooling trend occurred while the atmospheric concentrations of greenhouse gases were increasing. Liu et al. (ref. ³) coined the term “Holocene temperature conundrum” to highlight the contradiction between the cooling indicated by proxy evidence versus the warming simulated by global climate models, a trend reinforced in the most recent generation of climate models⁴."  So we had falling temperatures for millenia with rising CO2 levels. This was counter to the global climate models. Hmmm. So was this a time when CO2 didn't drive the climate? Was  it "inactive" like it was the previous 800,000 years in the ice core data as it passively followed the global temperatures and lagging them by 1000s  of years? In fact, the rise in CO2 in the mid to late Holocene probably was related to the rapid warming that occurred prior to 10,000 year ago. The lag effect was present suggesting CO2 had little to do with the climate system.  But in 1900 or so, all that changed and it suddenly became the dominant driver in the global climate system!!  Yeah that makes a lot of sense. / sarc.  And the rapid rise in temperature in the 1900s to early 2000s is superimposed on a very coarse and uncertain PROXY dataset. This is peer reviewed and  I am not impressed or convinced. And it is NOT PROOF just because it is peer reviewed!   People don't understand that. In fact, the lagging CO2 response seen during the mid to late Holocene cooling period just further proves that CO2 is a small component of the climate system.  That is "conveniently" ignored as one of their conclusions is "The GMST of the past decade (2011–2019) averaged 1 °C higher than 1850–1900¹¹. For 80% of the ensemble members, no 200-year interval during the past 12,000 years exceeded the warmth of the most recent decade." If this wasn't a conclusion this paper would have NEVER made it through the peer review gatekeepers who are climate alarmists. 

 

 

[Bhs1975]

This paper shows that SSTs where cooler in the tropics during that time and changes in ocean circulation not CO2 was in the drivers seat like it is now.

 

 

https://web.archive.org/web/20100119135516/http://www.agu.org/pubs/crossref/2002/2001PA000724.shtml

[donsutherland1]

4 hours ago, blizzard1024 said:

Thank you for the papers. I read both of them. The first paper does show a Holocene warm period in the higher latitudes of the NH of between 2 and 4C which I have read about before. It is also consistent with pollen samples in the northeast U.S which showed a more Oak, hickory, sweet gum like forest north into NY state the lower elevations of New England. The climate in these northern areas was more like Virginia or even north Carolina somewhere 6-8 thousand year ago. Tree line was farther north at least in Canada too. Spruce and fir retreated northward and up the slopes of the Appalachians and New England all based on pollen samples.  But I find it very confusing that the global  temperature anomaly only reached only +.7C globally during this time with such dramatic local climate changes.  Plus neither paper described how they stitched the ERA20C measured data which is much better and higher resolution to this proxy data(it is not perfect due to the various adjustments as discussed before). Apples are being compared to oranges here. These Hockey Stick looking graphs go back to MBH 98. Also they even admit that their proxy data showed  ":This cooling trend occurred while the atmospheric concentrations of greenhouse gases were increasing. Liu et al. (ref. ³) coined the term “Holocene temperature conundrum” to highlight the contradiction between the cooling indicated by proxy evidence versus the warming simulated by global climate models, a trend reinforced in the most recent generation of climate models⁴."  So we had falling temperatures for millenia with rising CO2 levels. This was counter to the global climate models. Hmmm. So was this a time when CO2 didn't drive the climate? Was  it "inactive" like it was the previous 800,000 years in the ice core data as it passively followed the global temperatures and lagging them by 1000s  of years? In fact, the rise in CO2 in the mid to late Holocene probably was related to the rapid warming that occurred prior to 10,000 year ago. The lag effect was present suggesting CO2 had little to do with the climate system.  But in 1900 or so, all that changed and it suddenly became the dominant driver in the global climate system!!  Yeah that makes a lot of sense. / sarc.  And the rapid rise in temperature in the 1900s to early 2000s is superimposed on a very coarse and uncertain PROXY dataset. This is peer reviewed and  I am not impressed or convinced. And it is NOT PROOF just because it is peer reviewed!   People don't understand that. In fact, the lagging CO2 response seen during the mid to late Holocene cooling period just further proves that CO2 is a small component of the climate system.  That is "conveniently" ignored as one of their conclusions is "The GMST of the past decade (2011–2019) averaged 1 °C higher than 1850–1900¹¹. For 80% of the ensemble members, no 200-year interval during the past 12,000 years exceeded the warmth of the most recent decade." If this wasn't a conclusion this paper would have NEVER made it through the peer review gatekeepers who are climate alarmists. 

 

 

The “lag” issue has been explained numerous times:

Step 1: Begin the release of CO2 — initial warming kicked off by natural processes was the mechanism

Step 2: Amplify the initial rise in temperatures — increasing atmospheric CO2 amplified the initial rise in temperatures.

Since the Industrial Revolution and especially during the 20th century and beyond, humanity has substituted itself for the natural mechanism in releasing CO2. Atmospheric CO2 is increasing and ongoing warming is the result. This is the expected climate response.

The only way one can claim that humanity has no role in driving current developments would if CO2’s physical properties were somehow altered only when human activities released it. Under such a claim, the rising concentration would be minor to irrelevant. That’s not the case. 

[bdgwx]

Consider a forced induction combustion engine. Air induction can both lead and lag the power level. When the turbocharger is internally forced via the exhaust the induction lags the power increase. When the turbocharger is externally forced via electric boost technologies the induction leads the power increase. In both cases the turbocharger is a significant contributing factor to the final power level of the engine. Earth's carbon cycle behaves in this manner as well. I think those that understand forced induction combustion engines will find the lead/lag behavior of CO2 in the climate system intuitive. BTW...BorgWarner does produce dual modulated turbochargers with both internal forcing (exhaust) and external forcing (electric).

 

[blizzard1024]

4 hours ago, donsutherland1 said:

The “lag” issue has been explained numerous times:

Step 1: Begin the release of CO2 — initial warming kicked off by natural processes was the mechanism

Step 2: Amplify the initial rise in temperatures — increasing atmospheric CO2 amplified the initial rise in temperatures.

And this is not how atmospheric physical processes behave. Something else kicks off warming. Obviously this is more dominant than CO2.  If CO2 was such a dominant factor, then how could the Earth cool while CO2 rises? So some other processes kicks off the warming of the planet, CO2 is passively following the temperature trends with a lag.  So warming occurs while CO2 is falling, then magically the CO2 molecules decide that they have to warm the planet and said feedback begins.  The Earth's atmosphere doesn't behave like a combustion engine either.  Basically when they release the data from the Vostok ice cores in the late 1990s and 2000s and this lag effect was found, objective scientists would have realized that CO2 is not the driver of the climate. It never was before, why now? It is a minor greenhouse gas. I have said this a million times. So you have a minor greenhouse gas CO2 that needs a strong water vapor feedback to really affect the climate system and somehow dominate it?  

What you are saying is that some other mechanism causes warming, then CO2 after several hundred to thousand years or so starts rising, then this kicks off the water vapor feedback? 
It makes more sense if you have warming or cooling from some other process that kicks off the water vapor feedback. Why is it just CO2? That is why the water vapor feedback is probably small because initial warming would have led to increased water vapor which then would warm the Earth. You don't even need CO2 in this argument. The water vapor feedback probably is small and natural mechanisms change the amount of clouds, water vapor, precipitation, and convection and this drives the climate. CO2 is on the sidelines with a small contribution. This is common sense.  The objectivity of mainstream climate scientists is gone because of money, fame, power and egos. 

 

 

[blizzard1024]

6 hours ago, Bhs1975 said:

This paper shows that SSTs where cooler in the tropics during that time and changes in ocean circulation not CO2 was in the drivers seat like it is now.

 

 

https://web.archive.org/web/20100119135516/http://www.agu.org/pubs/crossref/2002/2001PA000724.shtml

How do you know it is not ocean currents now? Oh yeah I forgot...climate models.  /sarc

[donsutherland1]

1 hour ago, blizzard1024 said:

And this is not how atmospheric physical processes behave. Something else kicks off warming. Obviously this is more dominant than CO2.  If CO2 was such a dominant factor, then how could the Earth cool while CO2 rises? So some other processes kicks off the warming of the planet, CO2 is passively following the temperature trends with a lag.  So warming occurs while CO2 is falling, then magically the CO2 molecules decide that they have to warm the planet and said feedback begins.  The Earth's atmosphere doesn't behave like a combustion engine either.  Basically when they release the data from the Vostok ice cores in the late 1990s and 2000s and this lag effect was found, objective scientists would have realized that CO2 is not the driver of the climate. It never was before, why now? It is a minor greenhouse gas. I have said this a million times. So you have a minor greenhouse gas CO2 that needs a strong water vapor feedback to really affect the climate system and somehow dominate it?  

What you are saying is that some other mechanism causes warming, then CO2 after several hundred to thousand years or so starts rising, then this kicks off the water vapor feedback? 
It makes more sense if you have warming or cooling from some other process that kicks off the water vapor feedback. Why is it just CO2? That is why the water vapor feedback is probably small because initial warming would have led to increased water vapor which then would warm the Earth. You don't even need CO2 in this argument. The water vapor feedback probably is small and natural mechanisms change the amount of clouds, water vapor, precipitation, and convection and this drives the climate. CO2 is on the sidelines with a small contribution. This is common sense.  The objectivity of mainstream climate scientists is gone because of money, fame, power and egos. 

 

 

The literature cites increasing Arctic solar insolation, often from fluctuations in the earth’s orbit, as one of the natural mechanisms that kicks off the initial warming. As temperatures rise, stored carbon is unlocked and the atmospheric concentration of carbon dioxide increases. In turn, the increased atmospheric concentration of carbon dioxide promotes additional warming. Given the physical properties of carbon dioxide, it should make no difference how the stored carbon dioxide is released. The impact should be the same if the physical properties of CO2 are understood correctly. The observed ongoing warming is consistent with what one would expect when atmospheric carbon dioxide increases.

I said nothing about feedbacks, as one is dealing with the much larger issue of forcings. Additional feedbacks, some of which are non-linear and some of which are still poorly understood, influence how much warming actually takes place. Nevertheless, the general scientific conclusion concerning the role increasing anthropogenic greenhouse gas forcing has played in driving ongoing warming is a very high confidence matter in science. The confidence level will likely be 99%-100% when the IPCC publishes its next assessment (an increase from the current 95% figure).

I strongly disagree that the objectivity of climate scientists has been corrupted by “money, fame, power and egos.” If anything, it is the movement that rejects AGW that faces that problem. It offers no credible empirically-supported alternative to AGW. It increasingly evades the research and publication route by which scientific knowledge is built/expanded/revised, likely because it is trapped by the limits imposed by science itself and it cannot bear subjecting its lack of alternative to rigorous scrutiny. Absent a concrete scientific basis for its positions, it increasingly displays motivated reasoning consistent with its sources of funding (often fossil fuel-related interests).

[Bhs1975]

The literature cites increasing Arctic solar insolation, often from fluctuations in the earth’s orbit, as one of the natural mechanisms that kicks off the initial warming. As temperatures rise, stored carbon is unlocked and the atmospheric concentration of carbon dioxide increases. In turn, the increased atmospheric concentration of carbon dioxide promotes additional warming. Given the physical properties of carbon dioxide, it should make no difference how the stored carbon dioxide is released. The impact should be the same if the physical properties of CO2 are understood correctly. The observed ongoing warming is consistent with what one would expect when atmospheric carbon dioxide increases.

I said nothing about feedbacks, as one is dealing with the much larger issue of forcings. Additional feedbacks, some of which are non-linear and some of which are still poorly understood, influence how much warming actually takes place. Nevertheless, the general scientific conclusion concerning the role increasing anthropogenic greenhouse gas forcing has played in driving ongoing warm is a very high confidence matter in science. The confidence level will likely be 99%-100% when the IPCC publishes its next assessment (an increase from the current 95% figure).

I strongly disagree that the objectivity of climate scientists has been corrupted by “money, fame, power and egos.” If anything, it is the movement that rejects AGW that faces that problem. It offers no credible empirically-supported alternative to AGW. It increasingly evades the research and publication route by which scientific knowledge is built/expanded/revised, likely because it is trapped by the limits imposed by science itself and it cannot bear subjecting its lack of alternative to rigorous scrutiny. Absent a concrete scientific basis for its positions, it increasingly displays motivated reasoning consistent with its sources of funding (often fossil fuel-related interests).

How many times you gonna rehash this? The SMF ain’t listening.

[blizzard1024]

4 hours ago, donsutherland1 said:

The confidence level will likely be 99%-100% when the IPCC publishes its next assessment (an increase from the current 95% figure).

No person making projections/predictions in atmospheric science more than a 5 days in advance is this confident. For the IPCC to be this confident, shows the political nature of this organization. 

[blizzard1024]

3 hours ago, Bhs1975 said:

How many times you gonna rehash this? The SMF ain’t listening.

This is central to the reason why CO2 doesn't drive the climate. As many times as it takes.  The hand waving explanations are not scientific. An objective climate scientist would seriously reconsider the role of CO2 in our climate since its levels follow temperature trends.  CO2 is not the world's thermostat. It leads to a little warming. The whole house of cards upon which  billions and billions of dollars rests on a shaky foundation. That is why people like you, mainstream climate scientists the media and left wingers are so defensive. They know it. They also have the gall to question seasoned sincere atmospheric scientists thinking they know more or ....that these scientists are being "paid off" by big oil. This is not true. It's an excuse.  The mainstream climate scientists need there to be a climate crisis or else their funding will eventually dry up. You know this. Everyone does. 

[blizzard1024]

4 hours ago, donsutherland1 said:

In turn, the increased atmospheric concentration of carbon dioxide promotes additional warming. Given the physical properties of carbon dioxide, it should make no difference how the stored carbon dioxide is released. The impact should be the same if the physical properties of CO2 are understood correctly.

But wait, why doesn't the initial warming lead to increases in water vapor which then amplifies the initial warming? H20 is the primary GHG.  This is the reason by the climate alarmists that doubling CO2 leads to more than 2C of warming. So why does the water vapor feedback do nothing or very little? Why isn't this mentioned. CO2 forcing is relatively weak. So you are relying on two feedbacks really. The warming is kicked off by the amount of solar radiation at 65N due to Milankovitch cycles and then CO2 increases which leads to H20 increases which then warms the Earth and dominates?  But somehow CO2 lags the temperature through the whole Ice core records.  This should have ended this insanity 20 years ago. 

"The observed ongoing warming is consistent with what one would expect when atmospheric carbon dioxide increases."  Correlation does not imply causation. There are dozens of other processes that could cause the ongoing warming which really isn't that extreme. 

[donsutherland1]

17 minutes ago, blizzard1024 said:

No person making projections/predictions in atmospheric science more than a 5 days in advance is this confident. For the IPCC to be this confident, shows the political nature of this organization. 

The problem arises when one tries to view climate through the lens of weather. Doing so only promotes misunderstanding. Weather and climate are not the same thing. 

https://www.ncei.noaa.gov/news/weather-vs-climate

Therefore, weather models and climate models are not the same thing. Some of the constraints that limit day-to-day weather forecasts beyond a few days are irrelevant at the much longer timeframes used in climate.

For example, one can’t forecast what the high temperature in Phoenix would be two weeks away with much precision. In contrast, one can forecast decadal averages for summer temperatures with far better accuracy. The RCP 4.5 scenario run in 2005 suggested that Phoenix would have an average summer (June 1-August 31) high temperature of 106.3 degrees for the 2011-20 period. In fact, the average summer high temperature was 106.4 degrees. Errors are larger for some locations, but overall the errors are typically less than 2 degrees and often less than 1 degree. 

On a hemispheric or global scale, the errors are even smaller than the regional ones. Overall, there is little question that the climate models provide useful information. They are also quite accurate.

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL085378

This is where the models add a lot of insight and it is within that global context that the IPCC can have very high confidence that anthropogenic greenhouse gases are the predominant driver of the world’s ongoing observed warming.

[donsutherland1]

19 minutes ago, blizzard1024 said:

But wait, why doesn't the initial warming lead to increases in water vapor which then amplifies the initial warming? H20 is the primary GHG.  This is the reason by the climate alarmists that doubling CO2 leads to more than 2C of warming. So why does the water vapor feedback do nothing or very little? Why isn't this mentioned. CO2 forcing is relatively weak. So you are relying on two feedbacks really. The warming is kicked off by the amount of solar radiation at 65N due to Milankovitch cycles and then CO2 increases which leads to H20 increases which then warms the Earth and dominates?  But somehow CO2 lags the temperature through the whole Ice core records.  This should have ended this insanity 20 years ago. 

"The observed ongoing warming is consistent with what one would expect when atmospheric carbon dioxide increases."  Correlation does not imply causation. There are dozens of other processes that could cause the ongoing warming which really isn't that extreme. 

Scientists recognize that, according to the Clausius-Clapeyron equation, the atmosphere holds approximately 7% more water vapor for ever 1 degree C warming. So, there’s little question that the initial warming also led to some increase in the atmospheric water vapor, as one feedback. The increase in water vapor amplified the warming.

https://yaleclimateconnections.org/2008/02/common-climate-misconceptions-the-water-vapor-feedback-2/

The major focus of the studies has been greenhouse gas forcing given its importance to the overall climate system. If the link between CO2 and global temperatures is “insanity,” even setting aside physics related to CO2’s properties, one should find a large number of research papers making exactly that case.  

[blizzard1024]

9 minutes ago, donsutherland1 said:

If the link between CO2 and global temperatures is “insanity,” even setting aside physics related to CO2’s properties, one should find a large number of research papers making exactly that case.  

You have too much faith is peer reviewed climate literature. There is a lot of bias. The gatekeepers are alarmists.  They have brought the field of climatology to a standstill by focusing on a small portion of the climate system, CO2. This has put back real research in climate at least a generation. 

[donsutherland1]

51 minutes ago, blizzard1024 said:

You have too much faith is peer reviewed climate literature. There is a lot of bias. The gatekeepers are alarmists.  They have brought the field of climatology to a standstill by focusing on a small portion of the climate system, CO2. This has put back real research in climate at least a generation. 

I have a lot of confidence in peer review. Even with its limitations, it is the most effective means for evaluating and validating research. Nothing else compares.

Further, just because climate research has all but rejected unproved alternative climate claims and peer review filters out claims for which there is little credible support does not mean that climate research has been set back. Climate research has made remarkable strides in explaining things that were poorly understood even a few decades ago. Much more remains to be learned, but the overall foundations of climate science are strong.

[skierinvermont]

On 9/26/2020 at 4:21 AM, blizzard1024 said:

Use the proxy data into the 21st century. You are comparing apples to oranges here. Why not look at the proxy data to the 21st century?   I think there is a divergence issue around 1960 though when proxy data shows a fall in temperature. That was Michael Mann's hide the decline "trick".  He wasn't hiding a real temperature decline as is often portrayed on other blogs. For some reason tree ring data diverge from temperatures around this time. I have seen this stitching of 20th century data to proxy data for over 20 years. I will research this by reading those papers again. I didn't get it before back 15-20 years ago. It looks fishy to me. But I will approach it with an open mind. Thanks. 

 

 

 

As long as appropriate error bars are used and the author is open and honest about what is happening, there is no problem with stitching.

You can have one graph of proxies, and another totally separate graph of instrumental temp, if you prefer. The conclusion is the same. Warming of the speed and magnitude recorded by instruments over the last 150 years would have been extremely unlikely given the proxy data.

[blizzard1024]

5 hours ago, skierinvermont said:

As long as appropriate error bars are used and the author is open and honest about what is happening, there is no problem with stitching.

You can have one graph of proxies, and another totally separate graph of instrumental temp, if you prefer. The conclusion is the same. Warming of the speed and magnitude recorded by instruments over the last 150 years would have been extremely unlikely given the proxy data.

If there was a warming or cooling spike of similar magnitude as today's say in the 1300s would the proxy data be able to detect it given how coarse the dataset is and that it is in fact proxy data?  The proxy data shown in this first paper of this topic shows little change in global average temperature during the Roman Warm Period, Dark age cold period, Medieval Warm period, It does show LIA cooling to some extent. The greenland ice core data clearly shows these temperature fluctuations back for much of the holocene with an overall trend similar to the first paper's results. However as you can see there are a lot of rapid fluctuations. How can we be sure this wasn't global in nature?

[donsutherland1]

2 hours ago, blizzard1024 said:

If there was a warming or cooling spike of similar magnitude as today's say in the 1300s would the proxy data be able to detect it given how coarse the dataset is and that it is in fact proxy data?  The proxy data shown in this first paper of this topic shows little change in global average temperature during the Roman Warm Period, Dark age cold period, Medieval Warm period, It does show LIA cooling to some extent. The greenland ice core data clearly shows these temperature fluctuations back for much of the holocene with an overall trend similar to the first paper's results. However as you can see there are a lot of rapid fluctuations. How can we be sure this wasn't global in nature?

The issue of the MWP and LIA has already been addressed by several people here at several times. Different proxies examined from different parts of the world show that the MWP and LIA were regional, not global, events.

Three papers and the abstract of another (the full copy of which can be requested from the authors):

https://www.nature.com/articles/ngeo1797.epdf?sharing_token=Pm1NFtFxqxcwIUqtvBVOsdRgN0jAjWel9jnR3ZoTv0OXdKps0x-mydYxlxY1CTS2FraCgd_SIOyFr3Frnr2wB7rEiUt5oncmTKp32KflJCHeITcA-EqP5p3xfWpkUotuN0E3ir4Us_bcTtsZ27MrFmdPv9A4iznKkWIxs3GlY8t2zgJ1RqKr1SMAGJNtp3FZCGkf9OhfrosIZ6HA_48P3A%3D%3D&tracking_referrer=www.realclimate.org

http://www.meteo.psu.edu/holocene/public_html/shared/articles/MannetalScience09.pdf

https://advances.sciencemag.org/content/1/11/e1500806

https://www.researchgate.net/publication/334662695_No_evidence_for_globally_coherent_warm_and_cold_periods_over_the_preindustrial_Common_Era

Finally, relying on a single proxy in one particular location to make a continental or global judgment is no different from relying on the temperature record of one location and making a similar judgment. If one wouldn’t make judgments about North America, the Northern Hemisphere or global temperatures based on the temperature record of let’s say only Seattle, why should one make similar judgments strictly from a single ice core measurement?

[Bhs1975]

The issue of the MWP and LIA has already been addressed by several people here at several times. Different proxies examined from different parts of the world show that the MWP and LIA were regional, not global, events.

Three papers and the abstract of another (the full copy of which can be requested from the authors):

https://www.nature.com/articles/ngeo1797.epdf?sharing_token=Pm1NFtFxqxcwIUqtvBVOsdRgN0jAjWel9jnR3ZoTv0OXdKps0x-mydYxlxY1CTS2FraCgd_SIOyFr3Frnr2wB7rEiUt5oncmTKp32KflJCHeITcA-EqP5p3xfWpkUotuN0E3ir4Us_bcTtsZ27MrFmdPv9A4iznKkWIxs3GlY8t2zgJ1RqKr1SMAGJNtp3FZCGkf9OhfrosIZ6HA_48P3A%3D%3D&tracking_referrer=www.realclimate.org

http://www.meteo.psu.edu/holocene/public_html/shared/articles/MannetalScience09.pdf

https://advances.sciencemag.org/content/1/11/e1500806

https://www.researchgate.net/publication/334662695_No_evidence_for_globally_coherent_warm_and_cold_periods_over_the_preindustrial_Common_Era

Finally, relying on a single proxy in one particular location to make a continental or global judgment is no different from relying on the temperature record of one location and making a similar judgment. If one wouldn’t make judgments about North America, the Northern Hemisphere or global temperatures based on the temperature record of let’s say only Seattle, why should one make similar judgments strictly from a single ice core measurement?

Cause he’s a dumb ass.

[rclab]

6 hours ago, blizzard1024 said:

If there was a warming or cooling spike of similar magnitude as today's say in the 1300s would the proxy data be able to detect it given how coarse the dataset is and that it is in fact proxy data?  The proxy data shown in this first paper of this topic shows little change in global average temperature during the Roman Warm Period, Dark age cold period, Medieval Warm period, It does show LIA cooling to some extent. The greenland ice core data clearly shows these temperature fluctuations back for much of the holocene with an overall trend similar to the first paper's results. However as you can see there are a lot of rapid fluctuations. How can we be sure this wasn't global in nature?

Very interesting graph, B. From a non skilled background and just looking at the last 700 years it sure looks like our species could have had some responsibility for reversing what might have been the end of the last interglacial period. As always ....

[donsutherland1]

1 hour ago, rclab said:

Very interesting graph, B. From a non skilled background and just looking at the last 700 years it sure looks like our species could have had some responsibility for reversing what might have been the end of the last interglacial period. As always ....

A quick note:

The posted chart does not include the most recent warming. It ends 95 years before present with 1950 constituting the present (thanks @bdgwx for that info.).

[donsutherland1]

1 hour ago, Bhs1975 said:

Cause he’s a dumb ass.

It's possible that he may simply have little understanding of paleoclimatology and how paleoclimatologists construct hemispheric and global temperature records, why one can have confidence in such records (especially when error bars are provided), etc. Meteorology/atmospheric science is a different field from paleoclimatology. Nevertheless, the basic statistical issue concerning the need to draw representative samples to gain insight into a population applies. In this case, the population is global temperatures during the MWP and LIA and the sample needs to include a sufficient number of proxies from around the world to provide a representative picture of the global temperatures.