2015 Global Temperatures

[skierinvermont]

Haha fair point.  I'd guess 2-2.5C myself, but there's is a lot of time to hash that out with emissions, ect.  I'm pretty sure through the next PDO cycle, say in 2030, we should know quite a bit more about how ocean cycles effect TCR.  Hopefully, most of us are alive then.

 

Or whether PDO 'cycles' even exist vs self-reinforcing 'phases'.

[blizzard1024]

Or whether PDO 'cycles' even exist vs self-reinforcing 'phases'.

 

What??? Whether PDO cycles even exist?? Oceanic temperature variations are the biggest factor in climate change and still swamp any human contribution from a trace gas that accounts for 7 to 25% of the greenhouse effect. There is NO way that CO2 concentrations are a bigger factor than ocean currents. The great pause in global temperatures is attributed to the cool cycle of the PDO. Wait until the AMO goes cold LOL. Then we will see temperatures fall back. Mark my words.

[ORH_wxman]

What??? Whether PDO cycles even exist?? Oceanic temperature variations are the biggest factor in climate change and still swamp any human contribution from a trace gas that accounts for 7 to 25% of the greenhouse effect. There is NO way that CO2 concentrations are a bigger factor than ocean currents. The great pause in global temperatures is attributed to the cool cycle of the PDO. Wait until the AMO goes cold LOL. Then we will see temperatures fall back. Mark my words.

It's questionable whether the PDO is truly cyclical is what he means. This is due to the variability surrounding the length and strength of the positive and negative phases. They aren't consistent. There's a rough 30 year period for each phase but sometimes it's more like 20 and sometimes it's 40. Even longer periods are evident in the paleo record beyond 200 years ago. So who knows exactly when these phases commence/terminate and how strong they are.

Also there is no evidence that ocean currents are more important. They even out over time. They can overwhelm CO2 on short timescales but they are irrelevant when talking on longer timescales. They don't create energy imbalance. They just move it.

[blizzard1024]

It's questionable whether the PDO is truly cyclical is what he means. This is due to the variability surrounding the length and strength of the positive and negative phases. They aren't consistent. There's a rough 30 year period for each phase but sometimes it's more like 20 and sometimes it's 40. Even longer periods are evident in the paleo record beyond 200 years ago. So who knows exactly when these phases commence/terminate and how strong they are.

Also there is no evidence that ocean currents are more important. They even out over time. They can overwhelm CO2 on short timescales but they are irrelevant when talking on longer timescales. They don't create energy imbalance. They just move it.

 

agreed. when I was talking about climate change I was referring to the decadal to century scale changes, not the very long term. The oceans certainly are a big storehouse for heat and dampen any climatic forcing unless major changes occur in oceanic circulations like when there was melting of the massive ice sheets. The climate is quite stable in the Holocene so any external forcing will be dampened.  This is not the case when there was large land ice sheets that at times melted fast.

[nflwxman]

Or whether PDO 'cycles' even exist vs self-reinforcing 'phases'.

I agree. I think many papers are erroneously attributing a 30 year hiatus in the mid 20th century to the PDO. That being said, the PDO can obviously impact 10-15 trends dramatically. IE-2003-2012.

[chubbs]

agreed. when I was talking about climate change I was referring to the decadal to century scale changes, not the very long term. The oceans certainly are a big storehouse for heat and dampen any climatic forcing unless major changes occur in oceanic circulations like when there was melting of the massive ice sheets. The climate is quite stable in the Holocene so any external forcing will be dampened.  This is not the case when there was large land ice sheets that at times melted fast.

 What ocean cycle explains the rise in temperature over the past 150 years - accelerating in the past 50? The overall pattern fits GHG forcing very well.

[blizzard1024]

 What ocean cycle explains the rise in temperature over the past 150 years - accelerating in the past 50? The overall pattern fits GHG forcing very well.

 

How do we really know what the ocean temperatures were in the 1800s or even prior to the satellite era?  Come on. Accelerating in the past 50 years? Really??  .5C in 50 years of the SST??? And that is piecing together datasets from ship reports which were very sparse to satellite data, sparse buoys to our recent ARGO floats ~ 3000 of them!! We are comparing apples to oranges here. There is no way to tell that there is even any warming let alone acceleration! Plus the SSTs from 2003 on have stablized suggesting that there is no upward trend on the ARGO floats which is our best measuring method yet. The pattern does NOT fit any GHG forcing....not at all.

 

[ORH_wxman]

How do we really know what the ocean temperatures were in the 1800s or even prior to the satellite era?  Come on. Accelerating in the past 50 years? Really??  .5C in 50 years of the SST??? And that is piecing together datasets from ship reports which were very sparse to satellite data, sparse buoys to our recent ARGO floats ~ 3000 of them!! We are comparing apples to oranges here. There is no way to tell that there is even any warming let alone acceleration! Plus the SSTs from 2003 on have stablized suggesting that there is no upward trend on the ARGO floats which is our best measuring method yet. The pattern does NOT fit any GHG forcing....not at all.

 

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You can't possibly believe that if you have read the literature on SST data. You don't need that many measurements to determine if we've risen significantly since the 19th century. You can question some of the regional trends with the lack of coverage and perhaps the error bars are larger in the late 19th century, but even accounting for error bars, there is zero chance the SSTs are not warmer now.

 

There are so many proxies as well to determine the rise in SSTs...SLR is one, melting glacier termina is another. These aren't direct SST measurements but they are strong proxies for a warming world and a warming world would have warmer SSTs given that 70% of the earth is covered by the oceans.

 

It's really not that hard to search google scholar for the info.

[blizzard1024]

You can't possibly believe that if you have read the literature on SST data. You don't need that many measurements to determine if we've risen significantly since the 19th century. You can question some of the regional trends with the lack of coverage and perhaps the error bars are larger in the late 19th century, but even accounting for error bars, there is zero chance the SSTs are not warmer now.

 

There are so many proxies as well to determine the rise in SSTs...SLR is one, melting glacier termina is another. These aren't direct SST measurements but they are strong proxies for a warming world and a warming world would have warmer SSTs given that 70% of the earth is covered by the oceans.

 

It's really not that hard to search google scholar for the info.

 

No one said the Earth wasn't warming some, but this easily could be a recovery from the Little Ice Age. Many glaciers have been retreating since the 1800s long before man had any influence on the climate. SLR has been slowly rising long before man had any influence on climate. The term that the SSTs are accelerating is very questionable and alarmist.

[blizzard1024]

Furthermore we simply do not know how much warming has taken place since the 1800s. It could be very small and insignificant our measurements now are different than they were back then. The climate system since it is covered by massive oceans takes a long time to warm or cool when looking at long term century long trends. There are short term fluctuations related to variations in ocean currents, the sun, changes in cloud cover (which could be the biggest contributor to warming and cooling trends) etc. The fact that there is so many adjustments down by a significant amount in the late 1880s/early 1900s makes me very leery.  I know there is the TOB but why not look at maximum temperature trends then??? what do they show???  Very little...  

[ORH_wxman]

No one said the Earth wasn't warming some, but this easily could be a recovery from the Little Ice Age. Many glaciers have been retreating since the 1800s long before man had any influence on the climate. SLR has been slowly rising long before man had any influence on climate. The term that the SSTs are accelerating is very questionable and alarmist.

Well you can always fall back on the radiative properties of CO2 if you are questioning the source of the warming. That would cause about a 1.1-1.2 warming per doubling by itself even if you thought the feedbacks were zero.

[blizzard1024]

Well you can always fall back on the radiative properties of CO2 if you are questioning the source of the warming. That would cause about a 1.1-1.2 warming per doubling by itself even if you thought the feedbacks were zero.

True. But how do we know that the oceans aren't going to damp the external forcing by increasing OHC which we have seen at least in the ARGO era?  That increase in OHC equates to a few hundreths of a degrees C which tells me that the oceans can pretty much  damp any external forcing unless it is truly catastrophic and rapid, like an asteroid, massive volcanic eruption, nuclear war, or a complete shutdown of the thermohaline circulation (which does not occur normally during interglacials). Plus clouds and tropical convection, how do they react to external forcing???  In any event, based on what the climate system has done in the last several decades there is little to be alarmed about in my opinion. And I base it on science and my knowledge of forecasting an uncertain chaotic system every day...the atmosphere. Climate scientists do not have this perspective.

[ORH_wxman]

True. But how do we know that the oceans aren't going to damp the external forcing by increasing OHC which we have seen at least in the ARGO era?  That increase in OHC equates to a few hundreths of a degrees C which tells me that the oceans can pretty much  damp any external forcing unless it is truly catastrophic and rapid, like an asteroid, massive volcanic eruption, nuclear war, or a complete shutdown of the thermohaline circulation (which does not occur normally during interglacials). Plus clouds and tropical convection, how do they react to external forcing???  In any event, based on what the climate system has done in the last several decades there is little to be alarmed about in my opinion. And I base it on science and my knowledge of forecasting an uncertain chaotic system every day...the atmosphere. Climate scientists do not have this perspective.

 

We know the feedbacks (OHC, clouds, etc) are extremely unlikely to be negative based on past paleo evidence...and based on energy budget during the instrumental temperature record. We can calculate the change in CO2 fairly accurately and we can calculate the change in temperature fairly accurately. There's a larger uncertainty in OHC and aerosol forcing, but even allowing for large uncertainty in these values, you almost always arrive at positive feedback. (i.e. greater than 1.2C per doubling of CO2) So all the uncertainties you listed above are built into these estimates based on energy budget...and they are more or less confirmed by paleo evidence we have...not that paleo evidence is the greatest since delta F parameter could be more and more different the further back we go...but it still provides us with a general independent estimate.

 

The amount of warming to expect is our real debate (whether it is 1.5C or 2.5C or 3.5C). What qualifies as "alarming" is also another topic.

[FloridaJohn]

No one said the Earth wasn't warming some, but this easily could be a recovery from the Little Ice Age.

 

Or, the Little Ice Age could have been the beginning of a long, slow slide into the next glacial period that we have somehow reversed.

[nflwxman]

No one said the Earth wasn't warming some, but this easily could be a recovery from the Little Ice Age. Many glaciers have been retreating since the 1800s long before man had any influence on the climate. SLR has been slowly rising long before man had any influence on climate. The term that the SSTs are accelerating is very questionable and alarmist.

 

What? This is proven with multiple lines of evidence.  There needs to be a physical reason other than "recovery from the little ice age."  What physical process drives that?  What does that even mean?

 

You seem to try to poke holes in the prevailing theory of climate change, but do not apply the same rigor to your own theories?  That's not how science works.  You need a viable alternative explanation to overturn the null hypothesis.

 

There are defined uncertainties in every variable you are bringing up in the literature.  The combination of those uncertainties still do not overwhelm the temperature change we've seen. It's really not even close.  Also, you can't forget that uncertainty works both ways.  Whose to say it's not worse than we think and that the past is actually cooler than our records indicate?

[StudentOfClimatology]

The idea of a climate system dominated by negative feedbacks is laughable, as is the idea of a stable, unchanging ESC/TCR. As the ENSO system proves, it only takes a shift in global circulation to dramatically alter global temperatures...that's all ENSO is.

As ORH alluded to, the paleo data not only reveals the the existence of positive feedback loops, but also the fact that they appear to be highly non-linear in nature. Both the TCR and ESC can vary significantly over time.

[blizzard1024]

We know the feedbacks (OHC, clouds, etc) are extremely unlikely to be negative based on past paleo evidence...and based on energy budget during the instrumental temperature record. We can calculate the change in CO2 fairly accurately and we can calculate the change in temperature fairly accurately. There's a larger uncertainty in OHC and aerosol forcing, but even allowing for large uncertainty in these values, you almost always arrive at positive feedback. (i.e. greater than 1.2C per doubling of CO2) So all the uncertainties you listed above are built into these estimates based on energy budget...and they are more or less confirmed by paleo evidence we have...not that paleo evidence is the greatest since delta F parameter could be more and more different the further back we go...but it still provides us with a general independent estimate.

 

The amount of warming to expect is our real debate (whether it is 1.5C or 2.5C or 3.5C). What qualifies as "alarming" is also another topic.

 

The paleo evidence of climate sensitivity relies on constant boundary conditions within our climate system which we know is not true. This has always bugged me in the literature. The climate system was completely different during the last glacial maximum and feedbacks had more or less effect than today. Just look at the temperature variations in the holocence vs the last glacial maximum and before that, the climate is very stable now vs when there were large ice sheets. Many feedbacks were amplified back then. You can't assume the feedbacks are the same from glacial to interglacial cycle. If someone can shed light on how this can be I would appreciate it. But the climate was so different during glaciations that feedbacks had to be of different magnitude. 

[ORH_wxman]

The paleo evidence of climate sensitivity relies on constant boundary conditions within our climate system which we know is not true. This has always bugged me in the literature. The climate system was completely different during the last glacial maximum and feedbacks had more or less effect than today. Just look at the temperature variations in the holocence vs the last glacial maximum and before that, the climate is very stable now vs when there were large ice sheets. Many feedbacks were amplified back then. You can't assume the feedbacks are the same from glacial to interglacial cycle. If someone can shed light on how this can be I would appreciate it. But the climate was so different during glaciations that feedbacks had to be of different magnitude. 

 

 

Well we have energy budget too like I already mentioned. It is very difficult to produce a negative feedback using energy budget unless many of the uncertainties all fall in the same direction...it's theoretically possible, but extremely unlikely, so there's no real practical use for the idea as it pertains to sensitivity discussion. It is the same as talking about like a sensitivity of 8C...theoretically possible but really so unlikely based on empirical evidence.

[The_Global_Warmer]

Things are certainly setting up for another record setting ssta year, month, week..

Its not seen here. But at the end of the period the gfs is showing a strong WWB over enso 4 pushing into enso 3 centered along 5N between 0 and 10N.

[The_Global_Warmer]

Enso is looking very favorable in the medium range for at least a moderate nino to emerge.

[dan11295]

Or, the Little Ice Age could have been the beginning of a long, slow slide into the next glacial period that we have somehow reversed.

 

I believe there was a recent paper, which I don't remember off the top of my head, which suggested that humans have actually had a significant impact on climate since about 4000 B.C. when expansion of agriculture and livestock domestication occurred. GHG emissions from these sources may have served to stabilze temperatures during the Holocene. Really the topic for another thread.

[StudentOfClimatology]

I believe there was a recent paper, which I don't remember off the top of my head, which suggested that humans have actually had a significant impact on climate since about 4000 B.C. when expansion of agriculture and livestock domestication occurred. GHG emissions from these sources may have served to stabilze temperatures during the Holocene. Really the topic for another thread.

That's very unlikely to have been the case, looking at the isotope ratios in the ice cores. If CO2 were to have increased enough to influence the climate, the ice cores would have picked up on it.

There's nothing to indicate any detectable anthropogenic forcing on the climate until the 19th/20th century, with the large majority of anthropogenic forcing occurring after 1950.

[The_Global_Warmer]

The cool waters of the NPAC during a +PDO appear to be in a battle stick around.

Inspite of the nino continuing to emerge.

[skierinvermont]

No one said the Earth wasn't warming some, but this easily could be a recovery from the Little Ice Age. Many glaciers have been retreating since the 1800s long before man had any influence on the climate. SLR has been slowly rising long before man had any influence on climate. The term that the SSTs are accelerating is very questionable and alarmist.

 

Whatever you want to call it 'a recovery form the LIA" or whatever - you're acknowledging it has warmed. The glaciers didn't melt by magic. They melted because the SSTs at their terminus melts them and causes calving. 

 

Likewise, the oceans didn't rise by magic. They rose because of warming. 

 

Finally, the ocean has not been rising "since before man." Sea level was higher 300-1,000 years ago than it was in 1950. You are factually incorrect. 

[csnavywx]

That's very unlikely to have been the case, looking at the isotope ratios in the ice cores. If CO2 were to have increased enough to influence the climate, the ice cores would have picked up on it.

There's nothing to indicate any detectable anthropogenic forcing on the climate until the 19th/20th century, with the large majority of anthropogenic forcing occurring after 1950.

This is a pretty speculative statement even though I'm pretty sure you think otherwise at the moment:

 

http://www.nature.com/news/2011/110325/full/news.2011.184.html

[StudentOfClimatology]

This is a pretty speculative statement even though I'm pretty sure you think otherwise at the moment:

http://www.nature.com/news/2011/110325/full/news.2011.184.html

It's just common sense..that "modeling study" flies in the face of all the proxy data in existence. The CO^2 fraction is well captured in the ice core data..both GISP/GISP2 and the Vostok cores are in near perfect agreement here, given the fact that it's a very wel mixed gas.

http://www.gisp2.sr.unh.edu

If there was any early/mid-Holocene anthropogenic forcing on CO^2 concentration, it was not enough to affect climate:

[PhillipS]

Keep in mind that the GISP2 data set ends at about 1855, thus leaving off a lot of recent data.

[chubbs]

Bill Ruddiman is the scientist who first proposed that man has influenced climate for thousands of years mainly through the impact of agriculture on CO2 and CH4. Below is a 2013  talk he gave that covers his theory and evidence. This hypothesis was novel and controversial when proposed in 2004. Over the years though it has been slowly gaining supporters but is not widely accepted yet.

 

https://www.youtube.com/watch?v=1TOTsmqgmL8.

[StudentOfClimatology]

Bill Ruddiman is the scientist who first proposed that man has influenced climate for thousands of years mainly through the impact of agriculture on CO2 and CH4. Below is a 2013 talk he gave that covers his theory and evidence. This hypothesis was novel and controversial when proposed in 2004. Over the years though it has been slowly gaining supporters but is not widely accepted yet.

.

Aa far as I know, it's not gaining much support from the paleoclimate community. Unless some new data were to miraculously enter the picture, nullifying the GISP and Vostok cores, I don't believe there's any way the theory could work, even hypothetically.

[PhillipS]

Bill Ruddiman is the scientist who first proposed that man has influenced climate for thousands of years mainly through the impact of agriculture on CO2 and CH4. Below is a 2013  talk he gave that covers his theory and evidence. This hypothesis was novel and controversial when proposed in 2004. Over the years though it has been slowly gaining supporters but is not widely accepted yet.

 

https://www.youtube.com/watch?v=1TOTsmqgmL8.

 

Thank you for sharing that link.  I thought Dr Ruddiman's lecture was fascinating and thought-provoking.