2015 Global Temperatures

[blizzard1024]

That's my take as well. There may be short periods of time where the rate is faster than the average, and there may be short periods of time where the rate is slower than the average, but the long term trend will average upward at the same rate.

 

so that's a change of 1.6C / century. You folks think that mankind can't adapt to that rate of change? The paleo records show faster swings in climate....

[nflwxman]

so that's a change of 1.6C / century. You folks think that mankind can't adapt to that rate of change? The paleo records show faster swings in climate....

The earth will warm faster than 0.2c/decade eventually due to positive feedbacks becoming stronger. As I started a few years ago, I would not be surprised to see us warming 0.25-0.3c/decade between 2010-2030.

[StudentOfClimatology]

so that's a change of 1.6C / century. You folks think that mankind can't adapt to that rate of change? The paleo records show faster swings in climate....

The more variability there is in the paleoclimate record, the higher climate sensitivity must be. So many seem to forget this.

The paleoclimate record suggests the system is inherently unstable and very sensitive to perturbation, as you noted. This suggests, statistically, that climate sensitivity is closer to 3-4C, and that the all-important TCR can change in the blink of an eye should certain boundary conditions be reached.

Given this, how can you justify ignoring the problem? If another Younger Dryas-caliber warming were to occur, it'd kill hundreds of millions of people in 5-10 years. Do you think we can "adapt" to a warming of 8 degrees centigrade in 5 years?

[stadiumwave]

Honest question: why are the RSS & UAH satellite measurements differing so much from the GISS & HadCrut?  Up until last year the trends were very similar but have diverged in a very noticeable alarming way.  What's the scoop from some of you that might know.

 

RSS

 

 

 

UAH

 

GISS

 

 

 

HADCRUT 4

 

[stadiumwave]

BTW...here's a very interesting article on the "missing heat" during the hiatus:

 

https://eos.org/articles/tracking-the-missing-heat-from-the-global-warming-hiatus

[ORH_wxman]

The best theory I've heard so far is that last year's heat was driven strongly by lower wind speeds globally...with the big focus over the N PAC. This would manifest itself as more warmth at the surface, but it wouldn't be felt higher up.

 

I would suspect that we'll see the satellites jump more this year as the Nino cranks up.

 

FWIW, that graph at the bottom looks like CRUTEM4 and not Hadcrut...CRUTEM is just the land temps.

[stadiumwave]

The best theory I've heard so far is that last year's heat was driven strongly by lower wind speeds globally...with the big focus over the N PAC. This would manifest itself as more warmth at the surface, but it wouldn't be felt higher up.

 

I would suspect that we'll see the satellites jump more this year as the Nino cranks up.

 

FWIW, that graph at the bottom looks like CRUTEM4 and not Hadcrut...CRUTEM is just the land temps.

 

Correct...my bad, it's Crutem.

 

Thanks for the explanation but I'm still skeptical that one or the other method is just wrong.

 

EDIT: And of course I agree they'll jump with Nino cranking up but they all will jump.  But that still doesn't account for a very noticeable difference.

[FloridaJohn]

so that's a change of 1.6C / century. You folks think that mankind can't adapt to that rate of change? The paleo records show faster swings in climate....

In two centuries of warming we will be +3.2C. What did the earth look like the last time it was that warm? How will that affect our current infrastructure?

[blizzard1024]

The more variability there is in the paleoclimate record, the higher climate sensitivity must be. So many seem to forget this.

The paleoclimate record suggests the system is inherently unstable and very sensitive to perturbation, as you noted. This suggests, statistically, that climate sensitivity is closer to 3-4C, and that the all-important TCR can change in the blink of an eye should certain boundary conditions be reached.

Given this, how can you justify ignoring the problem? If another Younger Dryas-caliber warming were to occur, it'd kill hundreds of millions of people in 5-10 years. Do you think we can "adapt" to a warming of 8 degrees centigrade in 5 years?

 

The Greenland ice core record showed major swings in local climate until all the ice sheets melted. Once that happened we entered the Holocene which has had a much more stable climate. The reason for such large shifts was from the melting of the massive amount of land ice during the last glacial maximum. This changed albedo farther south and affected ocean currents much more so than present. Now that we don't have that, the climate is much more stable. Ocean currents are not disrupted as they were...albedo changes are smaller now. So the boundary conditions are totally different today than when we had lots of land ice. That is why I don't think you can say the climate is that sensitive all the time.

[ORH_wxman]

In two centuries of warming we will be +3.2C. What did the earth look like the last time it was that warm? How will that affect our current infrastructure?

 

That would be highly unlikely if we were only warming at 0.16C per decade in the 21st century...unless we somehow increased our GHG emissions into the 22nd century....also an unlikely scenario. Warming rate would taper.

 

I'd expect to see higher rates of warming in the 21st century if we are going to warm over 3C from current levels in 2200.

[nflwxman]

That would be highly unlikely if we were only warming at 0.16C per decade in the 21st century...unless we somehow increased our GHG emissions into the 22nd century....also an unlikely scenario. Warming rate would taper.

I'd expect to see higher rates of warming in the 21st century if we are going to warm over 3C from current levels in 2200.

Most IPCC scenarios have us rising 0.2-.25C a decade in the next 3 decades or so.

[ORH_wxman]

Most IPCC scenarios have us rising 0.2-.25C a decade in the next 3 decades or so.

 

Yeah or even more ....RCP 4.5 has us around +1.6C on hadcrut4 by 2050...that would be an increase of nearly 1C from current levels over the next 35 years.

 

The RCP 8.5 scenario has us at over 2C by 2050.

[FloridaJohn]

That would be highly unlikely if we were only warming at 0.16C per decade in the 21st century...unless we somehow increased our GHG emissions into the 22nd century....also an unlikely scenario. Warming rate would taper.

I'd expect to see higher rates of warming in the 21st century if we are going to warm over 3C from current levels in 2200.

Yeah, that was where I was heading with my comment. Plus we're already at 0.65C up that ladder. Blizzard implied that mitigation at 0.16C/decade would be "easy". But even at that minimal rate, we can see where we are headed by looking at past climates. Now, add to that the likely increase in the warming rate, and the effects of potential tipping points, and mitigation will be much more difficult, and not inexpensive by any measure.

[Isotherm]

The more variability there is in the paleoclimate record, the higher climate sensitivity must be. So many seem to forget this.

 

 

Can you expand upon your reasoning regarding this statement as it pertains to the sensitivity of Earth's climate to Co2 radiative forcing? While variability in the past can be indicative that Earth is sensitive to changes in certain radiative forcing(s), how exactly does that prove that the climate is very sensitive (e.g. ECS of 4c) to the radiative forcing of Co2? How do we know which radiative forcing(s) induced the variability in Earth's history when there were multiple climate forcings to account for? I'm not sure how you've come to the following conclusion: because Earth has shown strong variability throughout history --> climate must be very sensitive to radiative forcings, but then make the next logical jump to --> climate must be very sensitive to Co2 radiative forcing (and for the sake of this, let's say an ECS of 3-4C).

[ORH_wxman]

ECS is approximately given by the equation ECS = F_2xCO2 ⨯ ΔT / (ΔF - ΔQ)

 

Where F_2xCO2 is the forcing of doubling of CO2, ΔT is the change in temperature over your chosen time period, ΔF is the total change in forcing, and ΔQ is the change in total heating rate of the earth...this last term is dominated by OHC uptake.

 

We know the numerators well...we know that F_2xCO2 = 3.71 W/m² and ΔT = ~0.85C if we are starting in the mid 19th century. It is the denominators that are quite uncertain. Mostly the ΔF term as included in it is aerosols and their feedbacks on clouds.

 

That is essentially the mathematical portion of the climate sensitivity debate.

[chubbs]

Plio-Pleistocene climate sensitivity evaluated using high-resolution CO₂ records

 

518, 49–54

(05 February 2015)

doi:10.1038/nature1415

 

MA Martinez-Boti, GL Foster, TB Chalk, EJRohling, PFSextopn, DJLunt RDPancost, MPS Badger & DNSchmidt

 

Theory and climate modelling suggest that the sensitivity of Earth’s climate to changes in radiative forcing could depend on the background climate. However, palaeoclimate data have thus far been insufficient to provide a conclusive test of this prediction. Here we present atmospheric carbon dioxide (CO₂) reconstructions based on multi-site boron-isotope records from the late Pliocene epoch (3.3 to 2.3 million years ago). We find that Earth’s climate sensitivity to CO₂-based radiative forcing (Earth system sensitivity) was half as strong during the warm Pliocene as during the cold late Pleistocene epoch (0.8 to 0.01 million years ago). We attribute this difference to the radiative impacts of continental ice-volume changes (the ice–albedo feedback) during the late Pleistocene, because equilibrium climate sensitivity is identical for the two intervals when we account for such impacts using sea-level reconstructions. We conclude that, on a global scale, no unexpected climate feedbacks operated during the warm Pliocene, and that predictions of equilibrium climate sensitivity (excluding long-term ice-albedo feedbacks) for our Pliocene-like future (with CO₂ levels up to maximum Pliocene levels of 450 parts per million) are well described by the currently accepted range of an increase of 1.5 K to 4.5 K per doubling of CO₂.

 

http://www.nature.com/nature/journal/v518/n7537/full/nature14145.html

[AvantHiatus]

Plio-Pleistocene climate sensitivity evaluated using high-resolution CO₂ records

 

518, 49–54

(05 February 2015)

doi:10.1038/nature1415

 

MA Martinez-Boti, GL Foster, TB Chalk, EJRohling, PFSextopn, DJLunt RDPancost, MPS Badger & DNSchmidt

 

Theory and climate modelling suggest that the sensitivity of Earth’s climate to changes in radiative forcing could depend on the background climate. However, palaeoclimate data have thus far been insufficient to provide a conclusive test of this prediction. Here we present atmospheric carbon dioxide (CO₂) reconstructions based on multi-site boron-isotope records from the late Pliocene epoch (3.3 to 2.3 million years ago). We find that Earth’s climate sensitivity to CO₂-based radiative forcing (Earth system sensitivity) was half as strong during the warm Pliocene as during the cold late Pleistocene epoch (0.8 to 0.01 million years ago). We attribute this difference to the radiative impacts of continental ice-volume changes (the ice–albedo feedback) during the late Pleistocene, because equilibrium climate sensitivity is identical for the two intervals when we account for such impacts using sea-level reconstructions. We conclude that, on a global scale, no unexpected climate feedbacks operated during the warm Pliocene, and that predictions of equilibrium climate sensitivity (excluding long-term ice-albedo feedbacks) for our Pliocene-like future (with CO₂ levels up to maximum Pliocene levels of 450 parts per million) are well described by the currently accepted range of an increase of 1.5 K to 4.5 K per doubling of CO₂.

 

http://www.nature.com/nature/journal/v518/n7537/full/nature14145.html

From what I gather, ECS could still be more elevated than the warm Pliocene given we haven't completely rid ourselves of the icehouse climate. A stable warm Pliocene world is very different from our own, with sea levels 20m+ higher and a non-existent Greenland ice sheet.

[AvantHiatus]

Waiting for TGW's update, global temps are shooting back up.

[The_Global_Warmer]

Haven't had time to look at them in a while.

May was already running warm with a .70C giss equivalent.

IIRC.

The warmest May on giss is below 0.80C

[AvantHiatus]

Another record on the way for sure.

 

 

 

Haven't had time to look at them in a while.


May was already running warm with a .70C giss equivalent.


IIRC.

The warmest May on giss is below 0.80C 

[wolfpackmet]

CFS dailies currently at ~ +0.250 C, the highest since mid March.  May-to-date is at +0.155 C with time for a slight increase.  GISS equivalent ~+0.75 maybe higher. 

[stadiumwave]

Great new study concerning the AMO

http://www.nature.com/nature/journal/v521/n7553/full/nature14491.html

[AvantHiatus]

Great new study concerning the AMO

http://www.nature.com/nature/journal/v521/n7553/full/nature14491.html

The 0.5C is a regional cooling. Another shadey paper from nature.

[stadiumwave]

The 0.5C is a regional cooling. Another shadey paper from nature.

 

If anyone on this forum denies natural variability contributing to the global warming of the last century then they are in league of their own.  There is no one credible in science that does such.  So why does the AMO/PDO talk make some posters nervous? I've noticed that for whatever reason it does.  Some of the most heated posting wars have been related to PDO/AMO.  I mean gee whiz, it shouldn't make anyone a denier of human contribution to acknowledge natures contribution also.

[LakeEffectKing]

If anyone on this forum denies natural variability contributing to the global warming of the last century then they are in league of their own.  There is no one credible in science that does such.  So why does the AMO/PDO talk make some posters nervous? I've noticed that for whatever reason it does.  Some of the most heated posting wars have been related to PDO/AMO.  I mean gee whiz, it shouldn't make anyone a denier of human contribution to acknowledge natures contribution also.

Too emotionally invested to be objective....that's my thinking...i.e. symptom of their confirmation bias thirst...

[The_Global_Warmer]

The evidence for the AMO and PDO is purely circumstantial.

The greenhouse effect and water vapor feedback are directly

Measured and observed.

[chubbs]

If anyone on this forum denies natural variability contributing to the global warming of the last century then they are in league of their own.  There is no one credible in science that does such.  So why does the AMO/PDO talk make some posters nervous? I've noticed that for whatever reason it does.  Some of the most heated posting wars have been related to PDO/AMO.  I mean gee whiz, it shouldn't make anyone a denier of human contribution to acknowledge natures contribution also.

Lets put AMO/PDO in the proper perspective. Certainly AMO+PDO impact global temperatures over periods of up to several decades however they have limited  impact on global temperatures over longer periods of time because they are oscillations. Currently 3-year running average AMO and PDO values aren't too far from where they were in 1900.

 

[stadiumwave]

Lets put AMO/PDO in the proper perspective. Certainly AMO+PDO impact global temperatures over periods of up to several decades however they have limited  impact on global temperatures over longer periods of time because they are oscillations. Currently 3-year running average AMO and PDO values aren't too far from where they were in 1900.

 

amo+pdo.png

 

And why are you posting this? Who doesn't know this?  Did you think I posted the link to the study thinking it denies human contribution to global warming?  Or possibly that the -AMO coming would eliminate global warming?  In no way was that my point.  But your post proves my point.  I believe people get some freaked out when discussing PDO/AMO because they think anyone bringing it up is denying human contribution to global warming.  But that's just stupid.  However, it's even more stupid when people (not you) deny the affects of the PDO/AMO on earth's climate.

[stadiumwave]

The evidence for the AMO and PDO is purely circumstantial.

The greenhouse effect and water vapor feedback are directly

Measured and observed.

 

 

Thanks for proving my point

[ORH_wxman]

And why are you posting this? Who doesn't know this?  Did you think I posted the link to the study thinking it denies human contribution to global warming?  Or possibly that the -AMO coming would eliminate global warming?  In no way was that my point.  But your post proves my point.  I believe people get some freaked out when discussing PDO/AMO because they think anyone bringing it up is denying human contribution to global warming.  But that's just stupid.  However, it's even more stupid when people (not you) deny the affects of the PDO/AMO on earth's climate.

 

 

It is definitely bizarre that there is some sort of phobia to natural variation amongst many when discussing climate change.

 

 

Natural variation is absolutely one of the most essential aspects of our climate system to understand when studying climate change, yet so many want to stick their fingers in their ears and not listen to it. It does not come across as very scientific.

 

 

But this discussion should really continue in the banter thread, and not here. This should be focusing on 2015.