Support the Arctic Sea Ice Forum and Blog

Author Topic: "Smart" and "Stupid" Questions - Feel Free To Ask  (Read 671953 times)

Rich

  • Guest
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2350 on: July 27, 2019, 11:13:14 PM »


There remains those events when warm air is intruding up from the Atlantic, originating in the Gufl of Mexico.

This phenomenon is best visible in winter, i.e. 0C in January at the pole, even though only briefly but clearly visible as a tongue of warmth protruding into the CAB.

The same thing can happen in summer as well, it's just not so obvious when the surroundings are not 40 below 0 but around zero as well.

Thanks for participating.

oren

  • Moderator
  • First-year ice
  • Posts: 6297
    • View Profile
  • Liked: 2314
  • Likes Given: 1953
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2351 on: July 27, 2019, 11:49:34 PM »
Rich, do you understand that a high pressure zone means sinking air, and that air warms as it sinks due to increasing pressure?

be cause

  • Nilas ice
  • Posts: 1398
    • View Profile
  • Liked: 604
  • Likes Given: 463
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2352 on: July 28, 2019, 01:30:35 AM »
.. one of the reasons dmi80 has returned to equeal  warmest of the season .. b.c.
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 + 2 = 2021 + 1 =  ' if only we could have seen it coming ' ...

Glen Koehler

  • Frazil ice
  • Posts: 354
    • View Profile
  • Liked: 344
  • Likes Given: 762
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2353 on: July 28, 2019, 05:45:06 AM »
Would anybody be able to tell me what the current consensus is on the degree of global dimming we currently have? My understanding was that it was somewhere between .8c and 1.2c but somebody in the 2019 melting thread said that it is now considered to be much lower than previously thought.

Charts from James Hansen and others indicate that aerosol blocking of incoming solar energy creates a negative forcing of about 0.5C.  Thus if we had current GHG levels without aerosols, global average surface temperature would be more like 1.65 C over 1850-1900 average (using NASA GISTEMP data) than the current 1.15 C.   So we are already doing inadvertent, ignorant geoengineering / solar energy management. 

Capt Kiwi

  • New ice
  • Posts: 18
    • View Profile
  • Liked: 5
  • Likes Given: 21
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2354 on: July 28, 2019, 08:38:01 AM »

Charts from James Hansen and others indicate that aerosol blocking of incoming solar energy creates a negative forcing of about 0.5C.  Thus if we had current GHG levels without aerosols, global average surface temperature would be more like 1.65 C over 1850-1900 average (using NASA GISTEMP data) than the current 1.15 C.   So we are already doing inadvertent, ignorant geoengineering / solar energy management.

Thanks Glen, that’s on the lower range of what I thought was likely so somewhat reassuring... i think.
A major economic downturn which is surely inevitable sooner or later, would likely result in a reduction of that .5c to something like .3c so a global temp rise of .2c is not too apocalyptic I guess. Cheers!

Glen Koehler

  • Frazil ice
  • Posts: 354
    • View Profile
  • Liked: 344
  • Likes Given: 762
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2355 on: July 28, 2019, 08:43:44 AM »
Unless people are burning furniture as cooking fuel! 
But this isn't funny really.  We've really got to get the politicians to wake up.
Who ever thought thermometer readings would become a matter of ideological distortion?

interstitial

  • Grease ice
  • Posts: 604
    • View Profile
  • Liked: 211
  • Likes Given: 76
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2356 on: July 28, 2019, 03:39:55 PM »
Most of the honest disagreement over how much warming man has caused is discussion of what the definition should be. It boils down to what time period to use to establish a baseline. I have seen arguments for baselines vary from 1980 to 2010 on one extreme and before major civilization on the other. With the implications of the Paris treaty many are disingenuous and just want to tip the results one way or another. Pre-industrial is how it is defined in the treaty but is highly subjective. Since the difference in 0.1 degree C could represent trillions in lost sales deniers try to cloud the issue. When I looked up industrial revolution timeline online postings listed starting dates from about 1700 to 1760. It follows that the baseline should end no later than 1760. Preferably the baseline would end by 1700. Some would argue we should use pre-homo-sapiens since we have made an impact on Earth’s climate for longer. As a supporting anecdote I read a study that said lead and tin pollution from early Roman Empire forges were detected in remote areas globally.

interstitial

  • Grease ice
  • Posts: 604
    • View Profile
  • Liked: 211
  • Likes Given: 76
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2357 on: July 28, 2019, 03:43:47 PM »

The first problem arises because methods of determining temperature before widespread temperature records beginning about 1880 are limited. While many of these techniques are quite impressive they tend to be tied to the growth and spread of living organisms. Information from these tends to regional and sporadic making their use difficult and subject to a high degree of interpretation.  While some disagree and think we should use pre 1880 baselines global warming is urgent and the advantage of a presumably lower baseline is offset by the delay required in gathering data which is more speculative. If someone develops better data my opinion may change but inaction is the wrong approach.


interstitial

  • Grease ice
  • Posts: 604
    • View Profile
  • Liked: 211
  • Likes Given: 76
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2358 on: July 28, 2019, 03:45:27 PM »

I believe someone at NASA first claimed that barring discovery of some new temperature record repository current records are insufficient to generate climate temperature records prior to 1880. From a practical standpoint it is generally agreed that there aren't enough temperature records before 1880.


As you can see from the graph differences in the interpretation of this data are minimal. What differences that occur stem from how to most accurately account for gaps in temperature data both in time and regionally. These discrepancies are especially evident at the poles but still manage a large degree of consistency.


So look at the data and tell me how you interpret it.


interstitial

  • Grease ice
  • Posts: 604
    • View Profile
  • Liked: 211
  • Likes Given: 76
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2359 on: July 28, 2019, 03:46:52 PM »

To me 1880 to about 1925 looks like about as good of a baseline as can be had from the data its relatively flat and includes the earliest data. I should get an average for the baseline but just eyeballing it looks like -0.3 C. I would say now we are at about 0.7 C. That indicates a warming of about 1 C since 1925. While others may not agree when I see numbers less than 1 C I think they are misinformed or denialists stalling for more time. 

https://qz.com/1055629/why-does-all-our-climate-data-start-in-1880/


https://climate.nasa.gov/news/2841/2018-fourth-warmest-year-in-continued-warming-trend-according-to-nasa-noaa/


interstitial

  • Grease ice
  • Posts: 604
    • View Profile
  • Liked: 211
  • Likes Given: 76
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2360 on: July 28, 2019, 03:49:10 PM »
Sorry about my post every time I post the font size and font seem to change randomly. :-[  Click to read chart data.

binntho

  • Nilas ice
  • Posts: 1519
    • View Profile
  • Liked: 528
  • Likes Given: 119
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2361 on: July 28, 2019, 04:07:59 PM »
I'm not sure what the question is here, Interstitial, but I for one quite enjoy looking at Holocene temperatures and I think that the general consensus is that they are getting quite reliable when looking at decadal changes.

Measuring the temperature of the Atmosphere is actually very difficult, but over the last two or three decades we have gotten a lot closer to being able to make factual statements about the temperature of the earth based on measurements. But even today, we have to rely on sporadic and geographically skewed point measurements or attempts to estimate the temperature from space using satellites.

So the question of when the temperature record became reliable enough - I guess it depends. When it comes to global warming, anything smaller than decadal averages are really just noise.

Anyway, this one is one of my favourites, a graph I cleaned from the Wikipedia site on Holocene temperatures, and added a trendline for the last 8000 years, as well as the 2016 average temperature.

EDIT: Forgot to add the image.
« Last Edit: July 28, 2019, 04:16:57 PM by binntho »
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

Shared Humanity

  • Guest
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2362 on: July 28, 2019, 04:08:17 PM »

To me 1880 to about 1925 looks like about as good of a baseline as can be had from the data its relatively flat and includes the earliest data. I should get an average for the baseline but just eyeballing it looks like -0.3 C. I would say now we are at about 0.7 C. That indicates a warming of about 1 C since 1925. While others may not agree when I see numbers less than 1 C I think they are misinformed or denialists stalling for more time. 

https://qz.com/1055629/why-does-all-our-climate-data-start-in-1880/




https://climate.nasa.gov/news/2841/2018-fourth-warmest-year-in-continued-warming-trend-according-to-nasa-noaa/

We may be at a warming of 1 C since 1925 but this is not the preindustrial baseline. If we want to identify when the industrial revolution began to have a real impact, we should look at atmospheric CO2 levels. If you look at the attached graph, there is a pronounced, rapid rise in atmospheric CO2 levels that begins around 1840. Atmospheric CO2 reached a level that had not been seen for at least 800 years and we have never looked back.

Never mind that we do not have an entirely accurate temperature record pre 1880, the baseline temperature is the 1st half of the 19th century and to use a later baseline hides the true anthropogenic impact. Given the serious effects of AGW, the impact must be calculated based on the 1st half of the 19th century. I have always questioned the accuracy of a later baseline and the motives of scientists who insist that this later baseline is preferred.

It may be that the difference between the 2 baselines is of little consequence but efforts to calculate the earlier baseline should be made.
« Last Edit: July 28, 2019, 04:43:09 PM by Shared Humanity »

Shared Humanity

  • Guest
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2363 on: July 28, 2019, 04:27:33 PM »
Here is the chart which was included in the article that was linked to. While it is true that estimates of global temps prior to 1880 are more uncertain, I leave it to the reader to decide if -0.3C is a good baseline.

When I eyeball the chart, it would seem that this baseline is most probably 0.5C too high which places us at a 1.5C increase in global temps over preindustrial.

(edit) Given the accuracy of the temperature record over the last 40 years, I find it odd that you would say "I would say now we are at about 0.7 C." when the chart clearly shows we are at 0.8C and rising rapidly.
« Last Edit: July 28, 2019, 04:34:53 PM by Shared Humanity »

interstitial

  • Grease ice
  • Posts: 604
    • View Profile
  • Liked: 211
  • Likes Given: 76
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2364 on: July 28, 2019, 04:33:06 PM »
Bintho
To clarify it is not that earlier temperature data lacks value but due to regional and time gaps it is less complete and precise.
Earlier in the thread the original question is how much warming has occured because of CO2 emmissions and ranges were given with numbers well below 1C and I didn't agree.
Shared Humanity
 I generally agree with you my main point is that warming exceeds 1 C. The numbers some were suggesting were as low as 0.6. Anyone who suggests it is below 1C is in my opinion misinformed or lying. Personally From what I have read I think we are at about 1.4C.

Shared Humanity

  • Guest
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2365 on: July 28, 2019, 04:38:34 PM »
Bintho
To clarify it is not that earlier temperature data lacks value but due to regional and time gaps it is less complete and precise.
Earlier in the thread the original question is how much warming has occured because of CO2 emmissions and ranges were given with numbers well below 1C and I didn't agree.
Shared Humanity
 I generally agree with you my main point is that warming exceeds 1 C. The numbers some were suggesting were as low as 0.6. Anyone who suggests it is below 1C is in my opinion misinformed or lying. Personally From what I have read I think we are at about 1.4C.

OK. I agree. Warming over preindustrial is a minimum of 1.4C but I would not rule out 1.6C.

binntho

  • Nilas ice
  • Posts: 1519
    • View Profile
  • Liked: 528
  • Likes Given: 119
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2366 on: July 28, 2019, 04:40:51 PM »
Well, if you look at my graph then we are clearly at c.a. 1.4 degrees above the lowest point around the middle of the 19th century.

But I don't really see that it makes any difference at all what baseline we choose, the heating is the heating and it is no more or less dangerous if we shift the baseline around.

As far as I know, meteorologists use 30 year baselines that shift every 30 years, so the current baseline is 1980-2010, which is e.g. used in this graph:
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

binntho

  • Nilas ice
  • Posts: 1519
    • View Profile
  • Liked: 528
  • Likes Given: 119
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2367 on: July 28, 2019, 04:45:52 PM »
Another thing that my earlier graph clearly shows is that the "preindustrial" baseline that is favoured by many is by far the lowest temperature point in the current Holocene. Some might call that "cherrypicking" ...

On the other hand, if you look at the trendline for the Holocene, you can see that the current warming is not only above a putative "preindustrial" baseline, it is actually above an underlying trend which I think would be a much fairer method of describing it.

The downward trend during the Holocene is caused by changes in insolation and some intrepid scientist might be able to calculate it ...
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

DrTskoul

  • Nilas ice
  • Posts: 1454
    • View Profile
  • Liked: 211
  • Likes Given: 60
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2368 on: July 28, 2019, 04:53:38 PM »
It has been estimated. It is due to orbital changes, next ice age was being predicted to start about 20,000 to 100,000 years from now.

Shared Humanity

  • Guest
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2369 on: July 28, 2019, 04:54:34 PM »
Well, if you look at my graph then we are clearly at c.a. 1.4 degrees above the lowest point around the middle of the 19th century.

Why are you using a "Global Lower Atmosphere"  temperature chart to make your point?

But I don't really see that it makes any difference at all what baseline we choose, the heating is the heating and it is no more or less dangerous if we shift the baseline around.

It makes a huge difference as it allows the "Don't be Alarmed Crowd" to obscure the fact that we are already at a very dangerous 1.5C level of warming over preindustrial.

As far as I know, meteorologists use 30 year baselines that shift every 30 years, so the current baseline is 1980-2010, which is e.g. used in this graph:

And why should I care what my local weatherman says when we are discussing global climate science and the dangerous changes we are driving? If it is OK with you, I'll stick with what the scientific research is telling us and leave it to my weatherman to get tomorrow's forecast wrong.


binntho

  • Nilas ice
  • Posts: 1519
    • View Profile
  • Liked: 528
  • Likes Given: 119
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2370 on: July 28, 2019, 04:58:44 PM »
It has been estimated. It is due to orbital changes, next ice age was being predicted to start about 20,000 to 100,000 years from now.
Yes, the famous Milankovich cycles. Given that we are halfway through our current interglacial, the next glaciation is sure to start within the next 10.000 years and to be nearing it's end in 100.000 years time, to give way to another interglacial.

So perhaps this AGW isn't such a bad idea after all?
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

binntho

  • Nilas ice
  • Posts: 1519
    • View Profile
  • Liked: 528
  • Likes Given: 119
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2371 on: July 28, 2019, 04:59:47 PM »
Well, if you look at my graph then we are clearly at c.a. 1.4 degrees above the lowest point around the middle of the 19th century.

Why are you using a "Global Lower Atmosphere"  temperature chart to make your point?
Was I making a point? What point? Besides, it was the first graph I found that clearly stated the baseline.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

Shared Humanity

  • Guest
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2372 on: July 28, 2019, 05:17:33 PM »
Well, if you look at my graph then we are clearly at c.a. 1.4 degrees above the lowest point around the middle of the 19th century.

Why are you using a "Global Lower Atmosphere"  temperature chart to make your point?
Was I making a point? What point? Besides, it was the first graph I found that clearly stated the baseline.

Your 1st graph does nothing of the kind. We are discussing global surface temperatures and you use a chart that measures something entirely different but, of course, you already know this.

Shared Humanity

  • Guest
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2373 on: July 28, 2019, 05:19:01 PM »
It has been estimated. It is due to orbital changes, next ice age was being predicted to start about 20,000 to 100,000 years from now.
Yes, the famous Milankovich cycles. Given that we are halfway through our current interglacial, the next glaciation is sure to start within the next 10.000 years and to be nearing it's end in 100.000 years time, to give way to another interglacial.

So perhaps this AGW isn't such a bad idea after all?

Thank you for so clearly revealing your motivation.

I have not paid close attention to your posts in the past as I generally read more closely the contributors here who help me learn the things I need to know. I now know where to place you with regards to perspective on AGW.

mabarnes

  • New ice
  • Posts: 54
    • View Profile
  • Liked: 23
  • Likes Given: 48
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2374 on: July 28, 2019, 05:44:11 PM »
Here's my stupid question, regarding "momentum."  I keep hearing that word - can someone enlighten me as to actual observations on such a thing...?  By this I mean serial correlation of extent and/or area ... any studies or data on this...?

Asking cuz at first-glance it seems to me counterintuitive - as ice melts, it cools the water, doesn't it?  As I recall it would cool 720 cubic km of water by 0.1 C to melt 1 cu km of ice, if it was only the water doing the heat transfer.  Is "momentum" something else entirely?  Weather?  Currents?

Appreciate any insight, thanks.  Been wondering ....

crandles

  • Young ice
  • Posts: 2752
    • View Profile
  • Liked: 163
  • Likes Given: 55
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2375 on: July 28, 2019, 05:54:33 PM »
Perhaps this series of posts by Neven is the explanation of the term though use goes back at least a further year as linked.

https://neven1.typepad.com/blog/2016/06/2016-melting-momentum-part-1.html

DrTskoul

  • Nilas ice
  • Posts: 1454
    • View Profile
  • Liked: 211
  • Likes Given: 60
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2376 on: July 28, 2019, 06:47:30 PM »
You can consider momentum as potential for extending ice melt. E.g. lots of melt ponds early in the season give rise to lower albedo and therefore lead to further adsorption of solar energy. They weaken the ice and can lead to destabilization and break up when winds and storms come by. Like a car without breaks rolls down a hill.

In the case of ice , small spells of bad weather do not stop the melting g trajectory of there is a lot of "momentum" early on.

Rich

  • Guest
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2377 on: July 28, 2019, 07:00:05 PM »
Is there a technical term for the Crack.

Is comes and goes as an aquatic version of a peninsula. Not quite a formal polynya because it isn't surrounded by ice.

In 5-6 days, "crack" might not do it justice. Maybe we can call it the Canadian Arctic Sea?

mabarnes

  • New ice
  • Posts: 54
    • View Profile
  • Liked: 23
  • Likes Given: 48
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2378 on: July 29, 2019, 01:15:48 AM »
Perhaps this series of posts by Neven is the explanation of the term though use goes back at least a further year as linked.

https://neven1.typepad.com/blog/2016/06/2016-melting-momentum-part-1.html

Thanks! Dr. T and Crandles ... that makes a lot of sense.

Michael Hauber

  • Grease ice
  • Posts: 900
    • View Profile
  • Liked: 77
  • Likes Given: 14
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2379 on: July 29, 2019, 03:48:57 AM »
Two aspects to melt momentum, especially when referring to May melt ponds.  Firstly If we have a period of weak cool weather with strong melt ponds, then the melt ponds absorb more heat than frozen ice and so the melt ponds might stay melted.  If we have a period of cool weather following weak melt ponds, or unusually strong cool weather then the melt ponds might freeze anyway.  This might reset the albedo effect as if the melt momentum hadn't happened, however the ice is still thinner because it was melting faster before the freeze.  And could there be other changes in melt ponds that would make them easier to form again  following a brief freeze than if they had to form from scratch?  Can melt ponds freeze on top and still have liquid underneath, but on top of the sea ice?
Climate change:  Prepare for the worst, hope for the best, expect the middle.

binntho

  • Nilas ice
  • Posts: 1519
    • View Profile
  • Liked: 528
  • Likes Given: 119
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2380 on: July 29, 2019, 05:31:09 AM »
Yes, the famous Milankovich cycles. Given that we are halfway through our current interglacial, the next glaciation is sure to start within the next 10.000 years and to be nearing it's end in 100.000 years time, to give way to another interglacial.

So perhaps this AGW isn't such a bad idea after all?

Thank you for so clearly revealing your motivation.

I have not paid close attention to your posts in the past as I generally read more closely the contributors here who help me learn the things I need to know. I now know where to place you with regards to perspective on AGW.
Was someone feeling a bit grumpy yesterday? One small joke and it's eternal banishment ...

My first graph was in response to somebody talking about the unreliability of pre-industrial temperature estimates. I disagree with that assessment when it comes to AGW because changes in global temperature can only be realisistically judged on a decadal scale. Proxy measurements have besides a much better spatial resolution than the point measurements that make up the "proper" temperature record, except for satellite measurements who have their own problems. So I don't really see that we have to have a "before and after" point where "proper" measurements began when we want to talk about AGW.

The second graph was to demonstrate the use of the 1980-2010 baseline, which is the "official" baseline when it comes to meteorology. It was the first temperature graph I found that clearly stated the baseline (which is unfortunately a separate problem - the baseline should always be clearly stated but rarely is). I borrowed the second graph from the Pettit climate graphs page (https://sites.google.com/site/pettitclimategraphs/pettit-climate-graphs)

But now I get jumped upon by a grumpy selfproclaimed non-reader of my posts, asking me why I was using this graph (which by implication was a no-no in polite society) to make my point (which I didn't know I was making!)

Then the talk veers away to the impending Ice age and I made a small joke and am hit by a ton of bricks!

So let me state my position as clearly as I can:

1) I believe that humanity has caused a rise in global temperatures in the region of 1.5 degrees Centigrade in the last 150 years or so.

2) I believe that this warming is continuning and even accelerating because of the common failure of humanity to stem CO2 pollution.

3) I belive that a rise of 1.5 in 150 years is catastrophic. A cataclysm that is slowly unfolding before our eyes. A threat to human civilization like none other.

And surprisingly enough, I find that many people on this forum are very ready to support points 1 and 2 but seem to think that there is still time to do something.

So I guess that I'll make everybody extremely stroppy by stating that a) there is nothing we can do and b) the catastrophe is already here.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

binntho

  • Nilas ice
  • Posts: 1519
    • View Profile
  • Liked: 528
  • Likes Given: 119
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2381 on: July 29, 2019, 06:05:16 AM »
Stating the baseline is very important and I'm surprised to see how often it's not done. The following is a good example, the graph is found on Wikipedia and shows an estimate for Holocene temperatures. (CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=466269)

Missing from the graph are 1) when does it end, 2) what is the baseline. I've seen this graph and others like it being used by denialists because the "now" in the graph is way below earlier Holocene temperatures.

Wikipedia does offer a more detailed description of the graph, where it says that the baseline is mid 20th century average temperature, and that the graph goes up to year 2000. Both statements cannot be true, since the graph ends well below zero and the year 2000 was significantly warmer than mid 20th century (it was even warmer than the warmest year of the temporary maximum in the 1940s).

I suspect that the graph ends in 1970 which is commonly used in paleoclimatic graphs. Does anybody know?

If we look at the 2016 point at around 0.8 degrees above baseline, this is the same as the HadCRUT figure for 2016 so one could be excused for thinking that the graph uses the same baseline, i.e. 1961-1990.

But the averages for the 1960s and the 1970s are around -0.05 for this baseline, which does not match the graph ending in approximately -0.2 degrees.

So again does anybody know what the baseline is here?
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

deconstruct

  • New ice
  • Posts: 54
    • View Profile
  • Liked: 24
  • Likes Given: 16
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2382 on: July 29, 2019, 09:12:46 AM »
Wikipedia does offer a more detailed description of the graph, where it says that the baseline is mid 20th century average temperature, and that the graph goes up to year 2000. Both statements cannot be true, since the graph ends well below zero and the year 2000 was significantly warmer than mid 20th century (it was even warmer than the warmest year of the temporary maximum in the 1940s).

I suspect that the graph ends in 1970 which is commonly used in paleoclimatic graphs. Does anybody know?
You are aware that the graph includes a small box with the recent temperature data up to the year 2000 which also includes the proxy-average as in the big graph? The year 2000 in that graph can well be the endpoint and it is also well above the baseline temperature, which could very well be the mid-20th century average.

Proxy data cannot typically go to the most recent year because of various reasons and the small box contains the necessary information to put those proxy temperatures in reference to the current temperatures. The recent temperature data was probably not put in to the bigger proxy-graph, because the time-frame of the recent temperature increase is so short (compared to the 12.000 year time frame of the graph, that the current temperature rise would only be a vertical bar along the right y-axis.

In addition, the temperature of the year 2016 is marked on the right end of the big graph also. So you can clearly see that current temperatures are well above any data-point in the whole 12.000-year proxy-average.

And wikipedia has a discussion page for each content, so you could just ask there or put forward critisism, as the creator(s) of that graphic will most certainly respond directly.

binntho

  • Nilas ice
  • Posts: 1519
    • View Profile
  • Liked: 528
  • Likes Given: 119
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2383 on: July 29, 2019, 09:16:50 AM »
I'm not looking for a lot of excuses that I could have made myself. I'd like to know what the baseline is and when (approx. what year) the thick line in the main graph comes to an end. Publishing a graph without that information is bad enough, but when someone writes an explanation on Wiki that is clearly wrong it get even worse.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

Rich

  • Guest
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2384 on: July 29, 2019, 09:23:27 AM »
Re: the discussion of disconnect between area / extent #'s.

My cursory understanding is that the ice is analagous r to the business cycle. Orders (area losses) precede cash receipts.

In June and early July we took a lot of ice orders. We were < 1k short of 21 straight days of century area losses. Extent losses were much lower than area losses during that period.

Since that 21 day streak, we've had 13 straight days below 100k and have been about 50k the last 5 days. Orders are drying up. Extent losses gave been high reflecting collections of June / July orders.

This is a question framed as a straw man. Is the straw man understanding basically correct?

Note: this applies to extent losses due to in situ melt. extent losses due to wind driven export would not be expected to be preceded by area losses.

oren

  • Moderator
  • First-year ice
  • Posts: 6297
    • View Profile
  • Liked: 2314
  • Likes Given: 1953
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2385 on: July 29, 2019, 11:38:19 AM »
Life is not so simple. Generally area losses are indeed a leading indicator of extent losses, with the lag highly variable. But sometimes area losses will actually translate to immediate and oversized extent losses, when a dispersed rubble region is decimated completely, often by a storm.
Sometimes area losses increase the potential for area gains, with no effect on extent - for example melt ponds on fast ice in the CAA and in the Siberian sector, often appear in mass and then drain. This happened very clearly this year. In addition, area losses in September could refreeze before extent manages to follow, this happened in 2016 in the pole region.

Phil.

  • Frazil ice
  • Posts: 362
    • View Profile
  • Liked: 45
  • Likes Given: 1
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2386 on: July 29, 2019, 01:20:03 PM »
Stating the baseline is very important and I'm surprised to see how often it's not done. The following is a good example, the graph is found on Wikipedia and shows an estimate for Holocene temperatures. (CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=466269)

Missing from the graph are 1) when does it end, 2) what is the baseline. I've seen this graph and others like it being used by denialists because the "now" in the graph is way below earlier Holocene temperatures.

As to where the graph ends, 0 BP is 1950 and the main axis shows a small extension beyond 0 BP so somewhere around 1970 seems reasonable.

Shared Humanity

  • Guest
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2387 on: July 29, 2019, 04:15:12 PM »
So perhaps this AGW isn't such a bad idea after all?

Thank you for so clearly revealing your motivation.

Was someone feeling a bit grumpy yesterday? One small joke and it's eternal banishment ...

If it was a joke, then you should attach the appropriate emoticon. There are a lot of people who occasionally visit this site and your comment could very well mislead them. As this site is intended to address the very serious issue of AGW, you should be more careful.

So I don't really see that we have to have a "before and after" point where "proper" measurements began when we want to talk about AGW.

I have already answered this question but the entire point of this site is to understand the impact that AGW has had already and will have in the future. To do this, you need to know the baseline which is simple to identify based on atmospheric CO2. The baseline is the 1st five decades of the 19th century and human induced warming now stands at 1.5C over baseline.

So let me state my position as clearly as I can:

1) I believe that humanity has caused a rise in global temperatures in the region of 1.5 degrees Centigrade in the last 150 years or so.

2) I believe that this warming is continuning and even accelerating because of the common failure of humanity to stem CO2 pollution.

3) I belive that a rise of 1.5 in 150 years is catastrophic. A cataclysm that is slowly unfolding before our eyes. A threat to human civilization like none other.

Thank you for clarifying your beliefs regarding AGW. I am in complete agreement with the above 3 statements.

So I guess that I'll make everybody extremely stroppy by stating that a) there is nothing we can do and b) the catastrophe is already here.

Of course, the bolded statement is absolute bullshit.

There are absolutely things we can do and we need to get started immediately. The latest IPCC report states clearly that we must eliminate all AGW emissions by 2050 to avoid catastrophic warming. (Lets set aside how each of us might view what is catastrophic as there is likely some disagreement here.) We have the knowledge, science, technology and resources to do exactly what the IPCC states is necessary and to suggest otherwise is defeatism in the face of a huge but solvable problem. This defeatist attitude is the next way that denialists will use to stall action.
« Last Edit: July 29, 2019, 04:22:12 PM by Shared Humanity »

Rich

  • Guest
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2388 on: July 29, 2019, 04:40:24 PM »
Nitpicky point - IPCC doesn't say we need to eliminate all GHG emissions by 2050, we need to get to NET zero.

Bigger point - Binntho omits that IPCC also indicates we need to reduce emissions by 45% by 2030. Arguably an order of magnitude more difficult than net zero by 2050.

Agree that deniers will use defeatism.

Regarding SH's assertion that ASIF is a site dedicated to fighting AGW.... I'll agree that ASIF is a premium knowledge resource resource regarding AGW and an asset. But I don't think you can claim that it is dedicated to fighting AGW w/o declaring it as your mission.

I would certainly welcome a formal declaration that stopping AGW is an essential part of the mission here.

gerontocrat

  • First-year ice
  • Posts: 9328
    • View Profile
  • Liked: 3726
  • Likes Given: 28
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2389 on: July 29, 2019, 05:29:20 PM »
Mission statements? bleah (In search of the vomit emoji)
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Pmt111500

  • Guest
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2390 on: July 29, 2019, 05:43:53 PM »
Mission statements? bleah (In search of the vomit emoji)
Is this it? 🤢 . Finland just had it's warmest weekend, possibly for the whole year, my place topped at 33,9°C, and the nearby park is again pretty trashed up. Maybe I'll go and clean it up a bit, later in this week, but it's not a mission. I just like parks with less trash.

SteveMDFP

  • Nilas ice
  • Posts: 1784
    • View Profile
  • Liked: 369
  • Likes Given: 23
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2391 on: July 29, 2019, 06:05:52 PM »
...Regarding SH's assertion that ASIF is a site dedicated to fighting AGW.... I'll agree that ASIF is a premium knowledge resource resource regarding AGW and an asset. But I don't think you can claim that it is dedicated to fighting AGW w/o declaring it as your mission.

I would certainly welcome a formal declaration that stopping AGW is an essential part of the mission here.

This is the "Arctic Sea Ice Forum," not the Climate Activism Forum.  We engage in science-based discussion, with articles, data, analysis, and interpretation.  Nothing wrong with that.

I'd guess 95% of those who post here recognize global warming as a civilization-threatening phenomenon.  I'd give a wild guess of 70-80% of non-posting readers also recognize this.

Declaring ASIF to be an activism hub undermines the credibility of the science discussions--thus counterproductive.  Careful, nuanced analysis of the science is and should be the centerpiece here, even when a few of the nuances might suggest "maybe it's not that bad" sometimes.  Seems to me the overwhelming body of evidence suggests things are worse than we thought before, but all the science is appropriate to discuss.

Many here individually already take dramatic personal action to try to move the needle.  There are side-threads where discussing such actions is welcomed by Neven.  That seems appropriate to me. 

Badgering anyone here to "do more" is just preaching to the choir.  It's pointless and distracting from the real work being done here.

That's how I see it.  If you disagree, there's little point arguing with me, take it directly to Neven, this is his garden.

Rich

  • Guest
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2392 on: July 29, 2019, 06:06:00 PM »
Mission statements? bleah (In search of the vomit emoji)

Heh heh. The ever present peanut gallery. I raise your rotten tomato and throw a raw egg in return.

What group ever achieved it's objective without declaring it's intention?

Where did I put that plastic straw? Must be around here somewhere.

Shared Humanity

  • Guest
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2393 on: July 29, 2019, 06:21:56 PM »
Mission statements? bleah (In search of the vomit emoji)


Tor Bejnar

  • Young ice
  • Posts: 3637
    • View Profile
  • Liked: 633
  • Likes Given: 407
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2394 on: July 29, 2019, 06:54:47 PM »
I want to add the note that in much geo-scientific literature, 1950 is used as the "now" date.  Per Wikipedia:
Quote
Before Present (BP) years is a time scale used mainly in archaeology, geology and other scientific disciplines to specify when events occurred in the past. Because the "present" time changes, standard practice is to use 1 January 1950 as the commencement date of the age scale, reflecting the origin of practical radiocarbon dating in the 1950s.
… 


Stating the baseline is very important and I'm surprised to see how often it's not done. The following is a good example, the graph is found on Wikipedia and shows an estimate for Holocene temperatures. (CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=466269)

Missing from the graph are 1) when does it end, 2) what is the baseline. I've seen this graph and others like it being used by denialists because the "now" in the graph is way below earlier Holocene temperatures.

As to where the graph ends, 0 BP is 1950 and the main axis shows a small extension beyond 0 BP so somewhere around 1970 seems reasonable.
Arctic ice is healthy for children and other living things.

gerontocrat

  • First-year ice
  • Posts: 9328
    • View Profile
  • Liked: 3726
  • Likes Given: 28
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2395 on: July 29, 2019, 07:07:33 PM »
To me, "Mission Statements" are like  "My Vision":-
_______________________________________________
Adams Family values
Wednesday:
I don't want to be in the pageant.

Gary:
Don't you want me to realize my vision?

Wednesday:
Your work is puerile and under-dramatized. You lack any sense of structure, character, or the Aristotelian unities.

Gary:
Young lady, I am getting just a tad tired of your attitude problem.
__________________________________________________
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

nanning

  • Nilas ice
  • Posts: 2378
  • 0Kg CO₂, 37 KWh/wk,125L H₂O/wk, No offspring
    • View Profile
  • Liked: 295
  • Likes Given: 20161
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2396 on: July 29, 2019, 07:08:03 PM »
Thank you Tor :).
"It is preoccupation with possessions, more than anything else, that prevents us from living freely and nobly" - Bertrand Russell
"It is preoccupation with what other people from your groups think of you, that prevents you from living freely and nobly" - Nanning
Why do you keep accumulating stuff?

Memshin

  • New ice
  • Posts: 2
    • View Profile
  • Liked: 1
  • Likes Given: 3
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2397 on: July 29, 2019, 07:39:16 PM »
Way above, in post #2332, I posted a stupid question on the relationship of 'specific heat' to warming. I fear that it has become lost among all the discussion here about how stupid, or not, subsequent "stupid" questions were. Anyone available to provide an answer?

crandles

  • Young ice
  • Posts: 2752
    • View Profile
  • Liked: 163
  • Likes Given: 55
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2398 on: July 29, 2019, 08:15:03 PM »
My first post, after lurking for several years! I am not a scientist, but read quite a bit of science in my spare time. This includes reading (and re-reading) large sections of the blog "Science of Doom" to try to familiarize myself with the basics of climate science.
I recently Googled "climate science for dummies" and one of the top results was this: https://sciencetrends.com/climate-change-dummies-basics-climate-change-physics/
The author claims that it is the 'specific heat' of various molecules that determines their green house gas property. This is quite different from what I've read elsewhere, which is that it is the ability of different molecules to absorb and re-emit long wave radiation that is important.
My question is: is there an additional role for specific heat in the dynamics of global heating, or is this author simply mistaken? (He does not seem from the article to be a denier, but might still just be misinformed)

My non expert answer:

I think he is just mistaken.

O2 and N2 being identical molecules on each end of the bond just don't have the modes of vibration to absorb and re-emit long wave radiation. Together with argon makes over 99% of atmosphere have completely negligible GHG effect. Therefore as a result remaining tiny proportions of the atmosphere like 420ppm of CO2 can have significant effects.

If Nitrogen and oxygen were only slightly worse GHGs as per his figures and total GHG effect is around 33C but represented 99% of atmosphere then very large proportion of GHG effect would be down to N2 and O2, and the effect we could get from doubling CO2 from .0028% of atmosphere to .0056% of atmosphere would be far smaller than we need worry about.

>additional role for specific heat
I wouldn't really know. I tend to doubt it but if there is an effect then it is very small.

Rich

  • Guest
Re: "Smart" and "Stupid" Questions - Feel Free To Ask
« Reply #2399 on: July 29, 2019, 08:25:59 PM »
To me, "Mission Statements" are like  "My Vision":-
_______________________________________________
Adams Family values
Wednesday:
I don't want to be in the pageant.

Gary:
Don't you want me to realize my vision?

Wednesday:
Your work is puerile and under-dramatized. You lack any sense of structure, character, or the Aristotelian unities.

Gary:
Young lady, I am getting just a tad tired of your attitude problem.
__________________________________________________

Despite my narrowly focused complaint of a few months ago Gerontocrat, I must confess that you are one of my favorite posters.

You're the Renaissance Man of ASIF. The guy from the Dos Equis commercials (The most interesting man in the world character).

If someone is going to watch the world come to an end or hang out and drink beer, I'd wager you would get most votes among the ASIF citizenry as the person to hang out with.

I'm trying to explore the subject of the world not ending. It's not a sexy topic but I'm trying to cultivate a market for it. Maybe with your array of experience and witticisms, you can help with that.

If we can make saving the world playful and snarky and fun, more people might be inclined to take action to do something about it. There's no pride of ownership here. If someone else like you can lead the way, I'll be a very happy follower.

« Last Edit: July 29, 2019, 08:44:04 PM by Rich »