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BornFromTheVoid

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2 hours ago, Sky Full said:

This is a very useful thread for those of us who are worried by the conflicting opinions and data which jostle each other in the climate warming debate and confuse the unqualified onlooker.  There is plenty of atmospheric temperature based evidence to demonstrate that the global climate is warming but, in my opinion, still far too much reliance being placed on the ability of the human race to brake or even reverse the process.  The issue I wish to raise relates to the increasingly rapid retreat of the worlds glaciers and the drastic reduction in the size of the Arctic / Antarctic ice sheets.  There can be no argument about this because photographic evidence clearly shows glaciers retreating back up mountains in every range in the world.  The Antarctic ice sheet has been shown by satellite images to be breaking up for decades now and we all know that the North Pole could be ice free within 20 years.  Given that the ice bound regions of the world have for millennia reflected back into space a portion of the Suns energy and prevented the oceans in those areas from absorbing heat from the sun, my worry is this: as the ice gradually disappears is it not the case that the sun will have an increasingly warming effect on the globe which becomes self-accelerating (i.e. the more the ice melts, the warmer it gets, and the more the ice melts etc....).  Land and oceans left ice free will absorb far more energy and contribute to the overall warming far more than when covered with ice.  It seems too late to hope that we can replace the ice which has already melted so, even if we reduce our emissions today, is it also too late to stop the rest of the ice from melting now?  If this is true, could the world continue to heat up due to its less reflective nature even with zero emissions from mankind?  Is this process being taken into account by climate warming models?  Have there been any studies to show what the world would be like - habitable or not? - if it were to become largely ice-free (apart from sea level rises which would be devastating enough on their own)?

Sorry .... Far too many questions in one post!

 

Yes, Ice-albedo feedback is a well know, and long known, phenomena. You are right about the consequences of it.

Indeed, aiui, a good portion of the projected modeled warming is due to ice-albedo warming - though exactly how much I'm not sure.

As to 'too much reliance being placed on the ability of the human race to brake or even reverse the process.' well, (as bftv said in this post) 'This all feels a bit like a gambler. Someone that had a short period of success but now is almost broke, with his home, family, and career on the line. He starts asking around for solutions, but with the caveat that nobody suggests he stops gambling or reduce how much he gambles. Anyone that suggests those things he decries as naive and unrealistic, insinuates ulterior motives for suggesting them and uses whatever he can to try attack their character.'

 

 

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5 hours ago, Devonian said:

Yes, Ice-albedo feedback is a well know, and long known, phenomena. You are right about the consequences of it.

Indeed, aiui, a good portion of the projected modeled warming is due to ice-albedo warming - though exactly how much I'm not sure.

As to 'too much reliance being placed on the ability of the human race to brake or even reverse the process.' well, (as bftv said in this post) 'This all feels a bit like a gambler. Someone that had a short period of success but now is almost broke, with his home, family, and career on the line. He starts asking around for solutions, but with the caveat that nobody suggests he stops gambling or reduce how much he gambles. Anyone that suggests those things he decries as naive and unrealistic, insinuates ulterior motives for suggesting them and uses whatever he can to try attack their character.'

Thanks for the reply Devonian (a great Epoch, that).  I hope it didn't sound like I am against any effort being made to counter man-made climate change - I am in favour of any steps we can take to reduce the threat of global warming - but I am increasingly coming to the conclusion that there is little chance of successful action given the current human population of the planet and its projected growth rate in the future.

4 hours ago, knocker said:

And

The albedo effect and global warming

https://skepticalscience.com/earth-albedo-effect.htm

needless to say this is a very complex area and research is ongoing

Thanks for this link Knocker - it's clearly an extremely complex phenomenon and its effects seem to be difficult to accurately forecast with current levels of analysis and observation.  Returning to my question regarding the habitability of the Earth if all the ice were to melt, there was a reference to this which implied that the extra water vapour in the atmosphere would create more clouds which, although they are reflective are even more effective as a greenhouse gas and so would also further increase global temperatures.  As I understand this, in an extreme future, the Earth could conceivably become another Venus shrouded in insulating clouds with runaway surface temperatures rendering all life impossible......

Best we try and find a solution before this happens, then.

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19 hours ago, Sky Full said:

 

Thanks for this link Knocker - it's clearly an extremely complex phenomenon and its effects seem to be difficult to accurately forecast with current levels of analysis and observation.  Returning to my question regarding the habitability of the Earth if all the ice were to melt, there was a reference to this which implied that the extra water vapour in the atmosphere would create more clouds which, although they are reflective are even more effective as a greenhouse gas and so would also further increase global temperatures.  As I understand this, in an extreme future, the Earth could conceivably become another Venus shrouded in insulating clouds with runaway surface temperatures rendering all life impossible......

Best we try and find a solution before this happens, then.

First a brief summation from Raymond Pierrehumbert

The fact that Earth maintained habitable conditions while Venus succumbed to a runaway greenhouse and got too hot, and Mars lost its atmosphere and got too cold, raises the question of just how narrowly Earth escaped the fate of Mars and Venus. How much could Earth’s orbital distance be changed before it turned into Mars or Venus, and how would the answer to this question change if Earth were more massive (making it easier to hold onto atmosphere) or less massive (making it easier to lose atmosphere)? If Mars were as large as Earth, would it still be habitable today? What if Venus were as small as Mars? Perhaps if the orbits of Mars and Venus were exchanged, our Solar System would have three habitable planets, instead of just one.

The range of orbital distances for which a planet retains Earthlike habitability over billions of years is known as the habitable zone. Determining the habitable zone, and how it is affected by planetary size and composition as well as the properties of the parent star, is one of the central problems of planetary climate.

But to be more specific regarding your question then yes the earth’s habitability will end when the sun leaves the main sequence and expands into a red giant but that is about four billion years hence.

But a habitable crisis could occur before that. In particular, as the sun continues to brighten, at some point the brightness will outstrip the ability of the silicate weathering process to compensate by drawing down CO2. At that point the earth would succumb to a runaway greenhouse, become lethally hot, and lose all its water to space.

In short I don't think we need concern ourselves about a runaway greenhouse effect but we should most be very concerned about the way we knowingly slowly destroying our planet

Edited by knocker

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4 hours ago, knocker said:

But to be more specific regarding your question then yes the earth’s habitability will end when the sun leaves the main sequence and expands into a red giant but that is about four billion years hence.

But a habitable crisis could occur before that. In particular, as the sun continues to brighten, at some point the brightness will outstrip the ability of the silicate weathering process to compensate by drawing down CO2. At that point the earth would succumb to a runaway greenhouse, become lethally hot, and lose all its water to space.

In short I don't think we need concern ourselves about a runaway greenhouse effect but we should most be very concerned about the way we knowingly slowly destroying our planet

Thanks Knocker - that was a very interesting quotation and summary.  You are an absolute mine of information and of links to others with information or data, and we are lucky to have you!

To take this question a little further, if it is unlikely that human actions alone could cause a runaway greenhouse effect in the foreseeable or even the far distant future, it must be arguable that there continues to be a reasonable hope for humankind to live out its natural evolution on earth.   I have always believed that even moderate climate change might be capable of upsetting the delicate balance of nature, eventually bringing about the extinction of all complex animal life on the planet and that this would then remain the state of the world for many millions of years until different forms of life emerge and evolve to cope with the new conditions, much like the events of pre-history.   Perhaps climate change / global warming could be limited in its effects, serious though they may be, and life including humans may continue to exist after the worst happens, albeit in much reduced numbers and variety and even perhaps at the extreme edge of survival?  Not that this is should provide any excuse to continue consuming the worlds resources at the present rate, of course....

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Thank you SF but this area is much luckier in having the commitment and knowledge of BFTV over the years 🙂

Edited by knocker

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Just a quick question to anyone who can answer.  The world as we know it is going through a warming phase  and if no action is taken this could well become unreversable   however  i understand ( and correct me if im wrong)  that with this happening Some scientists agree that some parts of the world  namely Northern Europe  will cool  some think it will stay the same    this is down to the amount of freshwater entering the oceans  and causing a already weaking jet stream to weaken further.  My question is how certain are scientists on this matter(judging by the split  i assume not very)     Is this also why the term Global Warming as been changed to climate change over the years?.  

Edited by weirpig

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2 hours ago, weirpig said:

Just a quick question to anyone who can answer.  The world as we know it is going through a warming phase  and if no action is taken this could well become unreversable   however  i understand ( and correct me if im wrong)  that with this happening Some scientists agree that some parts of the world  namely Northern Europe  will cool  some think it will stay the same    this is down to the amount of freshwater entering the oceans  and causing a already weaking jet stream to weaken further.  My question is how certain are scientists on this matter(judging by the split  i assume not very)     Is this also why the term Global Warming as been changed to climate change over the years?.  

Regarding the last question it hasn't been changed, they have long been used separately because they mean different things

https://skepticalscience.com/climate-change-global-warming.htm

https://climate.nasa.gov/resources/global-warming-vs-climate-change/

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16 hours ago, ALL ABOARD said:

Is there a thread for people who aren't sure about 'climate change'? 

This one?

Ask a question? Ask a question about what you're not sure about?

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I am going to attempt to rephrase an earlier (now removed) question in politically neutral terms that can surely cause no offense to any reader.

What percentage of the warming since 1980 or any other defined recent starting point of the AGW signal is attributable to natural variability? 

If we agreed that the CET has risen about 1 C deg since a pre-AGW mid-20th century average value, then what would it be if there was no human activity on the planet? 

And what is the reasoning behind that conclusion? 

(Just for the record, I would state my opinion that the warming is somewhere between 50% and 80% natural in origin, so the human signal is 20 to 50 per cent, and without human activity the mean CET would be 9.8 instead of 10.2.)

There is a related question that forms part of my own research focus. 

Does the AGW signal warm up all air masses proportionately? For example, are mild winter air masses warmed up by 1 degree as well as arctic air masses, or is it more that arctic air masses are warmed up 2 degrees and also we see them less often that causes the warming? 

(I have not finished the research ongoing to provide an opinion on this myself but could note that my study of Toronto temperatures over 180 years indicates that air mass temperatures are not changing very much, it is air mass frequency that has changed, and the biggest step function of that change was actually as far back as 1897 to 1915. This is something for which I can provide evidence when I publish the "Toronto 180" study that is in proof-reading stages now -- Toronto began recording in March 1840). 

Another question for you:

What part of the AGW process creates simultaneous surges of warming in distant locations, namely, Toronto and central England? Why are record high temperatures often set in clusters around the same months in these two distant locations? What leads you to think that this is not evidence of natural variability having a powerful influence? 

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21 minutes ago, Roger J Smith said:

What percentage of the warming since 1980 or any other defined recent starting point of the AGW signal is attributable to natural variability? 

If we agreed that the CET has risen about 1 C deg since a pre-AGW mid-20th century average value, then what would it be if there was no human activity on the planet? 

And what is the reasoning behind that conclusion? 

(Just for the record, I would state my opinion that the warming is somewhere between 50% and 80% natural in origin, so the human signal is 20 to 50 per cent, and without human activity the mean CET would be 9.8 instead of 10.2.)

I'll just deal with the first part as I haven't much time atm.

The most likely scenario for trends in global temperature since 1980 in the absence of AGW, is no warming trend, or at least a trend too small to detect over such a time. We would likely be within one or two tenths of a degree of the climatological average around 1980. Also, around half of the warming early in the 20th century is attributed to human activity. Based on the IPCC AR5, there was about 0.65C warming between 1950 and 2010.  The contribution of GhGs are estimated to be between about +0.5 and +1.3C, with a best estimate of about +0.9C. Other anthropogenic influences have a mainly negative forcing, such as aerosols and land use. The graph for this is posted below, and a link to the relevant IPCC chapter is also provided.

ipccnet.thumb.JPG.11387064a3c80ab1375bc00c4551dcda.JPG
https://www.ipcc.ch/site/assets/uploads/2018/02/WG1AR5_Chapter10_FINAL.pdf


Also, the most likely scenario, lets say from 1900 to now without the human contribution, would have been slow cooling. The long term trend for the 6-8,000 years before the turn of the 20th century was for cooling (strongest in the northern hemisphere summer), in line with expectations from the Milankovitch cycles.

Marcott.png

The reasoning for suggesting that humans are responsible for about 100% of the recent warming is from published research, including 100s of specific attributions studies dealing with the topic of assigning estimates of climate change to internal, external and anthropogenic factors.
Some examples include simple statistical analysis of past temperature change and variations in their drivers. How has the climate varied over the last 1,000 years? How have CO2, solar, volcanic activity and other important features varied? How unusual is the warming of the last 100 years in comparison? Based on our best understanding of the climate and our knowledge of how the forcings have changed, what can we attribute the rapid warming too? These kinds of questions inevitable lead to GhG emissions as the dominant cause.

Climate models are another tool (which are our best understanding of the physics governing the climate placed in a single numerical package) and doing things like running it with just natural drivers thousands of times and seeing if we can get something close to the observed temperature record during the last 150 years (we can't). Then adding in the known CO2 emissions, land use change, aerosols, etc.,  and seeing how that changes things. You can also run the models to simulate the climate over thousands or millions of years ago. Do the physics capture those variations well? How strong is the influence of natural GhG changes in these scenarios? Questions like these can help to determine how much our own emission of GhGs are influencing the climate now.

Another way is using the "fingerprints" of anthropogenic warming. Warming from particular sources act in different way, producing spatial and temporal temperature changes that are unique to them. For example, the thermosphere and stratosphere are expected to cool due to GhG induced surface warming  and ,as expected, both are cooling. If the warming was solar based we wouldn't see cooling in these layers.
We receive short wave radiation from sunlight, which is absorbed by the surfaces and re-emitted out as longwave radiation. GhGs absorb that longwave radiation and send some of it back to the surface, causing warming. As such we can measure that less longwave radiation is leaving the planet than expected and more is reaching the surface. This is another fingerprint for GhG warming (you can even measure the specific energy wavelengths are being altered, separating out the signal from water vapour, CO2, methane, etc).

Anyway, attribution is a big area with loads more aspects and detail involved. Way more than I have time to get into (or even fully understand!). But this should be an ok start. However, there is no evidence I've seen that natural variation is responsible for the 50-80% suggested.

For the other questions, warming varies regionally based on amplifying factors and circulation changes. The Arctic warms much faster due to ice and snow loss, reducing the reflectivity, allowing the surface absorb solar energy and thus to warm more (2 to 3 times faster than the global average). Coastal areas tend to warm more slowly due to the thermal inertia of the oceans. But I'll attempt more detail another time.

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Thanks, I appreciate the answers, I suppose what lies beneath the surface of the differences in opinion we apparently have (and I have little doubt that your viewpoint is that of the stated consensus) goes directly to this question:

Surely any analysis of current temperature trends will reveal that it is mainly based on air mass differentials over time. There is no evidence that we have the same air mass frequency as at some early point in the 20th century (I would say 1901-30) to get far enough back to a time that could not reasonably be held to be AGW-influenced). There is evidence that we have more frequent warm air masses than before, and less frequent cold air masses. This implies that the general circulation has changed. 

So putting that together with the above explanations, it can only mean one thing, the orthodox theory rests on the assumption that human activity has changed the general circulation. In simplistic terms, it has driven the storm tracks in temperate zones further north. I would not argue with the assumption that this has happened, only with the part that attributes most or all of it to human activity. Storm tracks were already moving north during the period 1870 to 1900, and what we have seen since then is more or less a linear extension of what we saw then.

Has the AGW research uncovered any actual cause and effect proof that human activity is driving the storm tracks further north? I think this is the main weakness that a skeptic of the theory could exploit. I would expect a fully human caused warming to be acting differently from that, warming up all air masses since we live within the source regions of all air masses. As I said in the locked thread, my concern now is that skeptics have therefore assumed the warming itself is over-rated, whereas I am taking a third-rail approach of saying, no the orthodox theory is quite right in its analysis of trends, but wrong in its attribution of cause and effect, meaning that we are preparing for a different set of outcomes (we might save ourselves from harm that I feel could be inevitable). This is why I am concerned anyway. As many have told me, the burden of proof is on me although given the time lines, I wish I got the same break that the IPCC have received because we may not have that much time left before the inevitable begins to appear. 

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20 hours ago, Roger J Smith said:

Another question for you:

What part of the AGW process creates simultaneous surges of warming in distant locations, namely, Toronto and central England? Why are record high temperatures often set in clusters around the same months in these two distant locations? What leads you to think that this is not evidence of natural variability having a powerful influence? 

Is that really relevant, Roger? I mean, why/how would a global warming-trend prevent clustering --  clusters are just a manifestation of the quasi-randomness of natural phenomena...?

Surely such events would occur in clusters (both temporal and spacial) whatever the prevailing background trend happened to be?

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Ed, it's only relevant because in the supposed pre-AGW period (which seems to be pushing back further each time I look) warming occurred simultaneously on many occasions, for example in the summers of 1911 and 1921. So to my mind, if this is continuing to happen, it points to a continued natural variability process at work. Human AGW signals would have no obvious physical reason to produce such results. Presumably, if you believe that recent warming is all down to us (and the above discussion seems to imply that 150% of the warming is down to us, we're overcoming a natural cooling supposedly) then should the warmth not be more evenly spread out in time? 

I really don't want to be antagonistic to anyone arbitrarily, but I cannot accept that we would now be in a natural cooling phase which is reducing a larger than observed AGW signal. And if so, why are we fighting it? Who wants to see a climate cooling off to Maunder levels? That would be a worse outcome than warming. Granted, those are questions for the political debate and not this thread perhaps. 

My reading of Milankovitch signals is that we are in an unusual flat era now that could last quite a while (10-20k yrs at least) so that there should not be much of a background trend from that source, since the post-glacial optimum (I would say that I agree with the graph supplied to about 1,000 AD, there has been much chatter about how warm the MWP really was, and then the Maunder cold seems to be shifted a bit towards the Dalton on the graph, maybe that's what their research indicated globally. I have some very interesting weather records from 1831-60 taken at Providence RI, link is here:

 

The Toronto records begin in March 1840. From an overlap of 20 years I can work out that the average lag time of progressive frontal systems was about the same as nowadays, 0.5 to 0.7 days on the average. Any given peak of warmth at Toronto will normally be followed the next day by a similar peak at Providence RI. But the climate back then appeared to be quite a bit colder in terms of air mass distribution, and the numbers at Toronto which has continued its obs to the present time show that the main warming took place around 1897 to 1915. Part of that is due to a fast growing urban heat island, but even the markers that are unaffected by the heat island change rapidly around then (low max tends to be resistant to heat island effects because of the wind speeds often associated). Anyway, I am working on updating the Toronto records which were published in 1967, and have found some interesting things which Net-weather readers can see for themselves when I post the entire file and commentary in the new year (needs some minor proofing at this point). 

As an example of what's interesting about this long period of record, the frequency of record low minima drops off sharply after 1895 (just like in Britain, a very cold February occurred then). But the frequency of record low maxima drops off less rapidly showing two minor resurgences in the 1920s and from 1978 to 1982. It has very recently begun to edge back up after hitting an absolute minimum 2005 to 2012. These different trends are what you would expect in a warming climate subjected to a growing heat island (the minima need a really cold air mass to overcome the 3-5 C heat island at Toronto, but that shrinks to 1-2 C deg in daytime and nearly zero on windy cold days). 

The years with the most record highs are not as recent as you might expect, although some of the top ten are recent. 1931 and 1936 beat out any of the warm 1998 to 2019 period. 1916, 1919, 1921 and 1955 are all in the top ten. A few recent peaks are similar to the UK, 2015 to 2017 seems to have been more prolific than most three year intervals recently. 

None of this really tells us much about the division between AGW and natural variability, but I was surprised how well the older record highs have held up after not seeing the data very much since I was "all over it" in my early days of weather interest (which would be 1967 to 1975 ish). Only a few more than random expectation numbers of record daily highs have been broken, and only one day entered the top ten of summer maxima (100+ in F as observed before 1976 there). Only four entered the top twenty (and three of those were in the 1980s, the new top ten entrant was 101 F in July 2011). The other days that have broken 100F at Toronto (downtown) are in 1854, 1911 (2), 1916, 1936 (4), 1948 (3) and 1953 (1). Even with the warmer nights of the modern large heat island, many top ten months are from before 1970. The warmest July is still 1921, the warmest Octobers (tied) are 1947 and 1963. 

What I did find was that two parts of the year have warmed more noticeably than the rest. These are mid-November to mid-December, and mid-February to mid-March. Most of the daily record highs in those intervals have been replaced more recently (December 1982 did considerable damage). Some other periods have fewer than even the random expectation number of new record highs. Both May and September are noticeably deficient. August has many new record high mins and very few new record high maxes. 

The way climate change is actually happening seems very complex and I am skeptical about anybody's ability to break down the component parts. This is why I am skeptical about projections into the future. But my guess is that warming is slowly accelerating regardless of cause and cannot be reversed (very easily at least, I am no expert on such schemes as scattering particles in orbit to reduce insolation, and I fear for unknown consequences of any such efforts). 

I think we could all agree that another glacial period (ice age in common parlance) would be the worst case scenario, we could more easily deal with a 10-30 metre sea level rise than continental glaciations. Maybe it's my location that predisposes me to think that. But maybe hunting mastodon is not that bad a job. 

 

Edited by Roger J Smith

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19 hours ago, Roger J Smith said:

Thanks, I appreciate the answers, I suppose what lies beneath the surface of the differences in opinion we apparently have (and I have little doubt that your viewpoint is that of the stated consensus) goes directly to this question:

Surely any analysis of current temperature trends will reveal that it is mainly based on air mass differentials over time. There is no evidence that we have the same air mass frequency as at some early point in the 20th century (I would say 1901-30) to get far enough back to a time that could not reasonably be held to be AGW-influenced). There is evidence that we have more frequent warm air masses than before, and less frequent cold air masses. This implies that the general circulation has changed. 

So putting that together with the above explanations, it can only mean one thing, the orthodox theory rests on the assumption that human activity has changed the general circulation. In simplistic terms, it has driven the storm tracks in temperate zones further north. I would not argue with the assumption that this has happened, only with the part that attributes most or all of it to human activity. Storm tracks were already moving north during the period 1870 to 1900, and what we have seen since then is more or less a linear extension of what we saw then.

Has the AGW research uncovered any actual cause and effect proof that human activity is driving the storm tracks further north? I think this is the main weakness that a skeptic of the theory could exploit. I would expect a fully human caused warming to be acting differently from that, warming up all air masses since we live within the source regions of all air masses. As I said in the locked thread, my concern now is that skeptics have therefore assumed the warming itself is over-rated, whereas I am taking a third-rail approach of saying, no the orthodox theory is quite right in its analysis of trends, but wrong in its attribution of cause and effect, meaning that we are preparing for a different set of outcomes (we might save ourselves from harm that I feel could be inevitable). This is why I am concerned anyway. As many have told me, the burden of proof is on me although given the time lines, I wish I got the same break that the IPCC have received because we may not have that much time left before the inevitable begins to appear. 

Global temperatures are monitored and they're rising on average, some would say accelerating. Like I mentioned, we can literally measure the energy imbalance caused by the increase in GhGs, which tells us beyond doubt that the atmosphere is heating up and will continue to do so. We can also measure the build up of heat in the oceans too and the thermal expansion that is causing. Even the height of the tropopause is increasing due to heating at the surface.
The evidence is pretty overwhelming that a change in circulation is not the cause.

I can provide some citations for all the above too, if needed. It just adds a lot of time getting them!

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I suppose what's difficult for me and I suspect for many other weather enthusiasts (and perhaps some professionals) is to picture the weather we're seeing now as artificially warmed up cold air, which is what is implied by the combination of statements above (natural cooling trend, human signal larger than the observed warming, no change in circulation). 

Is there any description that can avoid this apparent paradox, because I think many look at the weather (and as you know, thousands look at it in considerable detail day to day) and we see a warming climate that appears like a more frequent arrival of traditional warm air masses. I will be able to back that up with hard data in the study that I mentioned, but I expect it will show something like this for tropical air masses in summer at Toronto: 

1841-1900 frequency about 20%, mean air mass temps 92 F daytime, 68 F night

1901-1960 frequency about 30%, mean air mass temps 94 F daytime, 70 F night

1961-2019 frequency about 35%, mean air mass temps 95 F daytime, 72 F night

About half to three quarters of the air mass temperature increase would be attributable to the growth of the urban heat island and tall buildings inhibiting lake breezes. The frequency of these air masses is growing, whereas the natural cooling hypothesis would predict the opposite, just a larger increase in all air mass temperatures. Tell me where I'm wrong about that. And I don't think Toronto would be some isolated case, the climate of all eastern and central North American locations has changed in phase. My work on CET records suggests a somewhat similar progression although you have another 70 years of daily data to extend it back and there was probably a decrease in frequency of warm air masses after that first interval (1772 to 1840 using the above). "Tropical" is an air mass designation used differently in Europe and North America, you call a mild winter flow tropical whereas here it would be designated mP, actual mT air masses in the winter here would seldom if ever reach Toronto and would have 75/55 max/min characteristics if they reached DC or NYC. And my numbers are for summer, so looking at what might be called tropical air masses in Britain, I think there would be overlap with what North American analysts would call cP air masses of Pacific origin (typical July air mass temps would be 82-85 daytime and 60-65 night). So a comparison would be rather indistinct. Even so, the frequency of daily record highs seems to be always increasing. There again, I can't square that with any concept of a naturally cooling climate being artificially warmed. I would expect that to look more like this past month a lot more often than this past month has showed up. 

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IMO, the question is, or at least should be: How can an increase in 'artificial' CO2 produce anything that's different from what 'natural' CO2 causes (i.e. warming)? The imprint of varying GHG concentrations is clearly written on the paleoclimatic record, is it not?

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@Roger J Smith - storm tracks further north and more tropical air masses pushing north is one thing....but how de we square the reality of arctic warming with this? If it is merely a circulation change then surely the arctic wouldn’t melt so fast?

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@Roger J Smith It's quite normal for anomalous warmth to become the norm in a warming climate. This is because the temperature distribution gradually shifts to a warmer base state, so that temperatures that used to be warm and infrequent 100 years back are now close to average and relatively common, while the old average temperatures are slightly cool and less common. Here's a handy little animation to visualise the effect.
7a0cc1d750520bd47690ca1c94e93c42.gif

Even if you can attribute local warming to an increase in southerly winds, isn't it the basics of atmospheric circulation that if you see southerly winds in one area, you're gonna find northerly winds in another?  This redistribution of heat is completely different to the prolific accumulation of heat that's occurring across the planet.

That stuff is kinda redundant though. As I tried to explain previously, we can measure the difference in energy reaching the Earths surface and leaving the atmosphere. A clear imbalance is evident and we can tie this the GhGs. We can then measure the resultant accumulation of heat throughout the climate system, from the oceans to ice sheets to the atmosphere. We can also see that the pattern of warming has the distinct fingerprint of GhGs also. 

Numerous proxy records have noted the cooling over the last 8,000 years or so too, from the early Holocene warm period right up until we started pumping significant amounts of GhGs into the atmosphere. This really isn't even an area of controversy. It was a slow, long term cooling that we've already more than made up for globally (although the Arctic is still cooler than it was back about 10,000 ago.)

 

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Well maybe there is a very long-term cooling trend since the post-glacial optimum but I still don't buy that warming observed in any part of the 20th century can possibly be a naturally cooling climate radically warmed up by greenhouse gases. I continue to think it's a natural warming with an additional boost from greenhouse gases. So I plan to try to make this a third approach, distinct from both the IPCC consensus and the main body of skeptical thought which seems to be scattered among several positions, which include (a) whole thing is made up, no real changes, (b) and/or data are unacceptable, (c) yes warming, yes human activity at least half, but a natural cooling from solar minimum will overwhelm that and solve the problem at least for 20-30 years, and (d) nothing anyone can do, just react to actual changes as they occur.

I might have agreed with some blend of those skeptical positions to last year, but my latest research convinces me that both the IPCC and skeptical positions are equally invalid and would lead to poor results for humanity if adopted as the foundation for policy. My approach would strongly suggest monitoring for a nearly inevitable sea level rise and other changes, not all of which would necessarily be harmful, and deal with each with some foresight. My approach really says nothing different from the IPCC about fossil fuels being cut back, since there is nothing to be gained from ignoring that aspect. But after re-setting that component, I still believe that a natural warming trend may only slow down temporarily then resume when solar activity resumes. Perhaps it is solar activity that is causing the difference (over a longer term than 20-30 years). The 20th century was one of the most active solar cycle clusters of the entire record according to Schove. Only two other centuries seemed to match it (11th and 16th). Although rather active, the 18th century was not quite a match, and the 19th century backed off somewhat. This broadly correlates with the CET record, especially if you also add the inactive Maunder later 17th century. 

Another natural phenomenon which has been in phase with temperature changes (especially in North America) is the position of the North Magnetic Pole. As that has drifted northwest from around 70N 90W in 1839 to its current location (86N 170W), temperatures have increased steadily. If the circulation responds to any significant extent to the magnetic field, then this might be part of the explanation for northward-moving storm tracks.

To answer a specific question from Catacol, I would submit that a northward shift in storm tracks would be very conducive to temperature rises in the arctic, especially the Atlantic zone where storm tracks reach further north than in most other sectors, and it would be no surprise that Svalbard (Spitzbergen) is one of the fastest warming spots on the planet if they get into or at least close to warm sectors of travelling depressions more often. My study of climate records at Cambridge Bay and Resolute in the Canadian arctic, which appears in this forum and is regularly updated, shows a similar but less robust warming trend since about 1970 at those locations. However, they are far from flipping to a "new climate" -- the differences are rather small in comparison to the departures below -15 C which is a temperature that can easily sustain ice and snow cover. One of the factors often overlooked in assessing climate change in the arctic is sooty deposition which is largely sourced in Asia. This change to albedo of snow and ice in the Beaufort Sea zone may be more responsible than any other factor for diminishing ice cover there. 

One additional comment, the graphic showing a gradually shifting distribution of temperatures is no real proof of the IPCC position relative to my position. I would expect to see exactly that result from my hypothesis of gradually increasing warmer air masses. 

I have to say that I am also skeptical of the "99% consensus" statistic that we often hear. This does not match what I see in weather forums, albeit the 1% dissenting viewpoint may not always be that of credentialed "scientists" but some of the people who seem dubious about the IPCC position are far from being rookies or cranks, they are often leading members of the forums and people who have thought about weather data over many, many years. It seems odd to me that almost inevitably you find that the respected members of various weather forums take a somewhat dim view of the IPCC position. Can they all be wrong? Possibly, that happens in science. But could the IPCC be wrong? If they are, it will be potentially disastrous if we get the consequences anyway after actions are taken. My fear is that not enough action will be taken (by their standards) so they can easily say that the consequences are entirely due to that inaction, when possibly they were going to happen anyway. Does that matter? Well, truth matters, it is always good to know that one is proceeding on the basis of truth and not fiction. 

 

Edited by Roger J Smith

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RJS, whats been discussed about the long term cooling and anthropogenic warming isn't an idea, it's based on vast sums of empirical evidence, established physics, optics, chemistry etc. This stuff is also agreed on by a similar proportion of climatologists as biologists that believe evolution is real. Simply dismissing it because it does't square with you or doesn't feel right is the opposite of scientific.

It's been shown that the warming is not solar induced. As mentioned, the pattern of warming is not that which would be expected from solar heating, and the variations in the sun's output produce a radiative forcing that's negligible compared to many other drivers. So you can't just ignore that and simply state it's the sun. That's also not how science works

Also, black carbon has not been overlooked. First of all, satellites are continuously monitoring the albedo of the planet, the changes of which can be converted into a radiative forcing value. Overall, human activity has increased the planetary albedo, by converting forests into croplands  The two images below are from the last 2 IPCC reports, showing the radiative forcing from different factors. They specifically mention "black carbon on snow" in the AR4 report, while incorporating more of the black carbon influence in AR5, such as on ice. 
ar4_fig_spm_2.png ipcc_rad_forc_ar5.jpg

Gradually increasing warmer air masses across the globe require a cause and, through numerous lines of independent evidence, it's been clearly established that anthropogenic activity, mainly GhG emissions, is that cause.

The population is easily swayed by conspiracy theories, convincing sounding BS and confirmation bias. You see it with anti-vaxxers, flat-earthers, moon-hoaxers, people who genuinely think Trump is the second coming, etc.
It gets even worse when the topic becomes complicated, like climate change, and people would rather believe we weren't the cause. It gets worse again when the most powerful industries on the planet are pumping 10s of millions each year in active smear campaigns against scientists, spreading disinformation through networks of popular media outlets, blogs and think-tanks and lobbying governments and bribing politicians to act in the industries favour.
In these situations, public consensus is the worst thing you could use for establishing whether the science is accurate. The consensus of the actual experts, working, discovering and publishing on the topic in questions is vastly more valuable.

I think proceeding on the basis of scientific evidence, rather than faith and feelings, is what matters here.

Edited by BornFromTheVoid

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Well we seem to be at an impasse here because I cannot accept that the temperature trends from 1880 to 1950 show any real evidence of natural cooling with human warming overcoming it, the trends seem fairly obvious to me and I have always thought that in North America at least, the majority of scientists working in the field were seeing a natural warming trend. Frankly if I went onto American Weather Forum and blandly stated that temperature trends 1880 to 1950 show that, it would be "laughed out of court." So I don't really understand how the IPCC either hasn't accepted that, or has a different wording that might not be as unacceptable.

Just wondering also, if the 20th century warming cannot be natural in origins, then what caused the Medieval warm period? Many believe that it was equally warm compared to centuries before and after it. That must have had natural origins surely. So this long-term cooling trend seems to be capable of reversals on that time scale (one or two centuries).

All of the other connections in the above post are more or less irrelevant since I am not a flat earther, anti-vaxxer, moon landing hoaxer etc. My views on Trump might be more favourable than some but do not extend into the religious realm (earlier it was suggested that I was that person). 

Here's where I will leave the debate then, from my point of view, there is enough evidence to suggest that a natural warming trend was underway when the late 1970s early 1980s cooling intervened, then AGW combined with strong El Nino warmings reversed that situation from 1982 to 1990. What has happened since 1990 seems more open to the interpretation of the IPCC and I will go back to my research to investigate that in more detail. I do believe that the high solar activity of the 1917 through 2001 cycles was a factor in the warming, to what extent needs further investigation. 

Don't want to derail this thread so my next appearance in this sub-forum might be to discuss the results of the "Toronto 180" study that I have mentioned and which is almost ready for publication. I will attempt to stay away from anything political since frankly I don't know whether a belief in inevitable natural warming is going to produce any different political agenda than the one already in existence. The only change I would suggest is to start planning for the sea level rises which seem 60 to 80 per cent likely to me anyway (even if Greta has her way and we all stay home growing vegetables on our roof-tops). 

Edited by Roger J Smith

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