Climate Change - General Discussion : Read the Mod Note in post #1 before posting

Just watching the video, general comment is that I accept the physics as being valid but some of the assumptions about how the atmosphere actually works are perhaps not valid, the main objection being that all of these theoretical considerations seem to assume a steady-state atmosphere gaining only in carbon dioxide, methane and a few other greenhouse gases, but not seeing any overall change in water vapour (which is presented as a greenhouse gas in this lecture). This is perhaps where the entire debate should be centered because this is the main problem with the theory -- if cloudiness increases, the planet is likely to cool even though the assumption being made here is that any given greenhouse gas will prevent outgoing radiation in sync with its change in abundance relative to atmosphere as a whole.

So right there, with water vapour, you have an enormous uncertainty since much will depend on the distribution of cloudiness, if cloud increases more in cold climates than warm climates, one result may occur, if it's the other way around, a different outcome may occur.

Another problem I see is that while carbon dioxide may well be increasing entirely because of human activity, its contribution relative to water vapour may be fractional and therefore it returns the debate essentially to water vapour. So what if there are complex feedback mechanisms between the man-made greenhouse gas increases and water vapour? What if (as one example) the denser greenhouse gases create more stable air masses that can retain cloud cover in marginal situations where decades earlier they might have cleared out? (of course not all water vapour is in cloud but the cloud portion is important in determining incoming solar radiation in particular).

These are the sorts of complexities that these simplistic models do not seem to handle very well, if they did, predictions made around 1990 would be coming true in full rather than in part. And we are left with the ongoing uncertainty about what the climate should be doing, this entire field sometimes seems to have given itself an unwarranted right to shoo all other factors off the stage. If there were no human race or increasing greenhouse gases, what would the climate be doing over the period 1990-2020? Where should storm Georgina have been, or the earlier storm that hit Holland? Are they exactly the same as they would have been, albeit moving around air masses warmed up by 0.7 C, or are they running at higher latitudes, arriving earlier, later, with what intensity? Nobody really knows the answers to any of these questions and therefore the entire theoretical foundation is suspect (until we do know).

So this gets me back to my original base, which is to suggest that recent warming (which has flattened out since about 2006) could be partly anthropogenic, and is plausibly partly natural since solar activity was very high 1940 to 2000.

It's not so much that I dispute the physics, I just suspect that we are not anywhere near skilled enough in our understanding of how the complex machine works to say that our contribution has had all or most of the effects seen, and even if that's the case, these effects are not generally running at a rate equal to what the theory's own proponents were forecasting.

So it's mainly a question of scale, rather than yes or no do I accept the physics? The problem with saying I must accept the physics is that I apparently must accept the forecasts which are made by those who ask the question, and I definitely don't accept the higher two-thirds of those, because I suspect that at some point the atmosphere will fix itself, I don't think the planet can sustain a runaway greenhouse effect unless we are talking about massive increases in carbon dioxide that nobody is postulating. The most likely outcome is that these levels will flatten out later this century and slowly fall in the 22nd century given that we may then have much cleaner technologies (or 1% of our current population, a near extinction of the human race seems like a good bet on any number of fronts).

dense wrote: »

That is also the experimental socialist dream of local eco activists

.

Trust me, the last thing these bourgeoisie, pseudo 'socialists' want to see is the Socialistic dream, as envisaged by Marx, becoming a reality.

Here's the thing, lads, you need to explain how and why there is a global conspiracy amongst scientists of all stripes to push this agenda.
How did they manage to pull this amazing con off, and how do they continue to further indoctrinate students entering the field on an ongoing basis.

Without that, you don't have a leg to stand on

Wanderer78 wrote: »

I find it upsetting that some people still question the existence of climate change and our involvement in its development, we have to change our ways now, or this could exterminate our species and others. We can be a truly ignorant and selfish species at times

You must be living a very modest lifestyle.

M.T. Cranium wrote: »

Just watching the video, general comment is that I accept the physics as being valid but some of the assumptions about how the atmosphere actually works are perhaps not valid, the main objection being that all of these theoretical considerations seem to assume a steady-state atmosphere gaining only in carbon dioxide, methane and a few other greenhouse gases, but not seeing any overall change in water vapour (which is presented as a greenhouse gas in this lecture). This is perhaps where the entire debate should be centered because this is the main problem with the theory -- if cloudiness increases, the planet is likely to cool even though the assumption being made here is that any given greenhouse gas will prevent outgoing radiation in sync with its change in abundance relative to atmosphere as a whole.

So right there, with water vapour, you have an enormous uncertainty since much will depend on the distribution of cloudiness, if cloud increases more in cold climates than warm climates, one result may occur, if it's the other way around, a different outcome may occur.

You're right that there is some uncertainty about how clouds affect climate sensitivity, but among climate scientists, water vapour is almost always considered to be the most powerful positive feedback driving climate change, while clouds are considered to be likely positive, but very unlikely to be a strongly negative feedback. (ie, there there is still debate but there is no well evidenced theory that suggests that clouds are a powerful negative feedback)

First of all, all the water vapour in the atmosphere that hasn't condensed into clouds is always a greenhouse gas, and warmer air can hold more water vapour before it condenses into clouds

Secondly clouds themselves have both positive and negative feedbacks, during the day, they increase albido and reflect some of the sunlight. At night, they are a powerful positive feedback, trapping a lot of heat that would otherwise escape to space. Even at night, water vapour that is not condensed into clouds remains a positive feedback.

Another problem I see is that while carbon dioxide may well be increasing entirely because of human activity, its contribution relative to water vapour may be fractional and therefore it returns the debate essentially to water vapour. So what if there are complex feedback mechanisms between the man-made greenhouse gas increases and water vapour? What if (as one example) the denser greenhouse gases create more stable air masses that can retain cloud cover in marginal situations where decades earlier they might have cleared out? (of course not all water vapour is in cloud but the cloud portion is important in determining incoming solar radiation in particular).

The point is that CO2 causes enough warming to allow the air to hold more water vapour which in turn causes more warming.

These are the sorts of complexities that these simplistic models do not seem to handle very well, if they did, predictions made around 1990 would be coming true in full rather than in part.

Hold on now MT, Are you saying that because the 1990s climate models haven't been fully accurate (100%) that they haven't got predictive value? You know as well as anyone that weather is chaotic and models work on probability and can be thrown by unexpected or unaccounted for variations on a short term basis. The

The models have been accurate within their margin of error. Clouds are not modelled at a high resolution in the models due to restrictions in computing power, but they are accounted for using simpler algorithms that give a reasonable account of our current understanding of how clouds affect global average climate.

It is possible that some future study will prove that overall, when we account for every different type of cloud in every different location, that clouds might mitigate global warming but there is no good reason to believe that this will happen, and it's just as likely that as we understand more that clouds will be an overall positive feedback.

And we are left with the ongoing uncertainty about what the climate should be doing, this entire field sometimes seems to have given itself an unwarranted right to shoo all other factors off the stage. If there were no human race or increasing greenhouse gases, what would the climate be doing over the period 1990-2020? Where should storm Georgina have been, or the earlier storm that hit Holland? Are they exactly the same as they would have been, albeit moving around air masses warmed up by 0.7 C, or are they running at higher latitudes, arriving earlier, later, with what intensity? Nobody really knows the answers to any of these questions and therefore the entire theoretical foundation is suspect (until we do know).

It seems to be obvious that if we change any of the factors that feed into weather that any individual weather event would be different. Talking about individual weather events is a distraction. What climatologists say is that the dice are being loaded in favour of higher energy weather events.

So this gets me back to my original base, which is to suggest that recent warming (which has flattened out since about 2006) could be partly anthropogenic, and is plausibly partly natural since solar activity was very high 1940 to 2000.

Here's the solar output compared with global average temperatures. I really don't see how solar output correlates with the rising temperatures.

https://skepticalscience.com//pics/TvsTSI.png
(the image is too big, it ruins the formatting of the post so here's the link instead)

Here's the global average temperature up to 2017. (Note, if you took this graph in 2013, there would be a flat line, but the past 4 years a surge in warming has surged past the 2006 level)
I don't see any flattening since 2006.[img]Http://berkeleyearth.org/wp-content/uploads/2018/01/TimeSeries2017.png[/img]
or http://www.columbia.edu/~jeh1/mailings/2018/20180118_Temperature2017.pdf

It's not so much that I dispute the physics, I just suspect that we are not anywhere near skilled enough in our understanding of how the complex machine works to say that our contribution has had all or most of the effects seen, and even if that's the case, these effects are not generally running at a rate equal to what the theory's own proponents were forecasting.

The rate of change is within the margin of error for the models, which is basically all scientists expect from predictive models. There are natural factors that affect variability on short to medium term and at individual locations, but the models predictions are accurate. Contrast this with the predictions made by the climate skeptics which are a hodge podge ranging from a looming mini ice age (which is what the weather forum's own long running climate change thread was called when it was started a few years ago) up to the perennial skeptic argument that climate change has peaked and it's about to start falling back any year now.

So it's mainly a question of scale, rather than yes or no do I accept the physics? The problem with saying I must accept the physics is that I apparently must accept the forecasts which are made by those who ask the question, and I definitely don't accept the higher two-thirds of those, because I suspect that at some point the atmosphere will fix itself, I don't think the planet can sustain a runaway greenhouse effect unless we are talking about massive increases in carbon dioxide that nobody is postulating. The most likely outcome is that these levels will flatten out later this century and slowly fall in the 22nd century given that we may then have much cleaner technologies (or 1% of our current population, a near extinction of the human race seems like a good bet on any number of fronts).

The physics are not based on forecasts, they're based on fundamental calculations of greenhouse gases in the atmosphere. Radiative forcing is about as certain as any other scientific principle. Climate sensitivity is much less certain because it depends on assumptions that we have good reasons to believe are true within a range, but cannot say for sure.

Hoping that the climate will stabilize at some point in the future seems to me to be a tad unscientific, especially when you consider the tipping points that we could reach whereby we cause natural carbon sinks to begin emitting greenhouse gasses which could dwarf human emissions once it gets beyond that point. (what would happen if the rainforests started to die off for example)

Dakota Dan wrote:

You must be living a very modest lifestyle.

You d be surprised the amount of people that think climate change is complete nonsense, it was upsetting to hear the doomsday clock was advanced again yesterday, one of the reasons cited was indeed climate change.

Gaoth Laidir wrote:

??? Please elaborate

For some strange reason I'm unable to post Link, tis all over the internets, including rte

edit:

https://www.rte.ie/news/2018/0125/936016-doomsday-clock/

dense wrote: »

The end is nigh. Sort of.

The usual stuff inter-generational stuff, fretting about nuclear war etc.

Read it listening to Two Tribes by Frankie Goes to Hollywood for full effect;)


http://www.bbc.com/news/world-42823734

very reputable scientific organisation, regularly cited by well respected academics including noam chomsky. the Bulletin of the Atomic Scientists have now included environmental issues in their review system. even though i expected this advancement of the clock, its still disturbing to see it happen.

Akrasia wrote: »

The doomsday clock is a political device, not a scientific one. It's great for highlighting to the public what the most pressing concerns for human civilization are, but it's not going to convince anyone who doesn't accept that these problems are real.

That said, even the science doesn't convince certain types of people who believe in one world government and massive conspiracies to falsify temperature records as evidenced by certain posters on here who trawl through websites looking for headlines they can take totally and utterly out of context.

am i right in saying many scientists are indeed on the board of the atomic sciences?

Akrasia wrote: »

Yeah, they're scientists, and they're trying to approach it using a scientific methodology, but the outcome of a 'doomsday clock' is unscientific because there is no scientific justification for putting that hand at 2 minutes to midnight, or 90 seconds to midnight. There is no scientific way of calculating if the human species will be extinct or civillisation will end in a hundred years or a million years.

The doomsday clock is a measure of how worried these scientists are, but worry isn't a scientific measurement.

We should probably take notice of it, but not use it as a primary argument, but rather look at the individual underlying justifications for why these scientists feel so worried and assess what if anything we can or should do to reduce those risks.

some good points alright, even your own arguments about climate change are enough to justify this advancement in my opinion

Wanderer78 wrote: »

very reputable scientific organisation, regularly cited by well respected academics including noam chomsky. the Bulletin of the Atomic Scientists have now included environmental issues in their review system. even though i expected this advancement of the clock, its still disturbing to see it happen.

Hyperbole at its finest.

Gaoth Laidir wrote: »

The fact that this has been brought up as an attempt at a discussion on climate change is laughable. Unbelievable...

I note you're not so quick to admonish when someone on your 'side' of the debate puts forward a transparently terrible 'analysis'

Some of the 'arguments' put forward against climate change on this thread are nothing but a 'one world government' conspiracy theory and blatant misrepresentation of the sources.

dense wrote: »

Read it listening to Two Tribes by Frankie Goes to Hollywood for full effect;)

'Rage Hard' would be better!


"Though laughter of angels resounding
From heaven keep fighting the favours
of charlatan saviours, charlatan saviours"

Akrasia wrote: »

I note you're not so quick to admonish when someone on your 'side' of the debate puts forward a transparently terrible 'analysis'

Some of the 'arguments' put forward against climate change on this thread are nothing but a 'one world government' conspiracy theory and blatant misrepresentation of the sources.

I assume you're talking about dense? From what I have seen he has backed up every point with references, none of which, by the way, you have been able to discredit. I don't go for the one world conspiracy nonsense, so on that we agree, but looking at the science overall I believe that climate sensitivity is lower than widely accepted (by your 97% or otherwise), and definitely believe that the horror stories being portrayed by the likes of yourself, but especially Wanderer and his wheel of misfortune, are grossly exaggerated to the point of being hysterical.

https://www.theguardian.com/commentisfree/2017/dec/11/climate-scientists-emit-30000-tonnes-c02