Climate Change - The Scientific Debate (Vol. II)

[Jinx]

hairykrishna said:

There is more energy available - surface temperatures have risen. I'm not going through the CO2 absorption/thermalisation explanation again because we must have done it 3 times at least.

Storms require temperature differentials - if CO2 is globally raising temperatures then this differential does not increase. And if polar amplification is true this reduces. Ergo no additional energy for storms to use.
Scattering 15 micron IR does nothing given the rest of the IR spectrum is freely available to ignore CO2. You believe dipole moment changes are able to kinetically enhance colliding molecules in a gas - I have yet to see the evidence as conservation of momentum doesn't need internal molecular moment in the calculations.

[plunker]

Jinx said:

hairykrishna said:

There is more energy available - surface temperatures have risen. I'm not going through the CO2 absorption/thermalisation explanation again because we must have done it 3 times at least.

Storms require temperature differentials - if CO2 is globally raising temperatures then this differential does not increase. And if polar amplification is true this reduces. Ergo no additional energy for storms to use.

Some differentiation between storm types (tropical and extra-tropical) might be appropriate here.

From Bureau of Meteorology website:

To a first approximation a tropical cyclone is like a heat engine - it derives its energy from the heat that is released when water vapour that has been evaporated from the ocean surface (assisted by high winds and low pressure) condenses in the middle of the atmosphere. Mid-latitude cyclones (low pressure systems associated with fronts) primarily get their energy from horizontal gradients in temperature. Another important difference between the two is that tropical cyclones have their strongest winds near the surface while mid-latitude systems have their strongest winds many kilometres above the surface near the top of the atmosphere.

So tropical cyclones are fuelled by sea temperature, which is why they rapidy 'lose their legs' when they hit land and the hurricane season is in late summer when the sea is warmest, whereas extra-tropical cyclones get their energy from temperature/pressure differential, and the peak season (when the differential is highest) is in winter. I could see polar amplification being a factor for the latter but possibly not the former(?) which is possibly of comfort to us in the mid-latitudes, although we don't get off scott-free because I think storm precipitation is expected to increase.

[DibblyDobbler]

Evening All. Something that's been vexing me for a while - take Nasa's own figures lifted from here (and let's just assume they are 100% true and accurate). What I can see is that the smoothed temperature has gone up by around 0.8 degrees since 1970 (I picked 1970 as it was just about bang on the average). So that's 0.8 degrees in 45 years... less than 1 degree in nearly half a century.

Equally I could have picked 1940 as a starting point as it is also roughly average but that would seem unfair as I guess it's before man made CO2 really got going? Point being I hope both sides would agree I haven't 'cherry picked' on the dates.

Am I wrong in thinking this doesn't seem like very much of an increase? What am I missing? The graph looks kind of scary until you see the y axis - if you redid it with (for example) -40 to +40 as a rough guide to maximum and minimum natural temperatures it would basically look flat!

[robinessex]

DibblyDobbler said:

Evening All. Something that's been vexing me for a while - take Nasa's own figures lifted from here (and let's just assume they are 100% true and accurate). What I can see is that the smoothed temperature has gone up by around 0.8 degrees since 1970 (I picked 1970 as it was just about bang on the average). So that's 0.8 degrees in 45 years... less than 1 degree in nearly half a century.

Equally I could have picked 1940 as a starting point as it is also roughly average but that would seem unfair as I guess it's before man made CO2 really got going? Point being I hope both sides would agree I haven't 'cherry picked' on the dates.

Am I wrong in thinking this doesn't seem like very much of an increase? What am I missing? The graph looks kind of scary until you see the y axis - if you redid it with (for example) -40 to +40 as a rough guide to maximum and minimum natural temperatures it would basically look flat!

That level of rise is probably within the error bars !!! And still no one knows if it actually matters! Talk about a solution when no one knows if we have a problem !!!!!

[Jinx]

plunker said:

Some differentiation between storm types (tropical and extra-tropical) might be appropriate here.

From Bureau of Meteorology website:

To a first approximation a tropical cyclone is like a heat engine - it derives its energy from the heat that is released when water vapour that has been evaporated from the ocean surface (assisted by high winds and low pressure) condenses in the middle of the atmosphere. Mid-latitude cyclones (low pressure systems associated with fronts) primarily get their energy from horizontal gradients in temperature. Another important difference between the two is that tropical cyclones have their strongest winds near the surface while mid-latitude systems have their strongest winds many kilometres above the surface near the top of the atmosphere.

So tropical cyclones are fuelled by sea temperature, which is why they rapidy 'lose their legs' when they hit land and the hurricane season is in late summer when the sea is warmest, whereas extra-tropical cyclones get their energy from temperature/pressure differential, and the peak season (when the differential is highest) is in winter. I could see polar amplification being a factor for the latter but possibly not the former(?) which is possibly of comfort to us in the mid-latitudes, although we don't get off scott-free because I think storm precipitation is expected to increase.

So me the data - show me the temperature trends of the centre of cyclones and if they show a marked increase over a 30 year period (1 climate if you will) I will agree that precipitation has become more "extreme" .

[hairykrishna]

DibblyDobbler said:

Am I wrong in thinking this doesn't seem like very much of an increase? What am I missing? The graph looks kind of scary until you see the y axis - if you redid it with (for example) -40 to +40 as a rough guide to maximum and minimum natural temperatures it would basically look flat!

In terms of earth min to earth max 0.8 degrees is bugger all but this is a bit misleading. For some context the last ice age, where there was miles thick ice covering North America and a lot of Europe, had average global temperatures something like 4 or 5 degrees colder than today. A change of a few degrees in global mean represents a fairly dramatic shift in climate so most of a degree in less than a century is something worth paying attention to.

Edited by hairykrishna on Friday 4th November 13:50

[plunker]

Jinx said:

plunker said:

Some differentiation between storm types (tropical and extra-tropical) might be appropriate here.

From Bureau of Meteorology website:

To a first approximation a tropical cyclone is like a heat engine - it derives its energy from the heat that is released when water vapour that has been evaporated from the ocean surface (assisted by high winds and low pressure) condenses in the middle of the atmosphere. Mid-latitude cyclones (low pressure systems associated with fronts) primarily get their energy from horizontal gradients in temperature. Another important difference between the two is that tropical cyclones have their strongest winds near the surface while mid-latitude systems have their strongest winds many kilometres above the surface near the top of the atmosphere.

So tropical cyclones are fuelled by sea temperature, which is why they rapidy 'lose their legs' when they hit land and the hurricane season is in late summer when the sea is warmest, whereas extra-tropical cyclones get their energy from temperature/pressure differential, and the peak season (when the differential is highest) is in winter. I could see polar amplification being a factor for the latter but possibly not the former(?) which is possibly of comfort to us in the mid-latitudes, although we don't get off scott-free because I think storm precipitation is expected to increase.

So me the data - show me the temperature trends of the centre of cyclones and if they show a marked increase over a 30 year period (1 climate if you will) I will agree that precipitation has become more "extreme" .

I've no idea if such data even exists.

[Jinx]

plunker said:

I've no idea if such data even exists.

I can't find it yet - but will keep trying. Until then the increase in "extreme" precipitation should be considered mere speculation.

[DibblyDobbler]

hairykrishna said:

DibblyDobbler said:

Am I wrong in thinking this doesn't seem like very much of an increase? What am I missing? The graph looks kind of scary until you see the y axis - if you redid it with (for example) -40 to +40 as a rough guide to maximum and minimum natural temperatures it would basically look flat!

In terms of earth min to earth max 0.8 degrees is bugger all but this is a bit misleading. For some context the last ice age, where there was miles thick ice covering North America and a lot of Europe, had average global temperatures something like 4 or 5 degrees colder than today. A change of a few degrees in global mean represents a fairly dramatic shift in climate so most of a degree in less than a century is something worth paying attention to.

Edited by hairykrishna on Friday 4th November 13:50

Thanks for the reply. Well I guess you must be right given all the kerfuffle!

[Einion Yrth]

DibblyDobbler said:

hairykrishna said:

DibblyDobbler said:

Am I wrong in thinking this doesn't seem like very much of an increase? What am I missing? The graph looks kind of scary until you see the y axis - if you redid it with (for example) -40 to +40 as a rough guide to maximum and minimum natural temperatures it would basically look flat!

In terms of earth min to earth max 0.8 degrees is bugger all but this is a bit misleading. For some context the last ice age, where there was miles thick ice covering North America and a lot of Europe, had average global temperatures something like 4 or 5 degrees colder than today. A change of a few degrees in global mean represents a fairly dramatic shift in climate so most of a degree in less than a century is something worth paying attention to.

Edited by hairykrishna on Friday 4th November 13:50

Thanks for the reply. Well I guess you must be right given all the kerfuffle!

Except that the rise has scarcely changed since the Dalton minimum.

[mondeoman]

DibblyDobbler said:

hairykrishna said:

DibblyDobbler said:

Am I wrong in thinking this doesn't seem like very much of an increase? What am I missing? The graph looks kind of scary until you see the y axis - if you redid it with (for example) -40 to +40 as a rough guide to maximum and minimum natural temperatures it would basically look flat!

In terms of earth min to earth max 0.8 degrees is bugger all but this is a bit misleading. For some context the last ice age, where there was miles thick ice covering North America and a lot of Europe, had average global temperatures something like 4 or 5 degrees colder than today. A change of a few degrees in global mean represents a fairly dramatic shift in climate so most of a degree in less than a century is something worth paying attention to.

Edited by hairykrishna on Friday 4th November 13:50

Thanks for the reply. Well I guess you must be right given all the kerfuffle!

And that's your excuse? You must be right because of the kerfuffle? fk me!

[Gandahar]

I see both poles currently now having exceptionally low sea ice extent.




Antarctic had the first maximum extent in August this year during satellite records, which is interesting as Antarctic sea ice extent has been increasing for the last few years. Any thoughts from the skeptics on this fact, and also why Arctic is also so low at the same time?

Edited by Gandahar on Saturday 5th November 00:36

[Rhyolith]

Gandahar said:

I see both poles currently now having exceptionally low sea ice extent.




Antarctic had the first maximum extent in August this year during satellite records, which is interesting as Antarctic sea ice extent has been increasing for the last few years. Any thoughts from the skeptics on this fact, and also why Arctic is also so low at the same time?

Edited by Gandahar on Saturday 5th November 00:36

Thats almost certainly due to increasing persipitation. I don't know but Imagine the melt rates are still rising, but for the moment the increased snowfall (percipitation) is exceeding the ice loss through melting. This is educated speculation, it would take a study of melt specifically realtive to snow (aka the mass balance) to determine whether its true (this probably exists, I just cannot be bothered to find it )

The Arctic is sea ice and not comparable anyway ... unless your talking about the greenland ice sheet (the only ice sheet in the northern hemisphere)?

Edit: Oops, just spotted that both are sea ice! Will leave that there as it be interesting to someone, but bare it mind its probably not relativent to sea ice (which I know little about).

Edited by Rhyolith on Saturday 5th November 08:36

[Lotus 50]

Jinx said:

I can't find it yet - but will keep trying. Until then the increase in "extreme" precipitation should be considered mere speculation.

FWIW there is some evidence of increased "storminess" in the form of increased rainfall events in the UK. I posted this on the other CC thread a while back but no-one picked up on it.

http://meetingorganizer.copernicus.org/EGU2016/EGU...

It also shows up, to an extent in the rainfall/hydrological records for the area but the sediment record goes back much further than the measured data. Basically in records going back 600+ years 67% of the top 1% of floods have happened in the 21st century.

Edited by Lotus 50 on Saturday 5th November 15:10

[DibblyDobbler]

mondeoman said:

And that's your excuse? You must be right because of the kerfuffle? fk me!

Umm - hang on there old chap! I'm not claiming anything about anything - just trying to get some views as to whether the observed temperature increases (+0.8 degrees in nearly 50 years) are significant or not. It doesn't seem like much to me but clearly a lot of other people (and many scientists) thing it is a big enough deal to be worrying about.

For the record my view is that the world is warming (not by much so far) but that the case for this being caused by man made CO2 is as yet unproven. Not too controversial I hope

[Einion Yrth]

DibblyDobbler said:

For the record my view is that the world is warming (not by much so far) but that the case for this being caused by man made CO2 is as yet unproven. Not too controversial I hope

Pretty much my view, but with the added caveat that the data is so polluted that one would be hard put to come to any conclusions as to what was happening, let alone why.

[mondeoman]

Lotus 50 said:

Jinx said:

I can't find it yet - but will keep trying. Until then the increase in "extreme" precipitation should be considered mere speculation.

FWIW there is some evidence of increased "storminess" in the form of increased rainfall events in the UK. I posted this on the other CC thread a while back but no-one picked up on it.

http://meetingorganizer.copernicus.org/EGU2016/EGU...

It also shows up, to an extent in the rainfall/hydrological records for the area but the sediment record goes back much further than the measured data. Basically in records going back 600+ years 67% of the top 1% of floods have happened in the 21st century.

Edited by Lotus 50 on Saturday 5th November 15:10

If 67% of top 1% is 2, then none of these are big numbers, hence the use of percentages rather than absolutes. Always be wary of percentages, they are normally hiding something. Lies, damned lies and percentages...

[Gandahar]

mondeoman said:

Lotus 50 said:

Jinx said:

I can't find it yet - but will keep trying. Until then the increase in "extreme" precipitation should be considered mere speculation.

FWIW there is some evidence of increased "storminess" in the form of increased rainfall events in the UK. I posted this on the other CC thread a while back but no-one picked up on it.

http://meetingorganizer.copernicus.org/EGU2016/EGU...

It also shows up, to an extent in the rainfall/hydrological records for the area but the sediment record goes back much further than the measured data. Basically in records going back 600+ years 67% of the top 1% of floods have happened in the 21st century.

Edited by Lotus 50 on Saturday 5th November 15:10

If 67% of top 1% is 2, then none of these are big numbers, hence the use of percentages rather than absolutes. Always be wary of percentages, they are normally hiding something. Lies, damned lies and percentages...

Are you saying scientists cannot use percentages? Do you prefer fractions?

What sort of mathematics do you want to use when "measuring" things?

[Gandahar]

DibblyDobbler said:

mondeoman said:

And that's your excuse? You must be right because of the kerfuffle? fk me!

Umm - hang on there old chap! I'm not claiming anything about anything - just trying to get some views as to whether the observed temperature increases (+0.8 degrees in nearly 50 years) are significant or not. It doesn't seem like much to me but clearly a lot of other people (and many scientists) thing it is a big enough deal to be worrying about.

For the record my view is that the world is warming (not by much so far) but that the case for this being caused by man made CO2 is as yet unproven. Not too controversial I hope

Certainly not. What do you think the warming is due to?

And how do you think that is impacted by man made cooling such as aircraft contrails?

[mondeoman]

Gandahar said:

mondeoman said:

Lotus 50 said:

Jinx said:

I can't find it yet - but will keep trying. Until then the increase in "extreme" precipitation should be considered mere speculation.

FWIW there is some evidence of increased "storminess" in the form of increased rainfall events in the UK. I posted this on the other CC thread a while back but no-one picked up on it.

http://meetingorganizer.copernicus.org/EGU2016/EGU...

It also shows up, to an extent in the rainfall/hydrological records for the area but the sediment record goes back much further than the measured data. Basically in records going back 600+ years 67% of the top 1% of floods have happened in the 21st century.

Edited by Lotus 50 on Saturday 5th November 15:10

If 67% of top 1% is 2, then none of these are big numbers, hence the use of percentages rather than absolutes. Always be wary of percentages, they are normally hiding something. Lies, damned lies and percentages...

Are you saying scientists cannot use percentages? Do you prefer fractions?

What sort of mathematics do you want to use when "measuring" things?

Oh come on, you're not stupid. You know exactly what point I'm making. If there are only 3 floods in the top 1%, and 2 of those happened in the 21st century, that doesn't sound as scary as 67%.

Thinking about it, so what? Just means that 100% of 99% of floods DIDN'T happen in the 21st century. But that's a st headline.