General Climate Change Discussion.......

[Admiral_Bobski]

Over on the Arctic thread C-Bob posted;

"With regards to the bit I have highlighted above, I would like to point out that we clearly do a lot more to the Earth's surface than we do to the atmosphere. If we add to that fact these figures:

Surface Area of Earth: 5.1 x 10⁸km²

Volume of Atmosphere: 1.08 x 10¹²km³

...we can see that the atmosphere is a lot bigger than the surface of the Earth - four orders of magnitude bigger, to be exact. That fact, and that fact alone, is enough to consider your conclusion to be dubious.

CB"

Only if you feel the atmosphere is the same as the surface (and the oceans are the same as the surface)

It's never about how much you've got C-Bob, it's what you do with it that counts........of course if you have quite a lot then you need be necessarily gentle.....

Let's keep apples with apples on this one eh? The fact that we have impacted the atmosphere to the point of changing the weather patterns around the Antarctic (due to the impacts of the ozone there) illustrates quite well (I feel) that you don't need to have the massive statements

of man's destruction we see on the surface (be it deforestation, mono culture, opencast mining etc.) If we look at the oceans and the impacts there (from acoustic pollution through ocean acidification) we can see again that it is not all a matter of size or visibility of impact.

Gas ,fluid ,solid.All impacted, all altered by that impact. Dubious or myopic?

Hang on a second there, GW. It was you who said that when you see the devastating effects man has on the surface of the Earth, you fail to see how he can't be impacting the atmosphere.

I believe the "comparing apples with oranges" comparison was yours, not mine.

But, regardless, I shall leave you to trumpet the same old stuff again...

CB

Edited December 1, 2009 by Captain_Bobski

[Gray-Wolf]

But, regardless, I shall leave you to trumpet the same old stuff again...

CB

Practice makes perfect

[Cloudman]

Winterfreak: your question "So why do Gray-wolf's posts seem to contradict what he says? Who's right?" from Arctic thread.....

Climate change in general...CO2, despite increased levels, despite projected further increases; cannot warm the atmosphere by very much. The projections for future warming of 4-6c depend entirely upon positive feedback in the form of water vapour and clouds. The IPCC acknowledge and accept this but still assume the feedbacks will be positive, to date the information which has emerged since their projections show this to be a false assumption. Information upon clouds is still very much an 'unknown' but what we have learnt thus far, is that they react and show a negative feedback. Check out NASA's Aqua satellite data.

Clouds and water vapour feedback: I can't agree with what you say, firstly increased water vapour increases temperature, it is a greenhouse gas, increased high clouds cause warming but increased low clouds cooling. The role of clouds is complex and not fully understood but increased water vapour from CO2 induced warming is a strong positive feedback.

[jethro]

Clouds and water vapour feedback: I can't agree with what you say, firstly increased water vapour increases temperature, it is a greenhouse gas, increased high clouds cause warming but increased low clouds cooling. The role of clouds is complex and not fully understood but increased water vapour from CO2 induced warming is a strong positive feedback.

Welcome to the forum Clouds.

Increased water vapour from CO2 induced warming is a theoretical strong positive feedback. Without this theoretical positive feedback loop, warming from CO2 is/will be small.

Clouds not being fully understood is a bit of an understatement, we know very, very little, they are recognised as being one of the great unknowns in climate science. In addition to this, in the modelled projections for the future they are deemed to be a positive feedback with little empirical observation in support.

We did briefly touch upon this subject in a separate thread a while back, there are quite a few links in there:

[osmposm]

Just happened to be browsing the Met Office website and something on the homepage struck me, they are, on the same page, showing the effects of temperature increases if we don't cut our emissions and generally do as we are told like naughty children and their new tool for helping increase the efficiency of running an airline by better forecasting tools. Conflict of interest anyone?

I'm not saying this out of huge enthusiasm for widespread, cheap air travel, but I would think that with more accurate forecasting of the weather, you could fly the same planes to the same places with noticeably lower emissions.

Imagine the extra fuel burned changing height/direction to avoid unexpected (or unexpectedly active) storm systems. With accurate wind forecasts along the whole route (and a good computer), you could also perhaps tweak the line and altitude of the flight plan very precisely to avoid adverse winds as much as possible, and take maximum advantage of favorable ones. Planned altitude could perhaps be - maybe it already is - planned according to the air temp and density likely to be encountered en route, so the balance of low drag vs efficient engine running is at its optimum - there might even be changes to the engines' tuning possible if you know exactly what you'll be encountering.

I'm sorry if I'm talking complete nonsense here - it's pure speculation on a subject of which I know next to nothing.

Edited December 2, 2009 by osmposm

[Chris Knight]

I think the aviators figured this out some time ago. At Heathrow, for instance, if the wind is easterly, the normal landing and take-off flight paths are reversed, so planes take off into the wind (increasing their effective airspeed and lift at take off, saving considerable amounts of fuel).

[Dartmoor_Matt]

I'm not saying this out of huge enthusiasm for widespread, cheap air travel, but I would think that with more accurate forecasting of the weather, you could fly the same planes to the same places with noticeably lower emissions.

Imagine the extra fuel burned changing height/direction to avoid unexpected (or unexpectedly active) storm systems. With accurate wind forecasts along the whole route (and a good computer), you could also perhaps tweak the line and altitude of the flight plan very precisely to avoid adverse winds as much as possible, and take maximum advantage of favorable ones. Planned altitude could perhaps be - maybe it already is - planned according to the air temp and density likely to be encountered en route, so the balance of low drag vs efficient engine running is at its optimum - there might even be changes to the engines' tuning possible if you know exactly what you'll be encountering.

I'm sorry if I'm talking complete nonsense here - it's pure speculation on a subject of which I know next to nothing.

Or, from a purely economic point of view, squeeze that extra flight a day out of planes on short-medium haul flights.

[Cloudman]

Thanks, I will look in on that thread and maybe make some comments on Spencer's paper. The warming from doubling CO2 is about 1C without feedbacks, clouds are a negative feedback in climate models at the moment. Water vapour is a strong greenhouse gas and the earth would be a very cold place without it

I certainly agree that a lot more research is needed on clouds and cloud imapcts on climate.

[Dartmoor_Matt]

So, it seems that the glaciers in the Himalayas that the IPCC said were receding faster than any other part of the world aren't. Indeed, some are being observed to actually advancing. It never rains, but it pours eh.

BBC News

It's interesting, because' when I was in New Zealand in 2007 I went up to the Glaciers and the guides there said they were advancing not retreating.

[Methuselah]

So, it seems that the glaciers in the Himalayas that the IPCC said were receding faster than any other part of the world aren't. Indeed, some are being observed to actually advancing. It never rains, but it pours eh.

BBC News

It's interesting, because' when I was in New Zealand in 2007 I went up to the Glaciers and the guides there said they were advancing not retreating.

But, DM...No-one is saying that all glaciers everywhere are retreating. There are many parts of the world where the only meaningful effect of GW (so far) is a net increase in snowfall...

If the mean SL temperature at glacier 'x' rises from -45 to -40C, and the snowfall increases due to psychrometry, one would expect it (the glacier) to advance - I think??? :lol:

[Dartmoor_Matt]

But, DM...No-one is saying that all glaciers everywhere are retreating. There are many parts of the world where the only meaningful effect of GW (so far) is a net increase in snowfall...

If the mean SL temperature at glacier 'x' rises from -45 to -40C, and the snowfall increases due to psychrometry, one would expect it (the glacier) to advance - I think???

The IPCC did indeed say that the glaciers in the Himalayas were receding faster than anywhere else in the world.

[Methuselah]

The IPCC did indeed say that the glaciers in the Himalayas were receding faster than anywhere else in the world.

They could well be wrong. :lol:

Anyhoo, if the GFS is anything to go by, there'll advancing glaciers on the South Downs before February's out! :lol:

[Dartmoor_Matt]

They could well be wrong.

Anyhoo, if the GFS is anything to go by, there'll advancing glaciers on the South Downs before February's out!

And if they are wrong about that...

:lol:

Yup, I fully expect to be seeing polar bears in the next couple of weeks :lol:

[osmposm]

Or, from a purely economic point of view, squeeze that extra flight a day out of planes on short-medium haul flights.

Very true, Matt - though unless there are more flights overall (possible, I suppose, but often not economic), that would mean slightly fewer planes being needed by each airline, less being manufactured, and so once again a saving in emissions. Every little helps....if you believe in that sort of thing.

[SleepyJean]

I thought I'd bring this over here because it isn't really on topic on the other thread. I want to ask a question that I would really like a good answer to, though. Now I realise it may be a very basic question and you can probably direct me to other discussions where this has been answered. That would be jst fine, thanks Here goes....

I the CRU thread here was a little bit of an exchange between Devonian and myself:

"SleepyJean, on 01 December 2009 - 12:12 , said:

Thankyou Karl. I did't know that the CRU was the authority on climate change. I assumed they were a leading centre, but also that there were other places coming up with the same things. I am pretty shocked by that, to be honest.

The graphs on the first page answered another question for me, too. I had often wondered how it was that Greenland was green and vines were grown in Northumbria when temperatures now are supposed to be higher and neither of these things is currently true.

Hello SleepyJean,

The graphs on page two are interesting. Note the scale on the first one. See the temperatures? These are claimed to be for Northern Europe. Notice how the author of the article then compares those figures with a graph of Northern Hemisphere temperatures? This is and 'apples V oranges' comparision - it makes no sense, you have to compare like areas with like areas to compare temperature over time."

So I went looking into the temperature thing and I found a lot of graphs on Global Warming Art, which I am sure many of you are familiar with. I looked at the graphs of global temperatures, which go back over increasing lengths of time. Never mind the fact that this is data available to the public. I just want to know this. Current global temperatures are almost as cold as they have ever been. Ever. Most of the time in the past, global temps have been much, much higher than they are now. So my question is, why are we making so much fuss about the earth warming when it actually, according to the historical data, needs to warm up to reach the normal global average temperature of the last 450 million years?

Just wondering.....

[Dartmoor_Matt]

Nail on the head.

All this warbling by AGW alarmists is about what 'might' happen, not what 'is' happening. They yap on about ice melting and all that jazz, but the fact is, the ice does melt in the summer, something to do with the sun and the tilt of the earth, if its on one of its wobbles, you get warmer NH summers (or not depending on the wobble) this is what is commonly though to cause the 'mini ice ages', not cold winters, but cooler summers.

With reference to osmposm's post, I think Ryanair might just like to use the extra time to charge us a bit more to go to the toilet But the more ethically centred airlines might just give their staff some more time off...

As for Tesco... when are they going to stop it with the free carrier bags?! I had to pay 5p in M&S yesterday!

[Devonian]

I thought I'd bring this over here because it isn't really on topic on the other thread. I want to ask a question that I would really like a good answer to, though. Now I realise it may be a very basic question and you can probably direct me to other discussions where this has been answered. That would be jst fine, thanks Here goes....

I the CRU thread here was a little bit of an exchange between Devonian and myself:

"SleepyJean, on 01 December 2009 - 12:12 , said:

Thankyou Karl. I did't know that the CRU was the authority on climate change. I assumed they were a leading centre, but also that there were other places coming up with the same things. I am pretty shocked by that, to be honest.

The graphs on the first page answered another question for me, too. I had often wondered how it was that Greenland was green and vines were grown in Northumbria when temperatures now are supposed to be higher and neither of these things is currently true.

Hello SleepyJean,

The graphs on page two are interesting. Note the scale on the first one. See the temperatures? These are claimed to be for Northern Europe. Notice how the author of the article then compares those figures with a graph of Northern Hemisphere temperatures? This is and 'apples V oranges' comparision - it makes no sense, you have to compare like areas with like areas to compare temperature over time."

So I went looking into the temperature thing and I found a lot of graphs on Global Warming Art, which I am sure many of you are familiar with. I looked at the graphs of global temperatures, which go back over increasing lengths of time. Never mind the fact that this is data available to the public. I just want to know this. Current global temperatures are almost as cold as they have ever been. Ever. Most of the time in the past, global temps have been much, much higher than they are now. So my question is, why are we making so much fuss about the earth warming when it actually, according to the historical data, needs to warm up to reach the normal global average temperature of the last 450 million years?

Just wondering.....

It's back to what are reasonable comparisons.

Is it reasonable to go back 450 million years to make a comparison with now? I think not. For example if water can circulate around the equator without meeting land it can heat more and then move more heat north and south = a warmer planet. But now water can't do that (Isthmus of Panama - only been there for a few million years ). We also have a continent at the south pole and a mostly landlocked ocean at the north - pre disposing us to cold. We should be in a relatively cold time.

No, you have to compare now with similar times. That means it gets difficult to make valid comparisons much more than a few million years back.

Or, to adopt an absurd position, we could go further back and compare not with just after the big bang? Why not? Because it would be a comparison that makes no sense - which is my point.

So why is AGW a problem? Because it will (if right) cause temperature changes at a global rate that haven't been seen except at times of major global change. Do we want to inflict that on the planet? Why would we want to do that? Or risk that? Species can adapt to slow change but not to some of the rates of change that seem possible.

We're simply, imo, taking a unnecessary risk. Clearly others think otherwise. That's why we debate...

Edited December 2, 2009 by Devonian

[Dartmoor_Matt]

If only.

I just want someone to show to me that we are categorically doing stuff to warm the planet. I've looked, and I just can't see it. I can see that nature can warm the planet (and by nature I mean everything that isn't us, including the sun) and I can see that nature can cool the planet (including the sun) and then suddenly we get a theme. Uhuh, the sun. Without it, this planet wouldn't even exist, let alone be a frozen rock in the dark so to assume that it has little effect on the temperature is a little naive. Since the mid 50's output from the sun has been at quite a high maximum, and we see the temp creep up globally (and I mean creep) Then, as output declines to a minimum (a continuing minimum) we see global temps level off (with a creep downwards). I mean, you have to call a duck a duck. Or was it a spade.

So yes, it is entirely reasonable to compare with anywhere in history.

[Thundery wintry showers]

Put simply, we are burning fossil fuels and emitting greenhouse gases into the atmosphere. Increased GHG concentrations result in absorption of radiation from the Earth's surface and hence a rise in global temperature (by how much is one of the key points to be debated).

In addition we are flying at high altitudes creating contrails which cause some climatic forcing, one definite result being a reduction in diurnal temperature ranges. Whether the overall effect is warming or cooling is open to question.

In addition we are chopping down forests and urbanising rural areas which is changing the surface albedo of the planet, and most of these changes point to further warming.

We are also injecting anthropogenic aerosols into the atmosphere. Their effects on clouds and, by extension, overall global climate is open to question, but there's a very strong suspicion that their deposits are affecting the albedo of ice sheets and glaciers and contributing to warming & melting in those regions.

There are probably other potential anthropogenic forcings- those are just four examples.

[Devonian]

If only.

I just want someone to show to me that we are categorically doing stuff to warm the planet. I've looked, and I just can't see it. I can see that nature can warm the planet (and by nature I mean everything that isn't us, including the sun) and I can see that nature can cool the planet (including the sun) and then suddenly we get a theme. Uhuh, the sun. Without it, this planet wouldn't even exist, let alone be a frozen rock in the dark so to assume that it has little effect on the temperature is a little naive. Since the mid 50's output from the sun has been at quite a high maximum, and we see the temp creep up globally (and I mean creep) Then, as output declines to a minimum (a continuing minimum) we see global temps level off (with a creep downwards). I mean, you have to call a duck a duck. Or was it a spade.

So yes, it is entirely reasonable to compare with anywhere in history.

No, sorry DM, but it isn't.

Like I say if water is able to circle the equator the planet will be warmer - period. So, now is going to be colder than such times because water can't circle the equator. You have (have) to compare now with appropriate times.

Also, I'm afraid it simply is the case that CO2 is a ghg and without it this planet would indeed probably be a frozen rock.

Finally, the Sun. The Sun warms this planet from a few degrees above absolute zero (the temperature if it wasn't there) to about -18C - a LOT. Greenhouse gasses warm the planet to it's current average temperature of ~+14C. So, yes, of course the sun is vital, but,without the Sun AND greenhouse gasses the planet (like I say) would be a cold frozen rock.

Messing with the planets radiative properties is a fools game - imo. But, again like I say, other disagree and we debate the issue.

[Dartmoor_Matt]

Categorically? or potentially?

No, sorry DM, but it isn't.

Like I say if water is able to circle the equator the planet will be warmer - period. So, now is going to be colder than such times because water can't circle the equator. You have (have) to compare now with appropriate times.

Also, I'm afraid it simply is the case that CO2 is a ghg and without it this planet would indeed probably be a frozen rock.

Finally, the Sun. The Sun warms this planet from a few degrees above absolute zero (the temperature if it wasn't there) to about -18C - a LOT. Greenhouse gasses warm the planet to it's current average temperature of ~+14C. So, yes, of course the sun is vital, but,without the Sun AND greenhouse gasses the planet (like I say) would be a cold frozen rock.

Messing with the planets radiative properties is a fools game - imo. But, again like I say, other disagree and we debate the issue.

Without the sun, there would of been no gravity to pull all the bits of dust and debris together to create the earth, so no, it would not be a frozen rock, it would trillions of bits of dust floating around in space. But thats besides the point.

So you agree, if the suns output drops and stays low the temperature will fall?

[Devonian]

Categorically? or potentially?

Without the sun, there would of been no gravity to pull all the bits of dust and debris together to create the earth, so no, it would not be a frozen rock, it would trillions of bits of dust floating around in space. But thats besides the point.

So you agree, if the suns output drops and stays low the temperature will fall?

Of course! But, there is no evidence the Sun's output has varied by much more than fractions of a Watt/sqM over time. Otoh, anthro ghg's plus feedbacks might add several watts/sqM to Earth's energy budget - a change not to be taken lightly.

Matt I don't deny if the Sun warmed or cooled it would have an effect proportional to the amount of warming or cooling and I don't deny that if ghg concentrations are changed that also will have an effect.

[jethro]

Species can adapt to slow change but not to some of the rates of change that seem possible.

Firstly apologies if I seem to be picking up on just your posts, it's not intentional and certainly not personal, it's just you keep raising questions in my own mind.

Is there actually any evidence for your statement above? It's something which is repeated all the time (from many sources) but I've never seen anything concrete to back it up. Is it just one of those assumptions made on instinct or actual scientific fact?

Seems to me that if you just take the weather over one year, temperatures in this country can vary between (can't remember the exact records) -22c to 30c and we don't experience mass extinctions.

[Devonian]

Firstly apologies if I seem to be picking up on just your posts, it's not intentional and certainly not personal, it's just you keep raising questions in my own mind.

Is there actually any evidence for your statement above? It's something which is repeated all the time (from many sources) but I've never seen anything concrete to back it up. Is it just one of those assumptions made on instinct or actual scientific fact?

Seems to me that if you just take the weather over one year, temperatures in this country can vary between (can't remember the exact records) -22c to 30c and we don't experience mass extinctions.

No, but do beech trees grow in southern France? Or date palms here?

I think we both know plants and animals have normal ranges, climate ranges. Yes, they can adapt, but if the climate here become like that of central or southern France (and 2C would be close) can beeches up sticks and move? if it got really warm, could oaks thrive here? How many species do oaks support?

I'm not saying it's worlds end (before that is what I'm accused of by somebody) I just think the greater the change, well, the greater the changes.

Edited December 2, 2009 by Devonian

[Dartmoor_Matt]

Of course! But, there is no evidence the Sun's output has varied by much more than fractions of a Watt/sqM over time. Otoh, anthro ghg's plus feedbacks might add several watts/sqM to Earth's energy budget - a change not to be taken lightly.

Matt I don't deny if the Sun warmed or cooled it would have an effect proportional to the amount of warming or cooling and I don't deny that if ghg concentrations are changed that also will have an effect.

NASA has measured a 6% drop in solar irradiance at the UV wavelength since 1995, which they say isn't enough to see global cooling yet. Which is interesting.

I guess what I'm saying is, if we suddenly cut emissions without actually proving it was them pushing the temperature up and the sun decides to stay quiet, we might end up regretting not having that nice insulation.

Hence why I asked if there was any categorical proof, that it was GHG causing the largest proportion any past or predicted warming.

No, but do beech trees grow in southern France? Or date palms here?

I think we both know plants and animals have normal ranges, climate ranges. Yes, they can adapt, but if the climate here become like that of central or southern France (and 2C would be close) can beeches up sticks and move? if it got really warm, could oaks thrive here? How many species do oaks support?

I'm not saying it's worlds end (before that is what I'm accused of by somebody) I just think the greater the change, well, the greater the changes.

The Beech trees natural range is from Southern Sweden to Northern Portugal and Central Spain... so yes, they do.