bets on warming or temperature plateau on BBC

[Chris Knight]

http://news.bbc.co.uk/1/hi/programmes/more...ess/7370557.stm

http://downloads.bbc.co.uk/podcasts/radio4...080428-1630.mp3

First item after the introduction.

Peter Cockroft, BBC weather forecaster;

James D. Annan, Frontier Research Centre for Global Change, Japan;

put their money where their mouths are.

[Bobby]

NOAA and NASA have 2005 as the warmest year ever. NOT 1998. So why is it generally accepted that 1998 is the warmest year? I just don't understand.

Nuff said.

[Chris Knight]

NOAA and NASA have 2005 as the warmest year ever. NOT 1998. So why is it generally accepted that 1998 is the warmest year? I just don't understand.

Nuff said.

Perhaps NASA and NOAA are not the only fruits in the temperature measurement game, nor the most independent.

Edited April 30, 2008 by Chris Knight

[jethro]

Interesting stuff, thanks for that Chris.

A question though for all; it's a firmly held belief by those adherents to AGW that 10 years is not long enough to make any judgements on trends, hence the last 8-10 years are meaningless in a long term trend. Despite being a sceptic, I'd agree, in the grand scheme of things it doesn't tell us a great deal. However, those same adherents were adamant when temperatures began rising that 10 years of data were relevant, were important; indeed the first, second and third IPCC reports were using time spans of 5 years. So how come short time spans are important, are revealing when the trend is upwards but somehow irrelevant, meaningless when the trend is levelling or downwards?

Anyone have an answer? I can't figure it out.

[laserguy]

http://www.telegraph.co.uk/earth/main.jhtm...aclimate130.xml

And here's another one. For the fourth time saying it, "2008 - the year AGW leaves the building". Ok it's only a newspaper item but it,along with the stuff from Chris are the first chinks in AGW's creaking public edifice. Personally,I've seen it coming for ages. I find the double talk in the article amusing. Just as solar cycle 24 refuses to wake up,they keep putting back it's expected start date. Similarly,as AGW refuses to play ball,they keep on pushing back the resumption of the 'warming' already seen but which is now in limbo. My,they're having to pull out all the stops to explain the temperature stasis in this world of bumper CO2 emissions. Why? It's nothing to get worked up over;climate's doing it's own thing as always but it's deaf to the shouting,telling it of the CO2 in it's midst. Like the deaf guy in a panto with the villain creeping up behind him and the audience yelling "he's behind you"!, he neither knows nor cares.

[biffvernon]

Best to go to the horse's mouth. Here's James Annan's blog, where he writes about the BBC programme, the bet and it's background.

http://julesandjames.blogspot.com/

[Essan]

If 2008 isn;t cooler than recent years then we've seriously underestimated the extent of AGW!

The problem continues to be that people dismiss natural variability as if AGW means such variability no longer happens! As I've pointed out before, we can have a full blown ice age and still be experiencing AGW ...... Just because natural variability produces cold as well as warm years does not however mean that there is no underlying warming trend, nor, of course, that human activities do not have impacts on other aspects of climate.

[jethro]

What it could also mean is we've seriously over-estimated the impact of AGW. If scientists now accept and predict a period of cooling or levelling of temperatures due to natural causes, then they must also accept some of the previous warming was also due to natural causes. After all, if cooling can be caused by an in-active Sun and a negative PDO, then it follows the previous very active Sun and positive PDO must have contributed to the warming. If nothing else, it should surely help in deciphering the AGW signal from the natural?

[BLAST FROM THE PAST]

If 2008 isn;t cooler than recent years then we've seriously underestimated the extent of AGW!

The problem continues to be that people dismiss natural variability as if AGW means such variability no longer happens! As I've pointed out before, we can have a full blown ice age and still be experiencing AGW ...... Just because natural variability produces cold as well as warm years does not however mean that there is no underlying warming trend, nor, of course, that human activities do not have impacts on other aspects of climate.

Or more like it that GW exists but it is a natural phenomena. 10 years may not be enough but a further 10...the clock is ticking

BFTP

[millennia]

NOAA and NASA have 2005 as the warmest year ever. NOT 1998. So why is it generally accepted that 1998 is the warmest year? I just don't understand.

Nuff said.

Not according to this it isn't:

This is a graph of the tropical troposphere anomaly from a mixture of satellite and CRU measurements to March this year, and two things are obvious: the peak in temperature in 1998 and the continuing drop this year with another 0.3C drop in March - this is at the equinox when the sun is directly overhead the tropics!

[Osbourne One-Nil]

At the equinoxes, the sun is directly over the equator. It's overhead the tropics at summer and winter solstice.

[Devonian]

Not according to this it isn't:

This is a graph of the tropical troposphere anomaly from a mixture of satellite and CRU measurements to March this year, and two things are obvious: the peak in temperature in 1998 and the continuing drop this year with another 0.3C drop in March - this is at the equinox when the sun is directly overhead the tropics!

That's surely to compare the tropics with the figures for the globe as a whole that Magpie quotes? Why just the tropics? Other parts of the world have warmed a lot - and that just as irrelevant to global averages as any other bit of the total?

[Essan]

Or more like it that GW exists but it is a natural phenomena.

If you really believe that changes to CO2 levels, sulphate levels, ozone levels, albedo, soot emissions, urban development, rainforest burning, contrails etc etc are all either totally natural (ie would occur without humans being on the planet) or have a total of nil effect on the climate, then yes.

[millennia]

That's surely to compare the tropics with the figures for the globe as a whole that Magpie quotes? Why just the tropics? Other parts of the world have warmed a lot - and that just as irrelevant to global averages as any other bit of the total?

I fail to see how the part of the world from 20N to 20S can be called "irrelevant", especially as this is the area that should show a fingerprint CO2 warming according the IPCC 2007 report as it receives the greatest degree of solar forcing and therefore *should* show the greatest degree of CO2 absorbtion and temperature feedback.

So only two assumptions can come from this: the warming isn't occurring or the models upon the which IPCC projection of a tropical troposhere hot spot were made are wrong.

I don't pretend to know which of those assumptions is true, but in either case the persistent inability to observe the hotspot as shown by IPCC 2007 make me wonder why everybody remains so convinced CO2 is a primary driver, as opposed to a contributory driver.

As ever we just need more research into other potential sources of warming and stop diverting so much in resources to just one, otherwise we just risk missing something that may come back and bite us. The science is not settled, it is ongoing and will be for hundreds of years.

At the equinoxes, the sun is directly over the equator. It's overhead the tropics at summer and winter solstice.

At a solstice the sun is furthest away from the tropical belt in the opposing hemisphere so it makes sense that when the sun in in the middle of the tropics, over the equator at an equinox, it has equal effect on the entire tropics and therefore maximises the general effect.

This is why IPCC shows the projected hot spot as most intense at the equator and lessening as you move north or south.

Sorry if I didn't make myself clear on what I meant.

[Devonian]

I fail to see how the part of the world from 20N to 20S can be called "irrelevant", especially as this is the area that should show a fingerprint CO2 warming according the IPCC 2007 report as it receives the greatest degree of solar forcing and therefore *should* show the greatest degree of CO2 absorbtion and temperature feedback.

I said "and that['s] just as irrelevant to global averages as any other bit of the total". If Magpie quotes global temperatures how can you do other than an apples and oranges comaprison if you focus in on just tropical temperatures? It's like loosing and election but saying 'We didn't loose, we won the home counties' .

[millennia]

This is also interesting with regard to this thread with sign of the PDO reversal gaining strength, which is where I suppose the general potential for cooling may come:

http://earthobservatory.nasa.gov/Newsroom/...p3?img_id=18012

Edited May 1, 2008 by millennia

[SnowBear]

Tropic of Cancer, the northern most lattitude whereby the sun is seen directly overhead. (Summer Solstice).

Tropic of Capricorn, the southern most lattitude whereby the sun is seen directly overhead. (Winter Solstice).

Spring and Auntumnal Equinoxes, whereby the sun is directly over the Equator.

In truth the sun has least effect on either tropical area when at the equinoxes as the effect is balanced across both. At the solstices, either the northern or southern, they get the full effect of the overhead sun and thus are "in full flow" for that period of time. To get a true picture you have to take account of the full yearly effect of the seasonal shifting of the sun, not just at one point in my view.

[Essan]

What all this talk of tropics and equinoxes got to do with anything? Unless we're comparing temps over the period of one year and assuming the sun is the only factor?

[SnowBear]

Considering the tropics and equatorial region has a large effect on the global weather systems etc I would have thought it would have everything to do with it. How that area behaves from season to season and year to year cannot be discounted in my view along with a myriad of other systems, cycles and mechanisms.

[Thundery wintry showers]

I don't remember seeing any studies which suggested that the tropics would warm the most, it was always the polar regions of the Northern Hemisphere- and interestingly enough, those are indeed the areas that have warmed most over the past 30 years. Although it would be OTT to argue that this was entirely due to AGW as there have been natural cycles at work which have also biased the high-latitude temps upward in recent decades.

The problem with focusing on tropical temperatures is that it's a bit of a straw man attack on the AGW theory, note the "G" in AGW, i.e. it's about the trend in global temperature. There aren't many scientists out there who would argue that AGW means all parts of the world warming at the same rate, or indeed warming at all- certain localised areas could actually cool, it's all about the trend in mean global temperature.

Tropical temperatures are especially subsceptible to the ENSO signal, therefore in a strong La Nina phase we would expect a considerable cooling in those areas because of the La Nina, and therefore we would expect 2008 to be considerably cooler than 2007 in these areas.

[millennia]

I don't remember seeing any studies which suggested that the tropics would warm the most

I wasn't talking about the tropics warming the most I was referring to the IPCC report on model predictions for CO2 induced warming producing a tropical troposhere hot spot:

Model-calculated zonal mean atmospheric temperature change from 1890 to 1999 [degC per century] as simulated by the PCM model from [a] solar forcing, volcanoes, [c] well-mixed greenhouse gases, [d] tropospheric and stratospheric ozone changes, [e] direct sulfate aerosol forcing, and [f] the sum of all forcings [iPCC 2007, p.675]. Note the pronounced increase in warming trend with altitude as a 'fingerprint' of greenhouse forcing.

The US Climate Change Science Program report of 2006 also reported the conglomerate of the forcings:

and then procuded radiosonde data to show the actual anomaly pattern as observed:

I do not have an up to date actual observation chart, and therefore could only refer to the satellite chart which does provide troposhere temperatures up to March 2008 and still does not show the warming the models predicted. My point isn't about global warming it's about observing the effects of CO2 forcing as predicted by the IPCC and by which Govts all over the world are producing policies. The question is of the accuracy of the models if real observations don't confirm them.

I do not refute that observed temperatures have increased, or that polar warming has been measured to be stronger than tropical warming. To me that is a different arguement.

[jethro]

Originally the Hadley centre said I think last year, that they didn't expect temperatures to rise for the next year or so. A new study, just released, predicts cooling or levelling off for a great deal longer - link in another thread.

This prediction is made on the Atlantic Multidecadal Oscillation changing phase. Based on this, they predict roughly a decade of cooler temperatures. If you then add into this the other predictions and expectations of cooling relating to the PDO also flipping to it's negative phase, then the cooling could be larger or longer than this latest study estimates. That's not even taking into account the uncertainty of the Sun and whether or not cycle 24 will be large or small. The longer cycle 23 keeps going, the longer the delay in cycle 24 getting going, the greater chance there is, it will be moderate to small in amplitude. Add onto this the predicted (by Hathaway) very quiet cycle 25 expected, then I think there's more than an evens chance we will continue to see temperatures fall.

[biffvernon]

A new study, just released, predicts cooling or levelling off for a great deal longer - link in another thread.

This prediction is made on the Atlantic Multidecadal Oscillation changing phase. Based on this, they predict roughly a decade of cooler temperatures.

So disingenuous. It's a computer model that produces a scenario of cooler atmospheric temperatures than previously expected resulting from a change in ocean current. But there is no suggestion that the total heat of the ocean-atmosphere will cool. Far from it. Atmospheric temperatures rise all the more vigourously after about a decade.

It's no good double cherry-picking. You are just looking at the atmosphere and you are just looking at a limited time. Our knowledge of deep water temperatures is so limited that, by the paper's authors' own admission, the modelling results have a high level of uncertainty.

[jethro]

So disingenuous. It's a computer model that produces a scenario of cooler atmospheric temperatures than previously expected resulting from a change in ocean current. But there is no suggestion that the total heat of the ocean-atmosphere will cool. Far from it. Atmospheric temperatures rise all the more vigourously after about a decade.

It's no good double cherry-picking. You are just looking at the atmosphere and you are just looking at a limited time. Our knowledge of deep water temperatures is so limited that, by the paper's authors' own admission, the modelling results have a high level of uncertainty.

Disingenuous means - slightly dishonest(Cambridge dictionary)

The projections made by the IPCC are also based on computer models are they not? The model projections by them also have a high level of uncertainty, in fact even more so in this particular instance as they don't even include ocean currents or changes thereof, of things like the AMO or the PDO.

Listening to the latest research is not cherry picking, double or otherwise; it is taking on board new research which adds to the complete picture. The picture we currently have is incomplete, ocean currents being one of the least incomplete (IPCC). I completely fail to understand the reluctance of anybody to take on board new research, surely we need to progress?

Looking at a limited time? Absolutely, never said otherwise. As for atmospheric temps rising vigorously after about a decade; pure conjecture I'm afraid, no evidence to support it. At the moment.

"No suggestion that the total heat of the ocean-atmosphere will cool"; don't understand what you mean here.

[HighPressure]

Well I made my prediction of Southern Hemisphere to report @+0.4 and Northern @+0.7 giving a 2008 global mean of @+1 deg above average roughly flat lining from 2007. If this happens it will be the 8th consecutive year that temp has followed ozone depletion based on a 2yr lag. This will not prove Ozone as a contributory factor but will certainly show ozone as an accurate prediction method and I think it would add considerable weight to a drop in global temps in 2009 to @+0.8 (-0.2 deg on 2008).

Its only a theory but so far I have no reason to doubt it as 2008 appears to be going as predicted? No point me keep banging on about this as the proof is in the eating so they say

http://www.netweather.tv/forum/index.php?showtopic=45699