Hi mantra, I hope you are well and happy, I miss seeing your posts, I always enjoyed hearing your perspective, which was so often compassionate, as well as thoughtful.

It is funny how here I am almost the resident redneck, because I argue with the muslim posters, but on cracker, the arguments against them would have been so extreme, that I probably would have been defending them, to a degree.

At least with johnnie off the scene, we are now seeing our government moving on the climate change issue at last.
It is pretty complex, and how far we will go is anyone's guess, but at least we are past the sceptic stage that was entrenched by the libs.

Been mentioned many times the difference between facts and modelling...


but...

Case of the warm and
Jennifer Marohasy | August 23, 2008

WHEN Nicholas Stern released his influential British government report on the economics of climate change in October 2006, it said that the east coast of Australia had suffered declining rainfall. In the same year, the Howard government pledged an additional $500 million to stop the trend of rising salinity in the Murray River.

Three claims have been repeated so often they are accepted as fact: global temperatures are rising, we have less rainfall and so water is becoming scarce, and salinity in the Murray River is rising.

Of course there is the old adage: lies, damn lies, and then there are statistics. But we can keep it simple and just consider data from observations of the real world and from the most reputable institution since records began for the particular issue in which we are interested. It is important to not confuse real-world data (also known as observational data) with output from computer models because computer models generate scenarios that may or may not come true.

Observational data on rainfall for the entire east coast of Australia is available from the Australian Bureau of Meteorology with yearly averages for all the sites back to 1900.

But, contrary to the Stern report, this chart does not show declining rainfall; rather, it indicates that rainfall was very low in the early 1900s, that there were some very wet years in the late '50s and early '70s, and overall the trend is one of a slight increase in rainfall during the past 107 years.

Stern got it wrong, perhaps because he was confusing output from computer models with the real-world data. There are a lot of computer models that foretell dire environmental catastrophe that may not eventuate.

Rainfall data for the Murray-Darling Basin is also available from the Bureau of Meteorology. The overall trend is one of increasing rainfall since 1900. The past few years show below-average rainfall for the region and indeed there has been drought. The low river inflows have been exacerbated by more groundwater pumping, more plantation forestry, including in the upper Murrumbidgee, and more salt interception schemes along the Murray River.

Salt interception schemes evaporate water to trap the salt. In the '80s, computer models predicted that Adelaide's drinking water soon would be too salty to drink because of declining water quality and rising salinity levels in the Murray River. Measurements of salinity are recorded from many different sites along the Murray River, including at Morgan, which is immediately upstream from the offshoots from Adelaide's drinking water. The data from Morgan enables us to get an idea of how salt levels are trending in the real world, as opposed to computer-generated scenarios.

Concerns with salinity have resulted in levels being tested from the '30s. Salinity levels rose dramatically during the '70s and peaked at Morgan in 1982, which was a drought year. Then the Murray-Darling Basin Commission implemented a catchment-wide drainage management plan and started building salt interception schemes, and since then salinity levels have more than halved.

Measuring global temperatures is much more contentious than measuring salinity or rainfall. Issues include how to combine the data from all the weather stations across the globe and the data is usually presented as a temperature anomaly rather than, for example, just a global average. A temperature anomaly is derived from the average temperature for a specific but arbitrarily defined period and usually emphasises the extent to which temperatures have increased. The Bureau of Meteorology relies on the Climatic Research Unit at the University of East Anglia in conjunction with the Hadley Centre of the British Met Office for its information on global temperatures. This information is available on the internet going back as far as 1850 and shows the deviation from the period 1961 to 1990.

But when global temperatures are presented just as a simple average with a vertical axis that spans the range of temperatures experienced in a place such as Ipswich (west of Brisbane) during a single year, the global rise in average temperatures is not that obvious because the mean temperature since 1850 has increased by less than 1C.

The data from the CRU is generally accepted as accurate by those who subscribe to the idea that carbon dioxide is driving dangerous man-made global warming. In contrast, many sceptics of man-made global warming argue that the only reliable measure of global temperatures is from satellites.

Ross McKitrick from Canada's University of Guelph argues that 50 per cent of global warming measured by land-based thermometers in the US since 1980 is due to local influences of man-made structures, also known as the urban heat island effect. There also have been issues with the additions and losses of weather stations; for example, many weather stations were lost in places such as Siberia with the disintegration of the Soviet Union.

Thermometer temperature data has been collected in the polar regions only since the '40s and calculating the mean temperature at the poles is still difficult.

James Hansen, from the Goddard Institute for Space Studies, has explained the general difficulty of measuring surface temperatures.

etc, etc, etc  from the Australian

In denial on yet another topic i see FD,

wELL THANK YOU FOR THAT FACTUAL AND INSIGHTFUL REFUTATION.

rotflmao

Quote:


This seems a very vague and broad comment, trying to elicit a similiarly broad assumption.
As we see the East Coast of Australia, ranging through, Tropical, Sub-Tropical, and Temperate zones, it would seem unscientific to use this huge area as a single determinant in regard to rainfall patterns.

Do the models not predict different rainfall outcomes for different climates?

As Muso sems to have the most scientific knowledge in this area I was wondering if he has any thoughts on this?

I do accept the GW theory, but I admit to the fact that I am not able to objectively judge one set of scientifically presented contentions, as being more valid than another, hence my reliance on getting better analysis from those who understand it better.

Thanks muso, like you said previously, much of the denialist argument seems to rely on attempts to muddy the water, and even as a layman, when I see broad statements like the one I quoted, they just stand out as being designed to deliberately portray facts in such a way as to add to the confusion.

As you seem pretty up with the science, I saw just a little of the sixty minutes show which had some aussie scientist who said that because we have no sign of hot spots over the equator, which all the models predict, then the basic assumptions are all based on the wrong criteria.
Sorry it is such a vague description, but I only caught a few minutes whist doing other stuff, but do you know what he may have been referring to, and is his contention that without evidence of these hotspots, all the other science must be flawed?

freediver wrote on Sep 2^nd, 2008 at 11:22am:


My understanding of climate change is that the rising sea temps will kill the plankton which is THE source of oxygen on earth. Without a reliable source of oxygen, which has always been the role of the seas, our planet will become mars-like.

Prior to Earth Death, the tropics will change with equatorial bulge, bulging just that bit more, covering any low lying islands. With the change and/ or ceasing of the tradewinds, wild weather will constantly destroy what strives to survive there as cool winds interact more readily than now, with the warm winds of the equator.

There is a summary of the subject of Tropical tropospheric temperature trends over at Real Climate> I think that's what you were talking about:

http://www.realclimate.org/index.php/archives/2007/12/tropical-troposphere-trend...

"The basis of the issue is that models produce an enhanced warming in the tropical troposphere when there is warming at the surface. This is true enough. Whether the warming is from greenhouse gases, El Nino’s, or solar forcing, trends aloft are enhanced. For instance, the GISS model equilibrium runs with 2xCO2 or a 2% increase in solar forcing both show a maximum around 20N to 20S around 300mb (10 km):

The first thing to note about the two pictures is how similar they are. They both have the same enhancement in the tropics and similar amplification in the Arctic. They differ most clearly in the stratosphere (the part above 100mb) where CO2 causes cooling while solar causes warming. It’s important to note however, that these are long-term equilibrium results and therefore don’t tell you anything about the signal-to-noise ratio for any particular time period or with any particular forcings.

If the pictures are very similar despite the different forcings that implies that the pattern really has nothing to do with greenhouse gas changes, but is a more fundamental response to warming (however caused). Indeed, there is a clear physical reason why this is the case - the increase in water vapour as surface air temperature rises causes a change in the moist-adiabatic lapse rate (the decrease of temperature with height) such that the surface to mid-tropospheric gradient decreases with increasing temperature (i.e. it warms faster aloft). This is something seen in many observations and over many timescales, and is not something to climate models."

I just Googled the Sixty Minutes segment - That was Dave Evans our favourite rocket scientist. He's always loads of fun.

The gospel according to Dave (we are not worthy) is that Tropical Hotspots are a characteristic signature of the enhanced Greenhouse effect , and that their absence is proof that there is no Enhanced Greenhouse effect.  

No Dave - the hotspot is not an exclusive signature of the greenhouse effect - it is a signature of warming from any source, and

er - the hotspot is not actually missing.

Dave - That's an F. Don't give up the day job..... You know Consulting.... Ok Dave, but we won't actually tell anyone that consultant translates to "unemployed". It will be our secret.