johnbrandt wrote:

Loren Michael wrote:

Most of the energy consumption in our food system is not caused by transportation. Sometimes local food is more energy efficient. But often it's not. A carbon tax would often be greater on local food than its long-distance counterparts.

Back on topic...where's the scoffing comments that "It's all about averages", and "one change in temperature doesn't prove human-caused global warming is wrong" that is attracted by anyone who is a heathen to the cause brings up something about record cold spells?

I'd also like to seriously know why every single news item, web page, or study that sides with the "global warming is true and humans are causing it" side of the debate (which we are told "is over"...when it never even existed) is seen to be 100% factually correct, and every single news item, web page, or study that tries to deny it is 100% incorrect and probablt funded by big oil or big coal and should be ignored...? Selective critisism?

johnbrandt wrote: I'd also like to seriously know why every single news item, web page, or study that sides with the "global warming is true and humans are causing it" side of the debate (which we are told "is over"...when it never even existed) is seen to be 100% factually correct, and every single news item, web page, or study that tries to deny it is 100% incorrect and probablt funded by big oil or big coal and should be ignored...? Selective critisism?

johnbrandt wrote:"Per capita" emissions are a favourite of many commentators...I mean, how else can they sagely proclaim that Australia is the "largest emitter of greenhouse gases"...usually when they say this, people scratch their head and say "But...China is increasing in population every year by more people than our entire population...how can that be?" Simple...there's not many of us, and we rely on coal fired power because the government is too weak kneed to utilise our vast uranium resources for power, so the sums always make us look bad. Any small population in a modern industrialised country will look bad if you do the sum right. We are actually way down the list of emitters...until you divide it by population to try and make people accept austerity measures and harsh taxes, it doesn't work.

On another thread, they mention the "second warmest May on record". First off, why only bother with how far back official records go? How "warm" is it compared to the long stretch of history?

1880 was a long time ago...one warm period now 132 years later after the last record high does not a pattern make...

I just love the way human-caused global warming believers have an almost religious fervour that seems to believe the climate is unchanging, with a thermostat set just pleasantly to suit mankind, and which will never ever change in the future from the weather we see now

...well...the weather of a time chosen carefully to prove a point. It seems to totally ignore the fact that Earth has normally been either much hotter or much colder than we see at our blink-in-time existance, and that our entire civilisation has arising in one brief unusually temperate 10,000 year period. Telling a gullible public that the climate will never change and will always be balmy isn't telling them the truth. I guess the truth about how changeable our planet is, and not always just to suit mankind, would worry too many people...

How come when CERN announced they'd found the Higgs Boson the other day people like you just swallowed the news without question? Probably because even if you tried to criticize their results you couldn't, because you aren't a particle physicist. Furthermore, you trust that such a large number of professionals wouldn't tie themselves to a hoax? Yet suddenly when atmospheric physics is involved you become a leading expert? Why is this? Is being massively inconsistent a hobby of yours or something?

Macdoc wrote:

something about record cold spells?

and that would be where ??

johnbrandt wrote:

Macdoc wrote:

something about record cold spells?

and that would be where ??

...and so on just in this year so far

...guess that's why they changed it from "global warming" to "climate change"...

johnbrandt wrote:http://wattsupwiththat.com/2012/01/30/bitter-cold-records-broken-in-alaska-all-time-coldest-record-nearly-broken-but-murphys-law-intervenes/
http://www.dailymail.co.uk/news/article-2093450/UK-weather-Britain-braced-cold-snap-year-ice-snow-transform-countryside.html
http://en.wikipedia.org/wiki/2012_European_cold_wave

Ihavenofingerprints wrote:I did a search for this "that's why they call 'global warming' rather than 'climate change' now' line. And you've said it countless times. We've shown you why it's a nonsense claim, yet I would bet on you repeating it here at some stage in the future as well.

johnbrandt wrote:...and so on just in this year so far...guess that's why they changed it from "global warming" to "climate change"...

johnbrandt wrote:
...and so on just in this year so far...guess that's why they changed it from "global warming" to "climate change"...

Extremely hot
Filed under: Climate Science — stefan @ 26 March 2012
By Stefan Rahmstorf and Dim Coumou

One claim frequently heard regarding extreme heat waves goes something like this: ”Since this heat wave broke the previous record by 5 °C, global warming can’t have much to do with it since that has been only 1 °C over the 20th century”. Here we explain why we find this logic doubly flawed.

One can ask two different questions about the influence of global warming on heat waves (Otto et al. 2012), and we take them in turn.

1. How much hotter did global warming make this heat wave?

We have some trouble with framing the question like this, because it tacitly assumes that the same weather situation would have also arisen without global warming, only at a (say) 1 °C lower temperature level. That need not be the case, of course, since weather is highly stochastic and global warming can also affect the circulation patterns of the atmosphere.

But even if we accept the basic premise (and it could be meant in a purely statistical sense, although that is not usually how it is expressed), would an average anthropogenic warming by 1 °C in the relevant location mean that 1 °C is also the amount added to an extreme event? Only in a linear climate system. Imagine a heat wave that pushes temperatures up to 30 °C in a world without global warming. In the same weather situation with global warming, you might expect that this weather then results in a 31 °C heat wave. But that could well be wrong. Possibly in the situation with warming, the soil has dried out over the previous months because of that extra 1 °C. So now you lost evaporative cooling, the incoming sunlight turns into sensible heat rather than a large fraction going into latent heat. That is a non-linear feedback, and not an imagined one. Detailed studies have shown that this may have played an important role during the European heat wave of 2003 (Schär et al. 2004).

The basic phenomenon is familiar to oceanographers: if the mean sea level in one location rises by 30 cm, this does not mean that the high-tide level also rises by 30 cm. In some cases it will be more, due to nonlinear feedback. I.e., a higher water level increases the flow cross-section (think of a tidal inlet) and reduces bottom friction so the tide rolls in faster, reaching a higher peak. The tidal range increases as well as the mean sea level.

Numerous other non-linear mechanisms are possible, which we are only beginning to understand – think of the recent studies that show how changes in snow cover or sea ice cover as a result of global warming affect weather systems. Or think of factors that could affect the stability of particularly strong blocking events. Thus, we’d be very cautious about making an essentially linear, deterministic argument about heat extremes to the public.

In the scientific literature, the influence of global warming on extreme events is therefore usually discussed in terms of probabilities, which is more fitted to stochastic events. The typical question asked is:

2. How much more likely did global warming make this heat wave?

For this question, it is easily shown that the logic “the greater the extreme, the less global warming has to do with it” is seriously flawed. The change in probability of certain temperature values being reached can be visualised with a probability density function (see Figure). The probability distribution could be shifted unchanged towards warmer values, or it could be widened, or a combination of both (or some other deformation).


IPCC (2001) graph illustrating how a shift and/or widening of a probability distribution of temperatures affects the probability of extremes.

For illustration, let’s take the most simple case of a normal distribution that is shifted towards the warm end by a given amount – say one standard deviation. Then, a moderately extreme temperature that is 2 standard deviations above the mean becomes 4.5 times more likely (see graph below). But a seriously extreme temperature, that is 5 standard deviations above the mean, becomes 90 times more likely! Thus: the same amount of global warming boosts the probability of really extreme events, like the recent US heat wave, far more than it boosts more moderate events. This is exactly the opposite of the claim that “the greater the extreme, the less global warming has to do with it.” The same is also true if the probability distribution is not shifted but widened by a constant factor. This is easy to show analytically for our math-minded readers.


Graph illustrating how the ratio of the probability of extremes (warmed climate divided by unchanged climate – this increased likelihood factor is shown as a dashed line, scale on right) depends on the value of the extreme.

So in summary: even in the most simple, linear case of a shift in the normal distribution, the probability for “outlandish” heat records increases greatly due to global warming. But the more outlandish a record is, the more would we suspect that non-linear feedbacks are at play – which could increase their likelihood even more.

Climate Change, Extreme Weather Linked In Studies Examining Texas Drought And U.K. Heat

Reuters | Posted: 07/10/2012 3:36 pm Updated: 07/10/2012 4:45 pm
By Deborah Zabarenko

http://www.huffingtonpost.com/2012/07/1 ... 63014.html

* 2011 was among 15 warmest years globally - U.S. agency

* Extreme weather events show influence of climate change

* Greenhouse gas levels in atmosphere reaches new high

WASHINGTON, July 10 (Reuters) - Climate change increased the odds for the kind of extreme weather that prevailed in 2011, a year that saw severe drought in Texas, unusual heat in England and was one of the 15 warmest years on record, scientists reported on Tuesday.

Overall, 2011 was a year of extreme events - from historic droughts in East Africa, northern Mexico and the southern United States to an above-average cyclone season in the North Atlantic and the end of Australia's wettest two-year period ever, scientists from the U.S. National Oceanic and Atmospheric Administration and the United Kingdom's Met Office said.

In the 22nd annual "State of the Climate" report, experts also found the Arctic was warming about twice as fast as the rest of the planet, on average, with Arctic sea ice shrinking to its second-smallest recorded size.

Heat-trapping greenhouse gas concentrations - carbon dioxide, methane and nitrous oxide among others - continued to rise last year, and the global average atmospheric concentration for carbon dioxide went over 390 parts per million for the first time, an increase of 2.1 ppm in 2010.

"Every weather event that happens now takes place in the context of a changing global environment," Deputy NOAA Administrator Kathryn Sullivan said in a statement. "This annual report provides scientists and citizens alike with an analysis of what has happened so we can all prepare for what is to come."

Beyond measuring what happened in 2011, the international team of scientists aimed to start answering a question weather-watchers have been asking for years: can climate change be shown to be responsible for specific weather events?

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