Monday, October 22, 2007

Three Questions to the CSIRO

1. The CSIRO claim that we have seen an increased frequency in hot nights and a decreased frequency in cold nights. This is based on the statistic minimum temperature. Considering that the minimum temperature will generally occur after sunrise, can you explain why you choose to use the statistic minimum temperature to talk about temperatures at night, when in the minimum generally doesn't even occur at night?

2. Can you please explain the predictions of increased drought and flooding, coupled with a decrease in rainfall when you consider that the second half of the 20th century had a 9.5% increase in rainfall compared to the first half of the 20th century (an increase in every state), and that the number of very wet days and not significantly increased or decreased, neither has the number of days of no rainfall?

3. As Kerplunk puts it "If 'the science is settled' then why does the United Nations' IPCC need 17 climate models when just one should do?"

19 comments:

Anonymous said...

1) Because Earth's climate is a damped harmonic oscillator where amplitude is independent of frequency. By not using amplitude you are aliasing the data. Surely your supervisors have told you how dangerous this is?

2) Are you conducting time series analysis of rain gauges now? Or did CSIRO get the science correct but conclusions wrong? Isn't this a little strange?

3) Because science works on hypothetico-deductive reasong where you cannot prove anything, just disprove things. That is why gravitation and evolution will always be just theories. So if there were 17 models and one said that increasing CO2 lead to cooler temperatures you would have something. None do.

Please Jonathon, for your own sake learn about how climate operates. Pick up a textbook or something.

Jonathan Lowe said...

1) Nice answer, but it seems you must have replied to a different question, as, well, you failed to mention anything that the question asked.

2) Yes. Data taken straight from the BOM website. You can do the same analysis too if you want.

3) The question is in relation to temperature predictions into the future. One model, the most accurate, is all that is required, but, the IPCC likes to use many different models for some unknown reason - perhaps to somehow prove their case that more models showing an increase = more chance of an increase, which we all know, is incorrect.

Anonymous said...

1) Any other metric than minimum is senseless, as the amplitude is independent of the frequency. To take a standard 'nighttime' temperature is just interpolating at random intervals.

2) Perhaps you would like to think about how that sounds to other people.

3) Which is the most accurate? Which has the best radiation scheme? Science operates on dissent, which is why the convergence of the models is such a strong indicator that the theory is correct.

Jonathan Lowe said...

1) if the sun was a major contributer to global warming, then the maximum and minimum temperatures would be influeced by it because the minimum temperature is recorded after sunrise. My analysis suggests that there has been no overnight warming despite increases in minimum temperature.

2) I already have

3) Using a hold out sample and testing each of the models to predict int this sample will provide you with the most accurate model. No need to use many models with all different sorts of assumptions. Test on the past.

Anonymous said...

1) If you genuinely believe that, I would be delighted for you to state for the record that 6 am summer temp measures the same thing as 6 am winter temp. They represent just seasonal extrema don't they? Much the same as diurnal?

2) Belief in conspiracy theories is negatively correlated with IQ.

3) Please state which historical comparison to use when NCEP reanalysis is a model result in itself and paleoclimate reconstructions are point sources.

Jonathan Lowe said...

you don't think my trends are seasonally balanced?

Please feel free to constructively criticise the analysis that I did, or shut up.

Luke said...

Meanwhile http://www.mdbc.gov.au/__data/page/1366/RMSystem_Drought_Update10_October07.pdf

and I'm informed that temperatures have been WAY up across southern Australia with some of the warmest Jan-Sept temps ever. As Neville Nicholls has reminded us that the evaporative demand of the millenium drought is greater than the Federation drought. Droughts are not only rainfall influenced - greater evaporation makes a double whammy.

Luke said...

sorry wrong thread

Anonymous said...

I'm guessing that means you deleted my post. After complimenting you on your charming response, I went on to say that you can't assume seasonal invariance in a climate change scenario as the greenhouse effect is radiation based so has a stronger magnitude in summer than winter, so annual 6 am underestimates the trend and 6 am summer understimates the amplitude. If you measure 6 am temp in a climate where minimum changes between 5 am to 7 am min, what signal do you get? No trend. It is called aliasing.

Jonathan Lowe said...

thanks Anonymous,
I didn't delete your previous thread, not sure what happened there. I do account for seasonal variances in my analysis. And I have found no significant increases in temperature anomolies for stations whether this is summer or winter.

Jack Lacton said...

3) Because science works on hypothetico-deductive reasong where you cannot prove anything, just disprove things. That is why gravitation and evolution will always be just theories. So if there were 17 models and one said that increasing CO2 lead to cooler temperatures you would have something. None do.

CO2 is programmed as a forcing agent. Let's repeat that in case you don't understand how models work. CO2 is programmed as a forcing agent.

Of course the models show warming when CO2 increases. That's what they're programmed to do!

Anonymous said...

Have you seen the absorption spectrum of CO2? What else would be released but heat? Your argument is analogous to saying that gravity is programmed to operate towards the centre of mass.

Luke said...

Of course CO2 is programmed as a forcing agent coz it is: OK let's try some empirical measured evidence !

Radiative forcing-measured at Earth's surface-corroborate the increasing greenhouse effect
Philipona, R | Duerr, B | Marty, C | Ohmura, A | Wild, M
Geophysical Research Letters [Geophys. Res. Lett.]. Vol. 31, no. 3, [np]. Feb 2004.


Increases in greenhouse forcing
inferred from the outgoing longwave
radiation spectra of the Earth in
1970 and 1997
John E. Harries, Helen E. Brindley, Pretty J. Sagoo & Richard J. Bantges

NATURE |VOL 410 | 15 MARCH 2001 |

Mawson said...

The issue is, How is the model programmed to account for co2 induced warming

Anonymous said...

You take the pdf of outgoing long wave radiation and find the range for each greenhouse house which is absorbed. Then for this range you calculate the absorption energy involved given that for a photon it is proportional to frequency. Then given the energy absorbed in the photon collision you calculate the temperature change via the stephan boltzmann equation. It is called physics, although here it is probably better known as witchcraft.

mawson said...

And the values of the constants used are?

Anonymous said...

Planck's constant = 6.626068 × 10-34 m2 kg / s
Boltzmann constant = 1.3806503 × 10-23 m2 kg s-2 K-1

Mawson said...

Thanks.

I assume that this is then applied to the GCM's on a world wide basis, and by all the models currently in vogue.

Anonymous said...

Yes, all introduced with different radiation balances, different albedo parameterizations, different biogeochemical feedbacks, different carbon cycles, different spatial and temporal discretisations and different suoercomputer compilers, code and architecture. And they all give very similar results. It is called repeatability. THere might even be a few bugs in the code, but it will still be more accurate than the Excel IEEE noncompliant results we have seen here.