Archive for March, 2010

Fresh atmosphere in climate debate

March 21, 2010

Opinions have shifted recently regarding the issue of climate change. The credibility of so-called climate alarmist has suffered from the critical inquiries of the broader scientific community, the so-called climate skeptics, and various incidents. As much as I approve of the effect on re-opening the scientific discussion, I think it is probably for the same wrong reasons that led people to believe alarmist theories in the first place: primarily media sensationalism.

Science is not a popularity contest, it is simply the rigorous search of knowledge. The validity of anthropomorphic global warming theory and its predictions has little to do with mediatic debate around tornadoes, cold winters, Himalayan glaciers or a shady researcher. In that sense Al Gore (and others) have brought this upon the AGW community with his movie, An Inconvenient Truth, by using simplistic and shocking images (hockey stick, climate instability, polar bear, drowning cities). These talking points, like much politics?? certainly captured people's imagination and it encouraged them to trust superficial arguments. The result is a backlash as those claims are debunked.

Now, carbocentrists (a more suitable moniker for supporters of the AGW theory, coined by author Beno??t Rittaud) rightly argue that climate science is subtle and complex and that those headline-grabbing arguments are not the real core of the theory.
Fair enough, so what is the real core?

Maybe the IPCC report is not that relevant at this point, because of several faulty claims and its lack of political independence, but it at least spells out the carbocentrist theory. From what I understand, its main argument goes like this:

  1. climate models incorporate the state-of-art knowledge about physical phenomenon which underly climate,
  2. the models have been tuned to real-world data and produce results consistent with the temperature average measured for the last x decades,
  3. known factors which are explicitly not supported by the models are not expected to negate the results,
  4. CO2 is deemed the most important factor because models fail to match historical data if CO2 is not included,
  5. the models all tend to forecast a warming of the average temperature, across many runs with different CO2 emission scenarios.

I hope my summary is accurate. If it's not, I would love some carbocentrists lay the logic out properly.

Assuming the above reasoning, a number of questions I can think of would have to be addressed for it to be a strong argument:

  • If our physical understanding and modeling is good, why do we need multiple models?
  • How do we know that models are good at forecasting?
  • How do we know that the forecasts from different runs are properly distributed in terms of probabilities?
  • How much out-of-sample (ie. future data) do we need to collect to even consider invalidating a model (falsifiability)?
  • Given enough out-of-sample data and the wide range of predictions offered by the models, what variation between measurements and predictions would it take to invalidate a model?
  • How can we rely on "ab ignorantum" argumentation to claim that CO2 is the main factor? Ignorance of a better explanation is not conclusive proof.
  • Is average temperature a good measure to build scientific knowledge?
  • Given the non-linear and chaotic nature of weather, how can we exclude seemingly important factors?

Finally, I understand that politics cannot be completely taken out of the discussion, but we should do our best to separate the question of what we know and understand from what we should do about it. Policy decisions relate to primarily to politics and economics, and related to climate science only for understanding the expected effects on climate of the designed behavior change.

On-the-fly book scanning

March 18, 2010

Impressive piece of tech.
Riffle through the book under a high-resolution camera to scan through a book at around 200 pages per minute. Reference illumination (infrared grid pattern) lets the software determine the curvature of the page in each frame, as it is being flipped, and flatten the page’s image.

Stossel on Prohibition

March 7, 2010

The video above may have been blocked, here’s an alternative.

Economic analysis predicts that prohibition of voluntary activities is wasteful and dangerous. The consequences of turning morals into laws was illustrated by the alcohol prohibition in the US, amongst other examples.

Why expect that other prohibitions (drug usage, prostitution, organ trade) would be different?

It is important to distinguish activities that harm others (violence, theft, fraud), which should be condemned, from ones that merely offend others.
Similarly, we need to separate the crimes caused by prohibition itself and not impute them to the immoral activity.

What are Profits and What Function Do They Serve?

March 3, 2010
Full transcript in the author’s blog post. (via blog.mises.org)

This video describes the instrumental role of profits and losses as a signal to coordinate activity in society, and the government interferences on that signal.

Profits and losses exist in a system of private ownership and solve crucial knowledge and economic calculation problems in society: how do entreprenurs know what to produce and in what amounts to satisfy the greatest needs, how should different usages of resource be prioritized, which projects are wasteful and should be cancelled or made more efficient?

Overall, prices and the profit/loss system allow large scale coordination of activity and generate systematic feedback for adapting the production structure to best fulfill the demand of consumers in ever-changing and complex conditions.

French documentary revisits Milgram’s experiment

March 1, 2010

Extrait i comme icare

This segment from the 1979 french movie, “I as in Icarus”, depicts the famous and shocking Milgram experiment.

A soon-to-be-released documentary reconstructed this experiment under guise of a TV show. The purpose is to expose the power and dangers of TV, in particular reality TV shows and the spectator’s reaction and distance to violence depicted on TV.