About Asking the Right Questions

Here in Australia we have a national referendum every now and again, for such things as whether or not Australia should change from the monarchic model to the republican model.

Invariably -- as you'd expect from politicians -- the party in power in the federal government carefully crafts each referendum question in such a way that their preferred option is most likely to succeed: if you will, a variation upon the saying that "The devil is in the details".

Similarly so with many a scientific debate over the decades and centuries.

Australia is in the vice-like grip of a great drought, perhaps the worst for some centuries, and there's intense dicsussion of global warming and climate change. Are the "right questions" being asked about all this?

Upon this theme, at RealClimate there's an interesting recent post: Attribution of 20th Century climate change to CO2 (with lots of comments, too) ...

In public discussions there is often an emphasis on seemingly simple questions (e.g. the percentage of the current greenhouse effect associated with water vapour) that, at first sight, appear to have profound importance to the question of human effects on climate change. In the scientific community however, discussions about these 'simple' questions are often not, and have subtleties that rarely get publicly addressed.

One such question is the percentage of 20th Century warming that can be attributed to CO2 increases. This appears straightforward, but it might be rather surprising to readers that this has neither an obvious definition, nor a precise answer. I will therefore try to explain why.

For a range of findings, opinions and views see also:

• Climate change (Wikipedia)
• Forcings and Chaos in Global Climate Change
• Observational Estimates of Radiative Forcing due to Land Use Change in Southwest Australia
• Climate and Chemistry: forcings, feedbacks and phasings in the Earth System (CACHE)
• World Climate Report: Climate Forcings
  Global average temperature change projected from 16 different climate models for the 21st century if atmospheric CO2 levels are held constant at the year 2000 levels.
• Climate forcings in the Industrial era
• The Impossibility of Prediction - in which Michael Crichton, author of Jurassic Park, makes some very interesting points/claims!