I attended your fascinating lecture "Truth, an inconvenience" at Carleton University in Ottawa, ON, 2012-04-18. You explained social/cultural factors in one's forming strong views on controversies, especially on the topic of climate change.
If you recall, the Club of Rome's "The Limits to Growth (1972)" predicted that the world population growth will be exponential, and that the oil would last for only 30 years.
Well, 40 years later, however, fossil fuels are as abundant as ever. The world population has increased a lot, but it is expected to stabilise by 2050 or so.
So, there is a time-axis to vary the truth, perpendicular to the 2-dimensional plain representing the social/cultural factors which you explained during the lecture.
It is possible that in 100 years or so, scientific evidence will emerge that thanks to global warming with increased CO2 and CH4, there is enough food to feed all the population by preventing another ice age.
Of course, it is also possible that the vast majority of the world population is overweight or obese because of global warming which increased food production.
Whether global warming is true or not, I believe that the key for the Earth's sustainability is the political will to develop genetically modified plants that resist low-humidity and high-salt soil condition in order to halt and reverse the spread of deserts.
