Bjorn Lomborg

When thinking about the future, it is fashionable to be pessimistic. Yet the evidence unequivocally belies such pessimism. Over the past centuries, humanity's lot has improved dramatically - in the developed world, where it is rather obvious, but also in the developing world, where life expectancy has more than doubled in the past 100 years.

The price of diamonds can vary greatly depending on size, cut, color, and other factors, including whether they have a history. But because of the rarity of blue boron diamonds, they often fetch more money than gems of similar quality.