There are really two kinds of optimism. There's the complacent, Pollyanna optimism that says "don't worry - everything will be just fine" and that allows one to just lay back and do nothing about the problems around you. Then there's what we call dynamic optimism. That's an optimism based on action.

Agriculture is the #1 source of deforestation. By some estimates it accounts for 80% of the forests chopped down in the tropics.

New technology lets you grow the resource pie, which is the only way you can get out between that pincer of rising consumption (as we end poverty) and environmental and natural resource depletion.

If your incentives are set up wrong - if for some reason you reward people for behavior that's actually bad for your customers or your organization - then you're going to encourage that behavior.

Ozone and climate are global issues, and it's hard to find a way in which the benefits of shutting down carbon emissions are going to pay for themselves for any given power-plant, say.

Often we need to use policy to level the playing field, or to be sure that a technology is managed in a responsible way.

When it comes to trying to manage how our entire planet-wide market and all the people and businesses in it deal with nature and our natural resources - we first and foremost need to change the incentives.