There'll come a time when airplanes are much more efficient when it comes to producing lower levels of greenhouse gas emissions, there'll come a time when we'll be able to offset those emissions much more effectively than we do now. But alas at the moment, flying airplanes is really one of the least defensible things that we do and it's one of the things that I indulge in quite frequently, alas.

If you have a flat, fixed view of state interest then it is difficult to understand why some states adopt aggressive climate change policies, even when that risks economically disadvantaging them, and other states do not even when it would be in their economic interests to do so.

In much of the world today there are no more chilling words than "I'm from the United States and I'm here to help you."

Ethics is prescriptive and can change behavior, but usually only at the margins.

In the last few centuries we've managed to reduce how much we kill each other, we've learned some basic lessons about public health, and life is relatively good for more people than ever before.

I think the mother of all arguments against eating meat now is the climate change argument. Methane is a much more powerful greenhouse gas than carbon dioxide and when we eat meat we wipe away many of the good things that we do when we try to create greener and more sustainable practices in the rest of our lives. So if you add the concern for climate change with other concerns that were there. I think the case for vegetarianism is pretty overwhelming.

Philosophers (and probably most intellectuals) are more interested in pursuing what they see as the logical implications of their theories than they are in paying attention to the shlumpy diversity of defensible values that people actually have, and then trying to figure out how these might be negotiated in the life of an agent or community.