The most striking thing to me about human space flight and my own personal experience is that I've seen dramatic changes on… — John M. Grunsfeld Copy Share Image
As soon as you acknowledge that we're changing the planet on this scale, that it has very potentially massive repercussions and very… — Elizabeth Kolbert Copy Share Image
Human beings are definitely changing the planet, but how much impact they are having on climate, I don't know and I don't… — Felix Dennis Copy Share Image
