Your main leader and briefing about the Anthropocene are eye-openers (“Welcome to the Anthropocene” and “A Manmade World,” May 28, 2011). Forget about the Holocene, which started around ten-thousand years ago. This is the age of man, no doubt. And Paul Crutzen, an atmospheric scientist, proposed the new term a decade ago. The new name for the geological era is ushering a “paradigm shift” in our relationship with our world. Now that we have left such an indelible mark upon the earth, it is up to us to manage it, as well. Intelligence is our forte, after all. As you argue, geoengineering is thus the answer. What you skip, though, is geopolitcs, for planetary science and engineering will get nowhere without agreement about what is to be done when, where, and how. And that is the domain of politics, albeit on a planetary scale. Welcome to the Anthropocene, indeed! Optimists are especially welcome, too.