Peter Kareiva, Robert Lalasz, and Michelle Marvier assert that in the 21st Century, "conservationists will have to jettison their idealized notions of nature, parks, and wilderness... and forge a more optimistic, human-friendly vision... Conservation will likely continue to create parks and wilderness areas, but that will be just one part of the field's larger goals." Unfortunately, their article was written 100 years too late. -- By Kierán Suckling

In "Conservation in the Anthropocene," Peter Kareiva, Robert Lalasz, and Michelle Marvier argue that conservation needs to move beyond parks and protected areas. While their arguments and examples are drawn from terrestrial ecosystems, much of their article is relevant to marine ecosystems, my field of study, and the new frontier for conservation. -- By Ray Hilborn

For the past 30 years, those who pointed to the inherent weaknesses and contradictions in traditional approaches to conservation were treated at best as marginal, and at worst, as anti-environmental. How things are changing. Peter Kareiva, Robert Lalasz, and Michelle Marvier herald the pragmatic arrival of this kind of critical thinking into the mainstream. But there also lurk challenges and contradictions in Kareiva et al.'s insufficiently articulated vision of the economy. -- By Paul Robbins

We applaud Peter Kareiva, Robert Lalasz, and Michelle Marvier for broadening the constituency of the conservation movement, but regret that the message of "Conservation in the Anthropocene" seems at odds with their larger objective. For a reader outside the conservation community, the paper is likely to reinforce the misconception that the conservation movement is fueled by a dogmatic, nature-before-people ideology. At the same time, a reader within the conservation community is likely to chafe at the incompatibility of the authors' arguments with the consensus of best available science and with the scientific process in general.

We agree that conservation leaders should seek opportunities to come to the table with corporations. But engagement with industry introduces new risks, including the possibility that nonprofit organizations will damage their own credibility and the credibility of the movement through association with corporate "greenwashing" schemes. Effective negotiation, both with industry and with policy makers, requires a positive and forward-looking vision, along with a strategy for risk management. Unfortunately, we feel that neither a vision nor strategy have been outlined in the authors' paper, although we strongly suspect the authors are in a position to significantly inform both.

Conservation is improving in its treatment of indigenous communities and attitudes toward people. But we should not go overboard with self-congratulation on this front. The change is neither complete nor a done deal. Conservation must not fall back into the ideological and impractical fortress mentality, a mentality that is insensitive to humans with needs that might supersede biodiversity. -- Peter Kareiva, Robert Lalasz, and Michelle Marvier respond to their critics.