Ingrid Newkirk, 12/21/12

President and co-founder, People for the Ethical Treatment of Animals (PETA)

The NRA vigorously promotes hunting with all manner of weapons, from crossbows to rifles, which is why PETA parents and others are out protesting this week as the NRA mounts the bully pulpit to try to distance itself from a gun massacre that has shaken the country.

Owen Egerton, 12/21/12

Author

The Mayans have been getting some great press lately. They've cornered the market on apocalyptic predictions, at least for this week. But the truth is, the end has been nigh for centuries.

Susan Casey-Lefkowitz, 12/21/12

Director International Program, Natural Resources Defense Council

American leadership is critical to fighting climate change -- not just here at home but around the world. And leadership means that we can't let the fossil fuel industry undermine clean energy by continuing our dependence on coal and oil.

Robert Schrader, 12/21/12

Writer, photographer and editor of LeaveYourDailyHell.com

The good news is that I returned from Chiang Mai's "Tiger Kingdom" very much alive. The bad news? I found no evidence that definitively confirms or denies the farm's tigers are being sedated, propaganda publicity leaflets notwithstanding.

Scott Edwards, 12/21/12

Co-Director, Food & Water Justice Project

Each day brings new, irrefutable evidence that fracking is poisoning our communities. But the ban on fracking in Longmont, Colo. was nothing short of heroic given the massive amounts of money thrown about by the oil and gas industry leading up to the November vote.

Alex Palombo, 12/21/12

Director of Online Strategies, Progressive Strategies

The Mayans said the world was ending today. But I have a feeling that tomorrow, we'll still be here. Let's work together and curb this climate change so that our calendar doesn't run out.

George Zaidan, 12/21/12

Freelance writer, host and producer

Most squirrel observation is low-tech, involving a pair of binoculars and a notebook. SciStarter.com has a list of squirrel-related citizen science projects, and if you think you're sly enough to outsmart squirrels, we have a limited-time competition just for you!

Rev. Jim Ball, 12/21/12

Author, 'Global Warming and the Risen LORD: Christian Discipleship and Climate Change'

With our current situation of cheap natural gas, no price on carbon providing an incentive to decarbonize, and no carbon pollution regulation of existing coal plants, industry efforts are dead in their tracks.

Jeffrey Kimball, 12/21/12

Director, 'Birders: The Central Park Effect'

In the early morning hours, I joined 72 other volunteers for Audubon's 113th Annual Christmas Bird Count. Despite the intermittent drizzle and gray skies, we fanned out and spent the next four hours covering more or less every inch of the park in an effort to count each individual bird in those 843 acres.

Paul Raeburn, 12/20/12

Author, 'Do Fathers Matter? The New Science of Fatherhood'

The January issue of Esquire is out with an almost 8,000-word story called "Thank You for Fracking" by Tom Chiarella, which wants to be a manly, Esquire-ish, ultrahip analysis of a current environmental policy debate. It falls far short of that.

Mark Boslough, 12/21/12

Physicist; Fellow of the Committee for Skeptical Inquiry

The probability of impact by one of these before the end of the century is 0.0005 percent. On the other hand, recent research suggests a 2 percent probability of global catastrophe from anthropogenic climate change by the end of this century.

Maisie Greenawalt, 12/20/12

Vice President of Strategy, Bon Appetit Management Company

The physical conditions in the tomato fields were extreme. No shade, oppressively hot, with workers running with many pounds of tomatoes on their shoulders. I stood there fully aware that these workers are routinely exploited and sometimes physically enslaved. I had seen the overcrowded worker housing.

Lee Crockett, 12/20/12

Director, U.S. Fisheries Campaigns, Pew Environment Group

New England is famous for cod fishing. But the industry is ailing -- and the cure being proposed might be worse than the disease.

Scott Steen, 12/20/12

CEO, American Forests

Some people don't love trees as much as they used to. After the severe storms we have had this year, including Hurricane Sandy, city trees can seem like a dangerous liability. Are urban trees worth the risk they pose to houses, cars and people when a violent storm comes through?

Danielle Nierenberg, 12/20/12

Sustainable Agriculture and Food Policy Expert

As we start 2013, many people will be thinking about plans and promises to improve their diets and health. We think a broader collection of farmers, policy-makers, and eaters need new, bigger resolutions for fixing the food system -- real changes with long-term impacts in fields, boardrooms, and on plates all over the world.

The 420 Times, 12/21/12

Medical marijuana and natural healing magazine, the420times.com

With adults in Colorado and Washington now legally able to possess an ounce or less of marijuana for any reason, it's important to stop for a moment and take stock of the landscape when it comes to marijuana law reform.

John Tepper Marlin, 12/20/12

Chief Economist, NJ Institute for Social Justice

With Obama's reelection, in the teeth of huge spending by his opponents, the president is in a good position to get through elements of his original program that were left on the table. The devastation wrought by Superstorm Sandy may help make his case.