BONN—I missed a "conflict-of-interest"-themed session, but rumors are it was cathartic. Who in the activist crowd, after all, can pass up a chance to knock around "big polluters?"

Issues tend to gain a life of their own in the corridors during the climate talks. And so it is with a call to ban polluting business interests from the United Nations Framework Convention on Climate Change.

Should "people whose interests are so opposed to the interests we are trying to advance via the UNFCCC process," as I heard one activist say, be allowed in the same hall as negotiators?

As my 14-year-old daughter is overly fond of sighing: "Seriously?"

A closer look

Let's break this apart, since I try to act like a scientist some of the time.

The nascent campaign's slogan—"Kick big polluters out"—caught my attention: Maybe "small polluters" don't need to be kicked out? If that's true, who draws that line? (Good luck.)

And how far "out?" Should Big Pollution not play a role in getting me and my 13 companions from the talks to the next part of our Great Expedition: Iceland? (If so, good luck to us! Guess we'll all be kayaking those 863 kilometers, and that's from the UK!)

Who's a "polluter?" Agriculture accounts for 13 percent of humanity's greenhouse gas emissions—the second biggest share, behind the energy sector.

If methane-burping cows are out, does that mean Argentine rumpsteak will not be on tonight's menu? Or that I will not be able to rent a Made-in-China e-bicycle for my along-Rhine commute between the hotel and this center?

Really big polluters

Or what if we measure "big polluters" by per capita emissions?

As an American, I'm out: Average American emissions (~16 tons of CO2 per year) are 10 times those of a Costa Rican or Peruvian and double those of the average German.

Surely both camps would do better to acknowledge their common ground: Literally, the rooms here in this World Conference Center, and just below that, Rhine River alluvium.

They might share even more, however, and each acknowledge the profound limitations of their tribalism. For as I watch our students explore this center, I see clear need for this common ground—faked, imagined, geological—to be expanded.

The world's not black and white. Or even big and small.

Luckily for our students, the diaspora here at these talks exposes them to all that gray, one conversation at a time. We're all richer for it.

Tony Hartshorn is a professor of soil science at Montana State University. Follow him on Twitter @soildocTony and via #soilculture.

The Daily Climate is an independent, foundation-funded news service covering energy, the environment and climate change. Find us on Twitter @TheDailyClimate or email editor Brian Bienkowski at bbienkowski [at] EHN.org