Do you proudly reuse a shiny aluminum travel mug for your coffee every morning or do you think nothing of contributing to the mountain of disposable cups in the trash bin on the way to work?

Does it matter if your partner eats organic or prefers the fast-food drive-thru? Do you relish questions like these or do they make you feel like you're personally responsible for those poor polar bears stranded on pieces of ice as the Arctic sea ice melts?

Well, get used to it. As the debate about global warming comes down strongly in favor of green-leaning scientists over right-wing radio talk show hosts, the topic of going green is all the rage. And one's stance on aerosol spray cans and petrochemicals is becoming an increasingly significant indicator of social compatibility as we manage friends, family, business contacts, lovers, and life partners.

"For most people I know, it [green incompatibility] is a deal-breaker right off the top," says JB MacKinnon, a Vancouver-based journalist who co-authored, with his partner Alisa Smith, a book called The 100-Mile Diet (Plenty in the U.S.), about eating locally for a year (100milediet.org). "They probably wouldn't hook up with someone who drove an SUV. It's unfortunate, but I think it's true there are certain distances between two people that can look too great to bother traveling through."

He and his beloved never had to engage in the Prius-versus-Range Rover debate -- they've more or less been on the same UTNE Reader page since joining their university newspaper on the same afternoon 16 years ago.

But for others, the question of whether to use recycled toilet paper or what method of transportation to use can be a sticking point. Some singles, on their profiles, even go so far as to specify they're looking for someone with that extra something green -- a didgeridoo-playing, dreadlocked cyclist, say, or a hemp-wearing, organic-produce-buying social activist.

And, while navigating the dating scene, there's always the chance you'll order a rib-eye steak or a bottled water and your date will suddenly look at you like you're Satan incarnate.

Tina Wilson, however, will probably give you a break. "I think it all depends on the personalities involved," says Wilson, who is in the process of launching doubletruth.com, an online lifestyle magazine dedicated to the idea of what she calls "sustainable luxury."

"I'm a vegetarian but I'm not going to not date a meat-eater," she says. "If you're going to go for 100 per cent compatibility you're never going to find anyone. At this point I'm willing to consider someone without the same values. If you're on the activist route, though, maybe it won't work."

In any relationship, sacrifices have to be made. Though he and Alisa usually see eye-to-eye, MacKinnon says his partner had to be persuaded to take part in the complete change of lifestyle the 100-mile diet required. "She had a clearer view of the sacrifices involved," he notes.

But theirs was a minor difference compared to what No Impact Man and his wife have been going through. Colin Beavan and his wife Michelle Conlin were the picture of a cosmopolitan, eat-out-every-night, coffee-consuming couple when he convinced her to try a new lifestyle -- cutting their carbon footprint to zero, eating locally -- for one year. As of this writing, they were in their eleventh month.