Today is Earth Day, the day set aside 39 years ago to inspire awareness and appreciation of the earth’s environment. There will be no shortage of commemorative activities and people pumping their chests proudly proclaiming their dedication to preserving the environment we live in. But with this country and many parts of the world in the midst of a recession, one wonders which “green” people are more concerned about – the fragile ecosystem humans have drastically altered over centuries, or the rapidly disappearing greenbucks lining our wallets?

It's not cheap being "green". Want to buy a hybrid-electric vehicle? Be prepared to fork over several thousand dollars more than an equivalent gas-powered vehicle. Want to buy organic food or household products? Watch that grocery bill soar.

Even if you have the greenbucks to go green, consider that many conveniences of modern life we take for granted - mobile phones, portable electronics, computers, TVs – are still by and large environmentally unfriendly. Disposable batteries, CRT screens, and plastics line our landfills. That old, gas-guzzling SUV we trade in will likely find its way to a junkyard. Toxic chemicals continue to pollute lakes and rivers. And our electric utility grid becomes increasingly overloaded from air conditioners, appliances, and computers all vying for power.

Stringent regulations and the innovative use of technology have somewhat mitigated the effects of the environmental mess we’ve created. But there is a difficult - and likely costly - road ahead.

After a two-year study, the U.S. Environmental Protection Administration recently identified six greenhouse gases - carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride – as primary contributors to air pollution and a potential threat to public health and welfare. The proposed finding now goes through a public comment period, after which the agency will issue final findings and make recommendations.

What happens after that is anyone’s guess, but some observers speculate the EPA could devise stringent regulations on greenhouse gas emissions – regulations that could mean higher costs for businesses and consumers already ravaged by the recession.

The possibility we may pay more for environmental compliance is not striking a pleasant chord with NASA Tech Briefs readers, judging from response to this week's Question of the Week . So far, our readers' comments indicate that attempting to be “green” in 2009 and beyond will involve social, political, and economic considerations far more complex than the grassroots ideals perceived by Earth Day’s founders.