Back in 1996, already three years into the Net revolution, I recall sitting in San Francisco Bay Area (my home for 13 years) cafes, and realizing how all the talk I overheard was dominated by the Internet.

The guys at the table next to me were talking about their idea for an online toy company, the people next to them about their Web zine to compete with HotWired and those behind them about the launch of their new online stock-trading venture. At my own table, I was likely talking about online travel, virtual communities, web search or how to recreate the Whole Earth Catalog on the web. A cacophony of web dreams and net creations...Some were brought to fruition while others got no further than table-top doodlings.

In any case, conversation about the Internet was seemingly ubiquitous.

Now, from my perch in Portland, Oregon (a major node in the global transition toward sustainability) — the conversation is very different. In 2008, when I go to cafés in Portland, the conversation is on green buildings, solar PPAs, wind-power development, green-collar jobs, regional and organic foods and clean-tech relief and development efforts in the developing world (to name a few).

And it's not just Portland.

Clean tech, green biz and sustainability are now the stuff of café conversations (and new business formations) in such far flung locales as Toronto, Canada; Shanghai, China; and Bonn, Germany.

At a recent family gathering (in a restaurant, not a café) I was amazed at the level of discourse and familiarity with clean-tech issues among my siblings and cousins. One of them asked me about the issue of grid transmission constraints for moving wind-power resources from remote locations to urban centers, another wanted to better understand the environmental impact and lifecycle assessment of the battery packs in hybrid vehicles and yet another was grappling with the issue of carbon cap-and-trade versus a carbon tax.

In my estimation all this conversation and technology and business maneuvering is a good thing. We're no longer at the stage where people need to be introduced to these issues, we're at a stage where people are asking below-the-surface questions, devising innovative remedies and creating new business plans to address some of the greatest challenges of our time: resource constraints, environmental degradation, energy security and economic and job creation.

I've heard some recent rumblings on the web and in the blogosphere about the impending "green bubble." And in some ways they might be right — there could be a waning of "green" as the next "cool" thing. Some overvalued sectors will likely come back down to earth. Feel-good environmentalism in the form of "carbon offsets" for Hummer-driving, McMansion dwellers will certainly be exposed as being an inadequate solution. But I think something far more striking is happening. Green business, clean-tech and sustainability, like the Internet, are going to become ubiquitous. And by becoming so prevalent and embedded, they'll in many ways disappear.

Utilities won't just deliver cheap and reliable electricity (their age-old mandate), but now their business case will increasingly rely on delivering energy efficiency (including the smart grid) and low-carbon or zero-carbon emission energy sources (like solar power, wind power and geothermal). Builders won't just build skyscrapers that pepper the urban landscape, they'll develop smart buildings that reuse water, utilize significantly less energy and that are generally cleaner, brighter and healthier. Waste management companies won't just haul garbage to increasingly scarce landfills, but harvest their waste bounties as new recycled materials, energy feedstocks and fertilizers.

Don't get me wrong — the shift won't happen overnight. Neither is it a fait accompli. Instead, it will take a concerted effort among enlightened policy makers, technologists, entrepreneurs, business titans, academics, financiers, citizens and others over the next 10-20 years.

But the signs of the clean-tech transition to mainstream ubiquity are becoming clear. Just witness the following headlines from the Clean Edge web site over the past couple of months:

  • China To Double Renewable Energy Target

  • Las Vegas Hotel Becomes World's Largest LEED Certified Building

  • New Jersey Utility To Offer $105 Million in Solar Loans

  • EU Countries Near Agreement on Sustainability Criteria for Biofuels

  • AES and Riverstone Commit $1 Billion to Solar Joint Venture

  • Wal-Mart To Provide Energy-Audits for State Capitals

  • PGE Announces Landmark Deal for up to 900 MW of Solar Thermal Energy

  • GE Invests in Electric Vehicle Producer Think and Battery Manufacturer A123Systems To Commercialize Electric Car

So, when I travel around the country and overhear people in cafés talking about plug-in hybrid electric vehicles, the presidential candidate's stances on global warming or a new business plan for a clean-tech company — I don't get discouraged that it's a fad about to pop. I see it as the next big wave of innovation and entrepreneurship — and one that's getting firmly seated in our collective ethos.

That, I believe, is something to muse (and cheer) about.

Ron Pernick is co-founder and managing director of Clean Edge, Inc., coauthor of The Clean Tech Revolution, and Sustainability Fellow at Portland State University's School of Business.