When I first started researching my book Global Warming is Good for Business in 2007, terms such as "triple bottom line," "green technology" and "social entrepreneurship" were not commonly used or even understood. For most businesspeople, a sustainable business was one that continued to generate economic profits over time and had nothing to do with environmental impact, employee relations or community involvement.

By year-end 2010, however, in spite of one of the largest economic downturns in recent history -- or maybe because of it -- many industries are embracing a broader definition of sustainable business practices in the sense that they are actively looking for ways to generate less waste, cut costs, keep employees and increase profits. And while much of the hoopla about "doing the right thing" and "saving the planet" has died down in the past year, at least some environmentally sustainable business practices have become, well, business as usual for new ventures and established companies alike.

More and more companies are looking for the low-hanging fruit -- changing out light bulbs, turning off computers, recycling paper and ink cartridges, using ceramic coffee mugs instead of Styrofoam cups -- to save a few bucks (and maybe the planet, too). They may not be installing solar panels or other capital-intensive technologies, but they are making slow-but-sure incremental changes to the way they do business. And they are looking for ways to become even more sustainable, if only so they can boost sales by advertising that they are "green."

No doubt there are still business owners out there who are in denial -- so leery of the negative political connotations of "going green" that they steadfastly refuse to join the rest of the world. More common are those business owners who are simply so overwhelmed trying to make payroll that they don't have the time, energy or resources to set CO2 benchmarks or implement sustainable strategies. But even they are open to the idea of becoming more efficient.

If the buzzword for 2009 was "green" and the buzzword for 2010 was "sustainable," then I would say the buzzword for 2011 is going to be "efficient." With the economic recovery still plodding along, small businesses in particular are watching their pennies. They are uncertain about how the new government regulations are going to affect them and unhappy about the looming prospect of higher tax rates and excessive red tape (the proverbial granddaddy of all government inefficiencies).

Energy efficiency was one of the five leading sectors for venture funding in the third quarter of 2010, according toCleantech Group LLC. And experts predict that trend will continue into 2011 as entrepreneurs and investors join forces to bring energy-efficient technologies to market to meet the needs of businesses that must cut waste and reduce energy use.

Unlike "green" or even "sustainable," the goal of being more efficient is a business concept that appeals to everyone. And while some business owners are genuinely concerned about climate change and the environment, and others are committed to bettering the lives of their employees and adding value to their communities, many are just trying to break even and keep their heads above water. Regardless, everyone can benefit from being more efficient.