Robert Nickelsberg/Getty Images
You've heard of white-collar workers -- they're the suit-wearing lawyers, sales managers and bankers sitting behind office desks. Then there are the blue-collar jobs -- filled by the machinists, electricians and construction workers practicing their trade in factories and on building sites.
Today, there's a new trend in the job market. Millions of American workers are trading in their white or blue collars for a collar of a decidedly greener tint. With concerns about the environment at an all-time high, green-collar jobs have become the hot new employment sector. These jobs aren't as easily defined as white- or blue-collar jobs, because they can range from manual to managerial, but they all have the common goal of improving the quality of our environment by reducing waste and pollution.
Energy efficiency, alternative fuels, public transportation and recycling are just a few examples of green-collar industries. Green-collar jobs can be in large corporations, small businesses or nonprofit organizations. Proponents say these positions provide better opportunities than jobs in the traditional manufacturing sector because they pay higher wages and offer better career mobility.
America's interest in "going green" has skyrocketed in recent years. The research firm Clean Edge noted a 40 percent increase in revenue growth for solar, wind, biofuel and fuel cell energy in 2007 [source: Sightline Institute]. There are currently 8.5 million jobs in renewable-energy and energy-efficiency industries. According to estimates, by the year 2030, 40 million people -- or 1 in 4 American workers -- will be in fields such as renewable electricity production, alternative fuels, engineering and consulting, as well as energy-efficiency retrofits for homes and businesses [source: MacMillan].