And last year, Americans spent a great deal of money on them. But now, the government has cracked down on some companies, saying their green claims aren't accurate.
Critics call the marketing practice "greenwashing" -- a way to attract customers by labeling products as eco-friendly when they may not be. The problem is that there is no legal definition of what "green" is, so companies can make all sorts of claims without providing proof.
"Environmentally- friendly," "green" and "natural" are all labels with no legal meaning.
"It infuriates me," said Leigh Stringer, an environmental architect, a mother and author of "The Green Workplace."
Stringer tries to live green, especially because she has a 3-year-old daughter, she said. Greenwashed products make her angry.
"When I find that they haven't done the work -- they just slapped a green label on something -- and haven't really shown me that they've done the due diligence. ... I find it very frustrating," she said.
The Federal Trade Commission recently filed complaints about four textiles marketed as natural bamboo, which they're not.
"In fact, the fiber that's used in each of these is rayon," Jim Kohm of the FTC told "Good Morning America."
The FTC also recently brought cases against three products labeled biodegradable, when in reality they're unlikely to break down. Five of the seven companies involved in these cases have agreed to stop making the claims in question, without admitting fault.
"The reason the FTC is on the beat is we want to make sure consumers get what they're paying for," Kohm said.
"GMA" asked Scot Case of TerraChoice, a company that certifies green products for the Canadian government, to point out some packages that make confusing green claims.
Greenwashing category No. 1: Hyping what has been taken out of a product. One shaving cream product did that.
"The seal says no CFCs," Case said. "No chlorofluorocarbons. And what's interesting to me is that CFCs were actually banned in 1978. So they are promoting something that would be illegal if they were in there."
Greenwashing category No. 2: Not providing proof.
Speaking about a brand of drinking glasses bearing the chasing arrows symbol, Case said, "It could be a wonderful product, but they haven't told me how much recycled content. What's the source of that recycled content?"
Environmental trade-offs are category No. 3.
Case and "Good Morning America" examined a Poland Spring water bottle that's marketed as having an eco-shape.
"It actually does use 30 percent less plastic than other bottles. … But you still have this sin of the hidden trade-off. Given that you are shipping this product back and forth across the country, when you could in fact just get it out of your tap," Case added.
Poland Spring responds that most people drink bottled water when they're out and don't have access to their tap, and said its eco-shape bottle is better than any other disposable bottle or cup.
Greenwashing category No. 4: Self-made seals, from companies that put their own stamps on their packages instead of one awarded by a neutral third party.