Honolulu is among the 25 “greenest” large cities in the U.S., according to a study by online coupon site RetailMeNot.com and Ipsos Public Affairs.

The Earth-Day-inspired study found that while 46 percent of consumers are more inclined to buy a product if it is eco-friendly, 59 percent of respondents are unwilling to pay more money for an environmentally conscious version of a product or service.

The study delves into the environmental awareness of shoppers, studies shoppers’ demographics and the likelihood of each to make a green purchase, as well as whether retailer support for environmental causes influences purchases (only 15 percent of shoppers say this influences them).

RetailMeNot.com and CarbonFund.org have pledged to plant up to 5,000 trees, one for each click on its Earth Day deals page.