The vast majority (87 percent) of American consumers agree they are seriously concerned about the environment.

Most (73 percent) are looking to the federal government to strengthen their enforcement of green regulations, according to the 2007 GfK Roper Green Gauge study by GfK Roper Consulting, writes MarketingCharts.com (via Environmental Leader).

The top 5 environmental issues weighing heavily on Americans' minds, according to the study:

• Water pollution and rainforest destruction (56 percent each)
• Diminishing fresh-water supply (55 percent)
• Fuel and energy shortages (54 percent)
• Man-made outdoor air pollution (53 percent)

Segmenting consumers based on their green attitudes and actions, the study identified five key groups:

1. True-Blue Greens: Environmental leaders and activists most likely to walk the green talk representing almost one third (30 percent) of the population. Nearly half of them (48 percent) turn to environmental groups as their main source of green information.
2. Green-Back Greens: Do not have time to be completely green and are not likely to give up comfort and convenience for the environment, but are willing to buy green products. They represent 10 percent of the population. Nearly half of them (49 percent) get information on green issues from newspapers.
3. Sprouts: Environmental "fence sitters" who buy green only if it meets their needs; they account for just over one quarter (26 percent) of the population. One-third of them cite newspapers as their main source of green information.
4. Grousers: Generally uninvolved and uninterested in green issues, this segment believes individual behavior cannot improve the environment. They form 15 percent of the population. Newspapersserve as their major information source on green issues.
5. Apathetics: Not concerned enough about the environment to take action, this segment believes that environmental indifference is the mainstream. This group represents 18 percent of the population. TV programs are their main source of environmental information.

MarketingCharts offers up a host of other findings from the study, here.