The messages come from everywhere: Save the planet. Reduce your carbon footprint. Be eco-wise.

But how do consumers decide which product or action is healthier or more environmentally friendly? Sometimes the choices are clear; other times they're more murky. Here are some examples:

PAPER VS. PLASTIC

Both can be made from recycled materials and are recyclable. Paper is made by cutting down trees — which help absorb greenhouse gases — but then again, they're renewable. Plastic bags are often made of polyethylene, produced from natural gas, which is abundant but not renewable.

But it takes more water and energy to make paper bags than it does to produce plastic bags. Neither breaks down particularly fast in a landfill, though paper is compostible; plastics don't biodegrade easily.

An alternative is taking your own reusable cloth or plastic bag to the store. But consumers shouldn't stress too much, as long as they're recycling or reusing store bags, whether by filling paper with newspapers for recycling or carrying their lunch in plastic, said Chris Newman, an environmental scientist with the U.S. Environmental Protection Agency.

COMPACT FLUORESCENT LIGHT BULBS VS. INCANDESCENT

CFLs last longer and use less energy, but also are more expensive and contain toxic mercury. That means consumers must be careful how they clean up the bulbs if they break, and dispose of them properly.

But mercury also is a byproduct of burning coal. And the extra electricity needed to power incandescent bulbs often comes from coal-fired power plants. The toxin, which can cause neurological damage in children, can get into the food chain after settling into lakes and streams.

Eventually both CFLs and incandescent bulbs probably will be replaced by solid-state, or LED, lighting. But until then, environmental groups generally advocate consumers use CFLs, though people with children will want to take extra caution.

ORGANIC VS. CONVENTIONALLY GROWN FOOD

It's true that organic food, grown or raised without pesticides and herbicides, could be better for your health and the ecosystem. But if it is shipped from thousands of miles away, there is an environmental tradeoff because of the pollution caused by trucks traveling cross-country.

Some experts say you might want to consider passing on organic produce, for example, if it has a thick skin, like bananas, or outer leaves, like corn. Or you could make a point of buying locally grown food.

PESTICIDES VS. DOING NOTHING

Bugs in the house aren't just creepy and crawly. In the case of cockroaches, they can cause asthma in children. But spraying pesticides is not necessarily great for little lungs, either, and it's often just a matter of time before the critters return.

A better alternative is using baits — the roaches eat the poison, then take it back to their families, helping to end the roach life cycle, according to Tom Neltner, of the National Center for Healthy Housing and founder of Indianapolis-based Improving Kids' Environment. But parents have to be careful that children and pets don't come in contact with the baits, he said.

DRIVE-THROUGHS VS. GETTING OUT OF THE CAR

Idling a car engine for more than 10 seconds emits more pollution than turning it off and back on again. So if you're able, environmentalists recommend that you park your car and walk into the fast-food restaurant or the bank. Many cities recommend that drivers avoid idling as much as possible, especially on days when alerts are issued because of ground-level ozone and soot.

Or better yet, walk to the restaurant. If you can safely walk or bicycle, there is no environmental or health downside. And riding the bus or train helps take cars and trucks off the road, cutting down on tailpipe emissions, which account for a large percentage of air pollution in most urban areas.

CLOTH VS. DISPOSABLE DIAPERS

Disposable diapers are convenient, but can be costly over time and raise heath concerns over absorbent chemicals used to keep infants dry, such as sodium polyacrylate.

But cloth diaper services can be harmful to the environment because of chemicals used in laundering and carbon emissions released in pick-up and delivery. However, if laundering at home cloth diapers can be a cost-effective option.

Also efficient are all-in-one or "hybrid" diapers that usually consist of a washable cotton pant and a disposable diaper refill that can be flushed or used as wet compost. Organic disposable diapers offer an eco-friendly alternative to plastic, non-biodegradable ones left in landfills indefinitely.

Many parents use a combination of cloth and disposable diapers, depending on the circumstance and time of day.