Curbing climate change and creating a more sustainable community can start with making smart choices about how we spend our money.

Nearly 80% of Americans are concerned about the environmental impact of products they buy, according to a recent survey from GreenPrint, an environmental technology company. Food Business News reports that a similar percentage say sustainability is very or somewhat important when deciding which food and beverages to buy from grocery stores and restaurants.

Young people are powering this change in consumer behavior, experts say. "Millennials and Gen-Z are different from older generations in how they view services and the companies they buy from and work for. Each younger generation has stronger and stronger views about wanting to know what's in a product and how it impacts both people and the planet," says Andrew Winston, sustainability expert and co-author of "Net Positive: How Courageous Companies Thrive by Giving More Than They Take."

"Put in the larger sense, it's really people wanting to know the story of this thing they bought, where did it come from, who made it, were they paid a living wage and what's the carbon footprint," Winston says.

People are passionate, but they're also practical. They want ways to be more sustainable in their everyday lives that are convenient and save them money. Fortunately, community-based and out-of-the-box approaches can help people maximize what they already have while creating cost-effective (even free) ways to get things they need.

Read on for some inspiring examples in the growing movement to reduce waste, keep goods out of landfills and build strong networks to share resources.

A buy-nothing mission

Liesl Clark is proof that effective sustainability movements can grow from simple beginnings. Clark and a friend were upset about all the plastic that had washed up on the Pacific Northwest beach in Bainbridge, WA, where their kids played. Rather than turn their back on this problem, they spent time studying how that waste ended up in their community in the first place.

Their research led to action in 2013, when they started the Buy Nothing Project to limit the use of plastic — which winds up in every ecosystem (including their local beach) — by encouraging people to buy less and share more. "We thought maybe this project would last a month or so with our friends joining us, but in a matter of days we had thousands," Clark says. Now more than 5 million strong, the movement also includes a mobile app that simplifies resource sharing of everything from appliances to clothes to cleaning supplies.

Clark says they are focused on destigmatizing the act of asking for goods on the platform. Many people join the movement to give what they have in excess, rather than to look for items they need, but "we're trying to show the world that givers and askers balance each other out," she says. "And if we all have equal value in a local gift economy, we feel empowered that we are all contributing to the greater good."

The buy nothing movement is not necessarily against consumption. It's about building a circular economy that promotes sharing, leasing, reusing, repairing, refurbishing and recycling existing materials and products as long as possible.

That frees up resources for use where they can have the greatest positive impact. "What we've found is that people on our platform are not only saving money with us, but they are also freeing up money to support local businesses and spend on education," Clark says.

Sustainability through community

If you're wondering how to get started with a sustainability movement, it may help to look close to home. Many communities have online local or nonprofit groups that provide advice for sharing everything from resources to skills in more environmentally and budget-friendly ways.

With some of these groups, all that's required is time. That's especially true of time banking, the practice in which a person gives one hour of service and receives a one-hour credit for other community services. For example, you might offer to paint a room for someone in exchange for them teaching you a foreign language. TimeBanks.org has a directory of time banks across the United States that aim "to support the use of TimeBanking to build resilient, caring communities," according to the site.

Many other online communities already provide systems of bartering, sharing and time banking. For instance, your local online resource page or parents group often has freebies, rideshare options or volunteer opportunities to explore.

As small choices add up, large companies are taking notice. Corporations are also responding to the demand of consumers and investors for companies to adhere to a double bottom line.

This means they expect the companies they support to not only perform well financially but also employ practices that have a positive social impact. With regard to the environment, there is also the triple bottom line — meaning corporations should balance profit with both the social and environmental impact of their practices.

Overall, any solution to climate change will involve transforming how people consume goods and services. And while it's challenging — "this is a really hard time in history," Winston notes — many people are willing, or even eager, to alter their lifestyles. "There are billions of people living decent lives. They have enough, but they are also searching for well-being and happiness. And there seems to be a growing recognition that the way to achieve well-being and happiness is not through stuff."

— With additional reporting from Life and Money by Citi editors