When it comes to global warming, the planet may face a large and puzzling problem, but every person can make a difference, including every resident in Haverhill.

That was the message last week when residents got a 'convenient' lesson in the earth-saving efforts happening in Haverhill and ways they can make their city eco-friendly.

The list of eco-friendly efforts are things as simple as changing light bulbs, keeping tires inflated and using less hot water -- to planting trees, bringing your own bags to the supermarket and switching to wind, solar and hydroelectric power.

The lesson came along with the showing of the Academy-Award-winning film "An Inconvenient Truth" at Haverhill Public Library. Haverhill Recycling Committee and the Haverhill Energy Task Force hosted the event along with Haverhill Environmental League and the state-wide groups Clean Water Action and Environment Massachusetts.

For organizers, the film, which documents Al Gore's crusade to fight global warming, was the perfect way to start a dialogue about the environmental issues that face us and future generations, and what we, as individuals, can do to help.

"I think it is a movie that raises a lot of issues and provides a lot of important information that affects all of us," said Jim Paikos of the Haverhill Recycling Committee. "We're using it as a jump-off point to talk about clean energy, organic farming and recycling here in Haverhill."

Attendees were given the chance to peruse several displays about local environmental efforts and chat with those passionate about them.

"This (global warming) is a big problem and sometimes it's just overwhelming, but there are lots of things people can do on a local level," Paikos said. "It's big, but we can do something about it right here in Haverhill."

One of the biggest things is simply utilizing the city's recycling services. Recycling products like paper, plastic, glass and aluminum saves the environment. Currently, only paper products like newspapers, magazines, cereal boxes and junk mail are collected curbside; the other items are accepted at the 500 Primrose Street recycling area.

Recycling helps clean up the environment, but also gives money back to the city: The city pays $52.22 to dispose of every ton of waste, but gets paid $45 for every ton of paper products it sells to Haverhill Paperboard.

"You're helping yourself, you're helping Haverhill and you're helping the world," Paikos said of recycling.

But residents can also sign up for a clean energy program through National Grid.

Haverhill's Energy Task Force filed a report in July with 10 recommendations and one is to encourage residents to enroll in National Grid's GreenUp initiative.

Like recycling, the GreenUp plan has a monetary incentive for the city. It partners with Clean Energy Choice, a program of Massachusetts Technology Collaborative, and generates credits for clean energy grants.

So far, the city has $11,000 in credits, but according to Mike LaBonte of Haverhill's Energy Task Force, if the city can get 150 people to join, Haverhill will earn a two-kilowatt solar panel worth $35,000 that can be used on a city building.

Investing in clean, renewable energy now is a great way to ensure there will be plenty of energy in the future.

"They may be a little more expensive now, but eventually, they're going to be the cost-efficient ones," LaBonte said. "We have a finite supply of fossil fuels, so we'll have to do it sometime."