CUMBERLAND — The ongoing relationship between Earth and its citizens is a symbiotic one, but this mutually beneficial arrangement won’t continue if either entity falls below a certain level of wellness.

Celebrating Earth Day – as we did last Monday – is fine, but that day shouldn’t be the only 24 hours of the year people consciously think about reversing climate change, ending pollution and protecting Earth’s endangered species, which, without a serious reorganization of priorities, may soon include Homo sapiens.

But how can any one individual help sustain our wounded planet? Carpooling, composting, recycling and picking up trash are decent contributions. So are keeping the thermostat low in the winter, limiting air conditioner use in the summer and taking shorter, cooler, less-frequent showers. Walking or biking rather than driving, shutting off lights when leaving a room (or, better yet, not turning them on in the first place) and grocery shopping with cloth bags are helpful, too, as are using a clothesline rather than a dryer, buying food from local farmers and planting trees.

There are, however, many other, less-obvious ways everyone can contribute to humanity’s continued existence here on Earth. For example, any individual can:

Smile at strangers.

Shovel a neighbor’s driveway.

Always keep their word, but never make unkeepable promises.

Call their mom, their dad, their child or a friend.

Give someone a second chance. (Or, in exceptionally rare cases, a third one.)

Send a card for someone’s birthday. Or for no reason at all.

Help someone pick up the groceries they just dropped in the parking lot.

Visit a member of the support staff at work without asking for anything.

Be a gracious winner, or a good loser.

Thank someone.

Sincerely compliment somebody every day.

Pay for the car behind them at a highway tollbooth.

Take a distant parking place at the mall, leaving the closer ones for those who need them.

Sign someone’s petition.

Take the stairs instead of the elevator.

Share their lunch.

Leave a fresh roll of toilet paper in the bathroom before the current one runs out.

Vacuum under the couch.

Limit the number of times they go out to eat, but tip 30 percent when they do.

Add another hour of time to the meter right before leaving a parking space.

Donate blood.

Volunteer at the library. Or anywhere.

Grab an item off the top shelf for a shorter person, or get one from a lower shelf for a tall person.

Give someone the perfect gift just because, without waiting for Christmas or the recipient’s birthday.

Be the designated driver.

Pick up the check.

Do what Mom or Dad ask without complaining about it.

Hold the door open for whoever’s behind them, whether it’s a frail older person, a 6-foot-6, 300-pound bodybuilder or anyone at all.

Coach a youth sports team full of 10-year-olds and make sure everyone gets equal playing time, regardless of ability.

Tell the truth.

Speak up when they spot injustice.

Clean the bathroom.

Bring the mail to the neighbors.

Visit shut-ins.

Let someone else have the remote.

Play a card game somebody else chooses.

Help a friend relocate.

Be there for someone in need.

Think independently.

Stay informed and vote, but not for bullies and/or habitual liars.

Celebrate everything good their spouse is, and avoid fixating on whatever he or she is not.

Jump-start someone’s car.

Avoid procrastinating.

Do the laundry.

Give someone a plant.

Take a friend for a walk in the woods, or on the beach. Or take one solo.

Be grateful for good health, good friends and good fortune every day.

Donate clothing they don’t wear anymore.

Ask the neighbors if they need anything before leaving for the grocery store.

Clean the oven.

Give up a seat on the bus to someone older and smaller, or to someone younger and larger.

Go the extra mile.

Do at least five of these things every day.

Humanity cannot exist without a home any more than our planet can remain extant without physically, mentally, emotionally and spiritually healthy residents. The best way to make every day Earth Day is to support the environment, and one another.