Today we dwell on energy efficiency, flood and drought, carbon emissions, local food, collapsing colonies of bees and bats and the need to do things differently.
Local educators who guide people toward living sustainably teach those Earth Day lessons every day in classrooms, worship spaces and community gardens. The idea is to make environmental consciousness a daily habit, inseparable from consciousness.
"If the environment is this vague external concept that's somewhere else, you're not going to try to take those baby steps," said Rabbi Daniel Swartz, the spiritual leader of Temple Hesed, who incorporates environmental lessons into this religious teaching.
His strategy is twofold: Help people see how environmental concerns are linked to what they already care about - social justice, the economy, their grandchildren - and teach them to observe and appreciate the world around them.
"If you can get people doing those two things, then it starts to be not a separate subject," he said.
At the University of Scranton, chemistry professor Michael C. Cann, Ph.D., has worked for nearly a decade to make sustainability a common subject across the curriculum.
After integrating the concepts of "green," or environmentally benign, chemistry across science courses, he developed workshops to help professors in all disciplines incorporate sustainability into their lessons.
About 80 faculty members have taken part in the annual workshops since 2005, he said.
"The idea is that as students go through our curriculum, they see it in a theology class, and then they see it in a psychology class, then they see it in an economics class, in education, in chemistry, in business," he said. "They see how sustainability fits into all of these different areas and they realize that this is an all-encompassing thing."
With a broader audience, lessons about sustainability reach people who might not otherwise have looked for them, who might then incorporate them into their personal and professional lives.
Dr. Cann thinks the model is working, but "not fast enough for me."
"Frankly, we better figure this out," he said, "or humanity is going to be in for some very difficult times."
Some groups teach environmental sustainability through practical lessons in better living.
With community gardens and cooking classes, the Shalom Community Development Corporation of Greater Scranton is teaching people to make environmentally-friendly decisions by making healthy choices for their families. The audience - city dwellers, underprivileged youth, new immigrants - might not think of themselves first as environmentalists.
"It's all intertwined," director Jane Risse said. "Our health is completely dependent on the health of our planet."
Lackawanna College's Environmental Institute, which educates children, college students and adults about environmental appreciation and sustainability, has started a two-year degree program in ecological sustainability that is designed to be multidisciplinary.
Students take courses in green business, sustainable agriculture, field biology and mapping systems.
"It's a really, really diverse degree," institute director Jamie Reeger said, "which is what's needed to make a difference. We too often get put into silos and we can't change the world in a silo."
The institute's public programs are designed to be constructive because the challenges facing the planet can be "hugely overwhelming," she said. People might not take the first step if they do not feel like it is possible to make a difference.
"Teaching for hope is critically important," she said.
Contact the writer: llegere@timesshamrock.com