Earth Day dawns on a human world in constant motion.

Our jet contrails crisscross the sky, our roads stripe the landscape and our overwhelming populations are constantly on the move. Technology has wrapped the planet in an invisible web of electronic flashes that can instantly connect humans on opposite ends of the globe, yet can't seem to connect us to the ground we stand upon.

Our earth is the playing field, the staging ground, the backdrop of all this human drama. In the words of the late astronomer and author Carl Sagan, " ... every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every 'superstar,' every 'supreme leader,' every saint and sinner in the history of our species lived (here) - on a mote of dust suspended in a sunbeam. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves."

Two numbers stand between our busy life on this fragile blue planet, and Sagan's "great enveloping cosmic dark" - 383 and 350.

All human activity has generated carbon emissions since the Industrial Age that have raised the level of atmospheric carbon to today's level of 383 parts per million (ppm).

NASA scientist James Hansen, along with leading climatologists and environmentalists say we need to reduce that number to 350 ppm to avoid a series of catastrophic climate tipping points. These tipping points include rising oceans; trees migrating toward the poles; the loss of glaciers and sea ice that reflect sunlight, causing the oceans to warm more quickly; thawed permafrost that releases uncounted tons of methane into the atmosphere.

Individually, these tipping points are daunting. Together they equal a death sentence.

Hansen told a panel of scientists at the American Geophysical Union conference in January that "there looms a huge gap between what is understood (by scientists) about global warming and what is known by the public." He says, "We are closer to a level of dangerous, human-made interference with the climate than we realize."

But we haven't passed the point of no return.

"Not quite," says author and activist Bill McKibben in a recent Washington Post column. "Not any more than your doctor telling you that your cholesterol is way too high means the game is over. Much like the way your body will thin its blood if you give up cheese fries, so the Earth naturally gets rid of some of its CO2 each year. We just need to stop putting more in and, over time, the number will fall, perhaps fast enough to avert the worst damage."

Andy Revkin writes in The New York Times, "The stakes, for all life on the planet, surpass those of any previous crisis. The greatest danger is continued ignorance and denial, which could make tragic consequences unavoidable."

NASA scientist Hansen warns that we need an immediate moratorium on coal-fired power plants that can't capture their own carbon emissions. He suggests setting a carbon price to reduce fossil fuel use, and a "reward system for improved agricultural and forestry practices that sequester carbon could remove the current CO2 overshoot." With government policymakers on board, it appears still feasible to avert catastrophic climate change.

There is hope. This Earth Day, imagine what a sustainable society would look like:

- Grocery shopping means weekly trips to local farms to meet the people face-to-face who feed us.

- Buildings are EnergyStar-rated and some even produce their own electricity through solar panels. Perhaps whole neighborhoods produce their own electricity and food, and share a "cul-de-sac community garden and wind turbine."

- Cars are traded in for bicycles, as public transportation improves, and downtowns become more vibrant and walkable.

- Farmers plant wind turbines in farm fields for a second harvest of renewable energy.

- Communities began to process municipal solid waste into ethanol for cars and electricity. Some communities even find local sources for home heating like pelletized crop residues.

- Recycling becomes a way of life as public receptacles appear on street corners and in schools.

- No one would even consider purchasing something that wasn't made from recycled or reused materials.

- Asthma becomes a disease of the past as air quality improves, and buildings are made from materials that don't pollute.

- Local economies thrive as "green-collar jobs" create opportunities for native sons and daughters to find lucrative careers and affordable homes in their own hometowns.

All this is happening right now, in some small town, maybe even yours. It took our grandparents 3 1/2 years to transition to a wartime economy in World War II. It is time to tap that collective well of inner strength to meet the challenge of our changing climate.

Remember, we are the only force in the universe capable of saving us from ourselves.

Shawn Dell Joyce is a sustainable artist and writer who lives in a green home in the Mid-Hudson region of New York.

© Copley News Service

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