It’s hard to write a feel-good piece about the environment. In 2006, environmental science became a doom and gloom machine, spewing a stream of depressing data and predictions about what is happening to our common air, water, soil and wildlife. Some science promises good news, medical or technological advances, for example. But, as with art and the humanities, much of science is the risky search for cold, raw truth, unvarnished, the kind that commands awe or action.

The courage to speak the cold truth and act on it once distinguished great leaders in this country. For the environment, Theodore Roosevelt and Rachel Carson come to mind, and there are others. In the late 1880s, when such ideas were considered radical in America, Roosevelt and his friend, George Grinnell, advocated clean water and scientific management of forests and other resources for the nation’s health.

As president, Roosevelt, often in the face of powerful, special interests, preserved 51 natural refuges, 18 national monuments – including the Grand Canyon – the Tongass and Chugach forest reserves in Alaska, and 16 million acres of national forest land in the western United States. In 1962, Rachel Carson, despite vicious personal attacks by the chemical industry, told the people of the world in her book, “Silent Spring,” how their health, land, water and air were being poisoned by overuse of certain toxic insecticides, particularly DDT. We need such leaders today to safeguard our environmental security.

Why? Going into 2007, global warming continues unabated. Carbon dioxide and other pollutants are wrapping the Earth in a global hothouse. Most of the CO2 comes from automobiles, power plants and other industrial sources. The forecasts are frightening: melting icecaps, flooded coastal cities and human society ravaged by systems suddenly out of kilter – agrosystems, disease systems and ecosystems mutated by runaway climate change.

Global-warming deniers have a proven feel-good formula: Dismiss the science, much as the chemical lobby did about DDT and the tobacco lobby about smoking and cancer. They reject, out of hand, the unvarnished scientific findings and forecasts of greenhouse warming as “still too uncertain,” or part of a political conspiracy pushed by “environmentalists.” In the taxonomy of Orwellian Newspeak, environmentalists are put next to “liberals” in the axis of evil.

Environmentalists used to mean folks who wanted the water they drank, the air they breathed, the ground they played on and the food they ate to be free of pollutants and other crud. Thomas Jefferson was an environmentalist. He launched Lewis and Clark on the greatest environmental exploration of America in the belief that knowledge and conservation of nature were essential to every American’s life, liberty and the pursuit of happiness.

Were Jefferson, Roosevelt or Carson alive, they would be worried. The Andes have lost a quarter of their glaciers since 1970. The glacier in Glacier National Park is more than half gone. Earth’s atmosphere is about 2 degrees hotter (Fahrenheit), because of a doubling of CO2 since the industrial revolution. At this rate, the planet’s fever could shoot up 9 degrees by the end of the century.

Rising seas from melting polar icecaps could inundate parts of countries and coastal cities such as New York, New Orleans, London, Tokyo and Cairo. Dry areas of the world – South America, the Mediterranean coasts, the Middle East, southern Africa – will get even drier, their peoples and lands losing up to 30 percent of their water and much of their agriculture. Forget religion or oil: Wars will be fought over water.

Continued inaction will wreck economies and economic security. Every ton of CO2 pumped into the atmosphere will cost $85 in agricultural and industrial losses, in fighting the spread of virulent diseases, and in repairing physical destruction. That’s $17 trillion annually, because 200 billion tons of CO2 are pumped into the atmosphere each year.

Jefferson and Roosevelt would be outraged that overfishing and pollution were allowed to devastate about a third of all food fish – a whopping 2,200 species – since 1950, with the resulting collapse of the fishing economy in parts of the United States and other countries. Worse, the extra tons of CO2 in the atmosphere are turning the oceans more acidic, poisoning the coral reefs, plankton and snails, and threatening the food fish that depend on them – salmon, redfish and mackerel.

It’s time for public policymaking to protect and guarantee our environmental security. Policymakers need to heed the cold, raw science, not duck it. Steer the nation with this knowledge. Invest in smart new energy technologies, both renewable and nuclear. Work with states and nations to control growth in population, greenhouse gases and the Earth’s warming climate. Mount the bully pulpit to forge bold policies for the long term and the common good, particularly for our economic and environmental security. Because, in the 21st century, money, the economy and environment will be one color: green.