Hardly a week passes without a media story about rapidly melting polar ice, retreating glaciers, sea level rise, coral bleaching, severe weather events, amphibian extinctions, intense drought, widespread forest fires, insect infestations, and changes in seasonal animal migration patterns.

Here in Maine, gardeners are delighted to get into the soil earlier each spring, while ice fishermen have less time to spend on frozen lakes. As recent winter temperatures have fluctuated and gotten warmer, maple syrup production has been in decline. Lobstermen and clam diggers know that warmer waters are hospitable to diseases, and increasing ocean acidity will affect lobsters and other hard-shelled organisms. Seemingly small changes in temperature can have serious consequences.

Elizabeth Kolbert, author of “Field Notes from a Catastrophe: Man, Nature, and Climate Change,” points out that “the only period in the climate record as stable as our own is our own.” For nearly 10,000 years we have enjoyed what is aptly described as a “long summer whose warmth and stability the world had not seen for a half a million years.” The Earth’s thermostat, having settled at a comfortable average of 57 degrees Fahrenheit, has provided an interlude of optimal living conditions during which we have developed agriculture and modern civilizations. This is in contrast to prior (and perhaps future?) climate cycles that were far less favorable, including periodic inhospitable ice ages dominating large portions of the northern latitudes.

Even in more recent history, natural variations in weather patterns have brought severe hardship. Most notable is a period during the “little ice age,” decades around the 1690s . This was coldest time in 700 years. The “ice lingered till late in the year and autumn returned so promptly that the corn no longer had time to ripen.” Peasants, comprising 90 percent of the population and living off the land, suffered years of famine.

Ironically, the social and cultural advances achieved over several thousand years of human development are now imperiled by the very energy sources that fueled the industrial revolution and consumer society. Prior to the industrial period, atmospheric carbon dioxide levels remained at or below 280 parts per million. Since the 1700s, CO2 has grown to about 380 parts per million, the highest in about 650,000 years as determined from ice core records. The consensus statement by the American Geophysical Union mirrors other prestigious scientific organizations: “Natural influences cannot explain the rapid increase in global near-surface temperatures.”

If humans have the capacity to raise the thermostat, can they also discipline themselves not to raise it, or to turn it back down? Public concern about the risks posed by global warming is growing. We expect that government policy and the private sector will take appropriate actions to reduce risk. And, because it takes about 100 hundred years for CO2 to dissipate, prepare for the inevitable changes that will surely come. Business as usual could push the climate past a tipping point that might establish a less favorable climate for many generations, perhaps slowing the life-giving Gulf Stream current that warms the northern latitudes. Rapid change is not just dangerous because less of the planet would be habitable; equally troubling is that ecosystems would have too little time to adapt.

Despite a century of progress in climate science and widespread consensus about key theories, agreement about future conditions will still be debated. As researchers continue refining theories and making new discoveries, citizens and policymakers must move forward with actions designed to reduce and adapt to global warming. After more than a decade of mixed messages and contentious debate, media coverage of the topic is doing a much better job of describing the science and consequences.

Still, some industries support well-orchestrated and generously financed efforts to delay action on global warming. Twisting and manipulating scientific theories to sow doubts in the minds of the public is the typical ploy.

These strategies coupled with Bush administration inertia helped stall development of automobile fuel efficiency standards for 30 years and prevented development of a conservation and alternative energy-based policy. As noted by the Union of Concerned Scientists, “climate contrarians continue to attack the science in order to undermine an essential and rational basis for cost-effective, sustainable action on this global problem.” Such tactics were employed by the tobacco industry, with some success, to the detriment of public health.

Certainly the public deserves access to balanced perspectives on important issues. On the other hand, as world-celebrated linguist Deborah Tannen, author of “Argument Culture,” put it, “Global warming is an example of how our devotion to a two-sides notion of balance has gotten in the way of solving problems we face as a society.” She goes on to observe, “If you begin with the assumption that there must be an ‘other side,’ you may end up scouring the margins of science or the fringes of lunacy to find it.”

Ted Koffman, D-Bar Harbor, is House chair of the Legislature’s Natural Resources Committee. Bess Koffman, his daughter, is a graduate student at the Climate Change Institute at the University of Maine.