Decades ago, in elementary school, I remember my teachers encouraging students to "put on your thinking cap" when they wanted us -- as modern pedagogy would say -- to engage our cognitive skills.

Today, as we approach a new semester, I suspect that many teachers will encourage their students with similar language. Let's hope so, because now, perhaps more than ever, novel and independent thinking has some high hurdles to clear. And this is at a time when contemporary global challenges still require it.

Besides worldwide economic problems in dire need of quick, effective, compassionate solutions, environmental issues related to energy, such as the mitigation of pollution from the burning of fossil fuels, are a high priority.

Take my own field, air quality. The contaminants that require attention are the ones that can demonstrably foul the planet near and far, now and later. These include pollutants like air toxins and those "criteria" pollutants labeled so by the federal Clean Air Act -- specifically, particulate matter, sulfur dioxide, nitrogen dioxide, ozone, lead and carbon monoxide.

You may notice that carbon dioxide, a so-called greenhouse gas that occurs abundantly in nature and is essential for plant life, does not appear on that list. Nonetheless, it has recently been targeted for drastic reduction from industry smokestacks and vehicle tailpipes by the Environmental Protection Agency.

Part of the concern is that carbon dioxide and other greenhouse gases like methane allow short-wave energy coming in from the sun to reach and warm the Earth's surface, but impede the escape of the returning long-wave energy emanating from the planet. Thus, energy that should have radiated to space is trapped or absorbed, and in turn warms the Earth's atmosphere.

To many, that brief explanation, coupled with temperature graphs of dramatic recent global warming and climate model results predicting a sweltering orb by century's end, is enough to indoctrinate students from grade school to grad school in the belief that humans are about to destroy the world if something is not done immediately to stop them. One promoter of this idea has claimed that "[h]umankind has the potential to alter the climate of the Earth for hundreds of thousands of years into the future." In "The Long Thaw: How Humans are Changing the Next 100000 Years of Earth's Climate" (Princeton University Press, 2009), author David Archer added, "That I feel can be said fairly confidently."

With such confidence, coupled with near-total control of the education system, a progressive ideology permeates the developmental atmosphere of the modern classroom. And with it comes the suppression of ideas that may provide the ideal solutions to challenges like air pollution and climate change -- man-made or not.

In college, the views academics impress upon their students are all too frequently based on partisan progressive politics, radical professorial notions or hypotheses masquerading as well-established theories -- for example, anthropogenic global warming.

But the apparent current trend of shielding students from concepts that progressives think are bad science -- like the reasonable proposition that nature, not humans, is in charge of global climate change -- hinders students' development of critical thinking skills.

And yet everyone has been told that one of the esteemed goals of modern education is to develop critical thinking skills. So, put on your thinking cap, and think again.

Anthony J. Sadar is a certified consulting meteorologist and author of the new book "In Global Warming We Trust: A Heretic's Guide to Climate Science" (Telescope Books,