Conservative columnist Cal Thomas recently criticized Greta Thunberg as a know-it-all with an underdeveloped brain, incapable of critical thinking about climate change.

So, an adolescent cannot have valid ideas for shaping the future of her world, especially if those ideas are based on empirical information she obtained from books dedicated to science and the scientific method. No, better to follow Thomas's directive and listen to the pontifications of her betters, seasoned adults, like those who cannot read a morning briefing, much less a scientific textbook.

Thomas recommends, as alternative reading, a collection of newspaper articles gathered by Competitive Enterprise Institute, whose resume includes defending big tobacco's efforts to avoid cigarette warnings. Thomas's premise: The failure of the dire predictions in these articles to come true is proof global warming is a hoax.

Never mind most of these "catastrophic predictions" presaged actual policy changes, averting the catastrophic results; changes like passage of the Clean Water Act, dissemination of birth control information and development of a wheat hybrid that prevented mass starvation.

Perhaps Thomas should spend less time criticizing people of any age who are seeking solutions to our problems and more time expanding his underdeveloped brain with "scientific textbooks."

Sandy McCrea, Signal Mountain


Acid mine runoff threatens waterways

Acid mine drainage occurs when iron sulfide minerals released from abandoned and active coal mines are oxidized to form sulfuric acid that enters streams and waterways. Affected waterways are characterized by low pH values and high concentrations of dissolved metals.

North Chickamauga Creek is a tributary of the Tennessee River and is home to variety of fish and salamander species. For years, North Chick Creek has been affected by acid mine drainage from abandoned coal mines that have been leaching into the waterways.

It is estimated that 720 kilometers of streams in Tennessee are impaired due to acid mine drainage, and in North Chick Creek, aquatic organisms are being negatively affected.

Although efforts have been made to deal with acid mine drainage in North Chick Creek, it is still a problem today. Therefore, more people need to get involved with helping to prevent acid mine drainage from entering our waterways.

Anyone interested in helping with these efforts can volunteer or donate to the North Chickamauga Creek Conservancy.

Lillian Cloer, Chatsworth, Ga.


'Impeach' strategy not a good call for Dems

Clearly the Democrats are not interested in bolstering the roaring economy, improving health care or dealing with the immigration crisis. They are not interested in correcting the huge trade imbalances that have evolved.

Rather, they have strategically decided to throw all their "eggs into one basket" and run on only one issue for the next 13 month. That issue is "Impeach Donald Trump"! That is a very interesting strategy. It has never been tried before, to my knowledge. It is fraught with sizable dangers.

First, it is a very negative approach to campaigning.

Second, they have to convince a majority of Americans that Donald Trump is evil, wicked and a criminal.

And finally, they have to come up with clear, solid and concrete evidence to prove that the president has engaged in criminal activity that meets the high standard for impeachment. In this arena, the Democrats, so far, are seen as desperately flailing around in search of a crime. And they are spending millions of taxpayer dollars in this pursuit and using all of their time in this pursuit.

This strategy has a very great chance of failing, fortunately!

Jerry Johns, Ringgold, Ga.