"Understandable as this may be on one level," he added, "it is not responsible parenting."
So Hertsgaard and Alfonso have both taken steps to spur parents into action.
This year Hertsgaard and San Francisco mother/activist Lisa Hoyos formed Climate Parents, which they hope will give parents "voice and impact."
At the moment, the group isn't much more than a website ( www.climateparents.org), but Hertsgaard said they plan to ramp up as the November elections draw near.
"We think it's shameful that both Romney and Obama are saying nothing about this problem, much less about how they plan to address it," he said. "It is probably the greatest threat to our children's future."
Political activism is the goal, Hertsgaard said. Recycling is all well and good, but "it is far from sufficient."
Alfonso is the Pennsylvania field organizer for a group that wants to strengthen federal clean air regulations - Moms Clean Air Force.
Formed about a year ago, it has been active in Pennsylvania for only about two months, and has nearly 5,000 members here.
To Alfonso, Climate Parents and Moms Clean Air Force are slightly different takes on the same thing, really. They look at the environment today and how it does or will affect our children, and find it unacceptable.
About one of every four children in the region has asthma, and many have to limit outdoor activity when smog or other air pollution levels are high.
"To tell a 3-year-old child they can't go play outside because the air quality is so terrible is just unacceptable," she said.
We are, sadly, not as science-based a populace as we might be. Consider the discouraging French study published this year in the Journal of Environmental Psychology. It found that people were more likely to express "belief" in global warming if they were seated in a room with a dead ficus tree instead of a live one. As if climate change were a matter of belief instead of scientific proof, but that's an argument for another day.
Nevertheless, efforts like Hertsgaard's and Alfonso's may now resonate more.
Things seem to change by the day. Recently, a prominent climate-change skeptic who took a closer look at the numbers decided he was wrong.
In a new Rolling Stone article, eco-activist Bill McKibben looks at the "new math" of climate change and concludes that "the numbers add up to global catastrophe." The article is getting a lot of circulation among environmental groups.
And, of course, all this is happening during one of the warmest summers on record, with some areas of the country in a drought, others under siege from wildfires.
Hertsgaard can't remember a similar situation - one as dire, and one as difficult to grapple with - since nuclear proliferation.
He and the Moms acknowledge that their approach somewhat follows that of Mothers Against Drunk Driving, but perhaps with even higher hurdles.
After all, no one ever claimed that drunken driving was a natural occurrence instead of man-made, and there wasn't a Big Liquor spreading misinformation.
For Hertsgaard, things jelled when his daughter Chiara was born seven years ago - about the same time as Hurricane Katrina, and about the same time the climate debate changed. Before, it had been seen "as a very serious but preventable problem," he said. "If we did the right thing, we could still keep this disaster from occurring."
But suddenly, the impacts weren't something merely being predicted for 2100. They were happening already.
And his real epiphany was when he walked out of an interview in London and heard the laughter of nearby children. "In that moment, I stopped and thought, oh my God, Chiara has to live through this."
In his 2011 book, Hot: Living Through the Next Fifty Years on Earth, he coined the term "Generation Hot" for today's youths.
For Alfonso, the moment of clarity came when her daughter Fiona had what physicians are calling an "asthmatic episode" before her first birthday. Want to talk about scary?
Now 15 months old, Fiona has an inhaler. She has had nebulizer treatments. Fiona's brother, Reny, is 3 - and he recently accompanied Alfonso as she testified at a U.S. Environmental Protection Agency hearing on proposed smog standards and participated in a rally.
"Moms' voices are powerful," Alfonso said.
Dads', too, Hertsgaard would add. "We think parents have a unique moral authority to get past this political partisan divide and say, hey, fix this."
In honor of the Olympic Games in London, and to spur awareness, the Moms group is hosting a "Kid Olympics" from 10 a.m. to noon Thursday on the Benjamin Franklin Parkway between 20th and 21st Streets.
Look for the "Pass the Buck" water balloon toss, Legislative Hurdles, Carbon Footprint Sprint, High Ozone Day Dizzy Bat relay, and Melting Musical Glaciers. Winners get to make their own medals from recycled materials.
"GreenSpace" appears every other week, alternating with Art Carey's "Well Being" column. Contact staff writer Sandy Bauers at 215-854-5147, firstname.lastname@example.org, or follow on Twitter @sbauers. Visit her blog at www.philly.com/greenspace.