Wallace directed this short-but-mind-blowingly-critical question at Scott Pruitt, the head of the US Environmental Protection Agency. The context was climate change. The implication: What if you're wrong and carbon dioxide pollution -- from burning fossil fuels -- really is the main driver of global warming? That's what a near-consensus of climate scientists say, after all.
Pruitt earlier this year equivocated on this point, saying that he "would not agree that (carbon dioxide pollution is) a primary contributor to the global warming that we see."
"Mr. Pruitt, there are all kinds of studies that contradict you," Wallace said. "The UN's panel on climate change says it is at least 95% likely that more than half the temperature increase since the mid-20th century is due to human activities. NOAA -- that's our own National Oceanic and Atmospheric Administration -- says there's more carbon dioxide now than in the last 400,000 years, and NOAA says 2015 and 2016 are the two hottest years on record.
"Mr. Pruitt, are we supposed to believe that that's all a coincidence?"
After some back and forth, that all-important question. What if ...
"What if, in fact, the Earth is warming? What if it is causing dramatic climate change and that we as humans through carbon emissions are contributing to it?" Wallace asked.
"Simple question, what if you're wrong?"
"Look, let me say to you, CO2 (carbon dioxide) contributes to greenhouse gas, it has a greenhouse gas effect and global warming, as methane does and other types of gases," Pruitt said. "The issue is how much we contribute to it from the human activity perspective and what can be done about it from a process perspective, Chris."
Wallace: "But don't you think the fact that we have these coal power plants belching carbon emissions into the air, you don't think that had -- plays a role?"
Instead of answering that, Pruitt talked about how the US supposedly has been burning coal "in a clean fashion."
Coal isn't clean. It contributes pollution related deaths as well as global warming. It's dirtier than natural gas, for instance. The United States' first "clean coal" plant opened in January, according to the Washington Post, but there are serious doubts about the technology -- which is designed to sequester carbon dioxide pollution -- and its affordability.
But ... I'm not here to fact-check Pruitt. Plenty of journalists have done that. Instead, I want to talk about Wallace and his awesome question. Because it's one that could change the way Americans -- 47% of whom say global warming is natural or they are unsure of its cause -- think about the climate crisis.
I know this is true because I talked this week with Jerry Taylor, a climate-skeptic-turned-believer.
And that very question helped reframe his thinking.
Taylor is president of the Niskanen Center, which advocates for a carbon tax as a conservative solution to climate crisis. But before that, he spent 23 years at the CATO Institute, a libertarian think tank, where he advocated for a study-more-but-do-nothing approach to the climate crisis. It's a position that's not terribly far out of step with the Trump administration, which appears to be trying to inject false doubt into climate science as a way to justify gutting pollution regulations.
Taylor's belief in climate skepticism collapsed because of a few arguments, he told me. But the "what if" was critical. Here's the evolution: After going on a cable TV show to promote climate skepticism, Taylor told me, the opposing guest pushed him to reread the 1988 congressional testimony of climate scientist James Hansen, former director of the NASA Goddard Institute for Space Studies.
"I would like to draw three main conclusions," Hansen told Congress nearly 30 years ago. "Number one, the Earth is warmer in 1988 than at any time in the history of instrumental measurements. Number two, the global warming is now large enough that we can ascribe with a high degree of confidence a cause and effect relationship to the greenhouse effect. And number three, our computer climate simulations indicate that the greenhouse effect is already large enough to begin to affect the probability of extreme events such as summer heat waves."
"I was fairly shaken by it," Taylor told me.
He realized he had been misrepresenting the research by not acknowledging that Hansen had put forward a range of global warming and emissions scenarios. And then he started to think about the risks of inaction.
If there was even a small chance that global experts like Hansen were correct (97% of the world's climate scientists say humans are largely responsible for global warming, according to peer reviewed research) then the world was in beyond-serious trouble, especially the long term.
Taylor met with a risk-management expert at Goldman Sachs, the Wall Street bank, he told me, and he told Taylor people should think about the risks of the climate crisis the same way they do about the risks in financial markets.
"He made the point that the debate about the most likely outcome (of climate change) is a secondary matter," Taylor said. "There is a full range of outcomes here in play and in risk management you have to take a look at this full range of outcomes and hedge against them. No one in their right mind in financial markets would consider saying otherwise ... In financial markets it would be insane to not hedge against risks."
Again, his thinking was rattled.
"In every other context where you have this degree of risk and uncertainty we rightly hedge, we rightly address the full range of possible outcomes," Taylor said. "To not do so in the climate arena when you have this much at stake is incredible to me ... Do we really want to go to Vegas and put all our money on one roulette wheel and say, 'Well, that's the most possible outcome?'"
If society does nothing and continues burning fossil fuels, scientists say we can expect worsening super droughts, deadlier heat waves, mass extinction in the natural world and rising seas that, as Taylor put it, will sink half of Florida as well as many coastal cities.
It's not a matter of if as much as when.
And we know the more pollution we create the riskier this all becomes. (Which isn't a particularly comforting thought if you know that the world creates 1,200 metric tons of carbon dioxide pollution every second, according to the Global Carbon Project and Climate Analytics.)
Plus, there are a number of "co-benefits" of transitioning away from fossil fuels, from cleaner air to a stronger and more modern economy.
Still don't buy any of this?
Don't think it's a big deal?