Back in January, Rep. Alexandria Ocasio-Cortez made a comment about the world having only 12 years left to avert disaster. Here’s what she said: “Millennials and Gen Z and all these folks that came after us are looking up and we’re like ‘The world is going to end in 12 years if we don’t address climate change and your biggest issue is how are we going to pay for it?'” As I said at the time, that was clearly hyperbole but AOC has returned to this particular well several more times, each time leaving the impression that 12 years is some kind of hard cut off beyond which our future is in doubt. But as Ronald Bailey points out at Reason today, that’s simply not the case:

“Climate change is different because we have an expiration date. And the IPCC report says that we’ve got 12 years to turn it around, ” asserted Rep. Alexandria Ocasio-Cortez (D–N.Y.) during a recent MSNBC town hall. “So my concern is that we are going to be the frog in the pot of boiling water and we’re going to debate and debate and debate and debate and then when we finally pass something it is a wimpy carbon tax and our kids are doomed.”…

The IPCC asked a group of climate scientists to evaluate how it might be possible to keep the global mean surface temperature from rising 1.5°C above the average temperature of the late 19th century. (This is a more stringent target than that set under the Paris Agreement on climate change, which aims to keep global average surface temperatures to below 2°C by 2100.) The report’s authors calculated that in order to have a significant chance of remaining below the 1.5°C threshold, the world would have to cut its carbon dioxide emissions by 40 to 50 percent by 2030 and entirely eliminate such emissions by 2050. So yes, the report says there’s an expiration date if humanity decides to aim for that temperature target. But is it an expiration date for doom? Not so much.

According the report: “Under the no-policy baseline scenario, temperature rises by 3.66°C by 2100, resulting in a global gross domestic product (GDP) loss of 2.6%,” as opposed to 0.3 percent under the 1.5°C scenario and 0.5 percent under the 2°C scenario. In the baseline 3.66°C projection, the estimate of future GDP losses ranged from a low of 0.5 percent to a high of 8.2 percent. In other words, if humanity does nothing whatsoever to abate greenhouse gas emissions, the worst-case scenario is that global GDP in 2100 would be 8.2 percent lower than it would otherwise be.

If you accept the IPCC’s conclusions then their future will be warmer and less prosperous than it could have been plus a host of other potential problems. Here’s Bailey:

Coral reefs will likely be badly damaged by warmer seawater; storms may be worse; Arctic sea ice would disappear in the summers, possibly making northern hemisphere weather more erratic. And the summer temperatures in most American cities will resemble those that are currently several hundred miles further south and west of them.

Again, if you accept the conclusions of the scientists queried by the IPCC, those are some significant risks which you can certainly argue we should try to avoid. However, that’s not the same as saying we must pass the Green New Deal and eliminate all fossil fuels in the next decade or our grandkids are “doomed.”

AOC seems to believe capitalism is a major part of the world’s problem. Her Green New Deal seems aimed at curtailing capitalism as much as it is at curtailing climate change. She has argued as recently as last week during her MSNBC town hall that it’s not possible to address one problem (climate change) without addressing all of the other problems at the same time (job guarantees, free college, free health care, etc.).

AOC is presenting us with a stark choice between a less prosperous future (GDP losses as high as 8.2 percent) and a Democratic Socialist future with no downside and no cost. But that’s not an honest presentation of the choice she’s offering. To really decide how to proceed, we’d need some kind of estimate of the cost of AOC’s socialist alternative. But when asked what her GND will cost or how we will pay for it, she can’t answer or refuses to answer on the grounds that we’re in too much of a hurry to worry about it. She’s literally touting the cost of doing nothing while dodging the question of what it would cost to do something.

And independent attempt to put a bottom line on her plan has been dismissed as guesswork by her admirers. But even if that estimate is wrong, the fact remains that there is some significant cost associated with her plan. In other words, it’s fair to ask what the impact of her Democratic Socialism be on the economy in 50 or 80 years. Because the potential downside of Democratic Socialism is real and, in a worst-case scenario, could even turn out to be something like the dystopian doom AOC keeps talking about.