Rep. Alexandria Ocasio-Cortez Is Wrong: There Is No Looming Climate Change 'Expiration Date'

No, our kids will not be doomed in 12 years if we don't adopt her Green New Deal.

By Ronald Bailey of Reason. Excerpts:

"Does the report really conclude that "our kids are doomed" if such steep cuts are not mandated?

Hardly.

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.

Let's make those GDP percentages concrete. Assuming no climate change and an global real growth rate of 3 percent per year for the next 81 years, today's $80 trillion economy would grow to just under $880 trillion by 2100. World population is likely to peak at around 9 billion, so divvying up that GDP suggests that global average income would come to about $98,000 per person. Under the worst-case scenario, global GDP would only be $810 trillion and average income would only be $90,000 per person. Doom?

It should be noted that if global average temperature can be held to below 1.5°C or 2°C, the worse-case projections for those thresholds suggest that global GDP would be $875 trillion or $870 trillion, respectively; per capita incomes would be $97,500 or $97,000. By the way, average global GDP is now $10,500 per person.

Two other recent reviews of climate change econometric projections basically confirm the IPCC report's findings in this area. A recent report by the highly respected independent think tank Resources for the Future finds that the best-performing combined climate and econometric models "imply global GDP losses of 1–2 percent by 2100." The authors note, "While these impacts may appear modest, even a 1 percent loss to global GDP is equal to $800 billion today and could be 5-12 times greater by 2100 assuming 2-3 percent annual economic growth." In other words: Due to climate change, global GDP in 2100 would be about $10 trillion lower than it would otherwise have been.
A 2018 review by the Sussex economist Richard Tol examined the 27 currently published estimates of the total economic impact of climate change. He concluded that "a global mean temperature increase of 2.5°C would make the average person feel as if she had lost 1.3 percent of her income." Certainly a loss, but not doom."

"The congresswoman is right that most carbon taxes that have so far been enacted around the world are "wimpy." Nevetheless, most economists favor carbon taxes as the way to steer the economy toward lower carbon energy sources and spur technological innovation. One Swiss study calculated that a carbon tax rebated to taxpayers would abate a given amount of carbon dioxide emissions at about one-fifth the cost of the command-and-control regulations and subsidies favored in Ocasio-Cortez's Green New Deal."