Wrapping up our look at last summer’s DOE contrarian climate report, which is looking less contrarian and more prescient as time goes by, we turn to Chapter 11 on the global impact of US emission policies. The chapter begins by explaining the scale problem: unlike local air pollution, where emissions and concentrations are tied closely together, aka if a chimney is belching soot it hits the people who are close by and downwind and hits them pretty much right away, when it comes to CO2 levels the carbon cycle is big, slow-moving and global. So this year’s emissions hardly change the global concentration and thus this year’s emission reductions have minimal impact. Even if half the countries in the world cut emissions, it would take decades for the global CO2 level to change. Also, because CO2 does not respect borders, if the other half increase emissions in response, the global level would never change whereas if Los Angeles dealt with its own smog generation its local air pollution would fall dramatically, and did after the 1960s, even if cities in China were becoming enveloped in a toxic haze as many were. All of which should come as no surprise to CDN readers. But needed saying anyway, along with another key point.

The chapter then focuses in on US motor vehicle emissions as an example of the overall principle. And it should be obvious right away that if half the world acting together can barely affect the climate, one single sector in the US acting alone is less consequential. Should be. As the report observes:

“In 2022, the emissions from U.S. cars and light duty trucks totaled 1.05 billion metric tons of carbon dioxide (GtCO2, EPA 2024). Meanwhile global CO2 emissions from energy use totaled 34.6 GtCO2 (Energy Institute 2024). Hence U.S. cars and light trucks account for only 3.0 percent of global energy-related CO2 emissions. To a first approximation we can say that even eliminating all U.S. vehicle-based emissions would retard the accumulation of CO2 in the atmosphere by a year or two over a century. It would also reduce the overall warming trend by at most about 3 percent. For the period 1979-2023, which has the most extensive global coverage of a variety of weather data types, warming trends are determined to a precision of about ±15 percent, so the impact of reducing the rate of global warming by eliminating U.S. vehicle CO2 emissions would be far below the limits of measurability.”

In consequence, anyone pushing you to “think global, act local” to “stop climate change” or save the world or whatever heroic rhetoric they invoke is just uninformed. If climate change really is an existential threat, then little local actions are irrelevant. The world would need to shut down global fossil fuel use and get emissions to zero, and stop pretending that what passes for most modern climate policy, such as subsidizing windmills and electric cars, taxing cows and forcing homebuyers to install heat pumps, would have any effect, except to make us all poorer. At least, all of us who live in countries that are doing such things.