A little over a year ago, Robert Watson, former chair of the IPCC, and two co-authors published a report titled "The Economic Case for Climate Action in the United States." Based on trends over the past few decades, the authors estimated the current total annual cost in the U.S. of losses from weather events intensified by climate change and health damage from fossil fuel pollution to be $240 billion, which they described as "about 40 percent of current economic growth of the United States economy."
At around the same time, Mark Jacobson, Mark Delucchi and a carload of co-authors published an article in which they projected damages to health and property in the U.S. from climate change and pollution under "business as usual" to be around eight trillion dollars in 2050. A simple linear extrapolation between the two estimates suggests that the annual cost of climate change is increasing at around an 11 percent annual rate. Based on that extrapolation, the health and property damage cost of climate change can be projected to exceed annual GDP growth by 2026.
But wait. Watson's 40 percent figure compares average annual damage with some of the better recent years of growth. Even excluding years of recession and stagnation, in which growth was less than $240 billion, the remaining eight of the last 12 years averaged only around $430 billion a year in real GDP growth. Counting the recession and stagnation years, it's virtually break even.
But there's more. Part of that economic growth simply reflects expansion of the population. Real economic growth per capita in the U.S. has been even more anemic in the 21st century. Of course this means the cost of damage can be spread more thinly as well but the crucial point is still what happens to per capita income relative to the damage.
The future is hard to predict, so I tried a number of scenarios. First, if per capita growth continues at the rate it has since 2009, the U.S. has already entered the red zone where the cost of climate change exceeds growth by an increasing amount each year. If real per capita growth accelerates to 1.5 percent per annum that fateful point won't be reached until the year after next. A growth rate of 2 percent would postpone the day of reckoning until 2024, six years before the IPCC deadline for achieving net zero carbon emissions. To make it to 2030 without crossing permanently into the red would require a sustained rate of real per capita growth that hasn't been achieved since 1960-1970.
One more thing. As Andreas Malm wrote, the global warming effects of fossil fuel consumption are "seriously backloaded" and "substantially deferred." This year's climate damage is a consequence of actions taken decades ago and the greenhouse gases emitted today will not have their full impact until decades from now. How does one estimate, then, the contribution to intermediate consumption of the deferred cost of current emissions? How much should GDP be deflated to account for the artificial inflation of nominal value added by waste gases whose cost is off the balance sheet?
Let's assume that emissions in a given year contribute to 4 percent of climate change costs each year for the next 25 years. Why 25 years and why a constant percentage? Because it is better than attributing all of this year's cost to this year's emissions. Who knows? It probably makes more sense that choosing a "market-based" consumption discount rate of 4.3 percent. At any rate, considering the deferred nature of the climate costs moves the year in which GDP growth vanishes back. The 4 percent for 25 years scenario moves it back to 2007. The economy has literally been running on fumes for over a decade. Talk about "degrowth"!
It/s here. It's not going away. It only gets worse. The question isn't whether or not one "advocates" degrowth but whether or not one faces the stark reality and acknowledges the expiry of GDP growth and consequently the irrelevance -- and, frankly, mischief -- of the growth paradigm.