This may sound a little strange, but when I think back to my adolescence, I sometimes recall the faint smell of sewage.
When I was in high school, my family lived on the south shore of Long Island, where very few homes had sewer systems. Most had septic tanks and there was always a spot upwind that was constantly overflowing.
Most of Nassau County is finally sewered, but many American homes, especially in the Southeast, are unsewaged and have overflowing septic tanks on a scale far greater than I remember from my vaguely smelly hometown, and as such are both a nuisance and a threat to public health.
The culprit? Climate change. The Washington Post reported last week that “sea levels have risen at least 6 inches since 2010” along the Gulf Coast and South Atlantic Ocean. That may not seem like a big deal, but it translates into rising groundwater levels and increased risk of tanks overflowing.
The sewage crisis is just one of many disasters we can expect as the world warms, and it's far from the top of the list. But it seems to me that this crisis illustrates two points in particularly vivid terms. First, the damage from climate change is likely to be even worse than the pessimists think. Second, mitigation and adjustment will be necessary, because even if we take immediate steps to dramatically reduce greenhouse gas emissions, we will still face major impacts from climate change. But as a political problem, it will probably be much harder than it should be.
Regarding the first point: estimating the costs of climate change, and relatedly the costs that polluters impose for each tonne of carbon dioxide they emit, requires a blend of results from two disciplines. On the one hand, we need physicists to understand how much greenhouse gas emissions warm the planet, what changes that will cause to weather patterns, etc. On the other hand, we need economists to estimate how those physical changes will affect productivity, health care costs, etc.
In fact, there is a third dimension: social and geopolitical risks: how do we deal with millions and millions of climate refugees, for example? But I don't think anybody knows how to quantify those risks.
Either way, the physics of this effort look very solid. Of course, there has been a decades-long campaign aimed at discrediting climate research and, in some cases, smearing individual climate scientists. But if you step back from the aspersions, you'll realize that this has been one of the greatest analytical triumphs for climatology in its history. Climate scientists accurately predicted decades in advance that global temperatures would rise unprecedentedly, and they appear to have predicted the extent of it almost exactly.
The economic side of this effort seems shakier, and not because economists haven’t tried: in fact, in 2018 William Nordhaus won a Nobel Prize primarily for his work on the “Integrated Assessment Model,” which attempts to combine climate science and economic analysis.
But, with all due respect, Mr. Nordhaus was my first economics mentor! I have long worried that these models underestimate the economic costs of climate change because so many things that we haven't thought of could go wrong. The prospect of parts of America being flooded with sewage was not at all on my list.
Recent studies have tended to emphasize estimates of damage from climate change. Although uncertainties remain large, it is reasonable to expect that things will be much worse than expected.
So what can we do? Even if we take drastic steps to reduce emissions now, many of the impacts of past emissions are already priced in, so to speak, including much greater sea level rise than we've seen before. So we need to take a wide range of steps to mitigate the damage, like expanding our sewer systems to stop sludge building up.
But will we take those steps? Climate denial was originally about fossil fuel interests, and to some extent still is, but it has also become a front in the culture wars, with politicians like Ron DeSantis, the governor of Florida, one of the states most at immediate risk, seemingly deciding that even mentioning climate change is an act of wokeness.
Now imagine a clash between such politics and the urgent need for massive public spending on everything from sea walls to sewer systems to limit climate damage. Spending on that scale would almost certainly require new tax revenues. How quickly do you think right-wing culture warriors would come to terms with this?
That's why I'm so worried about the future of the climate. We probably won't do enough to limit emissions. President Biden has done much more than his predecessors, but it's still not enough. Donald Trump promised oil executives that if he won, he would reverse a lot of what Biden has done. More than that, we probably won't do enough to limit the damage.
So even before a global catastrophe occurs, it's easy to imagine dire outcomes in the not-too-distant future. Something bad is coming, and we're already starting to get a sense of it.
