Is climate change the most important global problem we face?

This seems on its face a good question. Economists like Bjorn Lomborg take this reductionist recipe, spice it with an unshakable confidence in future growth, and conclude that climate should be low on our list of priorities.

Lomborg’s arguments follow from his assumptions. If his conclusions are wrong as they appear, perhaps the logic is wrong, or the data, or the underlying premises. All of these are good places for skeptical inquiry, and may be fruitful, but there is yet another place to look. I suggest that Lomborg asks the wrong question.

Is greenhouse gas accumulation important than water security, food security, global health, or peace? Phrased that way, of course not. Climate is clearly in last place on such a list. It doesn’t require a team of Nobel laureates in economics to make the determination. The trouble is that these aren’t really separate questions at all!

If the 21st century goes badly, but not so badly that history comes to an end altogether, the disaster will be called a “war” or “anarchy” No matter which part of our portfolio as planet managers we neglect, failure will eventually come out as vicious, stupid, violent squabbles between mutually hostile groups.

Peace (or “free trade” as the economists insist on calling it) depends on food, water and health every bit as much as it depends on universal tolerance and a modicum of mutual respect. Roughly speaking, peace is a name for success and war is a name for failure.

War arises from two main causes: intolerant cultures and poverty. Poverty is almost always a factor.

Who is so poor that they become violently angry at people who are less poor than themselves? People who lack food, water, shelter, and medicine.

So, if we end up badly, the proximate cause will be resource contention; we will be fighting each other for food or water. We may think we are fighting over principle or religion, but in fact we will be fighting over table scraps.

There is some maximum population that the planet can support agriculturally. The limiting factor appears to be fresh water. In many places, water is obtained extractively rather than sustainably. Many argue that we already have exceeded our long-term carrying capacity. Some soil management practices are also extractive; depleting soils may also play a role in limiting population (see Joel Cohen’s magnificent book How Many People Can the Earth Support?).

Now consider what the impacts of climate change are on food and water security. As rainfall belts shift around, as the ocean circulation wobbles around from one year to another, annual climates will become unpredictable. Severe local events will increase as a consequence of te increased energy content of the wetter atmosphere, but subtropical dry belts will grow, and may show a marked wander from year to year. Pest ranges will broaden. Huge areas may become unsuitable for agriculture altogether. This appears to be happening even now in most of Australia. Meanwhile, coastal infrastructure will be under severe stress from sea-level rise.

None of this will be good for food, water, or medicine.

Climate change will not kill us before other problems do, but those other problems will have been greatly exacerbated by climate change. Investment in climate change is investment in food, water, health, and peace. That’s why the dichotomy that Lomborg proposes is nonsensical.

Interestingly, Lomborg is now further stacking the deck by limiting the question to five-year windows.

We don’t live in an economy; that’s an abstraction, a theory that is useful for some purposes and not others. We live on a planet, in fact, a biosphere, a unique collection of solids and liquids that miraculously has given birth to many amazing species, and most perplexingly, to ourselves. In the context of a billion year miracle we have no right to limit our thinking to five-year windows.