There was a story last week in Bloomberg about a global shortage of onions that is causing price inflation and follow-on impacts for other farm products.  The shortage of wheat last year, caused at least partially by Russia’s invasion of Ukraine, was widely publicized.  Onions are also a worldwide staple: the second most consumed vegetable in the world (the first is tomatoes), and they are a critical component of most cuisines worldwide.

Some people downplay the importance of fruits and vegetables in combating hunger and malnutrition compared to staple crops like grains and beans.  This is of course absurd.  Human beings can survive on staple crops, but they can’t stay healthy without eating produce (whether fresh, dried, frozen or canned).

The Bloomberg story details a number of factors involved with the shortage, including large-scale hording, but most are weather-related.  In other words, it’s not Covid or the supply chain that is causing problems, but rather climate change.

Given the ubiquity of onions, you might be surprised to hear that they are one the most sensitive crops to small changes in weather patterns.  Onions’ success as a human food is related to their genetic diversity as a species, rather than their adaptability.  That means that plant breeders have been able to develop thousands of varieties, each one suited to a particular part of the world and its climate.  But each of those varieties fits a very specific geographic — and thus climatic — niche.  In particular, their growth cycle is governed by changes in the length of daylight and the time of year, so any delays in planting can cause crop failures.   Temperature is also critical: Freezing weather when they are small will kill the plants.  And untimely “cold snaps” at the wrong time in their development will cause them to “bolt” to seed, which makes them inedible.  Too much rain when they are close to harvest and developing their skins will cause them to rot.  Extreme heat at the wrong time can cook the bulbs in the ground — especially a problem with red onions, which absorb sunlight instead of reflecting it.

Here at Terra Firma we consider onions a critical part of a good CSA box, and we strive to have them for as many months of the year as possible. We plant so-called “Short day” onions in the fall that form bulbs in the early spring when the daylength starts to increase and then — most years — harvest them in May when it’s warm and dry.  “Intermediate Day” onions get planted in February and harvested in June and July.  “Long Day” onions planted in mid-spring don’t start bulbing until the days start getting shorter again.  We harvest those in late summer and store them well into fall.  Each year we lose at least a percent of the onions to one or another weather-related cause, so doing multiple successions of onions over a long period reduces the risk of complete crop failure.

While not every human food crop is quite as persnickety as onions, most are predicated on some sort of climate reliability:  a certain number of months of a certain type of weather.  And in particular, a majority of food crops require either A) a dry period during harvest or B) a long period without freezing weather.

Perhaps no sector of agriculture is more sensitive to climate change as seed production:  a fundamental foundation of human civilization.  Many types of plants require a specific sequence of weather events in a particular order to produce viable seed:  warm dry weather for planting, enough cold weather to “vernalize” the plant and convince it that winter is occurring (but not to kill it), and then more warm, dry weather to allow the seeds to mature.  Seed crops also take much longer to grow than fresh crops.  And once harvest time approaches, as little as an overly strong wind — much less a hurricane or tornado — can cause total crop loss by “shattering” the seeds and dropping them on the ground before they can be collected.  If that occurs over a large enough area, it can cause a shortage of the crop the next year by limiting the amount of seed that is available.  Onion seed in particular is very time-consuming and difficult to produce, and seed shortages very likely contributed to the current shortage.

Terra Firma’s 2023 “short day” onion crop is suffering this winter from too much rain and cold and not enough sunshine. They are dramatically smaller in size right now than they should be on March 1st, in fact, they haven’t hardly grown at all since they were planted in November.  Garlic, which is slightly less sensitive to the weather, has grown a bit more — but is still half the size it normally would be now.  We don’t expect a bumper crop of either this year.

Climate change is not just global warming.  Yes, most places are getting hotter.  That alone would be a problem for farmers in many areas.  But the number of other extreme and chaotic weather events is increasing.  In the last ten years in California, we have had two droughts interspersed with three of the wettest and snowiest years on record. And after experiencing the hottest temperatures ever recorded here in September, we’re having the coldest winter  since 2011. Last year, unseasonal freezes wiped out crops in both California and Brazil.  And atmospheric warming is increasing the frequency and duration of extreme rain events.  Flooding at any time during the season for most crops causes yield losses or total crop failure.

As we move forward into a new climate, it’s more important than ever for the end-users of agriculture — i.e., all humans — to remember that our food supply will be facing challenges that it has never seen before.  And some of the foods you take for granted the most might be the ones that are most affected.