Climate change is complex and overwhelming in so many ways. I would be remiss if I didn’t touch on its impact on our food supply. After all, that’s what I write about – food and anything related to food. Climate change is and will play a permeating role in our food quality and availability.
My attention is focused on three main ideas. One, that the increase of CO2 in our atmosphere will affect the nutritional content of our food. Two, an uptick in severe weather and northward shifting plant zones will compromise crops. And three, strategies to mitigate climate change. Without mitigation, over time our plates will become less full, less nutritious and less diverse.
The addition of CO2 to our atmosphere has deleterious effects, yes. Interestingly, in general, more CO2 actually makes plants grow faster and bigger and have more yields, which would seem like a good thing, right? Here’s the catch: as carbon dioxide levels rise, major crops are losing nutrients. Not only are nutrient levels decreasing in major grain crops like rice but also in our vegetable crops. In both major grain crops and vegetable crops, the concentrations of carbohydrates are increasing, and proteins, magnesium, iron and zinc are decreasing. Again, scientific data shows that with higher concentrations of CO2 in our atmosphere, sugar values are increasing, and nutrients are decreasing for most crops, grains and vegetables.
A Politico article writes: “The great nutrient collapse. The atmosphere is literally changing the food we eat for the worse. And almost nobody is paying attention.” The author, Geoff Johnson, highlights studies on the effects of higher levels of CO2 in the atmosphere on crops. He summarizes, “These experiments and others like them have shown scientists that plants change in important ways when they’re grown at elevated CO2 levels… [for crops we] eat like wheat, rice, barley and potatoes – elevated CO2 has been shown to drive down important minerals like calcium, potassium, zinc and iron…The data we have which looks at how plants would respond to the kind of CO2 concentrations we may see in our lifetimes, shows these important minerals drop by 8% on average.”
Protein also drops by an average of 6-8 % depending upon the crop. In the scheme of things, you may be wondering if 8% really means that much. However, if the majority of your nutrients come from one source like rice, and you’re just barely getting enough nutrients to begin with – it could make a huge difference for overall world health. The National Institute of Health estimates rice is a staple for over half of the world’s population, and many people subsist on it. Rice is already a poor source of vitamins and minerals – and what if over the next few decades its nutrient content becomes even less?
“Studies focused on rice also showed decreases in B vitamins of 17-30%. Such decreases would have profound implications, given the millions of people already on marginal diets,” says the authors of Our Changing Menu.
The Environmental Protection Agency (EPA) states on its website, “Rising global average temperature is associated with widespread changes in weather patterns. Scientific studies indicate that extreme weather events, such as heat waves and large storms, are likely to become more frequent or more intense with human-induced climate change.” It then goes on to explain climate change indicators, such as U.S. and global temperatures, heat waves, and heavy precipitation, and then explains each climate change indicator and what it means.
An uptick of severe weather events affects our crop yields, and destructive weather patterns have been a running theme for the last 20 years or so. According to data collected by the Environmental Working Group, crop losses from climate crisis cost billions of dollars in insurance payouts. Indemnities for drought have gone up 400% in the past 25 years. Excess moisture indemnities have gone up 300% in the past 25 years. As droughts and floods increase, crop loss does as well.
Planting zones are the standard by which gardeners and farmers can determine which plants are most likely to thrive in a certain location. The USDA planting zones map was redone in 2012 to reflect zone changes from 1990 based on climate data. The Arbor Day Foundation has created an animated map to show the change in zones during this time period. As planting zones change, it reflects the environmental compatibility of certain plants within the area in which you live.
Talbot County’s planting zone has shifted from 7a to 7b. Shifts in zones means areas where certain crops have traditionally grown may no longer support that crop. Take wine, for example. In a recent article from Wine Enthusiast, “In the future, I expect growers to struggle with maintaining varieties in certain regions without major interventions,” says Elizabeth Wolkovich, associate professor at University of British Columbia. “If they don’t make major changes, I think they will see declining yields – already seen in Europe – and declining quality as the varieties become increasingly mismatched to the climate.”
A similar scenario is explored by The Guardian, “Regions growing coffee, cashews and avocados at risk amid global heating.” The same scenario is played out in orchards around the world where the fruit trees do not have as much chill time necessary for their spring cycle.
According to authors of Our Changing Menu, “Fruit and nut trees require a certain number of hours cold enough to keep the tree in its dormant winter phase. Without adequate winter chill, trees will set fewer or no blossoms and yields can drop dramatically. In 2017, Georgia, the peach state, had a winter that was simply too warm, resulting in an 85% loss of its peach crop.”
We are just beginning to feel the effects of climate change and for most of us, it may not have affected our dinner plates yet, but it will very soon. We need practical applications for moving forward because time will not allow us to stand still.
We Can Do It
1) Combine errands and carpool so we use the car less.
2) Make better menu choices by eating locally grown foods and limiting foods that are known to put a strain on the environment such as beef, for example.
3) Limit our demand on resources by being more energy conscious in our own homes. For example, installing LED lightbulbs or cutting your heat back by a degree or two – maybe 3? Choose appliances that use less energy. Clothesline, anyone?
5) Ask ourselves every day, can we do more with less?
6) Recycle, re-use, repurpose, fix rather than replace; limit our plastic purchases.
7) Work on limiting your food waste: plan meals, shop wisely, eat leftovers, compost.
8) Make our yards more climate friendly by reducing turf and increasing native plants and trees, starting a garden and learning about invasive plants.
9) Read more about climate change. I have compiled a list of sources, posted online at attractionmag.com under “Food for Thought.”
10) Talk about climate change; we cannot solve problems if we do not talk about them. Conversations lead to solutions.
On the upside, many of the changes we can make to help mitigate climate change also save us money. Many of the suggestions listed above are not new ideas. Sometimes the ways we can help with climate change aren’t always convenient to us, in fact most of the time they aren’t convenient at all. Maybe we don’t want to cut back the thermostat and put on a sweater, maybe we don’t like the idea of giving up a Friday night weekly burger routine. Change is hard. The good news is any change is better than no change. If you limit burger night to once a month, you just cut your burger consumption by 75%.
In many ways, we are already adapting to the changes on our planet. Many farmers are trying new farming methods with aeroponics, hydroponics, aquaponics, aquaculture, permaculture and organic agriculture. Science shows us that regions must adapt soon if we are to continue feeding everyone on the planet. I personally have noticed, with summers becoming hotter and more humid, that my tomatoes look exhausted by September. Not a decade ago, they could make it until the first frost in late October but that hasn’t happened in about five years. So, what am I going to do about it? I’ve decided to grow some varieties that are more tolerant of heat and humidity. Plants that typically are planted in the south are about to find their way into my garden this year. I love the names of these southern tomato varieties: Heatmaster, Dixie Red, Arkansas Traveler, and Jamestown. In a future article, I’ll let you know how these southern cultivars performed in Maryland.
For those of you that have been vegetable gardening for years, have you noticed any subtle but long-term shifts in your garden? I’ve noticed extra heavy rains in the spring that cause seeds to rot, and late unexpected cold snaps in May when my annuals are already in the ground. Gardening is always a combination of education and luck, but I’ve seen an uptick in unpredictable patterns. Plant stress is real.
If you’ve read this deeply into my column, then I’ve held your attention and you just might be the person to throw a pebble in the water and start a ripple effect. Mitigation is hard, it goes upstream. Can we change our routines and habits to help the planet? I believe we can. We did it in WW2 to bolster the war effort when citizens rationed foods and gasoline, learned to be clever with less and planted victory gardens. Americans banded together for a common cause then, and we can now. Small changes can add up – just think about how we got to climate change in the first place – we started burning coal in the 1800s and over time, along with other unfriendly planet practices, we arrived here – at a crossroads. Small changes over a long time do add up – climate change itself is proof of that.
I love peaches, and almonds, and prunes, and avocados and coffee and wine and… and… and…and if you do too, consider throwing a pebble the water.
I began writing this article about a month before the most recent report on Intergovernmental climate change was released on February 28, 2022. An analysis of this report by NOAA can be found under my resources list online.
Cathy Schmidt writes from Trappe where she and her husband Chef Brian Schmidt own Garden and Garnish Catering. A food explorer, Cathy loves to garden and cook from scratch.
Resources and Readings on Climate Change and Food
Hoffman, Michael P., Koplinka – Loehr, Carrie, and Eisman, Danielle. Our Changing Menu. Ithaca and London, Cornell University Press, 2021.
Little, Amanda. The Fate of Food. United States, Harmony Books, 2019.
Pogue, David. How to Prepare for Climate Change. New York, NY, Simon and Schuster, 2021.
Wormser, Owen. Lawns Into Meadows. San Francisco, California, Stone Pier Press, 2020.
NASA Study: Rising Carbon Dioxide Levels Will Help and Hurt Crops
Global Climate Change Impact on Crops Expected Within 10 Years, NASA Study Finds.
High CO2 levels will wreck plants’ nutritional value, so don’t plan on surviving on vegetables.
As Carbon Dioxide Levels Rise, Major Crops Are Losing Nutrients
Effects of Elevated CO2 on Nutritional Quality of Vegetables: A Review
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6104417/
The great nutrient collapse CO2 is changing the food we eat, for the worse. And almost nobody is paying attention.
https://www.politico.com/agenda/story/2017/09/13/food-nutrients-carbon-dioxide-000511/
Heat tolerant vegetable varieties
https://sites.udel.edu/weeklycropupdate/?p=14443
Heat Tolerant vegetable crops and cultivars for the changing climate.
Hidden shift of the ionome of plants exposed to elevated CO2 depletes minerals at the base of human nutrition
https://elifesciences.org/articles/02245
Increasing CO2 threatens human nutrition
https://www.nature.com/articles/nature13179
Natural History, Not Technology Will Dictate Our Destiny. Humans convinced of our own power and control – tend to ignore the laws of nature. But that is a mistake.
An overview of global rice production, supply, trade, and consumption
https://pubmed.ncbi.nlm.nih.gov/25224455/
Crop losses from climate crisis cost billions of dollars in insurance payoffs.
https://www.ewg.org/research/crop-losses-climate-crisis-cost-billions-dollars-insurance-payouts
What climate change means for the future of coffee and other popular foods
Regions growing coffee, cashews and avocados at risk amid global heating
How to start a vegetable garden.
https://extension.umd.edu/resource/how-start-vegetable-garden
Climate Change Indicators: weather and climate.
https://www.epa.gov/climate-indicators/weather-climate
Plant Hardiness Zone changes form 1990 to 2006
https://www.arborday.org/media/mapchanges.cfm
USDA Plant Hardiness Zone Map
https://planthardiness.ars.usda.gov
Climate Change is Rapidly Altering Wine As We Know It
https://www.winemag.com/2020/02/03/wine-climate-change/
Sacrificing For the Common Good: Rationing in WW2.
https://www.nps.gov/articles/Rationing-in-WWII.htm
Pogue, David. How to Prepare for Climate Change. New York, New York, Simon and Schuster, 2021.
Your Carbon Footprint: https://d1hbl61hovme3a.cloudfront.net/assets_us/your-carbon-footprint-1.28.21.pdf
University of Maryland Extension
Determinants of emissions pathways in the coupled climate-social system
The IPCC Climate Change 2022 Impacts Report: Why it matters.
https://www.noaa.gov/stories/ipcc-climate-change-2022-impacts-report-why-it-matters
Climate Change is rapidly altering wine as we know it, by Sarah E. Daniels.