Will Climate Change Rob Us of Our Favorite Foods Forever?
Some of your favorite dishes might soon disappear forever. Yes you heard that right! One of my favorite dish is kimchi and lately kimchi prices in south Korea have gone up by 70% as compared to last year and the reason is you guessed it right, Its all thanks to climate change. Well , this is because kimchi is made up of a particular type of cabbage called the Napa cabbage and it thrives well in cooler climates since climate change is causing the climate to be warmer it is getting difficult to increase the yield of these cabbages and hence prices shoot up.
According to the Korea Agro-Fisheries and Food Trade Corporation the retail price of a Napa cabbage is around $6.66 USD. This marks a 69.5% jump compared to the same time last year and a 32.7% increase over the three-year average price. Due to rising climate temperatures, both the cabbages and their seedlings are under high risk. Many of them perish under intense heat, causing instability in their supply. The climate crisis is making extreme weather heatwaves, droughts, storms, and floods more common every year. This is not only affecting the production of Napa cabbage but also some of our favorite crops like cocoa, rice, and potatoes. This will in turn, affect the production of our favorite chocolates, fried rice, and french fries as well. Just thinking about this makes me dizzy.
When thinking about the impacts of climate change on agriculture two of the key factors that come into play are CO2 concentration in the atmosphere and warmer temperatures.
Impact of CO2 in the Atmosphere
Carbon dioxide helps plants grow by increasing the rate of photosynthesis. Plants use sunlight to create sugars out of CO2 and water. When there’s more CO2 in the atmosphere, this process can go faster. CO2 concentration is currently around 420 ppm (parts per million) and reaching 570 ppm would mean global temperatures are 2°C to 2.5°C higher than pre industrial times. A study conducted by Rezeai et al.(2023) have shown that crops like wheat and rice yields increased by around 15% to 20% under high CO2 concentration whereas yields of maize and sorghum doesn’t have any impact under high CO2 concentrations.. This seems like a very good thing but we know that with increase in CO2 concentrations in the atmosphere this will lead to an increase in temperature as well. This simple and well known phenomenon is known as the green house gas effect.
Impact of Warmer Temperatures
Crops can grow at various temperatures, but each variety has an optimum temperature range where they thrive. When temperatures fall below or exceed this range, crop growth can slow, resulting in smaller grain sizes. Even brief exposure to extreme conditions, such as heatwaves or frost, can damage plant tissue and lead to crop failure. For instance, wheat grows best at temperatures around 15°C to 20°C, so if temperatures rise significantly above this range, it can negatively impact yield. Another example is napa cabbage thrives best in a temperature range of 15°C to 21°C. This optimal range supports all growth stages, ensuring good development. Seed germination is particularly sensitive, with the best results occurring at 18°C to 24°C. When the conditions are not ideal , this impacts the growth and the yield.
Taking these effects together how has these parameters currently affected the crops yield?
The world has already warmed by around 1.3°C compared to pre industrial temperatures. Atmospheric concentrations of CO2 have increased from around 280 to 420 ppm. What was the impact on crop yields and food production? We would expect the crop yields would have taken a significant hit worldwide due to climate change but what the numbers in the graph below actually tells us is that the change in crop yields globally over the period from 1961–2022 has in fact gone up by more than 100% for crops like wheat , maize and rice.
In another study by Gowda,P et al. (2018) they concluded that rising temperatures and carbon dioxide concentrations may increase some crop yields, but the yields of major commodity crops such as corn and rice are expected to be lower than they would in a future without climate change. In another study the author shows how crop yield growth might have been different for staple crops in a world without warming, based on the study by Toshichika Iizumi et al.(2018) from 1981 to 2010, In 2010, average maize yields were 5.2 tonnes per hectare. If there had been no climate change, the total yield would have been 5.4 tonnes per hectare. Soybean would have increased from 1.75 to 2.6 tonnes per hectare. Without climate change, that might have been 2.7 tonnes instead of 2.6 tonnes. The net impacts on rice and wheat have been negligible because we know that higher concentrations of CO2 can increase the crop yield and would also offset the warming.
Whether crop yield will increase or decrease in the future will not only depend upon climate change. We've seen major increase in crop production since 1961, mainly due to advancements in agricultural technology. While climate change will affect us in the future, I truly believe that we’re not powerless. we have always adapted to changing conditions, and we will continue to find ways to manage these challenges.
