Many of us have heard the term “climate change” and may wonder what exactly it means and if it could impact the world’s food supply. Certainly, the term itself implies a change in weather patterns, so it seems logical that such changes could lead to changes in farming practices—an aspect of food production that depends heavily on weather patterns. To learn more about climate change and how it may affect food production, we caught up with Dr. Michael P. Hoffmann, executive director of the Cornell Institute for Climate Smart Solutions (part of the College of Agriculture and Life Sciences at Cornell University).
What exactly is climate change? How long has it been happening, and why?
Climate change has been occurring and is observed over decades. Since about the time of the Industrial Revolution (the late 1800s) humans began burning more and more fossil fuels to power factories and warm homes, and for the transportation of people and goods. This increase in fossil-fuel use led to an increase in the concentration of greenhouse gases in the atmosphere, mainly carbon dioxide. Today, the concentration of carbon dioxide in the atmosphere is over 40 percent higher than it should be. Notably, a large majority of environmental scientific experts agree that climate change is happening and that humans are the cause.
Greenhouse gases are warming the atmosphere because they absorb heat radiating off the Earth’s surface. Imagine the heat radiating off a paved dark road on a hot sunny summer day. Some of that heat is absorbed by greenhouse gases and then re-radiated in all directions, essentially warming the atmosphere. Now, with these increased levels of greenhouse gases in the atmosphere, there are resultant increased temperatures globally—about 2 degrees Fahrenheit. The warming of the atmosphere is called “global warming” and because of a warmer atmosphere the climate is changing. For example, the growing season in the Northeastern United States has gotten longer by several days. Other things like melting glaciers, more intense storms, increased forest fires, and sea levels rising are also reflecting a changing climate.
How is climate change impacting food production and our access to foods?
Crops require air (which contains carbon dioxide), optimal temperatures, water, soil, and sunlight to drive photosynthesis. These necessities are all changing in availability, except sunlight.
The increase in carbon dioxide levels can help crop plants grow faster and bigger—a good thing, except with climate change this benefit is offset by more storms, droughts, etc. Also, increasing carbon dioxide will likely make it harder to control weeds with some herbicides and decrease the nutritional quality of staple crops like rice, in coming years—this will have profound implications worldwide.
The locations and timing of where precipitation (water, snow, etc.) falls are changing globally, meaning some areas now dependent on rainfall are in trouble—and this will worsen over time. More precipitation is falling as rain versus snow, which means less snowpack in the western mountains, an essential source of water for irrigation during the summer.
Ice is melting worldwide, and for Peru and Chile, which depend on glacial meltwaters to irrigate thousands of acres of farmland, this is a big deal. They export $4 billion of food to the U.S. each year—think blueberries during our winter: they come from this area. The glaciers are rapidly melting away with huge implications in the next few decades.
Temperatures are getting warmer but with this comes more heat waves that can harm crops. Rice yields decline with increasing nighttime temps, for example. Heat waves also interfere at critical times in plant development, such as during pollination.
Soil is changing because of higher temps, which increases the loss of carbon from the soil. Higher temps also mean more evaporation from crops and soils, making crop growth more challenging. Heavy rains are now more common and wash away soil and nutrients. These rains can also wash away crops in some cases. For additional information on how climate change is affecting agriculture see the Fourth National Climate Assessment.
What are farmers doing to help alleviate climate change impacts? What are some future practices you see that will be undertaken or should be undertaken to help alleviate climate change?
Farmers are doing a lot, including focusing on soil health, which can sequester carbon. Healthy soil is high in organic matter which helps water enter the soil when it rains and retain it during dry spells. Farmers are planting cover crops to hold the soil in place over winter and then tilling the cover crop into the soil to add organic matter. Additionally, farmers are using minimal till agriculture whereby crops are grown with less disturbance of the soil.
Many farmers are converting animal waste into energy for use on the farm. Numerous farmers also have renewable energy (solar, wind) in operation on their farms. Precision farming is another approach whereby fertilizers, pesticides and water are applied “precisely” or much more efficiently. The use of both traditionally bred crops, as well as genetically engineered crops, will help keep our food system secure. For the future of agriculture, we need wider adoption of climate smart agriculture, which encompasses all of the above actions and a lot more.
Are there things all of us can do to help climate change impacts?
We are all in this together, so we all need to act. We should reduce energy use wherever possible—transportation, in our homes, where we work, where we go to school and food choices. We should all be aiming to have a diet rich in plant-based foods.
Another important action for us to take is to talk about climate change more. Katherine Hayhoe, the “rock star of climate change communication,” considers it the most important thing we can do.
Anything else you’d like to add?
Climate change is a global issue impacting global agriculture and food system. Many companies are working on being prepared and are analyzing their value chains, but will it be enough?
We all eat, so can we use this exceptionally relevant topic to reach those who should act or those still not convinced that climate change is a real threat. Our forthcoming book is intended to do just that: Our Changing Menu: What Climate Change Means to the Foods We Love and Need (2020). Melting glaciers are bad enough, but the loss of coffee is downright terrifying. That gets my attention.
We appreciate Dr. Hoffmann’s input on this topic and welcome having more insights on the important impacts of climate change. We look forward to seeing positive outcomes unfold as the food and agriculture communities continue to mitigate the impacts of climate change.