Pro: Climate Change Will Cause Food Shortages
Climate changes projected by global climate models are consistent with observed climate changes of concern to agriculture (Ch. 2: Climate).41,42,43 Climate change has the potential to adversely impact agricultural productivity at local, regional, and continental scales.44 Crop and livestock production in certain regions will be adversely impacted both by direct effects of climate change (such as increasing trends in daytime and nighttime temperatures; changes in rainfall patterns; and more frequent climate extremes, flooding, and drought) and consequent secondary effects (such as increased weed, pest, and disease pressures; reduced crop and forage production and quality; and damage to infrastructure). While climate change impacts on future agricultural production in specific regions of the United States remain uncertain, the ability of producers to adapt to climate change through planting decisions, farming practices, and use of technology can reduce its negative impact on production (Ch. 21: Midwest, Case Study “Adaptation in Forestry”).45
Risks associated with climate changes depend on the rate and severity of the changes and the ability of producers to adapt to changes. The severity of financial risks also depends on changes in food prices as well as local-to-global trade levels, as production and consumption patterns will likely be altered due to climate change.10,46 Many countries are already experiencing rapid price increases for basic food commodities, mainly due to production losses associated with more frequent weather extremes and unpredictable weather events. The United States is a major exporter of agricultural commodities,47 and a disruption in its agricultural production will affect the agricultural sector on a global scale. Food security, which is already a challenge across the globe, is likely to become an even greater challenge as climate change impacts agriculture.48,49 Food security will be further challenged by projected population growth and potential changes in diets as the world seeks to feed a projected 9.8 billion people by 2050.50,51,52https://nca2018.globalchange.gov/chapter/10/ (Fourth National Climate Assessment)
Climate change threatens our ability to ensure global food security, eradicate poverty and achieve sustainable development. Greenhouse gas (GHG) emissions from human activity and livestock are a significant driver of climate change, trapping heat in the earth’s atmosphere and triggering global warming.
Climate change has both direct and indirect effects on agricultural productivity including changing rainfall patterns, drought, flooding and the geographical redistribution of pests and diseases. The vast amounts of CO₂ absorbed by the oceans causes acidification, influencing the health of our oceans and those whose livelihoods and nutrition depend on them. FAO is supporting countries to both mitigate and adapt to the effects of climate change through a wide range of research based and practical programmes and projects, as an integral part of the 2030 agenda and the Sustainable Development Goals.http://www.fao.org/climate-change/en
Con: Food Production is Growing and Safe
As our planet gradually warms, global crop yields and crop yields across the planet continue setting new records almost every year. Not just global, but U.S. crop yields also continue to grow, setting new records nearly every year.
Longer growing seasons, higher temperatures, and more atmospheric carbon dioxide are creating ideal crop conditions.
As global climate modestly warms, U.S. and global crop yields are setting new records almost every year. The same is true for nearly all other nations, too. Thanks in large part to longer growing seasons, fewer frost events, more precipitation, and the fertilization effect of atmospheric carbon dioxide, farmers are producing more food on less land, allowing them to feed a growing global population.
Crop Production Facts: The 2019 global crop year brought record production of the important cereal crops; corn, wheat, and rice. This builds on previous records set nearly every year during the past decade. Almost every important U.S. crop has set record yields per acre during the past three years (latest data for when this summary went to press in February 2020), with most of the top 10 years in yields-per-acre occurring during the past decade. For example, each of the three record-high corn yields have occurred during the past three years. Each of the five record-high rice yields have occurred during the past five years. Each of the past nine years have produced top-10 all-time wheat yields.
How Global Warming Benefits Crop Production: Global warming lengthens growing seasons, reduces frost events, and makes more land conducive for crop production. Global soil moisture has maintained pace or modestly improved as global temperatures have risen modestly, with greater oceanic evaporation leading to more global precipitation, especially during summer and fall crop seasons. Further, carbon dioxide greatly benefits crop production, as atmospheric carbon dioxide works as aerial fertilizer. Higher atmospheric carbon dioxide levels assist plant growth and resistance to drought and heat. It is for this reason that greenhouses often pump in elevated amounts of carbon dioxide.
Figure 1: Global Cereal Crop Production
More Information: Crop yields in nearly every country are growing, with many frequently setting new records. See the 25:35 mark and onward in the video linked above. The video is The Heartland Institute’s rebuttal to the United Nations’ 2019 Civil Society Conference.