The Day Breakfast Disappears with a 1°C Rise — The Real Impact of Global Warming on Our Tables

Introduction——What is happening in the world's fields

Do you think "the impacts of climate change will be felt in the latter half of the 21st century"? In fact, reports are emerging that the yields of staple foods we consume have already decreased by an average of 4-13%phys.org. Adding to this is a new paper in Nature. It presents a shocking estimate that a 1°C increase could result in a global average loss of 120 kcal, equivalent to a standard Japanese breakfast (a bowl of rice, miso soup, and pickles).

Key Points of the Study

1. Observation-based × Economic Model

   • Using data from over 10,000 administrative units measured from 1961 to 2020

   • Estimating "adaptation costs" by crop and region, linked to economic activities

2. Six major crops (corn, wheat, rice, soybeans, barley, cassava)

   • Account for about 2/3 of human calorie intake

3. Limits of Adaptation

   • Even with realistic measures like crop rotation, shifting sowing times, and improving cultivation management, only one-third of the total loss can be compensated

4. Regional Disparities

   • "Super fertile lands" in developed countries and small-scale farmers in the tropics are hit hardest at both extremes

   • Cold regions like Canada and Russia may relatively benefit

"The day will come when the Corn Belt is no longer the Corn Belt"—the words of co-author A. Hultgren weigh heavily.phys.org

Impact on Japan

According to the adaptation plan of the Ministry of Agriculture, Forestry and Fisheries (2023 revision), in Hokkaido, sugar beet and soybeans may see increased yields, while potatoes and wheat are expected to decrease in yield and quality. Additionally, in Honshu and further south, high-temperature ripening damage to rice (increase in immature white grains) is becoming more severe, and a 2°C rise is expected to significantly lower grades.maff.go.jp. Barley, soybeans, and sugar beet are greatly affected by precipitation variability, necessitating preparation for both heavy rain and drought risks.

Reactions on Social Media——Anger, Sarcasm, Hope

Four Strategies Looking Towards 2050

1. Smart Agri + Climate Data Integration

   • Real-time Field Control Using Ensemble Forecasts from the Meteorological Agency and NARO

   • Partial Irrigation by Drone Spraying, Avoiding Overdrying with Soil Moisture Sensors

2. Heat and Drought Resistant Varieties/Diversification

   • Rice: Crossbreeding Tropical Japonica × Temperate Varieties, Maintaining an 80% Ripening Rate Even at 38°C

   • Wheat: Reducing Lodging Risk During the Rainy Season with Spring Sown Early Maturing + High Protein Lines

3. Balancing Carbon Sequestration and Yield

   • Optimizing the Application Frequency of Cover Crops (e.g., Crimson Clover) and Yield Reduction Rate with AI

   • A Domestic Case of Reducing CO₂ Emissions by 15% with Wheat Straw Reduction and Semi-No-Till

4. Strengthening the Food Supply Chain

   • Introduction of "Edible Calorie Conversion" Indicator for Domestic Stockpiles

   • Reducing Losses with Decarbonization of Ports and Coastal Shipping and Establishment of Low-Temperature Logistics Networks

Examining the "Rice Will Increase" Myth

The paper reports a "50% probability of increased rice yield on a global average," but phys.org, we must not forget the characteristic of high water consumption despite being resistant to high nighttime temperatures. In Japan's major rice-growing regions, the double punch of water shortages and high-temperature ripening is anticipated, and increased yield does not equal security. Rather, colder regions and areas with low dam dependency may have an advantage.

Economic and Social Impact

• Surge in Food Price Index: International simulations predict a rise of up to 29% by 2050en.wikipedia.org

• Regional Disparities in Farmers' Income: Canadian soybean farmers see net gains from increased yields and CO₂ credits, while Japanese open-field vegetable farmers face profit margin declines similar to dairy farming due to rising electricity and material costs

• International Political Risk: Chain of export restrictions due to simultaneous multiple breadbasket failuresen.wikipedia.org

Conclusion—“Adaptation” is merely a means to buy time

Even with the accumulation of cutting-edge adaptation measures,the remaining losses average 70% globally. Nevertheless, CO₂ emissions continue to rise.

"Think of climate as 'land value.' Building a mansion on degraded land is meaningless"—the research team's words indicate that there is no choice but to simultaneously turn the wheels ofdecarbonization and adaptation, a stark reality.