More than half of the people in the world rely on rice as their main food source. However, as global warming raises the temperature of the earth and intensifies storms, droughts and heat waves, this essential crop faces a worrying future.
Scientists say that the danger of this development cannot be overemphasized. Rice is easily affected by extreme climates and grows in places that have experienced many climate changes. Any damage to this food source can cause serious problems.
Just look at the recent history. In 2008, concerns about the supply of rice exacerbated the food crisis that led to soaring prices. The ensuing panic caused global riots, from Bangladesh to Egypt to Haiti.
That was 13 years ago, when the population of the earth decreased by about 1 billion. In another 13 years, the world’s population is expected to increase by another 1 billion, and the total population is expected to reach 8.8 billion. At the same time, the world’s climate will continue to change.
Louis Verchot, head of the International Land Restoration Team, said: “When we will add 2 billion people to the population in the most vulnerable areas, this is indeed a wake-up call.” Tropical Agriculture Center. “We will need to really rethink how we organize our food system.”
Research highlights this concern.
The latest report of the Intergovernmental Panel on Climate Change-bringing together 234 scientists to synthesize recent climate research-warns that man-made global warming is happening at an unprecedented rate and is driving the deadly floods we have already witnessed , High temperature and drought (Climate line, August 9). These events pose a major risk to agriculture.
“Higher temperatures will lead to increased evaporation, resulting in soil drying, increased plant pressure and impacts on agriculture, even in areas where precipitation is not expected to change significantly,” the report noted.
The report concluded that if greenhouse gas emissions are not reduced, by the end of this century, it is estimated that about one-third of the world’s land will suffer at least moderate drought. Some changes such as sea level rise have been locked in.
Rice is particularly susceptible to these changes. Rice is usually grown in low-altitude ecosystems that are susceptible to rising sea levels, such as deltas. It also grows in areas that have experienced extreme heat. Scientists say that any additional temperature rise may cause it to exceed the threshold for healthy crop growth.
A sort of Study in 2018 inside Agronomy and Soil Science Archives Studies have found that by the end of this century, the increase in frequency and severity of hot weather may reduce rice production by as much as 40%.
“Most of the [world’s] Rice is currently planted in areas where the existing temperature is close to the optimum range for rice production,” the study pointed out. “Therefore, any further increase in average temperature or short-term high temperature in the sensitive growth phase will be catastrophic. “
Studies have pointed out that although rice can grow at a temperature of 40 degrees Celsius (104 degrees Fahrenheit), heat stress can impair its ability to pollinate flowers. Temperatures higher than 35°C will significantly reduce yield.
High temperatures at night can also affect productivity. A study It was found that every 1 degree Celsius increase in night temperature above 35 degrees Celsius would lead to a decrease of about 10% in rice yield.
It’s not just heat. The increased likelihood of floods and droughts also threatens production. Rising sea levels may flood low-lying farmland, as will sea water.
A sort of Paper According to the International Rice Research Institute, rice is expected to become “the most susceptible to the impact of future climate change.”
U.S. rice growers feel the heat
In a world where food systems are increasingly interconnected, the risks to rice are important.
Tim Benton, director of emerging market risk research at Chatham House, said: “One particularity of rice is that the market is very scarce because there is not much potential oversupply for demand.” “So if you are in Any failure in any place, it does tend to fundamentally affect international prices.”
For example, the United States plays a small but important role in the global supply chain. American farmers only produce about 2% of the global rice supply. However, according to statistics, their exports account for more than 6% of global exports. U.S. Department of Agriculture.
Almost all of these American farmers are located in six states: Arkansas, California, Louisiana, Mississippi, Missouri, and Texas. They are already experiencing the effects of extreme weather.
US rice growers send A letter According to Rice, after a year of severe storms, floods and droughts, last month it requested disaster assistance from Congress. The company defended rice producers in major rice-producing states.
This problem was magnified in late California, where rice is mainly grown in the Sacramento Valley. Tim Johnson, head of the California Rice Commission, said that due to years of low rainfall and snow, the state’s rice planting area is expected to decrease by 100,000 acres this year. A report From the local CBS radio station.
In some rice-growing areas prone to drought, productivity may decline even in favorable years.
Research by the International Rice Research Institute shows that this is because farmers who are worried about crop loss may avoid investing money in things like fertilizers and new seeds that help increase yields.
Amanda Carrico, a professor of environmental research at the University of Colorado at Boulder, said that if production declines and incomes decrease, farming families may relocate or send some members to find work elsewhere.
This is one of several problems faced by countries that rely on rice. The effects of climate change and land conversion exacerbated population surges—especially in rice-growing regions in Asia—may pose challenges for countries to maintain self-sufficiency in food production.
“This is a complete livelihood, a cultural crop, involving religion, belief, and stories. Life in Asia, especially Southeast Asia, evolved around rice,” said a senior scientist and climate change researcher at the International Rice Research Institute in the Philippines. The person in charge Bjoern Ole Sander (Bjoern Ole Sander) said.
A recent study led by Cornell University researchers found that global agricultural productivity has fallen by about 21% in the past 60 years due to climate change, and this effect is more pronounced in warmer tropical regions. Studies have found that part of the reason is that agriculture has not adapted to the new extreme climates, and the situation has gotten worse over time.
Ariel Ortiz-Bobea, associate professor at Cornell University School of Applied Economics and Management, said: “You don’t have to be a rocket scientist to know that these predictions are for higher temperatures.” The influence of orientation.”
His team at Cornell University is planning to study how much R&D investment is needed to maintain or offset the effects of climate change. One goal is to develop a strategy that does not just rely on using more fertilizer or expanding the area of production land.
“If we don’t increase productivity, then you will make up for the production deficit with more investment, which will have an irreversible impact on the environment,” Ortiz-Bobia said.
Plant early, reduce moisture, and cultivate new seeds
Since the Green Revolution in the 1960s changed global agriculture and brought high-yielding varieties, new planting methods and mechanization, rice production has increased substantially.
According to the latest rice outlook of the Ministry of Agriculture, global rice production is expected to reach a record 506 million tons from 2021 to 2022. It predicts that global consumption will reach a record 514 million tons.
Climate change may offset some of these benefits, especially if it leads to more deforestation or loss of wetlands, buffers for sea level rise, and natural sinks of carbon dioxide.
“The entire transformation of the landscape will truly put the entire human economic enterprise at risk. This will set back what we have achieved in many places over the past 40 years and will increase the vulnerability of the poorest people,” International Center for Tropical Agriculture Said Verchot.
To avoid these problems, researchers are working to make the food system more resilient. This includes decarbonizing irrigation systems and developing stress-resistant rice varieties that can withstand high temperatures or floods.
Sand said that the International Rice Research Institute has approximately 150,000 rice varieties in its seed bank. But most of them have not been planted or reached the scale of production. He added that countries also have their own rice research programs and continue to cultivate new varieties.
One goal is to develop seed varieties that are more tolerant to drought or high temperatures or that can be submerged in areas where more precipitation is expected. People are also increasingly aware of more traditional varieties, which are highly resistant to salt water and water shortages.
Better farm management can also help. Rice uses a lot of fresh water, but scientists have found that its growth is only half of the typical amount of water. This means that farmers can apply water-saving technologies in areas where drought is expected to increase.
Methane is a problem facing rice growers
Improved farming techniques can also reduce methane emissions, which is a powerful global warming gas.
Rice is the second largest source of agricultural methane after livestock. In Vietnam, a major rice producer, it accounts for 15% of the country Total emissions.
The study found that alternating wet and dry paddy fields can cut emissions by half and save up to 30% of irrigation water.
Planting at different times can also help. This is what the International Rice Research Institute did in collaboration with farmers in the Mekong Delta after the 2016 drought. Sander said that that year, hundreds of thousands of hectares of rice production fell, partly because of the influx of salt water into the fresh water supply for irrigation.
After that, the International Rice Research Institute promoted a new method: planting rice a few weeks in advance, so that when the salt water starts to flood the field, the rice will not be in the most vulnerable stage of growth.
Not all solutions are so simple. Extreme and compound events—such as continuous floods and droughts or droughts exacerbated by heat stress—will be more difficult to overcome.
As these disasters become more frequent, scientists expect production to fall more frequently. Scientists say that as the earth warms, the world needs to pay attention to one of the many reasons for rice.
“The carbon footprint of rice is so high, but the investment is still relatively low,” Sander said. “This is definitely a crop that deserves more attention.”
forward from Electronics News With permission from POLITICO, LLC. Copyright 2021. E&E News provides important news for energy and environmental professionals.