Arguably the most important crop on Earth, rice has been cultivated for roughly 10,000 years. It’s a staple food for more than half the global population, with about 90% cultivated and consumed in Asia.
But a new University of Washington study, recently published in Communications Earth & Environment, warns that this essential crop is in danger. Due to rising temperatures driven by climate change, projections show that Asia’s major rice-producing regions may soon pass the thermal limits that have remained consistent throughout the crop’s history.
Using satellite maps, agricultural records, archaeological data and climate projections, researchers found that domesticated Asian rice has never thrived where the mean annual temperature exceeds 28 degrees Celsius — 82 degrees Fahrenheit — or where the warm-season maximum temperature exceeds 33 C, or 91 F.
Climate projections estimate that, by the end of this century, the land area exceeding these temperature limits could expand by 10 to 30 times in Asia’s major rice-producing nations. This would create unparalleled challenges in a region where more than a billion people rely on rice cultivation for their livelihoods. While rice breeding programs offer some hope, the researchers found that even the major rice subspecies won’t thrive in the projected temperatures.
UW News spoke with Jade d’Alpoim Guedes, an archaeologist, UW associate professor of anthropology and co-author of the study, about the research and what it means for the future.
I can’t underscore enough how writing this study felt. Millions of people live in this region and depend on temperatures as we have known them to continue to live and farm there. This is beyond devastating, and we are beginning to see the impacts of processes like this already.
How did you become interested in this topic?
JDG: A lot of my research focuses on how climatic events have shaped people’s ability to farm or grow crops in environments around the world. One of the places I previously worked was the Tibetan Plateau, and some of my early research documented that there was a cooling event around 4,000 years ago that halted Tibetans’ ability to grow two critical crops, which were millets. They shifted to wheat and barley after that, and they’ve been growing them ever since.
I became interested in applying the same research to understand how our current unprecedented moment of climate change may impact crop distribution. I work in Asia, particularly China, and I’ve worked on rice for most of my career. Our team found that the same cooling event that affected Tibet had a major impact on rice genetics. In fact, it led to the development of cold-adapted temperate rice, which is the same type of rice that people rely on for subsistence today in Japan, northern China and Korea. It’s the short-grained sticky rice that’s cold tolerant, as opposed to the original form of rice that was a semi-subtropical cultivar.
We then became interested in the types of challenges rice will face moving forward. We pulled records of everywhere that rice has ever been cultivated in Asia throughout human history — and all the climatic conditions under which it’s been cultivated — and compared that to the types of situations that we’ll face under global warming today.
What did you find as you started looking toward the future?
JDG: Basically, we found that large areas that are major rice producers are going to face rising temperatures that are unprecedented in the history of rice cultivation. Over the course of the past 10,000 years and its domestication, rice has been adapted to cooler conditions and not to warmer conditions. We used a wide variety of forward-looking climate projection models, and all of those models seem to converge on the same point: Large parts of primary rice growing regions around the world are expected to surpass the known temperature limit where these crops can be cultivated.
I use the word unprecedented, and I don’t use it lightly. Another term I could apply to this would be no analog. There is no known situation over the course of rice’s cultivation where rice grew in regions which had such high mean annual temperatures. This crop has simply never experienced this before, so there is no data for how it will react. But we do have thousands of years of data saying that to date, it hasn’t been cultivated in temperatures like these. In fact, there are only two parts of the world today that have mean annual temperatures that are similar to those that we expect will occur in major rice producing regions of the world: the Sahara desert and parts of the Arabian peninsula. There is a reason these areas are largely desert. Most people think about water but temperature is a critical reason, too.
I can’t underscore enough how writing this study felt. Millions of people live in this region and depend on temperatures as we have known them to continue to live and farm there. This is beyond devastating, and we are beginning to see the impacts of processes like this already.
What are some recent examples of rising temperatures causing problems with crop cultivation?
JDG: In 2023, India halted the export of all non-basmati rice. Sona masoori rice, or the type of rice grown across most of low altitude South Asia, had such great losses due massive heat waves that the government stopped all exports. People were panic buying rice that year, even in the U.S.
With climate change, the temperature is not increasing in a completely linear fashion. But the average is increasing over time. As the average increases, there’s a higher probability of these extreme events occurring. It’s already happening in our lifetime, and this study is solid evidence for why addressing climate change should be an absolute top priority for all of us. Over a billion people on the planet are rice cultivators, and that is their primary means of livelihood. For a fourth of the world’s population, rice is a main staple in the diet.
We could have written this paper for so many crops, including wheat, corn and others. What we’re dealing with here is that plant photosynthesis just doesn’t function well above those temperature limits. We’re running into fundamental limits of photosynthetic biochemical process plants, which are temperature limited. There are not that many types of plants that can sustain life under conditions like that, and certainly they are not our major economic plants.
We live in an era where we have all experienced climate change. In 2026, most of the globe has experienced an extreme heat event. We understand how difficult this is for us as mammals to live through, and yet some of us have the privilege of escaping indoors or even to air conditioning. Plants, on the other hand, cannot move to escape the heat. I’m sure many here in Seattle remember the heatwave in 2021. The plants in our yard are still recovering from those short few days. That event caused billions of dollars in losses in the agricultural sector in the Pacific Northwest. Some berry and soft fruit farmers experienced nearly 100% crop losses. By midcentury, conditions like this could occur every five to 10 years and could have a huge impact on all plants, including the ones we rely on for food.
This also critically highlights why we need to expand rather than contract our dietary breadth. Sadly, the opposite of this is happening due to industrial farming practices. Humanity is relying on an increasingly narrow range of species. We are essentially putting all our eggs into one or just a few baskets when we need crop diversity.
What do climate projections take into account, and what can be done to change the path we’re currently on?
JDG: For this study, we used multiple climate projections based on what different countries’ carbon commitments will be moving forward. What we found is that even for climate scenarios where there is a strong global commitment to sustainability-focused growth, international cooperation, and an eventual transition to net-zero emissions, major rice growing regions are still impacted (SSP 1-2.6 on our maps). These impacts expand dramatically with other climate scenarios which assume less concerted action, and sadly this is consistent with where we are headed today which is probably somewhere between SSP 3- 7.0.
Our actions can change the course of what scenario we might be looking at with these maps. We have the technology to move forward with more climate-friendly solutions and many countries around the world are trying to take the lead while we lag behind. For instance, China, where I work, has made massive investments in public transit and railways. Nearly everybody in China drives an electric vehicle. I did not see a single gas-powered car last time I was there. We could do that here at home, and we’re not. Our politicians are making active choices to halt this type of action and at the same time we have the highest per capita emissions in the world. We could and should do much more. It can feel hopeless, particularly for those of us who live in a country where action from our politicians has been in a decades-long gridlock for meaningful change. But we shouldn’t stop lobbying for change.
We can also look at what steps we can make in our own lives to lower emissions. It’s worth noting that the vast part of emissions come from the top 1%, and that portion of the population can really drive meaningful personal action. Simple steps for those that have the means and access can be switching to solar if you own a home or taking public transit where you can.Asking honestly, how am I contributing to this and what can I do differently can always help. For me, the single largest part of my personal emissions was flying and I ceased a large part of all my noncritical travel for that reason. Emissions from short-distance flights and private jets contribute hugely to this issue.
No country will be immune to a crisis of this magnitude, and it is an issue that deserves global attention. While the impacts may initially appear distant to readers from the U.S., our interconnected economies mean that we will also be affected through global trade systems and shifting agricultural dynamics. The same environmental and socioeconomic processes influencing rice production in Asia will have comparable implications for crops such as corn in lower-latitude regions of the U.S. and even here in the Pacific Northwest, as we saw with the last heat dome. Addressing these challenges requires recognizing their global scope and engaging proactively with the evidence before us.
Other co-authors of the study were Nicolas Gauthier of the University of Florida and Michael D. Purugganan and Ornob Alam of New York University.
The study was funded in part by grants from the Zegar Family Foundation and the NSF Plant Genome Research Program.
For more information, contact d’Alpoim Guedes jguedes@uw.edu.