Skip to Main Page Content

New research shows climate change will reduce crop yields sooner than expected

March 25, 2014

Results from a new study co-authored by Netra Chhetri, a faculty member at the Consortium for Science, Policy & Outcomes at Arizona State University, show global warming of only 2 degrees Celsius will be detrimental to three essential food crops in temperate and tropical regions. And beginning in the 2030s, yields from those crops will start to decline significantly.

“This study has been able to quantify the likely impacts of differing degrees of climate change on yields, by crop and by region,” Chhetri said. “In general, Sub-Saharan Africa and South Asia showed significant yield reductions for the second half of the century.” Portrait of Netra Chhetri Download Full Image

In the study, the researchers created a new data set by compiling the results from 1,700 published simulations to evaluate yield impacts of climate change with and without adaptations for rice, maize and wheat. Due to increased interest on the impacts of climate change in global food security, the study was able to create the largest dataset to date on crop responses, with more than double the number of studies that were available for researchers to analyze for the previous IPCC Assessment Report in 2007.

“One of the most important findings of this study is that adaptation may not be as effective for rice and maize as it is for wheat,” Chhetri said.

The research paper, "A meta-analysis of crop yield under climate change and adaptation," published March 16 by the journal Nature Climate Change, feeds directly into the Working Group II report of the Intergovernmental Panel on Climate Change Fifth Assessment Report, which is due to be published at the end of March 2014.

In the Fourth Assessment Report, to which Chhetri was a contributing author, scientists reported that regions of the world with temperate climates, such as Europe and most of North America, could withstand a couple of degrees of warming without a noticeable effect on harvests, or possibly even benefit from a bumper crop.

With more data available now, researchers see a shift in consensus.

“Our research shows that crop yields will be negatively affected by climate change much earlier than expected," said Andy Challinor, University of Leeds professor and lead author of the study. "Furthermore, the impact of climate change on crops will vary both from year to year and from place to place – with the variability becoming greater as the weather becomes increasingly erratic.”

The researchers conclude that, on aggregate, we will see an increasingly negative impact of climate change on crop yields from the 2030s onward. The impact will be greatest in the second half of the century, when decreases of more than 25 percent will become increasingly common.

These statistics account for possible adaptation techniques by farmers to mitigate the effects of climate change, such as adjustments in the crop variety and planting date. Later in the century, greater agricultural transformations and innovations will be needed in order to safeguard crop yields for future generations.

“Climate change means a less predictable harvest, with different countries winning and losing in different years. The overall picture remains negative, and we are now starting to see how research can support adaptation by avoiding the worse impacts,” Challinor said.

Marissa Huth

communications specialist, School for the Future of Innovation in Society


ASU undergrads find success in entering medical school

March 26, 2014

More than 375 Arizona State University students have been accepted to medical schools over the past five years, many at the top schools in the nation. Sun Devils currently are cracking med school texts at Yale, Dartmouth, Columbia, Harvard, Stanford, Northwestern, Mayo and University of Chicago, to name a few.

ASU’s Health Professions Advising Office is a busy place, with about two dozen students visiting each day to find out what careers are available, what courses to take and what the requirements are for different professional schools. The office also advises students who are aiming for law school. med student simulating giving oxygent to mannequin Download Full Image

“Students are often surprised that we have such an active pre-professional advising program,” says Philip Scharf, senior academic director of the office. “I often talk to high school students who wonder why we don’t have a pre-med major. They don’t realize that medical schools aren’t interested in your undergraduate major. Schools look at your GPA, especially your science GPA, and your MCAT score.”

ASU has more than 20 pre-med science majors

ASU has more than 20 science majors that are considered pre-med, though many students are in engineering, business or psychology. Recently, several dance students and a piano major were accepted to medical school. English majors with a science background do particularly well on the MCAT, according to Scharf.

The ASU undergraduate curriculum provides an excellent grounding for medical school, Scharf says. ASU’s School of Life Sciences was recently ranked in the top 25 of all research institutions in the world by a leading higher education and careers research company based in the United Kingdom.

By sophomore year, students come to the pre-health office to sign up for field internships, and Scharf also encourages them to pursue research opportunities in their departments. By junior year, many take workshops on writing personal statements and applications. They keep track of the dates for the MCAT (medical school) and DAT (dental school) exams, and many will participate in mock interviews.

New BS in medical studies offered this fall

For the first time this fall, ASU will offer a bachelor's in medical studies through the College of Health Solutions, opening yet another pathway for students interested in health careers. The program will be rigorous and interdisciplinary, focusing on health promotion and exploring new delivery models.

Responding to planned changes in the MCAT as well as the evolving field of health care, the program will provide students a well-rounded foundation in social sciences, humanities, interprofessionalism and leadership, in addition to the medical science prerequisites necessary for graduate programs in medicine and health care.

“With health care reform, providers need to understand health policy and economics, and they should be better prepared to talk to their patients about issues of health promotion,” says Keith Lindor, dean of the College of Health Solutions. “This is a degree that will prepare people for health care delivery, how to better influence the health of a population before they become ill.

“Lifestyle choices having to do with food, exercise and stress are major determinants of the health of a population. Students coming into the health profession must understand their broader role. There’s so much to learn, why not take advantage of the undergraduate years to gain a background in these issues, rather than trying to force everything into three or four years of medical school?”

Core coursework will have medical focus

Some of the core coursework will be recast with a medical focus, Lindor says. An English class may focus on the literature of medicine, for instance, and a science class may be biostatistics. Other courses will include applied medical and health care ethics, global health and the cultural aspects of health.

“We hope this will be an attractive alternative for students not only from Arizona, but from other states, who want this kind of a program. Some medical schools will value this diversity of experience, and see it as a model of efficiency.”

Another advantage to the program is that it will give students the background to enter a number of different health-related careers, Lindor says. The vast majority of students interested in health don’t apply to medical school, and less than 50 percent of those who apply will be accepted. New occupations are constantly being formed, and as health care reform proceeds, new roles will be created.

ASU pre-med students have advantages over other schools

ASU students aiming for medical careers have enormous advantages over other schools in that there are so many opportunities at the university and in the Phoenix area for undergraduate research and clinical work, according to both Scharf and Lindor.

“We have formalized internship programs with Scottsdale Healthcare, Banner Good Samaritan, Maricopa Integrated Health Systems and Mayo Clinic,” says Scharf, “and students are good at finding work experience to gain credit. And while there are incredible research opportunities on campus, students also do research at the Translational Genomics Research Institute and at Barrow Neurological Institute.”

ASU has built a close relationship with Mayo Clinic, with Mayo medical students coming to campus to pursue dual degrees, and ASU pre-med students participating in activities on the Mayo Clinic campuses.

Selected ASU pre-med students from Barrett, the Honors College can apply to participate in Mayo Medical Scholars, a multi-year program in which they shadow physicians and have lectures and hands-on learning experiences at the Mayo Clinic campus in Phoenix. Another program, the Mayo Physicians of Tomorrow, provides an opportunity for selected students from Barrett to spend two weeks during the summer at an experiential learning program at Mayo Medical School in Rochester, Minn.

For more information on health-related majors at ASU, go to