What Climate Change Might Mean for Test Scores
Climate researchers estimate the average temperature across the United States will warm by 5 degrees Fahrenheit by 2050, and more frequent and severe hot spells could chip away at student learning over time, find researchers from the College Board, Georgia State University, Harvard University, and the University of California, Los Angeles.
The researchers analyzed longitudinal data for more than 10 million high school students in the classes of 2001 to 2014 who took the PSAT (a precursor to the SAT college entrance exam) at least twice. Their data were mapped and tied to geographic temperature data, as well as a 12,000-school survey of students, teachers, and counselors about air conditioning and heat discomfort.
After accounting for students' background, grade, and prior performance, the study found that for every degree hotter the average temperature in a school was in the year before the PSAT, its students showed a drop in scores equal to about 1 percent of their average learning for the year. While hot summer or weekend days did not affect students' test performance, every school day above 90 degrees in the year before the test lowered students' scores even further. Moreover, a particularly hot year continued to pull down students' academic achievement two, three, and even four years later.
Moreover, researchers found the effects of heat fell more heavily on black and Hispanic students and students in low-income communities. That's because these students are more concentrated in warmer states in the South and Southwest, and they are less likely than white or wealthier students to attend schools with up-to-date air conditioning systems. On average, the study found, black and Hispanic students attended schools in areas that were an average of 5 degrees Fahrenheit warmer than the schools attended by white students, and their test scores were hurt three to four times more by hotter days than white students' scores. Over a decade, researchers estimated that differences in average temperatures and access to air conditioning at school could explain 13 percent of the PSAT achievement gaps between white students and their black and Hispanic peers (which amounts to .8 of a standard deviation in test scores).
"We're not just thinking about how does heat affect you on a particular test day," said co-author Jonathan Smith, an assistant economics professor at Georgia State University, in a preview of the study at the Society of Research on Educational Effectiveness meeting in Washington, D.C., this month. Over time, he and his colleagues estimated a 5-degree hotter average temperature was associated with $1,000 less in adult income per student, or more than $1 million in lost income per school. "This is the first research showing that cumulative exposure to heat will directly impair human capital."
It's not clear what is behind the heat-related decline in test scores. Both students and teachers may find it more difficult to focus when they are physically uncomfortable, and students may be more prone to fall asleep in class. Higher temperatures can also increase indoor air pollution in schools, which is associated with lower memory and more chronic illness. On extremely hot days, some districts may cancel school or move students to different classrooms, cutting back class time. And air conditioning in schools reduced the effects of heat by 80 percent.
For more about how physical aspects of the school climate affect student achievement, see Education Week's special report.
Image Source: Getty