President Obama calls climate change “the greatest threat to future generations.” Yet Americans have not responded to his call to action, he acknowledged recently, because climate change “is not an instantaneous catastrophic event. It’s a slow-moving issue that, on a day-to-day basis, people don’t experience and don’t see.”

Yet parts of sub-Saharan Africa are already are seeing climate change’s diverse effects, which include rising temperatures and changes in precipitation patterns. “Africa is projected as the continent that will experience climate deviations earlier and more severely than any other region,” says Richard Munang, coordinator of the U.N. Environment Program’s Africa Regional Climate Change Program (UNEP).

The impacts of these effects on humans are likely to be significant. By 2020, “yields from rain-fed agriculture could be reduced by up to 50 percent,” according to the UNEP. “Global warming of 2 degrees C would put over 50 percent of the continent’s population at risk of undernourishment.” Another study by the U.N. Intergovernmental Panel on Climate Change notes that major staples such as wheat and maize could drop more than 20 percent in sub-Saharan Africa by 2050, leading to starvation, disease and political instability.

African farmers have already begun to adapt, but the speed and intensity of the effects of climate change may overcome their efforts. Development donors are now promoting “climate-smart” agricultural approaches to help farmers match changes in practice to changes in the world. But despite the clear need for such practices emerging in parts of sub-Saharan Africa, farmers have not warmed to them, according to Edward Carr, professor and director of Clark University’s International Development, Community, and Environment Department — and for good reason.

“Sometimes we’re coming in with climate-smart agricultural interventions thinking 20 years out; they’re thinking next harvest. And if the thing you bring in, in any way, shape or form, disrupts the next harvest, or challenges what they are doing to manage risk on that next harvest, they see that as enhancing climate risk,” Carr told an audience last week at the Woodrow Wilson Center for Scholars in Washington. “Why would they take that on? That’s not climate-smart to them.”

Carr’s research into climate change and food security rests on almost 20 years of experience in rural parts of sub-Saharan Africa, as well as his work for the U.S. Agency for International Development (USAID). He also was a consultant to the World Bank on issues of adaptation and development, and his Humanitarian Response and Development Lab (HURDL) in Clark’s George Perkins Marsh Institute currently works on projects with several large development donors. A geographer and anthropologist, he came to Clark last fall from the University of South Carolina.

Last week, he received the U.S. Department of Agriculture’s Abraham Lincoln Honor Award for Contributions to Global Food Security for his role as a lead author of the 2015 report on “Climate Change, Global Food Security and the U.S. Food System.” Among other findings, the report warns that “climate change is projected to result in more frequent disruption of food production in many regions and increased overall food prices.”

Later that day, Carr kicked off the Woodrow Wilson Center’s two-hour panel discussion on “Pathways to Climate-Smart Agriculture.” Funding agencies and governments hail the approach, which “can offer farmers in Africa substantial benefits in terms of increased productivity and income, better risk management and improved resilience to climate change,” according to the center. “Despite this focus, however, the adoption of CSA approaches and practices by smallholder farmers has been slow, piecemeal and largely unsustained.”

In his talk, Carr explained why. He and the HURDL team worked with the company Integra LLC and USAID on the “Pathways to Climate-Smart Agriculture in Africa” study. Carr, senior advisor on the study, and team members — which included Sheila Onzere, a research scientist at Clark — reviewed 500 research documents, interviewed 40 experts from funding agencies and universities, and surveyed over 200 farmers in Burkina Faso and Kenya.

Among other findings, the researchers discovered that African farmers are concerned with the initial start-up costs of agricultural adaptations, “whereas technical experts are concerned with long-term costs,” Carr explains. Furthermore, climate-smart approaches need “to align with social and cultural values and norms — farmer familiarity with practice makes a difference.”