The Bill and Melinda Gates Foundation grant, distributed over four years, is earmarked for scaling up regional innovations that build resilience against drought, heat waves and extreme flooding amplified by a warming world.
The funding was announced Monday at the COP27 climate summit in Egypt's Red Sea resort of Sharm el-Sheikh.
The money will be channeled to so-called climate-smart agriculture projects, including new digital technologies, innovations in livestock farming, and -- working with the UN's International Fund for Agriculture Development -- support for women smallholder farmers, Suzman said.
A "weather intelligence platform" developed with the Kenya Agriculture and Livestock Research Organization, for example, will allow farmers to better anticipate climate threats, with potentially crop-saving updates delivered via cellphone text messages.
"More funding is necessary to ensure agricultural and technological innovations are widely available to vulnerable communities," Bill Gates, who is not attending the summit, said in a statement.
Extreme weather has ravaged crops and reduced yields this year across four continents. In Africa, drought and flooding rains have destroyed crops and heightened food insecurity.
Agriculture forms the backbone of many African economies, employing on average over 50 percent of the labor force and accounting for a third of total African gross domestic product.
Organizations representing some 350 million family farmers, meanwhile, released an open letter to world leaders Monday attending the COP27 climate summit.
It put out a warning that global food security is at risk unless governments boost finance for small-scale production, and calling for a shift from industrial agriculture toward more diverse, low-input methods.
"The surge in hunger over the last year has exposed the fragility of a global food system" ill-equipped for climate shocks, the letter said.
"Building a food system that can feed the world on a hot planet must be a priority for COP27."
Analysts welcomed the new funding stream, but cautioned that much broader support was needed.
"The Gates Foundation initiative is important and timely, with COP27 being dubbed the 'Africa COP'," Elizabeth Robinson, director of the Grantham Research Institute on Climate Change and the Environment, told AFP.
"But the scale of the problem is such that governments, private sector and international organizations all need to increase their commitments to food security."
Overall, there is an annual $41 billion adaptation "finance gap" in Africa, according to the Global Center on Adaptation, based in Rotterdam.
Claire McConnel, a food and agriculture expert at climate policy think tank E3G, said philanthropic funding and public finance can play an "important role" in leveraging private sector investments for adaptation.
"Partnerships with African farmers' organisations and research institutes based on the continent will be key to ensuring investments meet farmers' needs and money is spent effectively and efficiently," she said, commenting on the announcement.