In his first appearance outside the United States since the end of his presidency, Barack Obama this week warned that agriculture is the second largest driver of greenhouse gas emissions after energy.

He spoke at the Seeds and Chips conference in Milan, Italy, an annual summit focused on technology, sustainability and food.

Obama warned that as climate change hampers crop yields around the world, soaring food prices could spur political instability.

He said if the world food system does not change course, the World Bank predicts that agriculture and land use change will account for as much as 70 percent of greenhouse gas emissions by 2050.

"The path to a sustainable future will require unleashing the creative power of our best scientists and engineers and entrepreneurs, backed by public and private investment," he said.

Obama also voiced concern about the influence of agriculture lobbyists in Washington, and agriculture committee members in Congress who protect the interests of the food industry.

Read More:

• Obama Speaks In Milan, With Food As Text And Politics As Subtext (New York Times)
• Remarks by President Barack H. Obama - 44th President of the United States (Seeds & Chips)