Environment and energy issues pose both threats and opportunities no matter where you sit. Leading experts discuss how two critical American actors are tackling these challenges: the business community and the U.S. military.

"Ultimately, whether Yemen is able to achieve its goals for social and economic development, will, to a large extent, depend on its future population growth and size," said Gary Cook, senior health advisor at the U.S. Agency for International Development, in his opening address at an all-day conference on the role of population, health, natural resources, and institutions in Yemen's political crisis.

A discussion on renewable energies and policies relating to Brazil.

Rural communities in developing countries understand that high population growth rates, poor health, and environmental degradation are connected, said Population Action International's Roger-Mark De Souza. An integrated approach to development – one that combines population, health, and environment (PHE) programs – is a "cost-effective intervention that we can do very easily, that responds to community needs, that will have a huge impact that's felt within a short period of time," said De Souza, who was joined by three other experts to discuss how to improve current efforts to expand the PHE approach.