What are some challenges of protecting national security.

global instability, military infrastructure, and homeland security.

Explanation:

Climate change will cause global instability; these disruptions will burden civilians and military institutions, around the world including the u. s military.

Transnational environmental problems. These include global environmental problems such as climate change due to global warming, deforestation, and loss of biodiversity.

Local environmental or resource pressures ...

Environmentally threatening outcomes of warfare.