The House’s new climate-change panel held its first substantive hearing, placing renewed emphasis on the national security threats posed by global warming.

Much of the discussion focused on alternative fuels such as nuclear power and clean coal. But the Select Committee on Energy Independence and Global Warming also delved into the military implications of climate change, which were highlighted in a report released this week by retired military leaders and the CNA Corporation, a nonprofit organization.

“The developing world will bear the brunt of the collateral damage from our historic global-warming emissions, but the United States will experience its own self-inflicted wounds, including threats to our national security and military readiness,” said Chairman Edward J. Markey, D-Mass.

Retired Army Gen. Gordon Sullivan, who participated in CNA’s study, said climate change could lead to droughts and famine in places such as Africa, which will cause mass migrations, undermine governments and give “non-state actors” a stronger foothold.

The report calls on the United States to take a leadership role in reducing global carbon emissions while making global-warming threats an integral part of military planning.

Lawmakers are pushing legislation that would require the administration to produce a National Intelligence Estimate on the security implications posed by global warming.

Majority Whip Richard J. Durbin, Democrat of Illinois, and Republican Chuck Hagel of Nebraska have introduced a bill (S 1018) in the Senate, and Markey said he plans to introduce a companion bill in the House.