Washington (CNN) A House Oversight Committee hearing to examine the impact of climate change on national security -- including military bases ravaged by extreme weather events -- devolved into partisan sniping, personal attacks and efforts to deny climate change represents a threat.

Committee chairman Elijah Cummings, a Maryland Democrat, opened the hearing by raising the record-breaking March floods at Offutt Air Force Base in Nebraska, home to US Strategic Command, and the wreckage Hurricane Florence inflicted in September on North Carolina's Camp LeJeune, where a Marine commander warned the impact of climate-related events has degraded Marine Corps readiness.

Beyond the domestic impact, Cummings quoted Director of National Security Daniel Coats' assessment that heat waves, droughts and floods are likely to fuel competition for resources, social discontent, migration and tension between states.

"There may be differences of opinion on how we should respond, but there should be no uncertainty about whether we respond," he said.

Surreal spectacle

That proposition was never put to the test.

Instead, the hearing became a surreal spectacle in which one side tried to address an issue that the other side largely refused to accept is valid.

Republicans used the hearing to assail Alexandria Ocasio-Cortez, the freshman New York Democrat, and the Green New Deal legislation she has championed. GOP members attacked the scientific consensus on climate change, argued Pentagon spending on climate preparedness is a waste of money, and complained the witness panel didn't include those anyone who denies climate change is a problem.

They bristled at criticism of President Donald Trump's proposal to form a panel to question the scientific consensus on climate change and whether it poses a national security threat -- despite Pentagon and intelligence community assessments that it does just that.

And they attacked one witness in particular -- former Secretary of State John Kerry, an architect of the US entry into the Paris Agreement from which Trump withdrew -- in particularly personal terms.

Playing "the 1% card"

Rep. Thomas Massie, a Kentucky Republican, said it was appropriate that someone "with a pseudo-science degree is pushing pseudo-science in front of our committee today." Kerry has a political science degree from Yale.

He also accused the former senator of playing "the 1% card," a reference to Kerry's personal wealth, after the former Secretary suggested taxes on the wealthy might be part of an answer to fund climate solutions.

At another point, Rep. Mark Green, a Tennessee Republican, urged that lawmakers "look at all the climate theories with a critical eye" and in the meantime argued that any Pentagon spending on climate preparedness is a waste of money.

"If we spend a Department of Defense dollar on non-war fighting capability it decreases our war fighting ability," Green said. "We must not use a single dollar of the Department of Defense budget to address the climate change issue."

That's not what Pentagon officials say.

The military impact

The top commander of the US Air Force said last week that the effects of climate change across the globe are a source of conflict the US may have to respond to militarily. Air Force Chief of Staff Gen. David Goldfein told the Senate Armed Services Committee the brutal 8-year civil war in Syria is a prime example.

The conflict began "because of a ten-year drought," and caused the movement of Syrian citizens to places "where they were not getting any support and therefore a civil war began." Goldfein added "we have to respond militarily very often to the effects globally of climate change."

Domestically, Pentagon officials have been struggling with the impact of climate change within the US as well.

"We desperately need the supplemental funding to recover from the natural disasters that hammered Tyndall and Offutt," Air Force Secretary Heather Wilson said at a Heritage Foundation event in March.

The Air Force requested $1.2 billion in supplemental funding for fiscal year 2019 and $3.7 billion over the next two fiscal years to rebuild Tyndall Air Force Base in Florida and recover Offutt Air Force Base. Without supplemental funding now, Pentagon officials say the Air Force will have to cut critical facility and readiness requirements, increasing Air Force wide operational risks and negatively impacting the recovery of Tyndall and Offutt.

Military bases

"There are other decisions we'll have to make if we don't [have supplemental funding] by May or June," Wilson said. "These are just the first decisions that we had to make yesterday ... 61 projects in 18 states are not going to happen because we have not gotten a disaster supplemental for Tyndall."

Marine Corps Commandant Robert Neller warned in September of similar damage to the military, saying the flooding damage at Camp LeJeune means "one-third of the combat power of the Marine Corps is degraded and will continue to degrade."

Rep. Eleanor Holmes Norton, a Democrat who represents the District of Columbia, noted that the Pentagon recently released a Congressionally mandated report that examined the vulnerability of military bases to climate events and found that 36 bases are vulnerable to wildfires , 43 to drought and 53 face recurrent flooding caused by sea level rise and storm surges.

"That's the defense department speaking," Holmes said.

Former Defense Secretary Chuck Hagel, another key witness who served under President Obama agreed, saying that climate issues are "a centerpiece for national security because not only does it affect the infrastructure, it affects readiness and preparation."

'On and on'

Seventeen F-22 fighter aircraft are "out of the lineup" because of hurricane damage at Tindell Air Force Base in Florida, he said. At Fort Bragg in North Carolina, "they can't train, they've got to rebuild, they've got to shift their people and their structures and their planning. You could go on and on."

"It is very clear that planning for climate change is not some frivolous waste of time or waste of money," Hagel said. "It is essential to our troops and to their wellbeing and to the national security of our country."

The hearing included surreal exchanges, including one between Massie, who kept asking Kerry about levels of carbon dioxide being far higher millions of years ago, suggesting concerns about their rise now are overblown.

"But there weren't human beings -- it was a different world, folks," Kerry said. When Massie asked how carbon dioxide rose to such levels without humans, Kerry said it involved geological events. When Massie asked, "did geology stop when we got on the planet?" an irritated Kerry said, "this is just not a serious conversation," he said.

'More leadership ...than President Trump has in his lifetime'

Republicans repeatedly used the hearing to criticize the Ocasio-Cortez's Green New Deal proposal. Hagel repeatedly pointed out that the hearing wasn't about the bill, but Kerry took the opportunity to defended the proposal and criticized Trump's leadership on the issue.

"We all have differences on one piece of legislation or another," Kerry said. "But in proposing what she has proposed together with Sen. (Ed) Markey, Congresswoman Ocasio-Cortez has in fact offered more leadership in one day or in one week than President Trump has in his lifetime on this subject."

Some Republicans raised questions about the cost of dealing with climate change -- particularly its impact on jobs.

Chip Roy, a Texas Republican, raised the costs of the proposed approach to climate change. And Republican Rep. Carol Miller of West Virginia emphasized that while she cared about climate change as a mother and grandmother, she saw the energy industry as a crucial employer in her district and that "quality of life directly corelates with access to affordable energy."

"The problem is ... we have been doing this in a way that's simply not sustainable," Kerry said. "There's no country in the world that's living sustainably today."

"You talk about your children and your grandchildren, if we don't protect our environment your grandchildren have a pretty tough go in 20, 30 years."