Potential 2016 GOP presidential candidate and former Florida governor Jeb Bush speaks at a business roundtable in Portsmouth, N.H. on Wednesday. (REUTERS/Brian Snyder)

BEDFORD, N.H. -- Jeb Bush believes that the Earth's climate is changing -- but don't just blame humans.

The former Florida governor, whose state bears the brunt of rising seas and a changing climate more than most, conceded Wednesday evening that humans are partly -- but not entirely -- responsible for the changes.

"The climate is changing. I don't think the science is clear on what percentage is man-made and what percentage is natural. It's convoluted," he told roughly 150 people at a house party here Wednesday night. "And for the people to say the science is decided on this is just really arrogant, to be honest with you. It's this intellectual arrogance that now you can't have a conversation about it even."

The issue of climate change came up as the host of the house party asked Bush to comment on a speech given Wednesday by President Obama, who said that climate change is a "serious threat" to national security.

"Climate change constitutes a serious threat to global security, an immediate risk to our national security," Obama told Coast Guard graduates in their dress white uniforms at the Coast Guard Academy in Connecticut, "and, make no mistake, it will impact how our military defends our country. And so we need to act— and we need to act now.”

In response, Bush said that climate change should be just "part of, a small part of prioritization of our foreign policy." He suggested that the United States should encourage countries that have higher carbon emissions rates to reduce them.

But, he added, "We've had a pretty significant decrease and we'll continue on, not because of Barack Obama, but because of the energy revolution." He credited hydraulic fracking, horizontal drilling and an increased use of natural gas for helping cut American carbon emissions.

"I don't think it's the highest priority," he said of climate change, "I don't think we should ignore it, either. Generally, I think as conservatives we should embrace innovation, embrace technology, embrace science. It's the source of a lot more solutions than any government-imposed idea and sometimes I sense that we pull back from the embrace of these things. We shouldn't. We're the party that should be the party of discovery, the party of science, the party of innovation and tear down the barriers so that those things can accelerate in our lives to find solutions for all these things."

Bush is in the midst of a two-day swing through New Hampshire, which holds the first Republican presidential primary next year. Bush said again on Wednesday that he is nearing a decision on whether to launch a campaign for president, but given the size and scope of his growing political operation, his candidacy is seen as a foregone conclusion.