The University of Houston symposium asked of climate change, “Is it a real threat?” But even energy officials in favor of the continued reliance on fossil fuels were quick to acknowledge that the threat is indeed real.

Where they may differ with their critics are on the solutions and whether the causes are scientifically definitive.

David Hone, a chief climate change adviser for Royal Dutch Shell PLC, said “the climate issue is only fully resolved when carbon emissions return to zero.”

He added shortly thereafter, “It’s going to be something that we have to do relatively quickly, because we are running out of time.”

The university’s energy symposium drew a packed audience at the on-campus Hilton, ranging from students to Marathon Oil President and CEO Lee Tillman, who attended but did not participate.

Hone also questioned the larger impact of relying on limited renewable and alternative energies, at least given current technology advancements.

“You think they’re going to reduce emissions, but do they really do that?” he said, asking whether the dent made is large enough while carbon emissions increase globally and in developing nations.

Hone’s answer — keeping carbon emissions out of the atmosphere by capturing waste carbon emissions from refineries and other fossil fuel plants and then finding long-term storage for the waste in underground geological formations and other locations. The process is commonly called carbon capture and storage, or CCS.

“CCS is the only technology that deals directly with the stock emissions issue, but this isn’t widely recognized,” Hone noted in his presentation.

On this, Richard Feely, a University of Washington oceanography professor and a senior fellow at the National Oceanic and Atmospheric Administration, found at least one issue to agree with Hone.

“I’m very much in favor of carbon capture,” Feely said, but he quickly noted that “leakages” are a significant concern with carbon storage and that the technology may not be advanced enough yet for large-scale use.

Student questions to Hone then pointed out that energy customers will pay for the carbon capture infrastructure and that segments of the energy sector stand to profit from building it up.

“At the end of the day, consumers will pay,” Hone said.

Feely though focused more of his discussion on the rapid acidification of the oceans from manmade carbon emissions. Feely noted that about 28 percent of carbon emissions enter the oceans — especially in the upper portions where most marine life exists — and that more than 90 percent of the emissions come from fossil fuel burning. Ocean acidity is up 30 percent since the beginning of the industrial age, Feely said, and it is rapidly increasing each year.

Coral reefs, mollusks and shellfish are among the most susceptible, he said, noting that shells actually dissolve in the carbonated waters.

“They’re very, very important to the food chain,” Feely said of the most vulnerable organisms. “This is a food security issue in a major way.”

He later added, “Humankind’s footprint in the ocean’s now clearly detectable.”

John Nielson-Gammon, a Texas A&M University professor and the Texas State climatologist, took a little less alarmist approach.

“It’s not the planet’s survival that’s at risk,” he said. What is at risk is the way of life that humans are accustomed to and our abilities, or lack thereof, to adapt to climate changes. The U.S. infrastructure — from flood protection to farming — was built to survive on existing climate levels.

“Our society has compartmentalized the world,” Nielson-Gammon said.

As the climate continues to warm, he said, Texas stands to suffer from water supply issues because of declining aquifer levels coupled with population increases.