By Seth Borenstein, AP Science Writer

It's a scary world out there, risk experts agree, but they say Donald Trump and Hillary Clinton often focus on the wrong dangers — fixing on hazards that are unlikely, or unlikely to cause massive pain.

The Associated Press asked 21 risk experts to analyze the presidential campaign and list what they consider the five biggest threats to the world. Climate change topped the list with 17 mentions, often as the top threat. It was followed by use of nuclear weapons, pandemics, cyberattacks and problems with high technology. Neither Trump's signature issues of immigration and terrorism nor Clinton's major concerns, financial insecurity and gun violence, made the list.

"I have not heard or read about any significant deliberations of the major risks that face our country today and tomorrow. Sad for the U.S.," said Bob Bea, a University of California Berkeley engineering professor who is a long-time expert in human-caused disasters.

Nuclear weapons could be one exception. The issue is not ignored, though the candidates come at it from opposite directions. Trump has suggested that Japan and South Korea should be free to develop their own nuclear weapons programs to counter North Korea, while Clinton says Trump is too unstable to be trusted with his own finger on the figurative nuclear button.

Economics and psychology professor George Loewenstein, co-director for the Center for Behavioral Decision Research at Carnegie Mellon University, was typical of the experts. He called climate change "a problem that threatens the very existence of the human race" and is already having devastating consequences around the world. He fretted that it has been barely mentioned in presidential debates, usually in context of Trump's questioning that it is happening.

But it's not just climate change, which Clinton does touch on in her speeches. The political campaigns often miss the real potential risks while exaggerating others, especially immigration and terrorism, the experts said. Extreme weather has killed more than twice as many people in the United States in the past 15 years as terrorist attacks, even including Sept. 11, 2001.

Fourteen of the 21 experts responded when asked to rate Clinton and Trump on handling risk. They gave Trump an average of an F and Clinton a C-plus.

Seth Baum, executive director of Global Catastrophic Risk Institute, said in general it seems Clinton "appears to be assessing risks based on more careful analysis, whereas Trump appears to rely more on intuition." Studies show that careful analysis does better than intuition, he said.

The results of the small AP survey are similar to those of a larger survey of 750 experts conducted this year by the World Economic Forum with the help from the National University of Singapore, the University of Oxford and the University of Pennsylvania. The Global Risks Report 2016 (pdf) found the five biggest global risks in terms of impact were: failure to deal with climate change, weapons of mass destruction, water crises, large-scale involuntary migration, and severe energy price shocks. It said the five big risks that are most likely are large-scale involuntary migration, extreme weather disasters, failure to deal with climate change, regional wars and major natural catastrophes.

Experts said sometimes people get risk wrong because they worry more about things they can't control. People fear flying in planes, which is safer than driving on a highway, because they lack control, said Miguel Centeno, founder of the Research Community on Global Systemic Risk at Princeton University.

"Trump is appealing to the general fear people have that that they don't control their lives or futures," said risk perception consultant David Ropeik , author of the books "How Risky Is It Really?" and "Risk." ''We direct that fear at immigrants or terrorists or political insiders who don't give a damn about anybody but themselves."

Some said the threats from immigration, terrorism and crime that Trump talks about are overblown. However, Ropeik said, "these rinks trigger much stronger emotional responses from the public since they feel like risks that just might happen to any one of us."

But risks that experts highlight, such as climate change or growing resistance to antibiotics, "are abstract, intellectual," Ropeik said. "They don't feel like something that could happen to us soon. So those aren't being talked about as much."

Between 2006 and 2015, 117 people in the United States died from terror attacks, according to the National Consortium for the Study of Terrorism and Responses To Terrorism, while 1,130 people died from extreme heat, according to the National Weather Service. When Sept. 11, 2001, is included, 3,124 people have died in the United States from terrorism in the past 15 years, but 8,635 died from extreme weather such as heat, hurricanes, lightning, tornadoes and floods, according to the weather service.

While many experts worried about cybersecurity and hacking or cyberterrorism, other concerns about technology also surfaced.

Carnegie Mellon's Loewenstein said he worries about changes in the economy from the rise of artificial intelligence and robots, such as self-driving cars. He said if the trend continues it will worsen inequality and increase the marginalization of those with limited education and skills. He said this risk "is probably too subtle as well as controversial" to make it into presidential debates.

Jennifer Kuzma, co-director of the Genetic Engineering Society Center at North Carolina State University and secretary of the Society for Risk Analysis, said she worries about misuse of emerging nanotechnology, biotechnology and neuro technology "for nefarious purposes."

But it's the disruption in crucial technology and the global trade that goes with it that worries Centeno of Princeton. If a good chunk of the world loses its electronic and internet connectivity, the results could be crippling, he said.

"Nobody ever talks about this," Centeno said. Technology has so changed our lives that "we've created a machine that we cannot live without."

His advice: "Be afraid. Be very afraid. But you've got to live."

To Learn More:

Network Newscasts of Presidential Campaigns Said to Offer the Least Substance in at Least Three Decades (by David Bauder, Associated Press)

American Voter Dissatisfaction with Two Likely Presidential Nominees Highest in Decades (by Dan McCue, Courthouse News Service)

Don’t Like Clinton or Trump? Just Shut Up and Watch TV (by David Wallechinsky, AllGov)