Bill Nye the Science Guy warns scorching weather is 'beginning of new normal'

Science TV personality and educator Bill Nye has warned the extreme weather currently sweeping the US is the start of a “new normal.”

Appearing on ABC’s “This Week”, he told host Martha Raddatz: “It’s the beginning of the new normal, with respect. So the latest — the latest research is that there’s not a turning point or a tipping point or a knee in the curve. It’s just going to get hotter and hotter and worse and worse and more and more extreme."

This comes as extreme weather events hammer the US. A railroad bridge collapsed during flooding in the Midwest that has led to water rescues, evacuations and at least one death and has brought additional misery during a vast and stubborn heat wave.

READ MORE: 'Multiple disasters all in one day' as extreme weather tears across the US

READ MORE: Train bridge collapses into a river after flooding near Iowa as eight times average rainfall hits

“So this is a taste of the normal of the future unless we, humankind, get to work and address it,” Bill Nye added.

He said there is “a situation now where El Niño is giving way to La Niña, where there’s a cooling in the Pacific Ocean which, strangely enough, leads to more hurricanes because there’s less vertical sheer, as we say, in the Atlantic.”

He added: "So we have a situation where we’re going to have this extreme heat and these crazy heat domes, these high-pressure systems that don’t move, and there are no clouds to reflect sunlight into space; they just get hotter and hotter,” he said. “And then we’re having these extreme weather events, big rain and wind coming in from the southeast to North America.”

The bridge connecting North Sioux City, South Dakota, with Sioux City, Iowa, collapsed into the Big Sioux River late Sunday, an emergency manager said. Images from local media showed a large span of the steel bridge partially underwater as floodwaters rushed over it.

Some of the trusses collapsed, Jason Westcott, an emergency manager in Union County, South Dakota, told KCAU-TV.

There were no immediate reports of injuries from the collapse. The bridge is owned by BNSF Railway, whose officials did not immediately comment.

Floodwaters have risen over days of heavy rain in South Dakota, Iowa, Minnesota and Nebraska. More rain is expected, and many rivers may not crest until later this week.

In northwestern Iowa, 13 rivers flooded, said Eric Tigges of Clay County emergency management. Entire neighborhoods, and at least one whole town, were evacuated, and the Iowa town of Spencer imposed a curfew Sunday for a second night after flooding that surpassed a record set in 1953.

“When the flood gauge is underwater, it’s really high,” Tigges said at a news conference.

Gov. Kim Reynolds declared a disaster for 21 counties in northern Iowa, including Sioux County. In drone video posted by the local sheriff, no streets were visible, just roofs and treetops poking above the water.

National Guard troops helped with water rescues and carted needed medications lost in flooding.