Weather researchers at Iowa State University say a shifting climate and warmer ocean temperatures are partially responsible for a record number of tornadoes this spring.

More than 100 were reported in Iowa, in May alone.

Eleven hundred tornadoes were reported regionwide in May -- from Texas to Minnesota, and from West Virginia to Georgia. That's more than twice the 30 year average.

One of the fiercest killed five people and injured dozens in rural Greenfield, Iowa.

ISU Severe Weather Meteorologist and Professor of Meteorology William Gallus said extreme heat from a changing climate has increased ocean temperatures, and is one contributing factor to this year's storms.

"Mexico and Texas were having record high temperatures," said Gallus. "That was allowing the Gulf of Mexico to rapidly warm up, get much warmer than normal, which means that is our main source of energy."

Gallus said the weather pattern known as El Niño -- characterized by warmer ocean temperatures that prompt more precipitation and provide fuel for severe weather -- is now shifting to La Niña, marked by cooler seas and drier weather.

That could cause the rest of the tornado season to be less active.

Gallus said the high number of tornadoes in the region was unusual, since climate change models predict Iowa and neighboring states west of the Mississippi should being seeing below average numbers, which they have in recent years.

"The long-term trend has been for tornadoes to be hitting more places east of the Mississippi River," said Gallus.

Gallus said data show tornadoes occurring on fewer days each year, but coming in clusters and with greater intensity.

He says some storms that have been listed as Category F3 are probably F5's, but measurement methods in some areas are not adequate to gauge the storms' intensity.




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A Knoxville-based environmental group is raising awareness about increasing U.S. nuclear weapons spending and supporting this week's global effort to ban nuclear arms.

The event, organized by the International Campaign to Abolish Nuclear Weapons, is focused on nine countries, including the U.S., spending more than $90 billion annually on nuclear weapons, the equivalent of more than $173,000 per minute.

Tanvi Kardile, coordinator of the Oak Ridge Environmental Peace Alliance, said the campaign backs the Treaty on the Prohibition of Nuclear Weapons. She stressed this week's campaign, called "No Money for Nuclear Weapons," is a rallying cry worldwide.

"To talk about how much money is being spent on nuclear weapons and how disproportionate it is compared to other facets of society that maybe we aren't putting as much money into," Kardile contended. "Such as health care, education, combating climate change, etc.; things that could actually benefit us as a society."

Besides the tax implications, Kardile pointed out her group is concerned with the ongoing risks closer to home, tied to enriching uranium and other activities at the Y-12 National Security Complex in Oak Ridge.

Kardile argued addressing the humanitarian consequences of nuclear weapons is crucial because in recent years, some global leaders have made threats about using them, amid growing international tensions and discord. She added the production and use of nuclear weapons are environmental hazards.

"I'd say the biggest risk comes from groundwater, and recreational water as well," Kardile emphasized. "Production causes radioactive materials to seep into the waterways, so it's really detrimental to the water we're drinking, the water we're using recreationally."

This month, Gov. Bill Lee announced a nuclear power and renewable energy company based in France is building a uranium enrichment plant in Oak Ridge. The multibillion-dollar centrifuge uranium facility is 750,000 square feet and is expected to employee 300 workers.

By Hunter Fore for Cronkite News.
Broadcast version by Alex Gonzalez for Arizona News Connection reporting for the Solutions Journalism Network-Public News Service Collaboration

On an overcast November morning, volunteers got to work to restore local river flow.

Drought and decreasing water availability have been ongoing problems throughout Arizona. In Tucson, drought along with new land developments are causing decreases in vegetation and wildlife habitat.

Watershed Management Group is a Tucson-based nonprofit that aims to fix this problem. The group aids in local water conservation, land restoration and river flow. It holds regular events to help the environment such as cleanups, workshops, fundraisers and classes. The group has a club called the River Run Network, which includes a biweekly email with invitations to events like creek walks and family education days to help restore Tucson's heritage of flowing rivers.

Watershed Management Group worked to remove an invasive plant from a riparian area in the Tanque Verde community of Tucson on Nov. 18.

The species of grass Arundo donax, more commonly known as "giant reed," is an invasive species in Tucson's riparian ecosystem, the wetland area between a body of water and land. Invasive species in those areas are harmful to the ecosystem, wildlife and the city's groundwater supply.

"Arundo is one of the invasive species that we focus on removing," said Hannah Nuest, a program coordinator for the River Run Network. "It sucks up to three to four times the amount of water that native plants do, which affects groundwater levels and river flow."

Tucson's drinking water comes mostly from the Colorado River, which is experiencing decreasing water levels, and from groundwater. But those underground aquifers are fed with water from natural areas like riparian preserves, and invasive species like arundo compete for that water, cutting into Tucson's water supply

"Invasive species also cause problems for tree canopy coverage," Nuest said. "Trees like the cottonwood and the mesquite need water closer to the surface, so when that water's being used up, the number of trees can decrease, causing habitat loss, less shade, more pollutants and hotter temperatures."

Arundo removal also helps the local ecosystem with flood risk reduction, water quality improvement and increased river flow.

"Arundo comes from the Mediterranean and was brought to the Tucson area around the early 19th century for landscaping," said Jim Washburne, Watershed Management Group's senior project specialist.

When arundo grass is present, nutrients that usually travel downstream are blocked. This prevents other plants from growing along waterways, which increases flood risks and decreases habitat potential.

Complete removal of every arundo plant would be nearly impossible, but removing even a small amount is good for the ecosystem, Washburne said.

"We typically do this every week in Tanque Verde," Washburne said. "This is our most consistent environmental event. It's important for the community to get involved in taking care of the land they live on."

According to Tucson's One Water 2100 Plan, which is a new city plan to improve water delivery methods, riparian preserve restoration not only increases local tree canopy coverage but helps the local economy by helping with cooler temperatures, more trees and more diverse water delivery options.

"Riparian areas are integral to the health of Tucson's water supply and economy," Washburne said.


Hunter Fore wrote this article for Cronkite News.


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Recent extreme wildfires in Wyoming burned nearly 500,000 acres and among those recovering are ranchers and their surviving livestock.

Wildfires burned through large swaths of ranch lands in northern Wyoming and southern Montana last month, including the House Draw Fire, which blazed across nearly 175,000 acres in Johnson and Campbell counties. No homes or human lives were lost, but important ranching resources were, such as hundreds of miles of fencing, winter forage and summer grazing grounds.

Micah Most, agriculture and natural resources educator for the University of Wyoming Extension, said livestock deaths are hard to tally, but the injuries are apparent.

"We're seeing a lot of cattle with injured feet, burned feet, from walking through or over the hot ground as they were escaping," Most pointed out. "A lot of stress just generally on those animals."

Most emphasized the outpouring of support from people in Wyoming and beyond has been "deeply meaningful." The office is coordinating hay donations, locals are helping with livestock relocation and a community network is hosting a drive for fencing supplies. Financial donations can be made to Wyoming Rancher Fire Relief and elsewhere.

Most explained some injured animals may need to be culled from the herd and sold at a discounted price. Extension offices across the state have been revisiting their emergency preparedness and response materials to help people and ranchers deal with increasingly extreme weather events.

"Finding ways to kind of harden your home area, maybe the home ranch place, and limit some of the risk factors," Most stressed.

The fires also burned through important habitat for pronghorn, mule deer and breeding grounds important to the greater sage grouse.