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U.S. may see 30-fold rise in extreme heat exposure by 2100, models say

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Aug. 17 (UPI) — Humans living in the United States will experience a 30-fold increase in exposure to extreme temperatures by the year 2100, according to an analysis published Monday in the journal Proceedings of the National Academy of Sciences.

To help local leaders and policy makers better prepare for the impacts of heatwaves and cold spells, scientists at Arizona State University set out to quantify human exposure to extreme temperatures during 21st century.

It’s not the first time researchers have measured the impacts of climate change on temperature extremes in the United States. The study, however, is one of the first to look at how urban development and population changes, in addition to greenhouse gas emissions, influence exposure to extreme temperatures.

“What was missing in our prior research was a human element, one directly tied to the climate results,” study co-author Matei Georgescu, an associate professor at Arizona State and a senior scientist at the Global Institute of Sustainability, told UPI in an email.

If temperatures rise dramatically in the middle of a desert, but no one is there to feel the relentless midday sun, does it matter? It doesn’t, Georgescu said, if one’s goal is to understand human exposure to temperature extremes.

“This work was particularly focused on communicating impacts that people experience,” he said.

The work was also focused on identifying the drivers of humans exposure to temperature extremes. Georgescu and his colleagues wanted to better understand the influence of the built environment and human movement patterns, and how people in different places experience temperature extremes.

“As we know, a particular temperature in one city may seem comfortable to its residents, but that same temperature may seem harsh to another city’s residents,” Georgescu said.

A mild day in Scottsdale might inspire residents in Fargo to crank up the air conditioning, for example. Likewise, on a 90 degree day, the dry heat of Reno feels less punishing than the humid heat of New York City.

To quantify the experiences of extreme weather in Fargo, Scottsdale and elsewhere, researchers used the metric person-hours. If 10 people are exposed to extreme temperatures for 10 hours, that’s 100 person-hours.

Quantifying human exposure to extreme temperatures can help policy makers prepare for — and potentially prevent — negative impacts on human health and infrastructure, like local power grids.

“For example, you will recall the Northeast Blackout of 2003 that affected some 50 million residents during the hottest time of the year,” Georgescu said. “The entire Northeast was in the dark, but more importantly, essential services, including air conditioning and transportation, were no longer available.”

The new research showed that while urban development influences human exposure to extreme temperatures, the major drivers are greenhouse gas emissions and population trends. This means that humans will be exposed to extreme temperatures the most in places where both temperatures and populations are rising.

In absolute numbers, the obvious cities like New York, Los Angeles and Atlanta will see the largest increase in person-hours exposure. The largest relative changes in person-hours related to heat exposure will be seen in Sun Belt cities, such as Austin, Texas, and Orlando, Florida.

CDC data suggests extreme cold is responsible for more fatalities each year than extreme heat, but as temperatures continue to rise and more people move south and west, Georgescu expects the pendulum to swing the other way.

But that doesn’t mean the dangers of extreme cold will go away. Some cities, including Denver, are expected to experience an increase in human exposure to extreme heat and extreme cold in the coming decades.

In total, by the end of the century, models suggest people in the United States will experience between 66 billion and 154 billion person-hours of extreme temperature exposure.

Moving forward, Georgescu and his colleagues plan to fine tune their models to provide local policy makers with more precise predictions. Researchers also hope to figure out how these changes in extreme temperature exposure translate to mortality outcomes.

They also want to help identify solutions, he said.

“The immediate next step is to characterize how these heat-health impacts may be reduced with commonly proposed thermal adaptation strategies such as cool and green roofs, street trees and incorporation of other engineered materials,” Georgescu said.



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NASA’s OSIRIS-REx touches down on asteroid Bennu to nab sample

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Oct. 20 (UPI) — NASA’s OSIRIS-REx touched down on asteroid Bennu on Tuesday evening in a mission to scoop a sample of rocks and dirt.

The spacecraft — the Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer — made soft contact with the asteroid at 6:12 p.m. EDT.

The historic “touch and go” event featured animation displaying OSIRIS-REx’s sample collection activities in real time. It takes time for real images of the touchdown to travel back to the Earth, so they won’t be released to the public until Wednesday.

The craft executed a series of maneuvers over the course of several hours before making soft contact with the surface of the asteroid to collect regolith, or rocks and dirt.

“It will be four and a half hours of anxiousness,” Beth Buck, OSIRIS-REx mission operations manager at Lockheed Martin Space, said in a news conference ahead of the event.

Buck made a comparison to the descent of a spacecraft on Mars, when there is typically “seven minutes of terror.”

The goal is to learn more about the solar system’s history and help “planetary defense” engineers with missions to protect earth from rogue asteroids. Bennu is believed to be a window into the solar system’s past since it’s a pristine, carbon-rich body carrying building blocks of both planets and life.

At around 1:50 p.m. EDT, the spacecraft left orbit around the asteroid before executing a series of burns to position itself over a sampling area nicknamed Nightingale.

Once in position, the craft began its approach to the asteroid at 5:50 p.m. EDT. It then spent about 15 seconds attempting to collect the regolith sample before backing away again.

The area, which is 52 feet in diameter, will make for a more demanding landing than expected, Kenneth Getzandanner, OSIRIS-REx flight dynamics manager at the NASA Goddard Space Flight Center in Maryland, said in the news conference.

The original mission called for a landing “zone” about 150% larger than Nightingale, at 82 feet, but that changed because Bennu was more rocky than expected.

The goal was to collect at least 1.7 ounces of fine-grained material, but the spacecraft can carry up to 4.4 pounds, Heather Enos, OSIRIS-REx deputy principal investigator at the University of Arizona said.

“I would love for that capsule to be completely full,” Enos said.

Though early images from the asteroid should hint at whether the mission succeeded, it will take engineers roughly 10 days to compare and analyze the mass before and after the maneuver to actually know how much dirt is inside the OSIRIS-REx.

If it failed, the spacecraft has enough fuel to attempt two more touch downs to collect material.

The spacecraft is expected to return to Earth, with the regolith sample from Bennu, in 2023.



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SpaceX scrubs Starlink launch until Thursday, if weather cooperates

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Oct. 21 (UPI) — Just three days after sending 60 more Starlink satellites into orbit, SpaceX is aiming to launch another batch of broadband satellites into space from Florida.

If the weather cooperates, Thursday’s launch will be SpaceX’s 15th Starlink mission.

Liftoff had been scheduled for 12:29 p.m. EDT Wednesday aboard a Falcon 9 rocket at Launch Complex 40 at Cape Canaveral Air Force Station, but controllers scrubbed the launch due to weather and rescheduled for 12:14 p.m. on Thursday.

With a launch Sunday, SpaceX increased the size of their Starlink constellation to nearly 800 satellites. The 15th mission will see another 60-odd satellites join the network.

“The goal of Starlink is to create a network that will help provide Internet services to those who are not yet connected, and to provide reliable and affordable Internet across the globe,” according to the Kennedy Space Center.

Weather for Wednesday’s planned launch had looked so-so and the Space Force’s 45th Weather Squadron predicted a 60 percent chance of favorable conditions.

“A mid-level inverted trough and associated easterly wave currently across the Bahamas will meander into the state over the next few days, bringing enhanced moisture, cloud cover, and instability with a higher coverage of showers and storms,” Space Force forecasters wrote.

They said Thursday’s forecast looks quite similar to Wednesday’s.

Earlier this month, SpaceX founder and CEO Elon Musk tweeted that Starlink’s constellation was big enough to begin beta-testing the Internet service system in both the United States and southern Canada.

SpaceX has already offered Starlink Internet services to emergency responders in wildfire-stricken areas of Washington State.

Washington’s Hoh tribe is also using the Internet service to provide their members online education and telehealth services.



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Chernobyl-level radiation harms bumblebee reproduction

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Oct. 21 (UPI) — Bees are more sensitive to radiation than scientists thought. Scientists found the reproduction rates of bumblebees declined significantly when exposed to Chernobyl-level radiation.

The research, published Wednesday in the journal Proceedings of the Royal Society B: Biological Sciences, suggests radiation in Ukraine’s Chernobyl Exclusion Zone could impair pollination services, triggering wider ecological consequences than previously estimated.

Humans are not allowed to live in the Chernobyl Exclusion Zone, the disaster area more directly impacted by the 1986 nuclear accident, the worst in history. However, the destroyed nuclear reactors are surrounded by forests that are populated by robust populations of birds, bears, bison, lynx, moose, wolves and more.

Efforts to gauge the effects of radiation contamination on insects have yielded mixed results in the past. While some studies have suggested insects are relatively radiation-resistant, others have demonstrated significant impairment.

When researchers exposed bumblebees in the lab to radiation dose of 100 µGyh-1, an amount approximating exposure inside the Chernobyl Exclusion Zone, reproduction rates among the bees dropped between 30 and 45 percent.

Researchers found a direct correlation between the size of the radiation dose and reproduction rate declines. Lower levels of radiation had a smaller effect, while larger doses yielded greater declines.

Scientists were surprised to find they were able to detect reproductive rate declines at very small levels of radiation exposure.

“Our research provides much needed understanding as to the effects of radiation in highly contaminated areas and this is the first research to underpin the international recommendation for the effects of radiation on bees,” lead study author Katherine Raines, environmental scientist at the University of Stirling in Scotland, said in a news release.



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