Climate Change, Nature, Science

Global Warming Hiatus? Not So Much

The "global warming hiatus" really wasn't. Read more in this post.
Arctic glaciers. Photo: Shutterstock

New data from the University of Alaska Fairbanks shows that missing Arctic temperature data, not the climate, created the seeming “pause” of global warming from 1998 to 2012.

In fact, the improved datasets the researchers gathered shows that the Arctic warmed six times faster than the global average during the so-called global warming hiatus.

Atmospheric scientist Xiangdong Zhang collaborated with colleagues at Tsinghua University in Beijing and Chinese agencies studying Arctic warming to analyze temperature data collected from buoys in the Arctic Ocean.

“We recalculated the average global temperatures from 1998 to 2012 and found that the rate of global warming had continued to rise at 0.112 degrees C per decade instead of slowing down to 0.05 degrees C per decade as previously thought,” Zhang said.

How did the data lead scientists down the wrong path before?

Most current estimates use global data that represents a long timespan and provides good coverage of a global geographic area. But the Arctic, being so remote, lacks a comprehensive network of instruments to collect accurate temperature data.

To improve the dataset, Zhang’s team relied on temperature data collected from the International Arctic Buoy Program at the University of Washington. For global data, the team used newly corrected sea surface temperatures provided by the National Oceanic and Atmospheric Administration. By doing so, the team was able to re-estimate the average global temperatures during that time with more accurate and representative data.

The global warming hiatus is a hotly debated topic among climate scientists. Some say that an unusually warm El Niño in 1997-1998, followed by an extended period afterward that didn’t have an El Niño may have disrupted global warming.

It was a nice dream, but unfortunately, the new data sets and resulting estimates prove conclusively that global warming did not pause at all. Not only that, but until recently, scientists didn’t consider the Arctic big enough to greatly influence global temperatures.

“The Arctic is remote only in terms of physical distance,” Zhang said. “In terms of science, it’s close to every one of us. It’s a necessary part of the equation and the answer affects us all.”

Advertisements
Environmental Hazards, Science

Scientists Find New Way to Process Radioactive Waste

The question of what to do with radioactive waste may have been solved by a team of Japanese scientists.
The question of what to do with radioactive waste may have been solved by a team of Japanese scientists. Photo: Shutterstock

Ever since the first atomic bomb was exploded during World War II’s Manhattan Project, and ever since the first nuclear power plant opened in Obninsk, Russia, radioactive waste has been accumulating. As the number of nuclear power plants and nuclear weapon plants increased, the question of what to do with all that waste has become one of the biggest issues facing science today.

The primary issue is what to do with radioactive waste after the uranium and plutonium have been recovered from spent nuclear fuel using standard reprocessing methods such as Plutonium Uranium Redox Extraction (PUREX).

Up until now, the most viable option for disposal of nuclear waste has been burying it deep underground. Other solutions such as partitioning and transmuting, which involve separating nuclear fuel into minor actinides such as neptunium, americium, and curium, have proven to be costly and cumbersome because of the need to separate isotopes before they can undergo transmutation. But now, a team of researchers at Tokyo Institute of Technology may have come up with a solution to the radioactive waste problem.

The team discovered a method of dramatically reducing the effective half-life of long-lived fission products (LLFPs) such as selenium-79, zirconium-93, technetium-99, palladium-107, iodine-129, and caesium-135. That method involves transmuting these isotopes in fast-spectrum reactors, which don’t need isotope separation like other methods do.

By adding a moderator (slowing-down material) called Yttrium deuteride (YD2), the team found that LLFP transmutation efficiency increased in the radial blanket and shield regions of the reactor. The researchers say this increased effectiveness is due to the moderator’s ability “to soften the neutron spectrum leaking from the core.”

Using this method, the researchers say, the 17,000 tons of LLFPs in Japan could potentially be disposed of by using 10 fast spectrum reactors. This method also has the advantage of contributing to electricity generation and supporting efforts toward nuclear non-proliferation.

Although ultimately, the best solution to the nuclear waste problem is to invest in non-toxic energy sources like solar and wind power, it’s a good thing these researchers came up with a way to decrease the toxicity of radioactive waste and give its by-products a new life—and a much shorter half-life.

carbon emissions, emissions, Science

Moving Bus Stops Could Reduce Pollution Exposure

Moving bus stops 120 feet from intersections can drastically reduce the amount of pollutants bus commuters are exposed to.
Passengers board an MTA bus in New York. Moving that stop away from the intersection could reduce the pollution to which transit commuters are exposed. Photo: Roman Tiraspolsky / Shutterstock.com

There’s no doubt that mass transit can make a huge difference in the overall air quality of cities. An increasing number of people are realizing that they can reduce their carbon footprint by riding a bus to and from work rather than being stuck in traffic in a car.

There’s just one problem with riding the bus, and that’s waiting for the bus.

Research has shown that in many cities in the United States and internationally, bus riders could spend 15 to 25 minutes each way waiting for a bus. This isn’t just a convenience issue; it’s a pollution exposure issue, too.

“The wait often means spending time in some of the most polluted locations in cities, close to intersections where cars, trucks, and buses are continually stopping and accelerating, spewing out high concentrations of noxious exhaust,” said Suzanne Paulson of UCLA, senior author of an article that appeared recently in the journal Environmental Pollution. “The exhaust contains gases and large amounts of ultrafine particles that are essentially unregulated by the Environmental Protection Agency because the EPA regulates fine particles by weight, and these particles weigh so little.”

The good news, according to the researchers, is that moving bus and light rail stops to locations 120 feet from intersections can significantly reduce the amount of pollutants to which bus commuters are exposed.

The researchers came to their conclusions by using a zero-emission vehicle equipped with instruments that measure ultrafine particles and tailpipe pollutants like carbon monoxide and nitrogen oxide. The studies were conducted in several neighborhoods in and around Los Angeles, over a 15-day period from summer into late fall in 2013 and over four days in the summer of 2014.

“We then combined and analyzed the data for each intersection to create high-resolution maps of pollutant concentrations along blocs,” said study lead author Wonsik Choi.

“Except in areas with minimal traffic, we always found there would be a significant reduction [of pollutants],” said Choi.

Traffic engineers believe that traffic flows better if bus stops are located after intersections rather than before. Better traffic flow can lead to less stop-and-go traffic, which would also improve air quality. The researchers caution that although moving the stops 120 feet from the end of a block will improve transit users’ pollution exposure, as long as that distance doesn’t put the bus stop in range of pollution from the next street.

Considering that most city blocks are about generally about 400 by 400 feet in size, it seems like it should be easy to move bus stops 120 feet away from intersections. That doesn’t mean buses won’t park all along a block where a stop is located, but it does mean that theoretically, passengers waiting for their bus will be able to do so in an area that exposes them to fewer pollutants.

Environmental Hazards, Science

Road Pricing Could Be the Most Effective Solution to Car Pollution

A researcher from the University of British Columbia has concluded that road pricing is the most effective traffic management strategy for reducing urban pollution.
Photo via Pixabay

Motor vehicles are a huge source of pollution in cities. For many years, governments have used traffic management strategies to try and reduce vehicle emissions—but few seem to have made as much of a difference as road pricing.

Road pricing is essentially a “pay per use” plan that levies charges such as road tolls, congestion charges, and charges designed to discourage the use of certain types of vehicles or fuel sources in order to reduce pollution and congestion within city limits.

University of British Columbia transportation expert and civil engineering professor Alexander Bigazzi reviewed 65 studies on traffic management strategies in Asia, Europe, and the Americas. He concluded that road pricing is the most effective strategy to reduce emissions and traffic.

Other traffic management strategies include speed enforcement programs, lane management (e.g., HOV lanes), road and congestion pricing, and trip reduction strategies such as telecommuting or ride sharing.

“The strategies with the best evidence of air quality improvements are area road/congestion pricing and low-emission zones,” Bigazzi said. “Other strategies have potential benefits, but there is less empirical evidence, either because the benefits are very small or because the benefits are offset by some other effect.”

Why are road pricing and low-emission zones so effective? A major reason is that they reduce the amount of driving. They also ease congestion and reduce emission rates. Low-emission zones also encourage people to buy cleaner vehicles.

Of course, road pricing has to be implemented on a pretty large scale in order to be effective. Cities can’t just implement road pricing on certain roads, because motorists would find other ways to get into the city where they are not faced with road pricing or low-emission zones.

“Hundreds of cities in Europe have congestion pricing or low-emission zones in their city centers and are enjoying improved traffic flow and air quality,” Bigazzi said. “These strategies haven’t been embraced in North America in the same way for a variety of reasons, but there are great potential benefits for cities here ready to embrace innovation.”

What do you think? Would you like to see cities use traffic management strategies like road pricing in order to reduce pollution, even if it meant less convenience for you? Do you think road pricing would work in your city? Please share your thoughts in the comments!

Nature, Science

The Dog Domestication Date Debate Has Been (Sort Of) Resolved

The dog domestication date debate may have been resolved, thanks to scientists from Cornell.
Photo: Shutterstock

You might not know this, but there are two distinct arguments about when dogs were domesticated. One group believes dogs were domesticated in the Paleolithic age (more than 17,000 years ago), and another believes dogs were domesticated much later, in the Neolithic age (17,000 to 7,000 years ago).

So, when exactly were dogs domesticated?

A team of researchers from Cornell University set out to find out which camp is right. They used 3-D scans of fossils to help determine the difference between wolves and dogs by studying ancient fossil canid mandibles (jaw bones) to determine if they were dogs or wolves.

How does mandible evolution distinguish a dog from a wolf? Wolves have fairly straight mandibles, while those of dogs are curved. These features become evident in 3-D scans.

The researchers, led by Abby Grace Drake, a senior lecturer in Cornell’s Department of Ecology and Evolutionary Biology, found that in the early stages of domestication, canids’ skulls changed shape, but the evolution of the mandible lagged behind.

“A lot of the fossil evidence for the date of dog domestication is based on morpohological [structural] analysis of mandibles,” said Drake, the paper’s first author. “Our study shows that when you measure modern dog mandibles and wolf mandibles using 3-D measurements you can distinguish them, and yet when we looked at these fossil mandibles, they don’t look like dogs or wolves.”

Although the team could distinguish 99.5 percent of modern dogs’ mandibles from those of wolves, a lot of the fossil mandibles couldn’t be classified as either dog or wolf. However, other data proved that the fossils were dog remains.

Other evidence from two Russian sites showed that the canid remains were found with human dwellings, and there were marks that revealed butchery—meaning that the dogs were eaten. In addition, isotope analysis of canid and human remains at both sites indicates that canids and humans both ate fish, and that humans were feeding the canids.

Drake said that since mandibles don’t appear to evolve as rapidly as the skull, they are not reliable for identifying early dog fossils.

However, 3-D analysis of canid skulls uses landmarks across the skull—differences in the angle of the muzzle, snout, and eye orbits—provides more evidence of dogs’ domestication time.

“The earliest dogs I’ve seen in my analysis were from 7,000 to 9,000 years ago,” Drake said.

Climate Change, Environmental Hazards, Nature, Science

Was Hurricane Harvey Caused by Global Warming? Not Entirely

Was Hurricane Harvey caused by global warming? Not entirely.
Cars submerged by flooding in the wake of Hurricane Harvey. Photo: michelmond / Shutterstock.com

Climate change is responsible for a lot of things, but it may not be directly responsible for Hurricane Harvey.

Harvey is not the first hurricane to hit the Texas coast.  A deadly hurricane struck Galveston in 1900, and that storm caused thousands to lose their lives, primarily due to the lack of warning. Meteorology was not an advanced science at that time, and there were no satellites to track the storms as they moved across the Atlantic Ocean.

However, climate change is almost certainly responsible for the epic rainfall and catastrophic flooding endured by the cities struck by Hurricane Harvey.

“This is they type of event, in terms of extreme rainfall, that we would expect to see more of in a warming climate,” Dr. Friederike Otto from the University of Oxford told the BBC.

In fact, the rainfall was so extreme that the National Weather Service had to add new colors to its rainfall maps to account for the intensity of Harvey’s rains.

There’s a physical law called the Clausius-Claperyon equation, which says that a hotter atmosphere holds more moisture. For every degree Celsius in warming, the atmosphere can hold 7 percent more water, which makes rainfall events more extreme.

The temperature of the seas also contributes to the strength of hurricanes.

“The waters of the Gulf of Mexico are about 1.5 degrees warmer than they were from 1980 to 2010,” Sir Brian Hoskins of the Grantham Institute for Climate Change told the BBC. “This is very significant because it means the potential for a stronger storm is there, and the contribution of global warming to the warmer waters in the Gulf, it’s almost inevitable that there was a contribution to that.”

Although there have been slow-moving storms over Texas in the past, some scientists still attribute the intensity of Harvey to climate change.

Professor Stefan Rahmstorf from the Potsdam Institute for Climate Impact Research says that a general slowdown in atmospheric circulation in the earth’s middle latitudes could be a result of changing climate in other parts of the world.

“This is a consequence of the disproportionately strong warming in the Arctic,” Rahmstorf said. “It can make weather systems move less and stay longer in a given location—which can significantly enhance the impacts of rainfall extremes.”

Other scientists think it’s a stretch to believe that the slowly moving nature of the storm is caused by climate change. “I don’t think we should speculate on these more difficult and complex links like melting in the Arctic without looking into these effects in a dedicated study,” said Dr. Otto.

In addition to the damage caused by the flooding, pollution is causing the floodwaters to become a toxic stew of sewage, garbage, chemicals from more than 20 Superfund sites in the Houston area, oil and petrochemicals from damaged refineries, and much more, are causing concern.

“There’s no need to test [the water],” Houston Health Department spokesman Porfirio Villareal told the New York Times. “It’s contaminated. There’s millions of contaminants.”

Climate Change, Nature, Science

Galápagos Seabird Population May Shrink Due to Global Warming

Nazca boobies and other animals are in jeopardy as water warms around the Galápagos Islands.
A Nazca booby guards her egg. Photo via Pixabay

The Galápagos Islands are the home of thousands of unique species. In fact, those islands were where Charles Darwin began writing about his findings on evolution. But at least one of these species is in jeopardy because of warming ocean temperatures.

Within the next century, rising ocean temperatures around the Galápagos Islands are expected to make the water too warm for sardines to tolerate.

Why is that important? Sardines are a key prey species for many seabirds including the Nazca booby.

Wake Forest University biologists published a study in the August 23 issue of the journal PLOS ONE about this phenomenon. They used decades of data on the diet and breeding of the Nazca booby to understand how the absence of sardines could affect the booby population.

They studied the diet, breeding, and survival of Nazca boobies as part of their study at Isla Españnola in the Galápagos Islands for more than 30 years. In 1997, halfway through their study, sardines disappeared from Nazca booby diet samples, replaced by flying fish.

Flying fish are less nutritious than sardines, and as researcher Emily Tompkins, lead author of the study, said, as flying fish replaced sardines in the birds’ diet, “reproductive success was halved.”

“If the current links between diet and reproduction persist in the future, and rising ocean temperatures exclude sardines from the Galápagos, we forecast the Nazca booby population will decline,” Tompkins said.

David Anderson, a professor of biology and co-author of the study, said, “Few connections have been made between ocean warming and population effects in the tropics, making this study significant.”

But the Nazca booby isn’t the only creature that could be harmed by rising ocean temperatures. The study suggests that other Galápagos predators that do well when sardines are available will have to adjust to a new menu within the next 100 years.

So many species have gone extinct or become highly endangered due to global climate change—probably including species we never even discovered—that it behooves us to act to stop, or at least slow, climate change. Given the United States’ exit from the Paris Climate Agreement, it’s up to other nations, and states and cities within the U.S., to step up and do something about this increasing danger to the survival of all animals, including humans.