Climate Change, Nature, Science

“Climate Engineering” Plan Could Have Unintended Consequences

A squirrel peeking out of a tree
“Climate engineering,” also known as geoengineering, in order to reduce climate change could have unintended consequences. Photo: Shutterstock

The world is facing a climate crisis, there’s no doubt about it. Some of the best and brightest minds in the world are working hard to come up with solutions. One such solution involves “climate engineering” in the form of spraying sulfur dioxide in the upper atmosphere to create a sulfuric acid cloud, as large volcanic eruptions do.

But as with most things, there are potential unintended consequences.

First, sulfuric acid is the main component of acid rain, which devastates forests, acidifies waterways to the detriment of aquatic life, and corrodes building materials and paints. In the United States, there were extensive efforts to clean up emissions from coal-fired power plants and steel refineries after it was discovered in the late 1970s that acid rain from these factories’ emissions was devastating forests in the Northeast.

Secondly, even if the world’s scientists decided that the risk of acid rain was less than the risk of absolute ecological disaster and decided to go ahead with their mission of spraying sulfur dioxide into the upper atmosphere, new research from Rutgers University shows that suddenly stopping the spraying would have a devastating effect on animals and plants.

Basically, if the spraying were to stop, the atmosphere would warm rapidly.

“Rapid warming after stopping geoengineering would be a huge threat to the natural environment and biodiversity,” said study lead author Rutgers Distinguished Professor Alan Robock. “If geoengineering ever stopped abruptly, it would be devastating, so you would have to be sure that it could be stopped gradually, and it is easy to think of scenarios that would prevent that. Imagine large droughts or floods around the world that could be blamed on geoengineering, and demands that it stop. Can we ever risk that?”

But how would “climate engineering” with sulfur dioxide work? Basically, the cloud of sulfuric acid that forms after the airplanes spray sulfur dioxide would reflect solar radiation and cool the planet. The spraying would lead to an even distribution of sulfuric acid clouds in the Northern and Southern Hemispheres, which could lower the global temperature by about 1 degree Celsius—about the level of global warming since the Industrial Revolution began in the mid-1800s.

However, planes would have to fly continuously into the upper atmosphere to maintain the cloud, because it would only last about a year if spraying stopped. But plants and animals simply can’t evolve that quickly, much less move quickly enough to find suitable new habitats.

“In many cases, you’d have to go one direction to find the same temperature but a different direction to find the same precipitation,” Robock said. “Plants, of course, can’t move reasonably at all. Some animals can move and some can’t.”

Another possible complication of the spraying plan: one side effect of it would be an El Niño warming of the surface waters in the Pacific Ocean, which would cause a devastating drought in the Amazon.

Ultimately, what it all comes down to is that sulfur dioxide spraying may not be a viable option to keep global climate change under control. Between the effects of acid rain and the need for animals and plants to find suitable new habitats rapidly if the spraying stops and the temperatures changes rapidly, spraying of sulfur dioxide sounds like it could well cause more problems than it cures.

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Climate Change, Nature, Science

‘Global Thermometer’ Is Tracking Temperature Extremes

A tropical area during low-water season.
Droughts in the tropics are just one consequence of rising global land temperatures. Photo: Shutterstock

According to a paper published in the Journal of Applied Meteorology and Climatology, large areas of the earth are experiencing rising maximum temperatures.

This may sound like a no-brainer, given that we’re in an era of unprecedented global warming, but the conclusions drawn through this research are based on changes in land surface temperatures rather than changes in air and water temperatures.

The researchers analyzed records from NASA’s Aqua satellite between 2003 and 2014 and found spikes in maximum surface temperatures occurred in the tropical forests of Africa and South America and in much of Europe and Asia in 2010, and in Greenland in 2012. These measurements coincided with phenomena including severe droughts in the tropics and heat waves and wildfires across the northern hemisphere. The 2012 land surface temperature spike in Greenland was associated with massive melting of the Greenland ice sheet.

What exactly is land surface temperature? It’s a measurement of the heat radiated by land—including soil, rock, and pavement—and vegetation such as trees and grass. Weather stations generally measure air temperatures just above the surface, so the satellite readings of land surface temperature are critically important in the study of global climate change.

“Imagine the difference between the temperature of the sand and the air at the beach on a hot summer day,” said study lead author David Mildrexler, who received his Ph.D. from Oregon State University. “The air might be warm, but if you walk barefoot across the sand, it’s the searing hot surface temperature that’s burning your feet. That’s what the satellites are measuring.”

The researchers studied annual maximum land surface temperatures averaged across 8-day periods throughout the year. They used data from the Aqua satellite, which crosses the equator in the early afternoon as temperatures reach their daily peak.

“As anyone who pays attention to the weather knows, the Earth’s temperature has incredible variability,” Mildrexler said. However, he added, the planet’s profile of high temperatures tends to be fairly stable from year to year. The researchers’ discovery of a consistent year-to-year profile allowed them to develop a new global-change indicator that uses the entire planet’s maximum land surface temperatures.

“The maximum surface temperature profile is a fundamental characteristic of the Earth system, and these temperatures can tell us a lot about changes to the globe,” said Mildrexler. “It’s clear that the bulk shifts we’re seeing in these maximum temperatures are correlated with major changes to the biosphere. With global temperatures projected to continue rising, tracking shifts in maximum temperature patterns and the consequences to Earth’s ecosystems every year globally is potentially an important new means of monitoring biospheric change.”

In other words, this new research supports the conclusions of a whopping 97 percent of scientists, who believe that global climate change is real, and it’s happening fast, and we need to do something to mitigate that before we reach a point of no return.

Climate Change, Conservation, Nature, Science

Great Barrier Reef May Be More Resilient Than Once Thought

New research indicates that the Great Barrier Reef may be more resilient than once thought--but that doesn't mean there's no reason for concern.
A sea turtle swims above the Great Barrier Reef. Photo: Shutterstock

New research gives us reason for hope that the Great Barrier Reef is not set up for doom, despite the extensive damage and bleaching of the reef itself.

Scientists at the University of Queensland, the Australian Institute of Marine Science, CSIRO, and the University of Sheffield have recently published a paper with the results of an extensive study in which they found that there are still 100 reefs on the Great Barrier Reef that could help to promote the regional recovery of its ecosystem.

The Great Barrier Reef consists of more than 3,800 individual reefs. These reefs have suffered unprecedented coral bleaching events over the past couple of years. Additionally, the coral-eating crown-of-thorns starfish has also been plaguing the reef system.

The new study shows that there are 100 reefs that fulfill three criteria to promote coral recovery. First, they should lie in cool areas and rarely experience damage from bleaching, thus being able to supply larvae to as many reefs as possible. In addition, reefs should be located in areas of current that can supply coral larvae to as many reefs as possible; and they should not spread the larvae of the crown-of-thorns starfish.

“Finding these 100 reefs is a little like revealing the cardiovascular system of the Great Barrier Reef,” said study author Professor Peter Mumby. “Although the 100 reefs only make up 3 percent of the entire GBR, they have the potential to supply larvae to almost half of the entire ecosystem in a single year.”

“The presence of these well-connected reefs on the Great Barrier Reef means that the whole system of coral reefs possesses a level of resilience that may help it bounce back from disturbances, as the recovery of the damaged locations is supported by the influx of coral larvae from the non-exposed reefs,” said study lead author Dr. Karlo Hock.

Dr. Hock added that this does not mean the Great Barrier Reef corals are safe or in great condition. There is still plenty of reason for concern when it comes to the health of the GBR. “The fact that the study only identified around 100 of these reefs across the entire 2,300-km length of the massive Great Barrier Reef emphasizes the need for both effective local protection of critical locations and reduction of carbon emissions in order to support this majestic ecosystem.”

However, the research also indicates that focusing efforts on these healthy and well-connected reefs, and continual monitoring of those reefs’ health, may be a step toward restoration of the reef. The ecosystem is still vulnerable to the effects of climate change and predation. So, there’s reason for hope, but that optimism must remain guarded until the forces that caused the death of vast swathes of the reef system can be controlled.

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.”

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!