Nature, Science

Dutch Toxic Landfill Site Now Capturing and Storing Carbon

The Volgermeerpolder, near Amsterdam, proves that peat bogs can be created artificially.
A peat bog. Photo: Shutterstock

The Volgermeerpolder, located near Amsterdam in the Netherlands, is a toxic waste site that was capped with foil and an artificial wetland on top.

According to researchers at Radboud University, six years after the opening of the wetland, it appears that the new site is already forming peat, which can capture and store carbon.

How does this work? Peat contains high levels of carbon, which binds pollutants. There is already a large layer of peat beneath the toxic landfill, which is preventing toxins from leaking from the landfill into the groundwater. That layer of peat has eliminated the need to dig up the entire toxic site at the Volgermeer. Instead, authorities were able to cap the site with a layer of foil.

If the foil were to tear, another protective layer of peat is forming on top of that protective barrier. Growing peat from scratch has never been attempted before, but it appears to be working.

Peat grows at a very slow pace—only about 1 millimeter per year on average—and researcher Sarah Faye Harpenslager says this growth is something that can’t be measured directly.

“That one millimeter falls outside of the margin of error,” she said. “But we can measure whether carbon is being captured and stored by determining the difference in carbon dioxide levels by taking the amount of carbon dioxide that is captured by plants and then subtracting the carbon dioxide that is released when those plans decompose. The less plants decompose, the more peat that is formed. The Volgermeer is indeed capturing and storing carbon, so peat is clearly being formed even though you can’t see it.”

Harpenslager and her colleagues also compared peat formation in ponds with different bottoms—sand, clay, or a layer of organic topsoil. The topsoil was shown to be the more fertile. “In ponds with a thin layer of topsoil, peat-forming plants grow most prolifically and capture the most carbon,” Harpenslager said. “For peat o form, it is essential that peat-forming plants such as common reed, cattail, and water soldiers start to grow here.”

According to the researchers, the results of their study are not just applicable to capping of polluted land. Their research shows that peat could also be important for the capture and storage of greenhouse gases through need peat formation and preventing subsidence.

Climate Change, Nature

Scientists Concerned About Rapid Change in Arctic River Ice

Arctic river ice is melting at an accelerating rate.

The Arctic continues to bear the brunt of climate change’s current effects, with new research showing that Arctic river ice is accruing in smaller amounts and melting earlier in the season.

Arctic groundwater comes to the surface and freezes on top of already frozen rivers, and these deposits of ice grow throughout the season until whole river valleys are covered. Some river icings have grown to over 4 square miles, and as deep as 33 feet. Traditionally, they start melting in the middle of July, which keeps many rivers running long after they would otherwise have dried up, and provides fresh water for many different creatures and habitats.

But over the past 15 years, there has been less of that ice forming, and it’s been melting about a month earlier. This means habitats that rely on that water melting later are getting less water overall, as it melts too soon and there is less of it to melt in the first place.

Looking at 147 rivers icings in the U.S. and Canadian Arctic using satellite data, Pavlesky and Zarnetske discovered that 84 of those are becoming smaller or disappearing earlier in the season. The minimum area of ice also shrank a lot during the study period. In 2000, there were 30 square miles of ice, but there were only 2 square miles in 2010. The minimum ice area has rebounded a little bit: it was up to 3 square miles in 2015.

“This is the first clear evidence that this important component of Arctic river systems—which we didn’t know was changing—is changing and it’s changing rapidly,” said lead author Tamlin Pavelsky of the University of North Carolina Chapel Hill.

The exact mechanisms of how climate change is affecting these rivers is as yet unknown, it could be that higher temperatures are directly affecting the ice, or that it is more subtly impacting groundwater, and how that water interacts with rivers.

“While glaciers tell us about climate in the mountains and sea ice tells us about sea-atmosphere interactions, the processes that control river icing may offer great insight into how groundwater and surface waters are connected in the Arctic and how our headwaters will be connected to the ocean in the future,” said study co-author Jay Zarnetske of Michigan State University.

In the meantime, these rivers and their related ecosystems are going to continue to change as the world’s overall climate warms.

Climate Change, Nature

Trees Have a Greater Impact on Climate than Previously Thought

Trees have a significant effect on the water cycle.
Trees have a significant effect on the water cycle, which aids in cooling the earth. Photo: Shutterstock

Trees are an important part of the conversation about global climate change, but according to a recent study, they haven’t been getting their dues. Much research has focused on trees as simple carbon sinks, and in general, it’s expected that they can’t offset the amount of carbon that is being out into the atmosphere. But many of those studies missed the forest for the trees, so to speak, and were looking at them from only a single viewpoint.

A recent study from the World Agroforestry Centre has compiled data from numerous other studies, from biologists, chemists, climate scientists, geologists, hydrologists, and even social scientists, and found that trees have a bigger impact that we thought. Trees have a significant impact on the water cycle, processing and redistributing water, which helps to cool the planet’s surface. Carbon sequestrations is essentially a byproduct of this.

Forests have an impact on food security and help to keep the world cooler despite rising temperatures. That will be especially important going forward, as the issue of climate change requires more than one approach. The Paris Agreement outlined both mitigation and adaptation in the future. The former means creating less pollution and increasing sequestration of carbon and other greenhouse gases where possible. The latter means finding ways to change agriculture, construction, and other human activities in ways that will work better with the changes happening to the Earth.

There is still much to be learned about how trees can help us to both mitigate and adapt to climate change, but this study is a good place to start.

“Some of the more refined details of how forests affect rainfall are still being discussed among scientists of different disciplines and backgrounds,” said Dr. David Ellison, lead author of the study. “But the direct relevance of trees and forests for protecting and intensifying the hydrologic cycle, associated cooling, and the sharing of atmospheric moisture with downwind locations is beyond reasonable doubt.”

Nature, Science

Researchers Test Climate Model Against Data From Holocene Period

Scientists have recently compared data from a climate model with evidence from the Holocene Period and found some interesting differences.

When it comes to studying climate change, researchers can only go back about 150 years before they run out of temperature and meteorological recordings to explore. For any time before that, they need to use a number of techniques to figure out what the climate was like in a given area for a given time period.

One such way of doing this is to study trees that were alive at the time, and see how their rings grew. Another is to study pollen embedded at the bottom of lakes, which can imply what plants were in an area and can help up understand what the climate was like.

Still another form is a climate model, which is based on simulating important climate drivers and how they interact. Recently, researchers applied such a model to the northern Mediterranean in the mid-Holocene period (between 9,000 and 5,000 years ago). The climate model found that the period was warmer than expected, especially because pollen-based studies had determined that the period was colder there than it has been since.

The difference between the climate model and the paleoecological evidence is due in part the pollen used for the measurements. The previous measurements were based on the existence of silver fir pollen, which would imply colder temperatures. However, other could be other factors at work there, which can be take into account by the climate model method.

At first, the model was rejected because it seemed too contradictory, but interdisciplinary research bore out that the model is right and the pollen is wrong, or at least incomplete.

“It is only discussions between researchers from differing disciplines which enabled the new hypothesis to be developed and examined in detail,” said study co-author Oliver Heiri of the University of Bern.

What all of this does say, though, is that researchers need to keep working to improve our methods for studying the history of the Earth’s climate. While it may seem more pressing to study the current changing climate of the planet, it’s hard to track change when you have nothing with which to compare it. Furthermore, looking at climate changes in the past can provide insight into how the world can adapt to current changes, and might even help scientists to find ways to reduce the effects of climate change.

Climate Change, Science

A Vaccine Against Fake Climate Science News?

Scientists may have come up with a way to "vaccinate" people against fake climate science news.

For those of us who follow climate science, it’s a well known fact that 97 percent of scientists agree that human activity has had an impact on the changing global climate. But we also know that there are plenty of people who refuse to acknowledge this truth, and that they have people constantly feeding them misinformation.

Amidst the current concern over fake news sites, which present lies and opinion as facts, a team of social psychologists have come up with a striking idea: creating a “vaccine” against fake news.

Vaccines work by introducing a safe amount of a disease to a body so that the immune system learns to fight it in case it’s ever exposed to the actual virus. The idea of the fake news vaccine is similar.

The researchers surveyed a group of more than 2,000 U.S. participants across the spectrum of age, education, gender, and politics, using information about climate change. First, they asked the readers what their position on the scientific validity of climate change. They then showed the participants factual and erroneous information on scientists’ beliefs about climate change.

Two groups in the study were randomly given “vaccines” against the misinformation. There was a general inoculation in the form of a warning that “some politically motivated groups use misleading tactics to try and convince the public that there is a lot of disagreement among scientists.” A detailed inoculation picks apart the Oregon petition, an effort to discount the validity of scientific consensus on climate change, by stating that some of the signatories are fraudulent and that fewer than 1 percent of the signatories have backgrounds in climate science.

The researchers found that the inoculation caused the fake news to become less effective in swaying participants’ beliefs about the reality of climate change.

In a study of readers without the psychological vaccine, people who were shown only fake science had a 9 percent chance of coming to believe it. But people given the vaccine were much less likely to buy into fake climate science later. These results were seen across readers identifying as Democrats, Independents, and Republicans.

“What’s striking is that, on average, we found no backfire effect to inoculation messages among groups predisposed to reject climate science, they didn’t seem to retreat into conspiracy theories,” said study lead author Dr. Sander van der Linden of the University of Cambridge in England.

So what does this mean? For those who write about climate change, there is a lesson to be learned, which is that it isn’t enough to just present facts about climate change. It’s also important to discuss the misinformation, even just enough to make readers aware of anti-science trends, to help prevent them from falling for those lies.

Climate Change, Nature, Sustainability, Uncategorized

Danish Seagrass Sequesters Carbon at Record Rates

Danish seagrass sequesters carbon at record rates.
Tropical seagrass. Photo: Shutterstock

Seagrass, a type of underwater plant which flowers and grows quite like terrestrial grasses, is apparently a huge contributor to the world’s ability sequester carbon. Seagrass grows in “meadows,” large patches dominated by one or two species, which are home to many shallow-water and coastal creatures. It forms an integral part of their local ecosystems.

But seagrass also sequesters carbon dioxide at a very high rate, and in one Danish bay, it’s much better at it than anywhere else. Outside of Thurøbund, no meadow seems to hold more than 11,000 grams of carbon per square meter, but the Danish bay sequesters upwards of 27,000 grams per square meter.

Biologists think this might have something to do with the protected nature of the bay. Not protected in a legal sense, but by having less direct contact with the larger ocean. There, when the plants die, they sink to the bottom of the ocean and get buried in sediment, so the carbon they had been storing stays there. In other meadows, these plants are washed out to sea, after which nobody is sure what happens to them.

Seagrass is threatened, as are so many species on the planet. Since 1879, the Earth has lost about 29 percent of its seagrass meadows. Denmark itself has lost between 80 and 90 percent since the 1930s. But because these plants are so good at storing carbon, it’s certainly worth our time to not only find ways to preserve those meadows which still exist, but to find ways to shore them up. If we can get more seagrass to grow, returning to levels before 1879, that could be a huge help in reducing global warming.

While the Earth’s processes of naturally sequestering carbon aren’t likely to save the day, they do put in a lot of work, and finding ways to increase the effectiveness with which they do so could make quite a difference.

Nature, Science

Tornado Outbreaks are Becoming Much More Frequent

Tornado outbreaks are becoming more frequent, and scientists are trying to figure out whether or not there is a connection to global climate change.
Photo: Shutterstock

A tornado outbreak occurs when six or more tornadoes appear in close succession, usually over a period of up to three days. They tend to be behind the most fatal tornadoes, and they’re something that people in “tornado country” have good reason to be concerned about. And according to a recent University of Chicago study, they’ve doubled in frequency over the last half century.

First, a basic primer in how tornadoes form: Warm, moist air near the surface of the earth meets with cold, dry air at higher altitudes. This forms bands of thunderstorms. Some thunderstorms transform into supercells if the wind increases in strength and changes direction with height. In about 30 percent of cases, according to research meteorologist Harold Brooks, these supercells lead to the formation of tornadoes. This happens when air descending from the supercell causes rotating winds near the ground.

Earlier research had predicted that a warming climate would increase the “convective available potential energy” (CAPE) and storm relative helicity, a measure of vertical wind shear in certain supercells. This would cause an increase in severe thunderstorms, which would lead to an increase in the number of tornado outbreaks.

However, what the researchers found was that the increase in tornado outbreaks seems to be due to an increase in storm relative helicity, which does not seem to be connected to global climate change.

“Our study raises new questions about what climate change will do to severe thunderstorms and what is responsible for recent trends,” says study co-author Michael K. Tippett of Columbia University. “The fact that we didn’t see the presently understood meteorological signature of global warming in changing outbreak statistics for tornadoes leaves two possibilities: Either the recent increases are not due to a warming climate, or a warming climate has implications for tornado activity that we don’t understand.”

Either way, the end result is the same: tornado outbreaks have doubled in frequency, causing more fatalities and more property damage than ever before, and that is something we need to address. Knowing, for sure, that tornadoes are more frequent means we can take steps to protect people, animals, and property from them.

Knowing that tornadoes are increasing in frequency, increased funding for warning systems, monitoring, and shelters would obviously be helpful in minimizing damage and loss of life. Although people who live where tornadoes are common are well educated on what to do in the event of a tornado, considering that tornadoes are now being seen with more frequency in areas such as the American Northeast, better education on tornadoes, how and when they form, and what to do when one touches down, would be beneficial for all people.