Categories
G24 INSTA NWT_Climate NWT_Environment Research SCI

Global warming ‘hiatus’ is about to end, study says

A new study suggests that the global warming “hiatus” is about to come to an end and make way for even higher temperatures. While the past four years have been the warmest on record, the new data suggests that natural factors are going to push our already heating planet even further into extreme temperature ranges.

“It will be even warmer than the long-term global warming is inducing,” said Florian Sevellec, lead author of the study.

The recent “hiatus” is the result of natural variability of the planet, which has been running for almost a decade.

“I’m not at all surprised by the results,” said John Fyfe, senior research scientist at the Canadian Centre for Climate Modelling and Analysis at Environment and Climate Change Canada. “And the reason for that is that we have gone down this long slowdown period primarily due to internal variability, and the expectation was that we’d come out of it.”

However, it is important to note that these predictions are based on probabilities, not certainties. In particular, the study’s model suggests that temperatures will be higher than predicted due to increased carbon dioxide levels.

“Because we tested it over the last century, we know that we are accurate for the likelihood,” Sevellac said. “But the likelihood doesn’t mean it will occur … there exists a small chance of being cold.”

While the study shows that Earth’s natural variability can have short-term influence, it also points to future trends.

“I think it’s also a demonstration that global warming will still be there after all this natural variability,” Sevellac said.

The findings were published in Nature Communications.

Categories
G24 INSTA NWT_Earth NWT_Environment SCI

Blocking sunlight to cool Earth decrease global warming crop damage

An new study suggests that blocking sunlight by injecting particles into the atmosphere will not offset the crop damage caused by global warming. The team behind the study analyzed past effects of Earth-cooling volcanic eruptions and how crops respond to changes in sunlight to come to their conclusion.

“Shading the planet keeps things cooler, which helps crops grow better. But plants also need sunlight to grow, so blocking sunlight can affect growth. For agriculture, the unintended impacts of solar geoengineering are equal in magnitude to the benefits,” said lead author Jonathan Proctor of the University of California, Berkeley. “It’s a bit like performing an experimental surgery; the side-effects of treatment appear to be as bad as the illness.”

“Unknown unknowns make everybody nervous when it comes to global policies, as they should,” said Solomon Hsiang, co-lead author of the study and also from UC Berkeley. “The problem in figuring out the consequences of solar geoengineering is that we can’t do a planetary-scale experiment without actually deploying the technology. The breakthrough here was realizing that we could learn something by studying the effects of giant volcanic eruptions that geoengineering tries to copy.”

The team stresses the more research is needed into the ecological and human consequences of geoengineering.

“The most certain way to reduce damages to crops and, in turn, people’s livelihood and well-being, is reducing carbon emissions,” Proctor said.

“Perhaps what is most important is that we have respect for the potential scale, power and risks of geoengineering technologies,” Hsiang added. “Sunlight powers everything on the planet, so we must understand the possible outcomes if we are going to try to manage it.”

The findings were published in Nature.

Categories
NWT_Climate NWT_Environment SCI

Climate impact is evident in the seasons

Scientists have determined that people are responsible for global warming by looking at weather records. They also can dust for fingerprints (ecological footprints) in other places.

A new study led by Lawrence Livermore National Laboratory’s Ben Santer looked for prints in a new place: the seasonal cycle of temperatures. The perfect tool for analyzing this is the global temperature record satellites produce.

The satellites do not go back quite as far as weather-station records, but the dataset is now long enough to be useful for climate studies. Several groups maintain separate satellite temperature datasets.

A huge amount of work went into all the necessary processing to produce temperature maps. Therefore, the different datasets do not always line up perfectly with each other.

Santer’s study involved using the most recent two versions of three different datasets. Each one tracks different layers of the atmosphere.

One record covers the lower troposphere. The other one covers the middle troposphere that is a little higher.

By tracking the difference between the coldest months and warmest summer months, they were able to see interesting regional patterns. The team averaged together the Northern Hemisphere’s mid-latitude stripe and discovered a larger seasonal temperature swing than in the Southern Hemisphere. The reason for this is there is a much greater area of land.

Nevertheless, this seasonal cycle has also increased significantly since 1979. It is a result of summer temperatures in the atmosphere rising faster than winter temperatures.

 

Categories
NWT_Climate NWT_Environment Research SCI

Global warming might cause insects to eat more crops, study says

A new study suggests that climate warming will increase crop losses for critical food grains due to the increased metabolic rate and population growth of insect pests.

“Climate change will have a negative impact on crops,” said Scott Merrill of the University of Vermont, co-author of the study. “We’re going to see increased pest pressure with climate change.”

The team found that just a 2-degree increase in global temperature averages will cause total crop losses of around 213 million tons for rice, wheat, and maize crops. These losses will stem from increased insect metabolism.

“When the temperature increases, the insects’ metabolism increases so they have to eat more,” Merrill said. “That’s not good for crops.”

However, the connection to population growth is more complicated. Since insects have optimal temperatures for population growth, losses will be highest in temperate regions and less severe in tropics.

“Temperate regions are not at that optimal temperature, so if the temperature increases there, populations will grow faster,” Merrill said. “But insects in the tropics are already close to their optimal temperature, so the populations will actually grow slower. It’s just too hot for them.”

Ultimately, farmers will have to find novel pest management methods, such as adding new crop rotations or boosting pesticide use. However, not all of these strategies will be available to every farmer.

“There are a lot of things richer countries can do to reduce the effect, by increasing pesticide use or expanding integrated pest management strategies,” Merrill said. “But poorer countries that rely on these crops as staple grains will have a harder time.”

The findings were published in Science.

Categories
NWT_Climate NWT_Environment SCI

Climate change could make Earth’s ecosystems unrecognizable

A new study suggests that dramatic changes in the Earth’s vegetation due to climate change could render the planet’s ecosystems unrecognizable.

“We’re already starting to see warning signs of big changes in vegetation across Australia, with declines in the Mountain Ash forests in Victoria and the Pencil Pine forests in Tasmania that are occurring, in large part, due to climate change,” said Simon Haberle from the Australian National University (ANU) Department of Archaeology and Natural History.

“Widespread and rapid changes to ecosystems are likely to have major knock-on effects for nationally important ecosystem services such as biodiversity, carbon storage and recreation,” he added.

“The palaeoecological data that was used for this study can be viewed as natural experiments exploring the response of ecosystems to drivers of change over time scales that can’t be captured by instrumental or historical records,” said Janelle Stevenson, co-author on the paper.

ANU analyzed datasets based on ancient pollen records from numerous sites in Australia and across the Pacific and South East Asia.

“Pollen reflects the changes in landscape and vegetation cover, and the beauty of these ancient pollen records is that they allow us to see these changes over thousands to millions of years,” Stevenson said. “The parts of Earth that had the biggest temperature increases over the time period analysed also had the most substantial changes in vegetation.”

“Our study provides yet another wake-up call that we need to act now to move rapidly towards an emission-free global economy,” she concluded.

The findings were published in Science.

Categories
NWT_Earth NWT_Environment SCI

Antarctic snowfall increased over the last two centuries

Antarctica has experienced a 10 percent increase in snowfall over the last 200 years, according to recent research set to be presented at the European Geosciences Union in Vienna, Austria

This new discovery comes from a group of scientists with the British Antarctic Survey, who analyzed Antarctic ice cores and found that the continent accumulated nearly 272 gigatons of water over the last two centuries. Almost all of that extra water came from increased snowfall.

Such information is important because, not only does it alter the current perception of Antarctica’s climate, but it could change current sea level rise models as well.

“There is an urgent need to understand the contribution of Antarctic ice to sea-level rise and we use a number of techniques to determine the balance between snowfall and ice loss,” lead author Elizabeth Thomas, a researcher with the British Antarctic Survey, said in a statement. “When ice loss is not replenished by snowfall then sea level rises.”

Satellite pictures — which often help researchers understand shifting climates — typically only give information going back 20 years or so. As a result, ice core analysis, which are able to track snowfall for several hundred years, are more effective. In this case, they revealed that Antarctica’s surface mass balance drastically shifted from snowfall throughout the twentieth century.

Though the snowfall is everywhere, it mainly concentrated on the Antarctic Peninsula. There, the annual average is 10 percent higher than it was 200 years ago.

This discovery could alter current perceptions of climate change, but the team states the findings do not override any observations of melting or glacial retreat. Even so, they will allow scientists make more accurate sea level rise predictions as time goes on.

“We know that the two major influencers affecting change — the mass gain from snowfall and the mass loss from melting — are acting differently from one another,” added Thomas, according to UPI. “Our new findings take us a step towards improving our knowledge and understanding.”

Categories
NWT_Climate NWT_Environment Research SCI

Scientists discover ‘ticking time bomb’ heated ocean under Arctic

Scientists just discovered evidence of a massive “ticking time bomb” in the form of a heated ocean underneath the Arctic Ocean. The reservoir penetrates deep into the polar region and threatens to melt the ice frozen on top.

“We document a striking ocean warming in one of the main basins of the interior Arctic Ocean, the Canadian Basin,” said oceanographer Mary-Louise Timmermans from Yale University.

Timmermans and her team examined temperature data on the Canada Basin from the last 30 years. The findings revealed that the amount of heat in the warmest region of the water had doubled during the period of 1987 to 2017.

The basin is formed from mixed layers of ocean water, with the warmer, saltier water trapped beneath cold, fresh water flowing at the surface. Although this unique dynamic is not new, the rapid heating conditions of the water underneath are concerning.

“Presently this heat is trapped below the surface layer,” Timmermans said. “Should it be mixed up to the surface, there is enough heat to entirely melt the sea-ice pack that covers this region for most of the year.”

“That heat isn’t going to go away,” said oceanographer John Toole from the Woods Hole Oceanographic Institution. “Eventually … it’s going have to come up to the surface and it’s going to impact the ice.”

Although it’s not an immediate threat, it could severely impact Arctic ice, and as of now, the ramifications are unclear.

“It remains to be seen how continued sea ice losses will fundamentally change the water column structure and dynamics,” the authors wrote, although they note that excess heat “will give rise to enhanced upward heat fluxes year-round, creating compound effects on the system by slowing winter sea ice growth.”

“We’re seeing more and more open water as the sea ice retreats in the summertime,” Timmermans said. “The Sun is warming up the ocean directly, because it’s no longer covered by sea ice.”

The findings were published in Science Advances.

Categories
NWT_Environment Research SCI

Scientists discover how to create mineral that can remove CO2 from atmosphere

Scientists just discovered how to rapidly create magnesite, which is a mineral that can store carbon dioxide (CO2). If it can be created at an industrial scale, it could pave the way to a method of removing CO2 from the atmosphere for long-term storage.

“Our work shows two things. Firstly, we have explained how and how fast magnesite forms naturally,” said project leader Ian Power of Trent University. “This is a process which takes hundreds to thousands of years in nature at Earth’s surface. The second thing we have done is to demonstrate a pathway which speeds this process up dramatically.”

The team was able to prove that magnesite can form within 72 days using polystyrene microspheres as a catalyst. And these microspheres are not changed by the production process, allowing them to be reused.

“Using microspheres means that we were able to speed up magnesite formation by orders of magnitude,” Power said. “This process takes place at room temperature, meaning that magnesite production is extremely energy efficient”

Although it is currently an experimental process, it is a promising discovery that could pave the way for carbon sequestration technology to combat climate change.

“It is really exciting that this group has worked out the mechanism of natural magnesite crystallization at low temperatures, as has been previously observed—but not explained—in weathering of ultramafic rocks,” said Peter Kelemen at Columbia University. “The potential for accelerating the process is also important, potentially offering a benign and relatively inexpensive route to carbon storage, and perhaps even direct CO2 removal from air.”

Categories
NWT_Climate NWT_Environment Research SCI

Corals in deeper waters are stressed too, study says

A new study suggests that corals in deeper waters are exposed to episodic thermal stress. Researchers previously believed that corals at a depth of 30 to 150 meters were safer than their shallow-water counterparts. But although the intervals of thermal stress they experience are different than corals at the surface, they still feel the effects of ocean warming.

The team reached their conclusions using almost two decades of data sets that include sea-surface temperature, sea level, and temperature observations that range from the surface to deep in the mesophotic zone. Using their unique approach, they were able to measure and predict the thermal stress of coral reefs at many depths.

“We’re now adding the dimension of depth into the problem where before we were only skimming the surface of what temperature stress meant for corals,” said Travis Schramek, lead author of the study. “We see that the heat-induced stress penetrates all the way into the mesophotic zone during larger bleaching events.”

“A surprising outcome of the study is that the oceanic conditions along the dramatic reef walls that are the boundaries of Palau are very representative of the broader Western Pacific,” said Scripps oceanographer Eric Terrill, senior author of the study. “As a result, we had a surprising amount of success in predicting the vertical structure of the temperature fields that the coral communities would be exposed to, even during El Niño conditions.”

The new insights from the study can help researchers predict the temperature stress on deep corals. Not only that, they can shed light on how the effects contribute to our understanding of the reef system as a whole.

The findings were published in Geophysical Research Letters.

Categories
NWT_Biology NWT_Environment SCI TECH

Trees can be genetically engineered not to spread, study says

Researchers just conducted the biggest field-based study ever on genetically modified forest trees and revealed that genetic engineering techniques can prevent seedling establishment. The results are important because of the recent concerns over the spread of genetically engineered  invasive or exotic trees past their boundaries.

“There’s still more to know and more research to be done, but this looks really good,” said corresponding author Steve Strauss. “It’s very exciting.”

The study examined 3,300 poplar trees across a 9-acre tract over the course of seven growing seasons. The team examined many different approaches for making the trees sterile, with a particular focus on 13 genes that are connected to making flowers or controlling reproduction onset.

The study is groundbreaking not only for its findings but for its massive duration and scope.

“I’m proud that we got the research done,” Strauss said. “It took many years and many people doing it, managing it.”

“People have this fear that GMO trees will take over the world, but these are containment genes that make taking over the world essentially impossible,” he said. “If something is GMO, people assume it’s dangerous—it’s guilty until proven safe in the minds of many and in our regulations today. In contrast, scientists say the focus should be on the trait and its value and safety, not the method used.”

Strauss also highlighted the fact that newer genetic techniques like CRISPR make it much easier to create contained trees more efficiently.

He also suggests that “the work focused on pollen and seeds, but poplar can also spread vegetatively—for example by root sprouts. But those are far slower, much narrower in distance, and far easier to control in and around plantations.”

The findings were published in Frontiers in Bioengineering and Biotechnology.