Why do climate models underestimate polar warming? ‘Invisible clouds’ could be the answer

Polar stratospheric clouds, also called nacreous or mother-of-pearl clouds, are not normally visible to the naked eye.
Photo Credit: Alan Light
(CC BY 4.0 DEED)

Stratospheric clouds over the Arctic may explain the differences seen between the polar warming calculated by climate models and actual recordings, find researchers from UNSW Sydney.  

The Earth’s average surface temperature has increased drastically since the start of the Industrial Revolution, but the warming effect seen at the poles is even more exaggerated. While existing climate models consider the increased heating in the Arctic and Antarctic poles, they often still underestimate the warming in these regions. This is especially true for climates millions of years ago, when greenhouse gas concentrations were very high. 

This is a problem because future climate projections are generated with these same models: if they do not produce enough warming for the past, we might underestimate polar warming – and therefore the associated risks, such as ice sheet or permafrost melting – for the future. 

This missing information caught the attention of scientists from the UNSW Climate Change Research Centre. 

How Mega-Floods can be Predicted

Flooding in Germany 2021
Photo Credit: Martin Seifert
Public Domain

When floods are predicted only on the basis of local data, there may be unpleasant surprises. A new method makes it possible to significantly improve predictions - using international data from hydrologically similar areas.

What can we expect in the worst-case scenario? In regions with a high risk of flooding, this is an important question: what extreme events should the protective measures be designed for? Often this is answered simply by looking at history: The worst flood events of the past decades or centuries are regarded as a realistic upper limit for what can be expected in the future.

However, this can be misleading, as so-called "mega-floods" have shown in recent years. Time and again, extreme flood events occur, extraordinary outliers that were not considered possible on the basis of local data. However, a major research project carried out under the leadership of TU Wien (Vienna) has now been able to demonstrate: If one considers the entire European continent, these local surprises are no longer surprising at all. If data from other regions with similar hydrological conditions is taken into account, the extent of these "mega-floods" suddenly becomes predictable. This has drastic consequences for the way in which flood protection must be dimensioned. The results have now been presented in the journal Nature Geoscience.

SwRI-led Lucy observes first-ever contact binary orbiting an asteroid

This image shows the asteroid Dinkinesh and its satellite as seen by the Lucy Long-Range Reconnaissance Imager (LORRI). As NASA's Lucy Spacecraft departed the system, the SwRI-led Lucy team captured this image at 1 p.m. EDT (1700 UTC) Nov. 1, 2023, about six minutes after closest approach. From a range of approximately 1,010 miles (1,630 km), the satellite is revealed to be a contact binary, the first time such an object has been seen orbiting another asteroid.
Image Credit: NASA/Goddard/SwRI/Johns Hopkins APL

After the Southwest Research Institute-led Lucy mission flew past the asteroid Dinkinesh, the team discovered that it is even more “marvelous” as its newly discovered satellite is now shown to be a double-lobed moonlet. As NASA’s Lucy spacecraft continued to return data acquired during its first asteroid encounter on Nov. 1, 2023, the team discovered that Dinkinesh’s surprise satellite is itself a contact binary, made of two smaller objects touching each other.

In the first image of Dinkinesh and its satellite taken at closest approach, the two lobes of the contact binary lined up, one behind the other, appearing to be one body from Lucy’s point of view. When the team downlinked additional images captured after the closest encounter, the data revealed that Dinkenesh has a double moonlet.

“Contact binaries seem to be fairly common in the solar system,” said John Spencer, Lucy deputy project scientist, of the Boulder, Colorado, branch of the San Antonio-based SwRI. “We haven’t seen many up close, and we’ve never seen one orbiting another asteroid. We’d been puzzling over odd variations in Dinkinesh’s brightness that we saw on approach, which gave us a hint that Dinkinesh might have a moon of some sort, but we never suspected anything so bizarre!”

Why are songbirds larger in colder climates?

A song-sparrow
Photo Credit: Anish Lakkapragada

Scientists have unlocked the genetic basis underlying the remarkable variation in body size observed in song sparrows, one of North America’s most familiar and beloved songbirds. This discovery also provides insights into this species’ capacity to adapt to the challenges of climate change.

The study, published today in Nature Communications, used genomic sequencing to successfully pinpoint eight genetic variants, or DNA mutations, largely responsible for the nearly threefold difference in body size observed across the song sparrow range from Mexico to Alaska. For instance, song sparrows that live year-round in the Aleutian Islands can be up to three times larger than their counterparts in the coastal marshes of California.

Katherine Carbeck, the study’s first author and a PhD candidate in the faculty of forestry, University of British Columbia, explains that body size varies predictably in many species that inhabit vastly different climatic conditions, aligning with “Bergmann’s rule” which states that organisms in cooler climates tend to be larger as an adaptation to regulate body temperature.

Under Pressure: Seeing the Squeeze in Living Organisms

Double emulsion droplet (pink and cyan) located in between cells (yellow) of a living zebrafish embryo. Monitoring the changes in droplet size allows scientists to measure the osmotic pressure in the tissue.
Image Credit: © PoL / Antoine Vian

In order to survive, organisms must control the pressure inside them, from the single-cell level to tissues and organs. Measuring these pressures in living cells and tissues in physiological conditions has been very challenging. Now, researchers from the Cluster of Excellence Physics of Life (PoL) at the Technical University in Dresden (TU Dresden), Germany, report in the journal Nature Communications a new technique to ‘visualize’ these pressures as organisms develop. These measurements can help understand how cells and tissues survive under pressure, and reveal how problems in regulating pressures lead to disease. 

When molecules dissolved in water are separated into different compartments, water has the tendency to flow from one compartment to another to equilibrate their concentrations, a process known as osmosis. If some molecules cannot cross compartments, a pressure imbalance, known as osmotic pressure, builds up across them. This principle is the basis for many technical applications, such as the desalination of seawater or the development of moisturizing creams. It turns out that maintaining a healthy functioning organism makes the list too. 

30-foot whale shark spotted off Kāneʻohe Bay by UH researchers

University of Hawaiʻi at Mānoa researchers spotted the world’s largest fish species, a 30-foot whale shark, a mile off Kāneʻohe Bay near Kualoa Ranch on November 2.

Researchers from the Hawaiʻi Institute of Marine Biology (HIMB) Shark Research Lab were returning from conducting field work when they spotted seabirds flying over what they suspected was a bait ball, where small fish swarm in a tightly packed spherical formation near the surface while being pursued and herded by predators below.

Mark Royer, a HIMB shark researcher, went into the water to see what sealife had gathered to feed and was surprised to see the whale shark.

“It is surprising,” said Royer. “[Whale sharks] are here more often than we think, however they are probably hard to come across, because I didn’t see this animal until I hopped in the water.”

Scientists use quantum biology, AI to sharpen genome editing tool

ORNL scientists developed a method that improves the accuracy of the CRISPR Cas9 gene editing tool used to modify microbes for renewable fuels and chemicals production. This research draws on the lab’s expertise in quantum biology, artificial intelligence and synthetic biology.
Illustration Credit: Philip Gray/ORNL, U.S. Dept. of Energy

Scientists at Oak Ridge National Laboratory used their expertise in quantum biology, artificial intelligence and bioengineering to improve how CRISPR Cas9 genome editing tools work on organisms like microbes that can be modified to produce renewable fuels and chemicals.

CRISPR is a powerful tool for bioengineering, used to modify genetic code to improve an organism’s performance or to correct mutations. The CRISPR Cas9 tool relies on a single, unique guide RNA that directs the Cas9 enzyme to bind with and cleave the corresponding targeted site in the genome. Existing models to computationally predict effective guide RNAs for CRISPR tools were built on data from only a few model species, with weak, inconsistent efficiency when applied to microbes.

“A lot of the CRISPR tools have been developed for mammalian cells, fruit flies or other model species. Few have been geared towards microbes where the chromosomal structures and sizes are very different,” said Carrie Eckert, leader of the Synthetic Biology group at ORNL. “We had observed that models for designing the CRISPR Cas9 machinery behave differently when working with microbes, and this research validates what we’d known anecdotally.”

New strategy may halt tumors' aggressive response to glucose deprivation

The figure shows the expression of a differentiation marker in the tumors of mice treated with the glucose inhibitor, the epigenetic inhibitor, or both. Top left image is the placebo, top right is the glucose inhibitor, bottom left is the epigenetic inhibitor and bottom right is the glucose inhibitor and epigenetic inhibitor. The brown signal indicates the presence of the differentiation marker. The treatment with the glucose inhibitor (top right) reduces the brown signal, whereas the addition of the epigenetic inhibitor rescues the expression of the differentiation marker.
Image Credit: Dr. Claudio Scafoglio.

One of the hallmarks of cancer cell development is its dependence on sugar, especially glucose, to grow and divide. Scientists have long been studying how to restrict or block this process that promotes tumor growth, called glycolysis, from happening as a possible effective strategy against cancer.

Previously, researchers from the UCLA Health Jonsson Comprehensive Cancer Center identified a specific protein sodium glucose transporter 2, or SGLT2, as a mechanism that lung cancer cells can utilize to obtain glucose. Drugs that inhibit SGLT2 are already FDA approved for other conditions and the UCLA team found these drugs could also delay the development of lung cancer and improved survival when tested in mice, suggesting these drugs could be repurposed for lung cancer treatment.

However, while inhibiting glycolysis can slow down the growth of tumors, the researchers found it can also make cancer cells more aggressive, making the cancer harder to treat. This led the team to look at other mechanisms of resistance in the tumors that still grow while being treated with SGLT2 inhibition that may link glucose restriction to increases aggression.

‘Neglected’ Dinosaur Had Super Senses

A family of Thescelosaurus emerges from safety to forage in the forests of the Hell Creek Formation, 66 million years ago.
Illustration Credit: Anthony Hutchings.

A CT scan of an often-overlooked, plant-eating dinosaur’s skull reveals that while it may not have been all that “brainy,” it had a unique combination of traits associated with living animals that spend at least part of their time underground, including a super sense of smell and outstanding balance. The work is the first to link a specific sensory fingerprint with this behavior in extinct dinosaurs.

The dinosaur in question, Willo, is a specimen housed at the North Carolina Museum of Natural Sciences. Willo is a Thescelosaurus neglectus – a small (12 feet or 3.6 meters long) but heavy (750 pounds or 340 kilograms) herbivore that lived in what is now North America just before the end-Cretaceous mass extinction event, 66 million years ago.

Willo’s scientific name roughly translates to “wonderful, overlooked lizard.” But David Button, a former Brimley Postdoctoral Scholar at the North Carolina Museum of Natural Sciences and North Carolina State University, decided to look more closely at this “overlooked” dinosaur’s skull. Button is currently a research associate at the University of Bristol in the U.K.

The kids aren't alright: Saplings reveal how changing climate may undermine forests

A University of Arizona-led experiment exposed different species of trees to heat and drought to study how young trees respond to climate change. After 20 weeks of drought and a one-week heat wave, this Douglas fir sapling was dry and brittle.
Photo Credit: Alexandra Lalor

UArizona researchers studied how young trees respond to a hotter, drier climate. Their findings can help shape forest management policy and our understanding of how landscapes will change.

A University of Arizona-led experiment exposed different species of trees to heat and drought to study how young trees respond to climate change. After 20 weeks of drought and a one-week heat wave, this Douglas fir sapling was dry and brittle. Alexandra Lalor

As climate scientist Don Falk was hiking through a forest, the old, green pines stretched overhead. But he had the feeling that something was missing. Then his eyes found it: a seedling, brittle and brown, overlooked because of its lifelessness. Once Falk's eyes found one, the others quickly fell into his awareness. An entire generation of young trees had died.

Falk – a professor in the UArizona School of Natural Resources and the Environment, with joint appointments in the Laboratory of Tree-Ring Research and the Arizona Institute for Resilience – refers to this large-scale die-off of the younger generation of trees as a recruitment failure. This is particularly devastating for a population of trees because the youngest are essential for forest recovery following massive die-off events, such as severe wildfires and insect outbreaks, both of which will become more frequent as the climate continues to change, he said.