Connect with us


The race for climate change solutions leaves researchers divided



A squadron of planes flies overhead, releasing trails of sulfur and other aerosols into the air. A fleet of ships traverses the ocean, spraying plumes of saltwater mist into the air. A wall of fans gently hums between grassy hills in the Icelandic countryside.

These images are not from a movie, they are very real concepts and technologies put forth by scientists in Apocalypse Plan B, a documentary from The Nature of Things.

We have entered a new era of combating climate change — with carbon capture and geoengineering technologies — where science fiction is becoming science fact.

Carbon and climate events

More than half of humanity’s CO2 emissions have been released into the atmosphere since 1990. Each year, more than 34 gigatonnes of carbon dioxide are pumped into the atmosphere — almost three gigatonnes a month, which amounts to enough carbon to fill New York’s Central Park with a mass of coal half a kilometre high.


As our carbon output continues, global temperatures increase, which disrupts weather patterns and results in higher temperatures, more intense storms, increased drought and warming oceans. These events have a cascading effect, leading to species loss, poverty and displacement.

Though we’re already witnessing some of these problems, climate scientist Michael Mann says we still have time. “The science tells us that it’s not too late to prevent the worst impacts of climate change if we reduce carbon emissions by 50 per cent within this decade,” he says. “It’s a tough task, but we can do it.”

Scientists are racing to find solutions to pull carbon from the atmosphere. Some have taken the more controversial approach of using human intervention to cool the planet, although this solution doesn’t come without consequences.

Climate change and inequality

David Keith, a Harvard University physicist, is in favour of intentionally increasing Earth’s reflectivity. His proposal involves a fleet of aircraft spraying sulfur and other aerosols into the atmosphere, where they would divert sunlight away, effectively cooling the planet. It’s a concept known as solar geoengineering.


Dimming the sun by adding more gas to the atmosphere | Apocalypse Plan B

This scientist has a proposal to fight climate change: intentionally release tonnes of sulphur gas into the stratosphere using aircraft, to dim the sun’s rays.

However, this strategy could affect Earth’s natural systems, disrupting plant productivity, ocean currents and atmospheric wind patterns, which could have an outsized impact on populations that depend on these systems for their livelihoods.

Climate inequality is a concern as temperatures continue to rise. Populations in low-income countries are more likely to experience consequences from climate change and the costs of mitigating it, namely by reducing emissions. These disproportionate impacts can further increase poverty in these communities.

But Keith insists climate justice is the basis for his idea, and that the reduction in temperatures would benefit those living in hot countries the most. But Indian scientist and environmental activist Vandana Shiva disagrees.

“You block the sun, what you’re basically doing is you’re cursing the 80 per cent of humanity and all the beings on this Earth who depend on the green leaf for their survival,” she says.

Shiva believes climate justice is about listening to those whose livelihoods depend on the natural environment rather than imposing solutions on them.

“We have not forgotten that colonialism began with the excuse of the white man’s burden,” she says.

Human intervention is only one of the ways scientists are exploring to cool the planet. Some researchers think the solution is not to fight our natural systems, but to work with them.

Natural options

The first mangrove forest that Lola Fatoyinbo ever visited as a graduate student was in Everglades National Park, Florida. “It’s actually one of my favorite sites in the whole world,” she says.

Fatoyinbo is an environmental scientist who likes looking at forests — a lot of forests.

Working with a team from NASA, she uses a combination of 3D scanning and satellite imagery to determine the density of forests around the world and their carbon content.

Fatoyinbo is one of the scientists who sees the planet’s natural systems as a solution for removing carbon from the atmosphere. During the spring and summer months in the Northern Hemisphere, carbon dioxide is pulled from the atmosphere as the Earth’s forests turn green once more, removing a significant amount of greenhouse gases from the atmosphere.

When considering carbon-storage solutions, Fatoyinbo stresses the importance of these forests — especially mangrove forests.

“One of the really big advantages of mangroves is that they have a really high carbon-storage capacity,” she says. “Mangroves store about three to five times more carbon than a tropical rainforest. That’s really a huge amount of carbon, and this is just in the first metre of soil.”

As climate events worsen, Fatoyinbo is seeing the depletion of these carbon stores. Mangroves, which historically have been able to withstand storms and the rising sea level, are not able to tolerate the intensity and frequency of storms resulting from climate change, as they have less time to recuperate. Some become “ghost forests” — a haunting name for these ecosystems when they haven’t been able to recover and die.

“There’s no way to see what we’re seeing and not worry,” she says.

For Fatoyinbo, the protection of these forests is an essential step for removing carbon from the atmosphere. “[The] restoration of mangroves, forests and wetlands — these are really important mechanisms that are part of the fight,” she says.


Every spring and summer, toxic rivers of CO2 are removed from our atmosphere – thanks to trees and plants | Apocalypse Plan B

Lola Fatoyinbo is a NASA research scientist who studies forest ecosystems from space. Using data gathered from instruments on the space station, she’s able to map the world’s forests, and the effect they have on our planet.

British environmental writer and activist George Monbiot agrees with Fatoyinbo’s approach.

“Our chances of getting through this century — let alone those that follow — depend to a very large extent on whether we can restore many of the world’s wild ecosystems,” he says.

According to Monbiot, the fastest way of removing carbon from the atmosphere is to turn it into solid carbon in the form of trees, wetlands and other ecosystems. However, this requires an understanding of how land is used, or rather misused.

Half of the world’s habitable land is used for agriculture, and Monbiot points out, “twenty-eight per cent of the planet’s terrestrial surface is used for keeping grazing livestock,” he says. “That extraordinary area … is used to produce just one per cent of the world’s protein. This is a phenomenally wasteful way of producing our food.”

Despite the bleakness, Monbiot feels there’s still time to change.

“It really is not too late because social change can happen at great speed,” he says.

Moving forward

Against a backdrop of extreme climate events, carbon buildup and indecision, time is running out, and these scientists know it. Whether by radical human intervention or protection of natural systems, they all agree that action is needed to slow the damage caused by climate change.

Mann wryly sums up the urgency of the situation: “The good thing is that if we screw up this planet, we’ve got another one to go to — Oh no, wait. No, we don’t. Do we?”



Source link

Continue Reading


Scientists Identify Intense Heatwaves At The Bottom Of Ocean




Underwater heatwave can have significant impacts on marine life. (Representational Pic)

Global warming is causing temperature across the globe to rise. The rate has increased in the last decades, with climatologists warning of the extreme effects that the mankind has to experience. The scientists have also been tracking temperature data streaming in from ocean surfaces. But in a shocking discovery, they have found that marine heatwaves can unfold deep underwater too, even if there is no detectable warming signal above. The discovery is based on new modelling led by researchers at the US National Oceanic and Atmospheric Administration (NOAA).

The research detailing the underwater heatwave has been published in Nature Communications.


“This is the first time we’ve been able to really dive deeper and assess how these extreme events unfold along shallow seafloors,” the study’s lead author Dillon Amaya, a climate scientist with NOAA’s Physical Science Laboratory, is quoted as saying by Science Direct.

It is based on the analysis of underwater temperature of continental shelf waters surrounding North America.

“This research is particularly significant as the oceans continue to warm, not only at the surface but also at depth, impacting marine habitat along continental shelves,” said co-author Clara Deser.

The scientists found that marine heatwaves can be more intense and last longer than hot spells at the ocean surface, though it varies from coast to coast.

The simulations found that bottom marine heatwave and surface marine heatwave tend to occur at the same time in shallow regions where surface and bottom waters mingle. But in deeper parts of the oceans, bottom marine heatwaves can develop without any indication of warming at the surface.

Temperature spikes along the seafloor ranged from half a degree Celsius up to 5 degrees Celsius, the research further found.

According to NOAA, marine heatwaves are periods of persistent anomalously warm ocean temperatures, which can have significant impacts on marine life as well as coastal communities and economies.

According to data, about 90 per cent of the excess heat from global warming has been absorbed by the ocean, which has warmed by about 1.5 degrees Celsius over the past century.


Source link

Continue Reading


Watch the Chelyabinsk Meteor Breakup in this Detailed Simulation



The people of Chelyabinsk in Russia got the surprise of their lives on the morning of February 15, 2013. That’s when a small asteroid exploded overhead. The resulting shockwave damaged buildings, injured people, and sent a sonic boom thundering across the region.


The Chelyabinsk impactor was about 20 meters across. It broke up in the atmosphere in an airburst and sent a shower of debris across the landscape. The event awakened people to the dangers of incoming space debris. Since we experience frequent warnings about near-Earth objects, scientists want to understand what a piece of space rock can do.

These days, there are many observation programs across the planet. For example, NASA operates its Sentry System and ESA sponsors the NEODyS project. They and others track incoming space rock. The observation data help predict the impacts of all but the very smallest asteroid chunks that come our way. Despite those programs, it’s inevitable that something like the Chelyabinsk asteroid chunk will slip through. So, it’s important to understand what happens during such an impact.



Modeling the Chelyabinsk Meteor

Scientists around the world began studying the event almost as soon as it happened. They collected bits of the debris and studied images of the entire event. Researchers with the Planetary Defense program at the Lawrence Livermore National Laboratory recently released a highly detailed 3D animation of a simulated chunk of space rock modeled after the Chelyabinsk impactor. They based the materials of the object in their animation on meteorites recovered from the ground.

[embedded content]
Fully 3D simulation of the Chelyabinsk meteor break up in Earth’s atmosphere. The meteor is shown as a contour of the damage state (white intact, black fully damaged). Shock-heated air nodes are displayed as points colored by their temperature. Initially, fracture begins at the rear of the object. The crack then propagates forward eventually splitting the object into three coherent fragments. The fragments are disrupted shortly thereafter.

Because people recorded the event with cell phones and security cameras, the team compared their model to what everybody witnessed. It turned out to be very close to what actually happened.

“This is something that can really only be captured with 3D simulation,” said Jason Pearl, lead researcher on the project. “When you combine LLNL’s specialized expertise in impact physics and hydrocodes with the Lab’s state-of-the-art High Performance Computing capabilities, we were uniquely positioned to model and simulate the meteor in full 3D. Our research underlines the importance of using these types of high-fidelity models to understand asteroid airburst events. A lot of smaller asteroids are rubble piles or loosely bound collections of space gravel, so the possibility of a monolith is really interesting.”

So, How Did the Chelyabinsk Object Shatter?

The most often-asked question about the rock that smacked into Earth over Russia was: was it a single chunk of debris? Or was it a flying rubble pile? If it was a monolithic chunk of rock, that would imply specific details about the strength of the rock and how it broke up. If it was a flying rubble pile, it might have broken up earlier and higher in the atmosphere. The LLNL experiment implies strongly that the impact was a single monolithic rock. It broke up under the heat and pressure of atmospheric entry.

Images from a 2D Spheral simulation showing the fragmentation of the Chelyabinsk bolide as it descends through the atmosphere. Image courtesy of LLNL Planetary Defense program.

To model the impactor and its behavior, the research team used a computational method called “smoothed particle hydrodynamics (SPH).” It models an object in a fluidic flow. In this case, it treats the atmosphere as a fluid. The model also simulates what happens as a Chelyabinsk-sized hunk of rock moves through the simulated air.

In their simulation, the team found that the incoming object started to break up from the rear and the cracks moved from back to front. The timescale of crack propagation toward the front of the asteroid controls the time at which the asteroid splits into smaller fragments while entering Earth’s atmosphere. A collection of fragments lies near the shock front and that shields the rest of the fragmenting rock. Finally, when the impactor reaches about 30 kilometers above Earth’s surface, intact fragments separate. That’s when the debris is exposed to the free stream. Eventually, the debris cloud decelerates very quickly and the remaining fragments continue to break up as they fly through the air toward the ground.

The Physics of the Breakup

The disintegration of the Chelyabinsk object provided scientists with a “physics-rich” event to study. According to LLNL physicist Mike Owen, the coupling of the asteroid to the atmosphere depends on how much surface area it has. The greater the surface area, the more exposure it has to heat, stress and pressure. Those all combine to break it up.

“As the asteroid enters the atmosphere, you start to have sort of a catastrophic failure,” Owen said. “And it tends to compress in the direction of travel. It was like the asteroid was being squeezed in the direction of travel, breaking into distinct pieces that started to separate and break perpendicular to the direction of travel. All of a sudden, you’ve got a lot more material being exposed to the hypersonic interaction with the air, a lot more heat being dumped in, a lot more stress on it, which makes it break faster and you get sort of a cascading runaway process.”

Using Chelyabinsk To Understand Future Impacts

Models of impactors like this one provide insight into future events when chunks of space rock will hit Earth. One long-term goal would be to use such models to assess what will happen to a target region during an impact. Meteoric impacts are natural disasters that affect our planet just as fires and floods do. As such, there’s a need to predict and understand them so that people can be more prepared.

Researcher Cody Raskin points to our increased ability to detect such incoming impactors. “If we can see a small asteroid approaching Earth in time, we could run our model and inform authorities of the potential risk, similar to a hurricane map,” said Raskin. “They could then take appropriate protective actions, such as evacuating residents or issuing shelter-in-place orders, ultimately saving lives.”


Source link

Continue Reading


Stephen Hawking thought his thesis in ‘a brief history of time’ was wrong



In 2002, Thomas Hertog was urgently summoned to the office of his esteemed mentor, Stephen Hawking. With a sense of excitement radiating from his eyes, the renowned cosmologist communicated to Hertog through his computer-controlled voice system, declaring that he had experienced a change of heart. “My book, A Brief History of Time, is written from the wrong perspective,” Hawking announced. This statement consigned the popular scientific tome, which had sold over 10 million copies worldwide, to the waste bin. According to a report from the Guardia, Hertog, and Hawking then embarked on a new project, aiming to encapsulate their latest ideas about the universe in a fresh way.

Five years following the passing of Stephen Hawking, his final theory, titled On the Origin of Time, is set to be published in the UK next month. At a Cambridge festival lecture on March 31st, cosmologist Thomas Hertog, currently affiliated with KU Leuven University in Belgium, will discuss the origins and themes of the book. According to Hertog, Hawking struggled to comprehend how the universe was able to create conditions that are so perfectly suitable for life. These conditions include a precise balance of particle forces that enable the existence of chemistry and complex molecules, as well as the presence of only three dimensions of space that allow for the formation of stable solar systems and habitats for living organisms. Some cosmologists assert that without these specific characteristics, life as we know it may not have come to fruition in the universe.

A quick glance at Hawking’s life

Stephen Hawking was born on January 8, 1942, in Oxford, England. His father was a medical researcher, and his mother was a secretary. From an early age, Hawking was interested in science, especially physics and astronomy. He attended University College, Oxford, where he studied physics and graduated with honors in 1962. He then went on to pursue graduate studies in cosmology at Trinity College, Cambridge.

It was during his time at Cambridge that Hawking was diagnosed with a rare form of motor neuron disease that left him wheelchair-bound and unable to speak without the use of a computerized voice synthesizer. Despite this debilitating condition, Hawking continued his studies and research, becoming one of the most brilliant and influential scientists of his generation.


In 1974, Hawking proposed the theory of Hawking radiation, which suggested that black holes could emit radiation and eventually evaporate over time. This groundbreaking work established Hawking as a leading figure in theoretical physics, and he continued to make significant contributions to the field throughout his career. He also wrote several popular science books, including the best-selling A Brief History of Time, which helped make complex scientific ideas accessible to a wider audience.

Hawking received numerous awards and honors for his contributions to science, including the Albert Einstein Medal, the Presidential Medal of Freedom, and the Copley Medal, the highest honor of the Royal Society. He also served as the Lucasian Professor of Mathematics at Cambridge, a position once held by Isaac Newton.

Hawking passed away on March 14, 2018, at the age of 76, leaving behind a legacy of scientific achievement and popularizing science for the general public. His work has inspired countless people around the world to pursue careers in science and to explore the mysteries of the universe.


Source link

Continue Reading