Category Archives: Science

Soil takes in far less CO2 than previously thought


More grim climate change news, this time from the University of California, Irvine:

By adding highly accurate radiocarbon dating of soil to standard Earth system models, environmental scientists from the University of California, Irvine and other institutions have learned a dirty little secret: The ground will absorb far less atmospheric carbon dioxide this century than previously thought.

Researchers used carbon-14 data from 157 sample sites around the world to determine that current soil carbon is about 3,100 years old – rather than the 450 years stipulated by many Earth system models.

“This work indicates that soils have a weaker capacity to soak up carbon than we have been assuming over the past few decades,” said UCI Chancellor’s Professor of Earth system science James Randerson, senior author of a new study on the subject to be published Friday in the journal Science [$30 to read]. “It means we have to be even more proactive in finding ways to cut emissions of fossil fuels to limit the magnitude and impacts of climate warming.”

Through photosynthesis, plants absorb CO2 from the air. When trees and vegetation die and decay, they become part of the soil, effectively locking carbon on or beneath the Earth’s surface – keeping it out of the atmosphere, where it contributes to global warming. In their study, the researchers showed that since this process unfolds over millennia versus decades or centuries, we should expect less of this land carbon sequestration in the 21st century than suggested by current Earth system models.

“A substantial amount of the greenhouse gas that we thought was being taken up and stored in the soil is actually going to stay in the atmosphere,” said study co-author Steven Allison, UCI associate professor of ecology & evolutionary biology and Earth system science.

In recent years, scientists have used highly complex, computer-based Earth system models – compilations of code integrating data on the planet’s oceans, land surfaces, ice masses, atmosphere and biological systems – to draw conclusions about potential future changes in regional and global temperatures, drought, sea levels and other phenomena.

The models don’t explicitly provide the age of carbon in soils, but lead author Yujie He, a UCI postdoctoral scholar when the study was conducted, said that she and her colleagues figured out a way to improve them through simplification and the addition of dating methods well-established in the scientific community.

“Radiocarbon is an excellent tool for understanding soil dynamics,” He said. “Our study demonstrated that by working to reduce the complexity of Earth system models and combining observational data, we could get them to reveal surprising findings.”

The authors said that adding more carbon to that which has been in the ground for thousands of years is problematic given the pace at which the Earth seems capable of integrating it.

“If we waited 300, 400, 1,000 years, then that carbon – we think – would go into the soil. But that’s not going to help us in dealing with climate change, which is happening now,” Allison said. “You have to do a lot of risk assessment to say, well, what’s the actual cost of just waiting for that sequestration, and what policies should we implement to avoid that possible cost? That’s outside the realm of our actual work here, but what we can say is that the problems of carbon emission and climate change are worse than what we expected previously.”

Also contributing to the study were Susan Trumbore of the Max Planck Institute for Biogeochemistry, Margaret Torn and Lydia Vaughn of the Lawrence Berkeley National Laboratory, and Jennifer Harden of Stanford University and the U.S. Geological Survey.

Study links gut microbes to childhood obesity


We’ve long been fascinated with the growing body of studies focusing on the most-long-ignored cells within our bodies, cells that outnumber all the other cells of our flesh, blood, and bones combined.

And they aren’t even our own cells.

Rather, they are the bacteria inhabiting our viscera, cells without which we would quickly wither and die.

But more than that, the bacteria, which infuse our bodies with a host of chemicals derived from the food we eat, differ within each of our bodies and the differing populations have been linked to a whole host of afflictions, ranging from links between our intestinal microbes and multiple sclerosis, rheumatoid arthritis, chronic fatigue syndrome, anorexia, Alzheimer’s disease, diabetes, and even our emotional states.

And now comes a study establishing a link between intestinal microbes and childhood obesity.

From the Endocrine Society:

Children and teenagers who are obese have different microorganisms living in the digestive tract than their lean counterparts, according to a new study published in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism.

The study is the first to find a connection between gut microbiota, also called gut flora, and fat distribution in children and teenagers.

Obesity affects 17 percent of children and teens nationwide, according to the U.S. Centers for Disease Control and Prevention. Childhood obesity is associated with an estimated $14.1 billion in additional prescription drug, emergency room visit and outpatient visit costs each year, according to the Society’s Endocrine Facts and Figures Report.

“Our findings show children and teenagers with obesity have a different composition of gut flora than lean youth,” said the study’s senior author, Nicola Santoro, MD, PhD, Associate Research Scientist in the Department of Pediatrics at Yale University in New Haven, CT. “This suggests that targeted modifications to the specific species composing the human microbiota could be developed and could help to prevent or treat early-onset obesity in the future.”

The study examined gut microbiota and weight in 84 children and teenagers who were between 7 and 20 years old. The participants included 27 youth who were obese, 35 who were severely obese, seven who were overweight and 15 who were normal weight. Researchers analyzed the participants’ gut microbiota. The participants underwent an MRI to measure body fat partitioning, provided blood samples and kept a three-day food diary.

The researchers found eight groups of gut microbiota that were linked to the amount of fat in the body. Four of the microbial communities tended to flourish in children and teens with obesity compared to their normal-weight counterparts. Smaller amounts of the other four microbial groups were found in participants who were obese compared to children and teenagers of normal weight. The gut microbiota found in youth who were obese tended to be more efficient at digesting carbohydrates than the gut flora of teenagers and children of normal weight.

In addition, the children with obesity tended to have higher levels of short chain fatty acids in the blood than children of normal weight. The study found short chain fatty acids, which are produced by some types of gut bacteria, are associated with the production of fat in the liver.

“Our research suggests that short chain fatty acids can be converted to fat within the liver and then accumulate in the fat tissue,” Santoro said. “This association could signal that children with certain gut bacteria face a long-term risk of developing obesity.”

The study, “Role of Gut Microbiota and Short Chain Fatty Acids in Modulating Energy Harvest and Fat Partitioning in Youth,” have been published online [open access] ahead of print.

Other authors of the study include: Martina Goffredo of Yale University in New Haven, CT, and Universita’ Milano Bicocca in Milan, Italy; Kendra Mass, Emily Ann McClure and Joerg Graf of the University of Connecticut in Storrs, CT; Elizabeth J. Parks of the University of Missouri in Columbia, MO; David A. Wagner of Metabolic Solutions Inc. in Nashua, NH; and Mary Savoye, Bridget Pierpont and Gary Cline of Yale University.

The research was funded by the American Heart Association, the Yale Center for Clinical Investigation, the Allen Foundation Inc., and the National Institutes of Health’s National Center for Advancing Translational Sciences.

While folk and traditional medical practitioners weren’t aware of bacteria, they devoted considerable attention to the study of our feces, the most directly observable result of the action of the interaction of intestinal bacteria, our bodies, and the foods we consume.

What we find odd is that its taken so long for Western medicine to discover the proverbial elephant in the room.

What

Scientists issue a political climate change call


Today marked a major political intervention by scientists, ubcluding 30 Nobel laureates, calling for an end to the politicizatuion of climate scientists and urging world leaders to reject calls to opt out of the Paris climate accord.

The signatories, all members of the National Academy of Sciencea, represent leading researchers from the Mericas, Europe,m Asia, and Africa.

The call to action comes as right wing populists running for office across the globe are calling climate change a hoax and rejecting calls for corporations to cut their carbon emissions.

Here’s the text of the letter, with the full list of signatories at the link:

Human-caused climate change is not a belief, a hoax, or a conspiracy. It is a physical reality. Fossil fuels powered the Industrial Revolution. But the burning of oil, coal, and gas also caused most of the historical increase in atmospheric levels of heat-trapping greenhouse gases. This increase in greenhouse gases is changing Earth’s climate.

Our fingerprints on the climate system are visible everywhere. They are seen in warming of the oceans, the land surface, and the lower atmosphere. They are identifiable in sea level rise, altered rainfall patterns, retreat of Arctic sea ice, ocean acidification, and many other aspects of the climate system. Human-caused climate change is not something far removed from our day-to-day experience, affecting only the remote Arctic. It is present here and now, in our own country, in our own states, and in our own communities.

During the Presidential primary campaign, claims were made that the Earth is not warming, or that warming is due to purely natural causes outside of human control. Such claims are inconsistent with reality.

Others argued that no action is warranted until we have absolute certainty about human impacts on climate. Absolute certainty is unattainable. We are certain beyond a reasonable doubt, however, that the problem of human-caused climate change is real, serious, and immediate, and that this problem poses significant risks: to our ability to thrive and build a better future, to national security, to human health and food production, and to the interconnected web of living systems.

The basic science of how greenhouse gases trap heat is clear, and has been for over a century. Ultimately, the strength of that basic science brought the governments of the world to Paris in December 2015. They went to Paris despite pronounced differences in systems of government, in national self-interest, in culpability for past emissions of greenhouse gases, and in vulnerability to future climate change. The leaders of over 190 countries recognized that the problem of human-caused climate change is a danger to present and future citizens of our planet. They made national commitments to address this problem. It was a small but historic and vital first step towards more enlightened stewardship of Earth’s climate system.

From studies of changes in temperature and sea level over the last million years, we know that the climate system has tipping points. Our proximity to these tipping points is uncertain. We know, however, that rapid warming of the planet increases the risk of crossing climatic points of no return, possibly setting in motion large-scale ocean circulation changes, the loss of major ice sheets, and species extinctions. The climatic consequences of exceeding such thresholds are not confined to the next one or two electoral cycles. They have lifetimes of many thousands of years.

The political system also has tipping points. Thus it is of great concern that the Republican nominee for President has advocated U.S. withdrawal from the Paris Accord. A “Parexit” would send a clear signal to the rest of the world: “The United States does not care about the global problem of human-caused climate change. You are on your own.” Such a decision would make it far more difficult to develop effective global strategies for mitigating and adapting to climate change. The consequences of opting out of the global community would be severe and long-lasting – for our planet’s climate and for the international credibility of the United States.

The United States can and must be a major player in developing innovative solutions to the problem of reducing emissions of greenhouse gases. Nations that find innovative ways of decarbonizing energy systems and sequestering CO2 will be the economic leaders of the 21st century. Walking away from Paris makes it less likely that the U.S. will have a global leadership role, politically, economically, or morally. We cannot afford to cross that tipping point.

Yet another earthquake, same epicenter


And just like the last one, less than two hours earlier, this one has been rated as a 3.0 temblor, though it felt considerably stronger, rattling our belongings, unlike the earlier shaker.

According to the U.S. Geological Survey, the quake struck at 09:31 with an epicenter three kilometers north of Casa esnl and at a depth of 11.3 kilometers, four-tenths of a kilometer nearer clear blue Southern California sky than the last one.

Given yesterday’s 2.5 shaker at the same epicenter,  we think we’re in the midst of what they call an earthquake swarm, and we sure hope things settle down soon.

Welcomed to L.A. by yet another earthquake


And the epicenter of today’s magnitude 3.0 quake was the same as yesterday’s 2.5 shaker [revised downward from the initial report of 2.7], just 3 kilometers north of the new Casa esnl in Gardena.

The U.S. Geological Center pegs the quake as a 3.0 temblor, with the epicenter 11.7 kilometers below the surface.

We could actually feel the directionality of the quake as we were sitting in front of our computer at 07:43 this morning.

Here’s the map of the quake and the range of its impact from the USGS:

blog-quake

Welcomed to Los Angeles, by an earthquake


We moved into out new apartment in Southern California on the first. And it took less than three weeks for Mother Earth to give us a welcome.

It happened at 19:50, and we were sitting on our new couch when a single sharp jolt, accompanied by a sound like a car hitting the corner of our apartment building in Gardena.

The U.S. Geological Survey earthquake site gave us the info, and we discovered the epicenter was three kilometers north of our house and registered as a 2.6 shaker.

Here’s the L.A. regional map with the quake epicenter, 11 kilometers beneath the surface, shown by the yellow star [more info on the quake here]:

blog-quake

Rising oceanic CO2 levels damage brains of fish


The latest research on the consequences of the gunger for fossil fuels, via the University of Miami Rosenstiel School of Marine and Atmospheric Science:

In a first-of-its-kind study, researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science and the ARC Centre of Excellence for Coral Reef Studies at James Cook University showed that increased carbon dioxide concentrations alters brain chemistry that may lead to neurological impairment in some fish.

Understanding the impacts of increased carbon dioxide levels in the ocean, which causes the ocean to become more acidic, allows scientists to better predict how fish will be impacted by future ocean acidification conditions.

“Coral reef fish, which play a vital role in coral reef ecosystems, are already under threat from multiple human and natural stressors,” said lead author of the study Rachael Heuer, a UM Rosenstiel School alumna which conducted the study as part of her Ph.D. work. “By specifically understanding how brain and blood chemistry are linked to behavioral disruptions during CO2 exposure, we can better understand not only ‘what’ may happen during future ocean acidification scenarios, but ‘why’ it happens.”

In this study, the researchers designed and conducted a novel experiment to directly measure behavioral impairment and brain chemistry of the Spiny damselfish, (Acanthochromis polyacanthus) a fish commonly found on coral reefs in the western Pacific Ocean.

During a three-week period, the scientists collected spiny damselfish from reefs off Lizard Island located on Australia’s Great Barrier Reef. The fish were separated into two groups–those exposed to ordinary CO2 “control” conditions and those exposed to elevated CO2 levels that are predicted to occur in the near future, but have already been observed in many coastal and upwelling areas throughout the world. Following the exposure, the fish were subjected to a behavioral test, and brain and blood chemistry were measured.

The unique behavioral test, employed a two-choice flume system, where fish were given the choice between control seawater or water containing a chemical alarm cue, which they typically avoid since it represents the smell associated with an injured fish of its own species.

The researchers found that the damselfish exposed to elevated carbon dioxide levels were spending significantly more time near the chemical alarm cue than the control fish, a behavior that would be considered abnormal. The measurements of brain and blood chemistry provided further evidence that elevated CO2 caused the altered behavior of the fish.

“For the first time, physiological measurements showing altered chemistry in brain and blood have been directly linked to altered behavior in a coral reef fish,” said UM Rosenstiel School Maytag Professor of Ichthyology and lead of the RECOVER Project Martin Grosell, the senior author of the study. “Our findings support the idea that fish effectively prevent acidification of internal body fluids and tissues, but that these adjustments lead to downstream effects including impairment of neurological function.”

“If coral reef fish do not acclimate or adapt as oceans continue to acidify, many will likely experience impaired behavior that could ultimately lead to increased predation risk and to negative impacts on population structure and ecosystem function,” said Heuer, currently a postdoctoral researcher at the University of North Texas. “This research supports the growing number of studies indicating that carbon dioxide can drastically alter fish behavior, with the added benefit of providing accurate measurements to support existing hypotheses on why these impairments are occurring.”

The study, titled Altered brain ion gradients following compensation for elevated CO2 are linked to behavioural alternations in a coral reef fish,  [open access]was published in the Sept. 13 online issue of the journal Scientific Reports. The study’s co-authors include: Rachael Heuer; Martin Grosell; Megan J. Welch and Jodie L. Rummer and Philip L. Munday from the ARC Centre of Excellence for Coral Reef Studies at James Cook University.

The National Science Foundation, a University of Miami Koczy Fellowship, and the ARC Centre of Excellence provided funding support for the study. Heuer was also funded by an NSF Graduate Research Fellowship to conduct the research.