Category: Global Warming

Species Shifting Their Range Due to Climate Change May Have Enabled the “Playing Around With Resources” That Invented Farming

(p. D6) In the 1990s, archaeologists largely concluded that farming in the Fertile Crescent began in Jordan and Israel, a region known as the southern Levant. “The model was that everything started there, and then everything spread out from there, including maybe the people,” said Melinda A. Zeder, a senior research scientist at the Smithsonian National Museum of Natural History.

But in recent years, Dr. Zeder and other archaeologists have overturned that consensus. Their research suggests that people were inventing farming at several sites in the Fertile Crescent at roughly the same time. In the Zagros Mountains of Iran, for example, Dr. Zeder and her colleagues have found evidence of the gradual domestication of wild goats over many centuries around 10,000 years ago.

People may have been cultivating plants earlier than believed, too.

In the 1980s, Dani Nadel, then at Hebrew University, and his colleagues excavated a 23,000-year-old site on the shores of the Sea of Galilee known as Ohalo II. It consisted of half a dozen brush huts. Last year, Dr. Nadel co-authored a study showing that one of the huts contained 150,000 charred seeds and fruits, including many types, such as almonds, grapes and olives, that would later become crops. A stone blade found at Ohalo II seemed to have been used as a sickle to harvest cereals. A stone slab was used to grind the seeds. It seems clear the inhabitants were cultivating wild plants long before farming was thought to have begun.

“We got fixated on the very few things we just happened to see preserved in the archaeological record, and we got this false impression that this was an abrupt change,” Dr. Zeder said. “Now we really understand there was this long period where they’re playing around with resources.”

Many scientists have suggested that humans turned to agriculture under duress. Perhaps the climate of the Near East grew harsh, or perhaps the hunter-gatherer population outstripped the supply of wild foods.

But “playing around with resources” is not the sort of thing people do in times of desperation. Instead, Dr. Zeder argues, agriculture came about as climatic changes shifted the ranges of some wild species of plants and animals into the Near East.

Many different groups began experimenting with ways of producing extra food, which eventually enabled them to start a new way of life: settling down in more stable social groups.

For the full story see:

Carl Zimmer. “The First Farmers.” The New York Times (Tuesday, October 18, 2016 [sic]): D1 & D6.

(Note: the online version of the story has the date Oct. 17, 2016 [sic], and has the title “How the First Farmers Changed History.”)

The 2015 study co-authored by Dani Nadel and mentioned above is:

Snir, Ainit, Dani Nadel, Iris Groman-Yaroslavski, Yoel Melamed, Marcelo Sternberg, Ofer Bar-Yosef, and Ehud Weiss. “The Origin of Cultivation and Proto-Weeds, Long before Neolithic Farming.” PLOS ONE 10, no. 7 (July 22, 2015): e0131422.

When Ocean Temperatures Dropped 30 Million Years Ago, Some Species Migrated to Warmer Waters; Others Developed New Traits

(p. D2) The Southern Ocean around Antarctica was once warmer. Then about 30 million years ago, the temperature dropped. Few fish could survive temperatures that were just above seawater’s freezing point, and they either migrated to warmer waters or went extinct.

One bottom-dweller held on. Through the power of natural selection, its descendants developed traits that let them survive these unlikely conditions. Today, the Antarctic blackfin icefish, or Chaenocephalus aceratus, thrives in these frigid waters with no scales, blood as clear as water and bones so thin, you can see its brain through its skull.

For the full story see:

JoAnna Klein. “Skullduggery: It’s Not Hard to See How His Brain Works.” The New York Times (Tuesday, March 5, 2019 [sic]): D2.

(Note: the online version of the story has the date Feb. 28, 2019 [sic], and has the title “How the Icefish Got Its Transparent Blood and See-Through Skull.”)

The article quoted above references the following academic article:

Kim, Bo-Mi, Angel Amores, Seunghyun Kang, Do-Hwan Ahn, Jin-Hyoung Kim, Il-Chan Kim, Jun Hyuck Lee, Sung Gu Lee, Hyoungseok Lee, Jungeun Lee, Han-Woo Kim, Thomas Desvignes, Peter Batzel, Jason Sydes, Tom Titus, Catherine A. Wilson, Julian M. Catchen, Wesley C. Warren, Manfred Schartl, H. William Detrich, John H. Postlethwait, and Hyun Park. “Antarctic Blackfin Icefish Genome Reveals Adaptations to Extreme Environments.” Nature Ecology & Evolution 3, no. 3 (March 2019): 469-78.

Repeated Interbreeding of Brown Bears and Polar Bears Illustrates Fuzziness of Defining a Species

(p. D1) Naturalists have been trying for centuries to catalog all of the species on Earth, and the effort remains one of the great unfinished jobs in science. So far, researchers have named about 2.3 million species, but there are millions — perhaps even billions — left to be discovered.

As if this quest isn’t hard enough, biologists cannot agree on what a species is. A 2021 survey found that practicing biologists used 16 different approaches to categorizing species. Any two of the scientists picked at random were overwhelmingly likely to use different ones.

“Everyone uses the term, but no one knows what it is,” said Michal Grabowski, a biologist at the University of Lodz in Poland.

The debate over species is more than an academic pastime. In the current extinction crisis, scientists urgently need to take stock of the world’s biological diversity.

. . .

(p. D4) As scientists gather more genetic data, fresh questions are emerging about what seem, on the surface, to be obviously separate species.

You don’t have to be a mammalogist to understand that polar bears and brown bears are different. Just one look at their white and brown coats will do.

The difference in their colors is the result of their ecological adaptations. White polar bears blend into their Arctic habitats, where they hunt for seals and other prey. Brown bears adapted for life on land further south. The differences are so distinct that paleontologists can distinguish fossils of the two species going back hundreds of thousands of years.

And yet the DNA inside those ancient bones is revealing an astonishing history of interbreeding between polar bears and brown bears. After the two lineages split about half a million years ago, they exchanged DNA for thousands of years. They then became more distinct, but about 120,000 years ago they underwent another extraordinary exchange of genes.

Between 25,000 and 10,000 years ago, the bears interbred in several parts of their range. The exchanges have left a significant imprint on bears today: About 10 percent of the DNA in brown bears comes from polar bears.

Beth Shapiro, a paleogeneticist at the University of California, Santa Cruz, said that the interbreeding most likely occurred when swings in the climate forced polar bears down from the Arctic and into brown bear territory.

For the full story see:

Carl Zimmer. “Defining A Species Is Open To Debate.” The New York Times (Tuesday, February 20, 2024): D1 & D4.

(Note: ellipsis added.)

(Note: the online version of the story has the date February 19, 2024, and has the title “What Is a Species, Anyway?”)

The 2021 survey mentioned above was more fully detailed in:

Stankowski, Sean, and Mark Ravinet. “Quantifying the Use of Species Concepts.” Current Biology 31, no. 9 (May 10, 2021): R428-R429.

Life Was Resilient Even in the Face of Earth’s Greatest Disaster

(p. D2) The asteroid moved 24 times faster than a rifle bullet as it struck Earth some 66 million years ago. Its supersonic shock wave flattened trees across North and South America, and its heat wave sparked incomprehensibly large forest fires.

The event lofted so much debris into the atmosphere that photosynthesis shut down. The non-avian dinosaurs disappeared. And nearly 75 percent of all species were extinguished.

. . .

But even at ground zero, life managed to return, and quickly.

New findings published in the journal Geology . . . [online on January 17, 2020 [sic]] revealed that cyanobacteria — blue-green algae responsible for harmful toxic blooms — moved into the crater a few years after the impact.

For the full story see:

Shannon Hall. “Small Survivors: They Were Left Off Killer Asteroid’s Hit List.” The New York Times (Tuesday, February 18, 2020 [sic]): D2.

(Note: ellipses, and bracketed date, added.)

(Note: the online version of the story has the date Feb. 1, 2020 [sic], and has the title “Asteroid That Killed the Dinosaurs Was Great for Bacteria.” Where the wording differs between the versions, the passages quoted above follow the usually more detailed wording of the online version.)

The findings published in Geology and mentioned above appear in the article:

Schaefer, Bettina, Kliti Grice, Marco J.L. Coolen, Roger E. Summons, Xingqian Cui, Thorsten Bauersachs, Lorenz Schwark, Michael E. Böttcher, Timothy J. Bralower, Shelby L. Lyons, Katherine H. Freeman, Charles S. Cockell, Sean P.S. Gulick, Joanna V. Morgan, Michael T. Whalen, Christopher M. Lowery, and Vivi Vajda. “Microbial Life in the Nascent Chicxulub Crater.” Geology 48, no. 4 (2020): 328-32.

Humans’ Adaptive, Flexible Intelligence Evolved Where Climate “Change Was Dramatic, Frequent, Unpredictable and Stressful”

(p. C9) In “Origins: How Earth’s History Shaped Human History,” astrobiologist and professor of science communication Lewis Dartnell argues that “there is a clear causal chain taking us from the politics and socio-economic conditions of today, to their roots in historical agricultural systems, and then further back to the geological tapestry of the ground beneath our feet.”

. . .

The final sentence he offers as summation—“The Earth made us”—can be read two ways, capturing the parallel themes of “Origins.”

With emphasis on “us,” it refers to the origin of the genus Homo, a clade of naked apes giving rise to our species, H. sapiens, the greatest biological superpower of all time, one so potent that all others in our genus are extinct. Why did this emergence take place in the cradle of the East African Rift and nowhere else? And why did the arrival of our genus broadly coincide with the onset of high-frequency climatic swings about two million years ago? Mr. Dartnell concludes that this recently uplifted and intricately rifted landscape created a mosaic of habitats dominated by lakes that further amplified the climatic oscillations between dry-wet and hot-cool conditions. Change was dramatic, frequent, unpredictable and stressful. Thus “intelligence” became “the evolutionary solution to the problem of an environment that shifts faster than natural selection can adapt the body . . . driving . . . ever more flexible and intelligent behavior.”

For the full review, see:

Robert M. Thorson. “The Earth and Us.” The Wall Street Journal (Saturday, April 23, 2022 [sic]): C9.

(Note: ellipsis between paragraph, added; ellipses within paragraph, in original.)

(Note: the online version of the review has the date May 9, 2019 [sic], and has the title “‘Origins’ Review: The Earth and Us.”)

The book under review is:

Dartnell, Lewis. Origins: How Earth’s History Shaped Human History. New York: Basic Books, 2019.

Low Water Level of Panama Canal Due to El Niño, Not Due to Global Warming

(p. D5) The recent drought in the Panama Canal was driven not by global warming but by below-normal rainfall linked to the natural climate cycle El Niño, an international team of scientists has concluded.

. . .

The scientists found that scant rain, not high temperatures that cause more water to evaporate, was the main reason for low water in the canal’s reservoirs. The weather records suggest that wet-season rainfall in Panama has decreased modestly in recent decades. But the models don’t indicate that human-induced climate change is the driver.

“We’re not sure what is causing that slight drying trend, or whether it’s an anomaly, or some other factor that we haven’t taken into account,” said Clair Barnes, a climate researcher at Imperial College London who worked on the analysis. “Future trends in a warming climate are also uncertain.”

El Niño, by contrast, is much more clearly linked with below-average rainfall in the area, the scientists found. In any given El Niño year, there’s a 5 percent chance that rainfall there will be as low as it was in 2023, they estimated.

For the full story see:

Raymond Zhong. “Study Acquits Global Warming in Drought at Panama Canal.” The New York Times (Thursday, May 2, 2024): A9.

(Note: bracketed date added.)

(Note: the online version of the story has the date May 1, 2024, and has the title “Drought That Snarled Panama Canal Was Linked to El Niño, Study Finds.”)

The report co-authored by Clair Barnes and mentioned above is:

Barnes, Claire, Steve Paton, RF Stallard, H De Lima, B Clarke, M Vahlberg, S Sivanu, A Amakona, K Izquierdo, F Otto, M Zachariah, S Philip, M Mistry, R Singh, and J Arrighi. “Low Water Levels in Panama Canal Due to Increasing Demand Exacerbated by El Niño Event.” In World Weather Attribution Report, May 1, 2024.

Volcanoes Are Proof of Concept That Geoengineering Can Counter Global Warming

(p. C11) ‘Volcanoes get a bad press,” Clive Oppenheimer writes at the beginning of “Mountains of Fire: The Menace, Meaning, and Magic of Volcanoes.”

. . .

Most people know that erupting volcanoes can affect the climate. But there are nuances: “You might expect that volcanoes, with burning flames, spewing molten hot lava and searing ash, would heat up the planet, but in fact they do the opposite.” An addendum, also counterintuitive: “Though several factors . . . influence how much an eruption cools the climate, it is the amount of sulphur blasted into the stratosphere that is critical.”

. . .

. . ., Mr. Oppenheimer’s scientific expertise is what’s most important—for his book and for the rest of us.

For the full review, see:

Howard Schneider. “Explorer of the Underworld.” The Wall Street Journal (Saturday, Oct. 7, 2023): C11.

(Note: ellipses added.)

(Note: the online version of the review has the date October 6, 2023, and has the title “‘Mountains of Fire’ Review: The Vital Volcano.”)

The book under review is:

Oppenheimer, Clive. Mountains of Fire: The Menace, Meaning, and Magic of Volcanoes. Chicago: University of Chicago Press, 2023.

In Australia and Japan “Coral Appear to Be Migrating Poleward”

(p. A9) Scientists are still learning about corals’ ability to adapt to climate change. Efforts are underway to breed coral that tolerate higher temperatures. In a few places, including Australia and Japan, coral appear to be migrating poleward, beginning to occupy new places.

For the full story see:

Catrin Einhorn. “Scientists Say Rising Ocean Temperatures Are Damaging Coral Reefs Around the World.” The New York Times (Tuesday, April 16, 2024): A9.

(Note: the online version of the story has the date April 15, 2024, and has the title “The Widest-Ever Global Coral Crisis Will Hit Within Weeks, Scientists Say.”)

Too Little Carbon Dioxide Caused Earth to Be a Frigid Barren “Snowball” for 56 Million Years

(p. D4) Around 717 million years ago, Earth’s humid landscapes and roiling blue waters transformed into a frigid, barren world. Scientists nicknamed this stage of geological history, and others like it, Snowball Earth.

What exactly froze the planet nearly solid has been a mystery, as has how it remained that way for 56 million years. On Wednesday, a team of researchers at the University of Sydney said they have it figured out. Earth’s glaciation, they say, may have come from a global drop in carbon dioxide emissions, a result of fewer volcanoes expelling the gas into the atmosphere.

Less carbon dioxide makes it more difficult for Earth’s atmosphere to trap heat. If the depletion were extreme enough, they argued, it could have thrust the planet into its longest ice age yet.

The theory, published in the journal Geology, adds insight to the way geological processes influenced Earth’s past climate. It may also help scientists better understand trends in our current climate.

. . .

Dr. Dutkiewicz and her colleagues turned their eyes to volcanoes because of a newly available model of Earth’s shifting tectonic plates. As the continents spread apart, they studied the changing length of the mid-ocean ridge — a chain of underwater volcanoes — predicted by the model.

The team then calculated the amount of volcanic gas emissions at the beginning of, and throughout, the ice age. Their results showed a drop in atmospheric carbon dioxide sufficient to initiate and sustain a 56-million-year glaciation.

A reduction in volcanic gas emissions has been proposed as an explanation for Snowball Earth before. But according to Dr. Dutkiewicz, this is the first time researchers have proved that the mechanism was viable through modeled computations.

For the full commentary, see:

Katrina Miller. “How Earth Stayed Frozen for So Long.” The New York Times (Tuesday, February 13, 2024): D4.

(Note: ellipsis added.)

(Note: the online version of the commentary was updated February 12, 2024, and has the title “How Earth Might Have Turned Into a Snowball.”)

The paper in the journal Geology mentioned above is:

Dutkiewicz, Adriana, Andrew S. Merdith, Alan S. Collins, Ben Mather, Lauren Ilano, Sabin Zahirovic, and R. Dietmar Müller. “Duration of Sturtian “Snowball Earth” Glaciation Linked to Exceptionally Low Mid-Ocean Ridge Outgassing.” Geology 52, no. 4 (2024): 292-96.

Carbon Dioxide Greens the Earth as Plants Slow Global Warming

(p. D3) For decades, scientists have been trying to figure out what all the carbon dioxide we have been putting into the atmosphere has been doing to plants. It turns out that the best place to find an answer is where no plants can survive: the icy wastes of Antarctica.

As ice forms in Antarctica, it traps air bubbles. For thousands of years, they have preserved samples of the atmosphere. The levels of one chemical in that mix reveal the global growth of plants at any point in that history.

“It’s the whole Earth — it’s every plant,” said J. Elliott Campbell of the University of California, Merced.

Analyzing the ice, Dr. Campbell and his colleagues have discovered that in the last century, plants have been growing at a rate far faster than at any other time in the last 54,000 years. Writing in the journal Nature, they report that plants are converting 31 percent more carbon dioxide into organic matter than they were before the Industrial Revolution.

. . .

Since plants depend on carbon dioxide to grow, scientists have long wondered if that extra gas might fertilize them.

. . .

In the mid-2000s, atmospheric scientists discovered a powerful new way to measure plant growth: by studying an unimaginably rare molecule called carbonyl sulfide.

Carbonyl sulfide — a molecule made of a carbon atom, a sulfur atom and an oxygen atom — is present only in a few hundred parts per trillion in the atmosphere. That is about a million times lower than the concentration of carbon dioxide. Decaying organic matter in the ocean produces carbonyl sulfide, a gas that then floats into the atmosphere.

Plants draw in carbonyl sulfide along with carbon dioxide. As soon as it enters their tissues, they destroy it. As a result, the level of carbonyl sulfide in the air drops as plants grow.

. . .

But Dr. Campbell and his colleagues found that it hasn’t increased very much. As we have been adding carbonyl sulfide to the atmosphere, plants have been pulling it out. In fact, the scientists found, they have been pulling it out at a staggering rate.

“The pace of change in photosynthesis is unprecedented in the 54,000-year record,” Dr. Campbell said. While photosynthesis increased at the end of the ice age, he said, the current rate is 136 times as fast.

With all that extra carbon dioxide going into plants, there has been less in the air to contribute to global warming. The planet has warmed nearly 2 degrees Fahrenheit since 1880, but it might be even hotter if not for the greening of the Earth.

For the full commentary, see:

Carl Zimmer. “MATTER; A Global Greening.” The New York Times (Tuesday, April 11, 2017 [sic]): D3.

(Note: ellipses added.)

(Note: the online version of the commentary has the date April 5, 2017 [sic], and has the title “MATTER; Antarctic Ice Reveals Earth’s Accelerating Plant Growth.”)

The paper in Nature mentioned above is:

Campbell, J. E., J. A. Berry, U. Seibt, S. J. Smith, S. A. Montzka, T. Launois, S. Belviso, L. Bopp, and M. Laine. “Large Historical Growth in Global Terrestrial Gross Primary Production.” Nature 544, no. 7648 (April 16, 2017 [sic]): 84-87.

Musk Calls German Anti-Electric-Vehicle Ecoactivists “Dumber Than a Doorstop”

(p. B1) GRÜNHEIDE, Germany—When Tesla opened its first full-scale European factory in this sleepy community outside of Berlin, Elon Musk was feted as a hero, the chancellor gave a speech and workers cheered the rollout of new Model Ys.

On Wednesday [March 13, 2024], almost two years to the day later, Musk was back, this time to cheer up workers after an act of sabotage by suspected eco-activists shut down the plant for more than a week.

. . .

Tesla didn’t respond to requests for comment on the various incidents. In a post on his X social-media platform, Musk has called the eco-activists “dumber than a doorstop” for their criticism of electric vehicles.

As the plant’s managers and workers gathered in a tent on the factory grounds for a “team huddle” on Wednesday, Musk could be seen carrying his son. Hoisting the boy onto his shoulders amid calls of “Elon, Elon,” he shouted back: “They can’t stop us!” and “Ich liebe Dich!”—German for “I love you.”

As he left, reporters asked him whether he was still committed to expanding the plant and producing vehicles in Germany.

“Yes, absolutely,” he said. “Germany rocks!”

For the full story, see:

William Boston. “Tesla Faces Blowback in Germany.” The Wall Street Journal (Friday, March 15, 2024): B1-B2.

(Note: ellipses, and bracketed date, added.)

(Note: the online version of the story has the date March 14, 2024, and has the title “Elon Musk’s Plans to Conquer Europe Collide With Germany’s Culture Wars.”)