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Notebook Science




Climate faux pas

Researchers messed up the math

A recent global warming study shows there’s still a place for skeptics in the world of science.

After a team of climate scientists announced its newly published research showing that the oceans were warming much faster than previously thought, mainstream news outlets ran with the story.

But there was a problem: The study’s math was wrong.

The researchers had asserted that between 1991 and 2016, Earth’s oceans absorbed 60 percent more heat per year than current estimates. They concluded countries would need to slash global fossil-fuel emissions by an additional 25 percent above current proposals.

Soon after Nature published the study on Oct. 31, Nicholas Lewis, an independent climate scientist, discovered an error in the authors’ calculations. When the math was corrected, the results did not show an increase in ocean heat, Lewis wrote on the blog Climate Etc.

Some mainstream climate scientists defended the error as an example of science working the way it should. “Science is a human endeavor and it’s therefore imperfect. What’s important is that results are scrutinized and replicated by others so that we can assess what is robust and what isn’t,” Gavin Schmidt, director of the Goddard Institute for Space Sciences at NASA, told the AFP news service.

But the fact that the study passed peer review and was published in the first place suggests scientists may too quickly accept anything supporting the mainstream global warming narrative. The error wasn’t difficult to find, according to Lewis: “A quick review of the first page of the paper was sufficient to raise doubts as to the accuracy of its results.”

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Joe Raedle/Getty Images

Fish killed by red tide in Sanibel, Fla. (Joe Raedle/Getty Images)


Year-long tide

Algae bloom off Florida coast has many more-than-human causes 

This month marks a full year that the noxious red tide, a harmful algae bloom that can kill fish and cause respiratory irritation in humans, has plagued the Florida coast. These algae blooms are nothing new for Florida, but the long duration of this one has some environmentalists pinning the blame on global warming and other human activities.

But other experts caution that red tides in Florida go as far back as the time of the Spanish explorers, long before human activity caused much impact. And the current bloom is not that unusually long, according to David Shormann, a marine chemist. Between 2004 and 2006 Florida experienced a bloom that lasted 17 months, and a 21-month bloom occurred a few years before that, he wrote in an op-ed for the Cornwall Alliance for the Stewardship of Creation.

A combination of interrelated processes causes algae blooms, Shormann explained. Tropical weather systems and trade winds carry iron-rich dust from the Sahara Desert that settles in the Gulf of Mexico in the late summer and early fall. The iron enables blue-green algae to flourish, and that algae converts nitrogen gas to nitrate. Karenia brevis, the red tide algae, needs nitrate, so Karenia blooms follow close on the heels of blue-green blooms. The toxins from Karenia kill certain kinds of fish whose decomposition releases more nutrients that allow the Karenia to continue blooming.

Also, Florida soil is naturally rich with phosphorous, another key nutrient for algae. When it rains, phosphorous from the soil makes its way to the coastal waters, feeding the blooms even further.

Fertilizers and sewage also contain nitrogen and phosphorous compounds, Shormann noted, and farmers should do everything they can to keep their soil and fertilizer out of the sea. But, he said, much of what causes red tides has nothing to do with human activity.

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Jack Guez/AFP/Getty Images

(Jack Guez/AFP/Getty Images)


Abuzz over glyphosate

A weed killer’s effect on microbes may be linked to bee deaths 

Scientists say honey bee populations continue a serious, mysterious decline around the world, and that’s a problem for the agriculture industry, which relies on bees for pollination. Now a study suggests that glyphosate, the world’s most widely used weed killer, may be harming the insects.

According to the study, published Sept. 24 in the Proceedings of the National Academy of Sciences, glyphosate disrupts microbes in the bees’ digestive system, making them vulnerable to deadly infections. Previously, researchers did not consider the chemical a threat to insects and animals because it targets a cellular pathway that only plants and some bacteria possess.

In the PNAS study, researchers gave hundreds of bees a syrup containing glyphosate doses that mimicked the environmental levels bees would encounter if foraging among flowering weeds. They then compared those bees to another group of bees that received syrup without glyphosate.

After three days, the scientists found significantly lower levels of S. alvi, a bacterium that appears to protect bees from dangerous infections, in the bees that received glyphosate. Only 12 percent of the bees that ingested the chemical survived an infection caused by a bacterium commonly found in trace amounts in beehives. By comparison, 47 percent of the glyphosate-free bees survived the infection.

What about glyphosate and human microbiomes? According to Science magazine, humans likely encounter only very low exposure to glyphosate, and their guts harbor different microbes than bees’.


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