Tagged: University of Florida

Successful experiment to simulate warming of Arctic permafrost

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Although vegetation growth in the Arctic is boosted by global warming, it’s not enough to offset the carbon released by the thawing of the permafrost beneath the surface, University of Florida researchers have found in the first experiment in the Arctic environment to simulate thawing of permafrost in a warming world.

Twice as much carbon is frozen in Arctic permafrost as exists in the atmosphere today, and what happens to it as it thaws – releasing greenhouse gases that fuel climate change – is a key question, said professor Ted Schuur…

“The plants like it when they’re warmer, so their growth is increasing, and if you just watch the tundra in the summertime and you look at the balance between what the plants are doing and what the soil is doing, the plants actually offset everything that happens in the soil. They’re growing faster, getting bigger and taking carbon out of the air,” Schuur said. “From the perspective of climate change, that’s a good thing, tundra vegetation is making up for any carbon you’re losing from the soil.”

The hitch? The Arctic’s short summers do not make up for the long winters.

Researchers are interested in the permafrost of the polar regions because these soils – permanently frozen at great depths and for tens of thousands of years – are vulnerable to global warming…

As the experiment continues into the next three-year cycle, Schuur said he is looking for a point at which the plants hit a growth limit and stop absorbing more carbon, while the thawing permafrost continues to release carbon…

One of the successes of the experiment, Schuur said, was finding a way to model carbon release from permafrost in the environment on a year-round basis. Previous studies had used miniature greenhouses in summer months, but creating a warming situation in the winter was more challenging.

“We wanted to warm the tundra and cause the permafrost to recede. This is the first experiment to isolate that effect in the field, so the first thing we show is that we’re able to simulate what will happen in a future world when the permafrost degrades,” Schuur said…

The studies confirm that a significant amount of carbon is released from thawing permafrost and highlight that there are factors beyond simply temperature that affect carbon release, Schuur said.

New variables identified by Professor Schuur and postdoc researcher Susan Natali range from water content to the ratio of nitrogen to carbon in the permafrost soil.

There’s the added existential fillip that these researchers are staff at a university in Florida – therefore they’re overseen by politicians and ideologues who refuse to accept any scientific acknowledgement of climate change.

In fact, there is at least one city in another neo-Confederate state where local politicians made it illegal for public funds to be used to publish any document describing sea levels as rising – even though that happens to be a problem in that city. :)

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Something else the US gave to the world: red imported fire ants!

Red imported fire ant invasions around the globe in recent years can now be traced to the southern U.S., where the nuisance insect gained a foothold in the 1930s, new University of Florida research has found.

Native to South America, the ant had been contained there and in the southeastern U.S. before turning up in faraway places in the last 20 years — including California, China, Taiwan, Australia and New Zealand…

The team’s findings could prove helpful in finding new ways to control the invasive species, Solenopsis invicta, Ascunce said. Americans spend more than $6 billion a year to control the ants and offset damage they cause, including medical expenses and $750 million in agricultural losses.

Fire ants are very annoying pests, and they cause people to suffer,” Marina Ascunce said. “People who are allergic can die (from ant stings).” Red imported fire ants are highly aggressive. They have a painful sting, often discovered by humans only after stepping on a mound.

The research team used several types of molecular genetic markers to trace the origins of ants in nine locations where recent invasions occurred. They traced all but one of the invasions to the southern U.S. The exception was an instance where the ants moved from the southeastern U.S. to California, then to Taiwan.

“I thought that at least one of the populations in the newly invaded areas would have come from South America, but all of the genetic data suggest the most likely source in virtually every case was the southern U.S.,” she said.

The study results show the problematic side of a robust global trade and travel network.

RTFA for details on how folks combat the mean little critters. Resign yourself to the fact that all the efforts to keep dangerous volunteer species, animal, vegetable and insectivorous – effective in the past – will need to be upgraded continually in a global economy. :)

Lice DNA shows when humans started wearing clothes

A new University of Florida study following the evolution of lice shows modern humans started wearing clothes about 170,000 years ago, a technology which enabled them to successfully migrate out of Africa.

Principal investigator David Reed, associate curator of mammals at the Florida Museum of Natural History on the UF campus, studies lice in modern humans to better understand human evolution and migration patterns. His latest five-year study used DNA sequencing to calculate when clothing lice first began to diverge genetically from human head lice…

“We wanted to find another method for pinpointing when humans might have first started wearing clothing,” Reed said. “Because they are so well adapted to clothing, we know that body lice or clothing lice almost certainly didn’t exist until clothing came about in humans.”

The data shows modern humans started wearing clothes about 70,000 years before migrating into colder climates and higher latitudes, which began about 100,000 years ago. This date would be virtually impossible to determine using archaeological data because early clothing would not survive in archaeological sites.

The study also shows humans started wearing clothes well after they lost body hair, which genetic skin-coloration research pinpoints at about 1 million years ago, meaning humans spent a considerable amount of time without body hair and without clothing, Reed said…

Lice are studied because unlike most other parasites, they are stranded on lineages of hosts over long periods of evolutionary time. The relationship allows scientists to learn about evolutionary changes in the host based on changes in the parasite…

Picture some True Believer accidentally wandering onto campus and bumping into an undergraduate student who knows more about the evolution of humans than some out-of-date book still copyright by the Royal family of England – since 1611.

I’m not certain I could keep a straight face long enough to discuss Apples, serpents and shame.

Where was all that CO₂ stored at the end of the Ice Age?

New University of Florida research puts to rest the mystery of where old carbon was stored during the last glacial period. It turns out it ended up in the icy waters of the Southern Ocean near Antarctica.

The findings have implications for modern-day global warming, said Ellen Martin, a UF geological sciences professor and an author of the paper, which is published in this week’s journal Nature Geoscience.

“It helps us understand how the carbon cycle works, which is important for understanding future global warming scenarios,” she said. “Ultimately, a lot of the carbon dioxide that we’re pumping into the atmosphere is going to end up in the ocean. By understanding where that carbon was stored in the past and the pathways it took, we develop a better understanding of how much atmospheric carbon dioxide the oceans can absorb in the future…”

The implications are that while large amounts of carbon could be stored in the ocean when there was a great deal of sea ice, the opposite is the case in a world that is warming, with less ice, which allows more carbon dioxide to be released into the atmosphere, Martin said. Thus, in a warming scenario the oceans may not be able to store as much carbon dioxide as they could under glacial conditions

The oceans are a critical part of the carbon dioxide cycle, Martin said. “The oceans have 60 times more carbon dioxide in them than the atmosphere, so when we worry about what’s happening with carbon dioxide in the atmosphere, we often look to the oceans as a potential source or sink.”

The concentration of carbon dioxide in the atmosphere during the glacial periods was about 200 parts per million, compared with 280 parts per million during a typical interglacial period, Martin said. Today that level has soared to about 380 parts per million, she said.

The time period that encompasses the last glacial period to the current interglacial period when carbon dioxide levels went up very quickly is often referred to as the “mystery interval” because scientists hadn’t known where the carbon was stored, Martin said.

“Now we have a better understanding of how the system worked,” she said.

Bravo! Deeper understanding, another avenue opened for investigation for those paleoclimatologists working hard at becoming forecasters.

Better wages if you’re overweight – if you’re a man

We have posted before on how obese women have a far harder time climbing the career ladder than their slimmer female counterparts, while men actually improve their chances of reaching the corner office when they gain weight.

Now, a new study goes a step further by showing that employers seem to treat women exactly the way the fashion industry does – by rewarding very thin women with higher pay, while penalizing average-weight women with smaller paychecks. Very thin men, on the other hand, tend to get paid less than male workers of average weight. Men earn more as they pack on the pounds – all the way to the point where they become obese, when the pay trend reverses.

The study is the first look at the effects of being very thin on men vs. women…led by Timothy A. Judge of the University of Florida found very thin women, weighing 25 pounds less than the group norm, earned an average $15,572 a year more than women of normal weight. Women continued to experience a pay penalty as their weight increased above average levels, although a smaller one — presumably because they had already violated social norms for the ideal female appearance. A woman who gained 25 pounds above the average weight earned an average $13,847 less than an average-weight female.

Men were also penalized for violating stereotypes about ideal male appearance, but in a different way. Thin guys earned $8,437 less than average-weight men. But they were consistently rewarded for getting heavier, a trend that tapered off only when their weight hit the obese level. In one study, the highest pay point, on average, was reached for guys who weighed a strapping 207 pounds…

Do you see body-image stereotypes at work in your workplace?

BTW, Professor Judge has a good thing going. He did a related study in 2003 which indicated that taller people made more money.