Climate Change, Nature, Science

Global Warming Hiatus? Not So Much

The "global warming hiatus" really wasn't. Read more in this post.
Arctic glaciers. Photo: Shutterstock

New data from the University of Alaska Fairbanks shows that missing Arctic temperature data, not the climate, created the seeming “pause” of global warming from 1998 to 2012.

In fact, the improved datasets the researchers gathered shows that the Arctic warmed six times faster than the global average during the so-called global warming hiatus.

Atmospheric scientist Xiangdong Zhang collaborated with colleagues at Tsinghua University in Beijing and Chinese agencies studying Arctic warming to analyze temperature data collected from buoys in the Arctic Ocean.

“We recalculated the average global temperatures from 1998 to 2012 and found that the rate of global warming had continued to rise at 0.112 degrees C per decade instead of slowing down to 0.05 degrees C per decade as previously thought,” Zhang said.

How did the data lead scientists down the wrong path before?

Most current estimates use global data that represents a long timespan and provides good coverage of a global geographic area. But the Arctic, being so remote, lacks a comprehensive network of instruments to collect accurate temperature data.

To improve the dataset, Zhang’s team relied on temperature data collected from the International Arctic Buoy Program at the University of Washington. For global data, the team used newly corrected sea surface temperatures provided by the National Oceanic and Atmospheric Administration. By doing so, the team was able to re-estimate the average global temperatures during that time with more accurate and representative data.

The global warming hiatus is a hotly debated topic among climate scientists. Some say that an unusually warm El Niño in 1997-1998, followed by an extended period afterward that didn’t have an El Niño may have disrupted global warming.

It was a nice dream, but unfortunately, the new data sets and resulting estimates prove conclusively that global warming did not pause at all. Not only that, but until recently, scientists didn’t consider the Arctic big enough to greatly influence global temperatures.

“The Arctic is remote only in terms of physical distance,” Zhang said. “In terms of science, it’s close to every one of us. It’s a necessary part of the equation and the answer affects us all.”

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Nature, oceans

New Study Says Sea Animals Eat Plastic Because of Its Taste

A new study says that sea animals may like plastic because it tastes good.
These coral polyps are feeding–and most likely ingesting lots of microplastics in the process. Photo: Shutterstock

Scientists have long known that plastic in the oceans can mimic prey, causing huge problems for sea life. But what they didn’t know is that even corals eat plastic.

Corals don’t have eyes, and they don’t move from their location, so why would they eat plastic? Apparently because it tastes good, according to a recent study from Duke University.

This taste factor may also be true for other sea life. After all, anecdotal evidence suggests that our cats and dogs eat plastic because they like the taste and/or the texture, so why wouldn’t sea life have the same reaction?

Microplastics, tiny pieces of weathered plastic less than 5 millimeters in diameter, have been accumulating in the world’s oceans for 40 years or more, and now they’re ubiquitous in the marine environment. They don’t just pose threats to corals, they also pose a threat to foraging sea animals including birds, turtles, mammals, and invertebrates.

Because plastic is largely indigestible, it can lead to intestinal blockages, create a false sense of fullness, or reduce energy reserves in animals that eat it.

“About eight percent of the plastic that coral polyps in our study ingested was still stuck in their guts after 24 hours,” said study co-lead author Austin S. Allen, a Ph.D. student at Duke.

Plastics can also leach hundreds of chemical compounds into the bodies of the creatures that eat it and into the environment as well. The biological effects of most plastic compounds are unknown, but we do know that some have already been shown to cause harm. For example, phthalates are confirmed environmental estrogens and androgens—that is, hormones that affect sex determination.

“Corals in our experiments ate all types of plastics, but preferred unfouled microplastics by a threefold difference over microplastics covered in bacteria,” Allen said.

“When plastic comes from the factory, it has hundreds of chemical additives on it. Any one of these chemicals or a combination of them could be acting as a stimulant that makes plastic appealing to corals,” said Alexander C. Seymour, a GIS analyst at Duke, who co-led the study with Allen.

The researchers hope their findings will encourage more scientists to study the role taste plays in determining why marine animals ingest microplastics.

“Ultimately, the hope is that if we can manufacture plastic so it unintentionally tastes good to these animals, we might also be able to manufacture it so it intentionally tastes bad,” Seymour said. “That could significantly help reduce the threat these microplastics pose.”

Conservation, Nature

Parrot Population Threatened By Human Activity

Almost 40 percent of the wild parrot population in the Neotropics is being endangered by hunting and habitat encroachment.
A pair of scarlet macaws in flight. Photo: Shutterstock

A new paper published in the journal Biological Conservation shows that more than 38 percent of the Neotropical parrot population of the American continent (Neotropic) is endangered by human activity.

The main dangers: hunting for the local and international trade, and loss of natural habitat.

Despite the fact that the Wild Bird Conservation Act (1992) and the permanent ban on wild bird trade set by the European Union in 2007, capture for the pet trade has been one of the main threats to wild parrots in the Neotropic region. In Africa, the trade of the gray parrot played the main part in its local extinction in Ghana and other areas of Africa. In Brazil, some of the most threatened species are the Spix’s Macaw and the Red-tailed Amazon. The sun parakeet and brown-backed parrotlet are also vulnerable because of their already-small population sizes.

Although the laws are designed to protect these and other birds, the legal and illegal trade of birds is still a problem in South America, Southeastern Asia, and the Middle East. Mexico and Nicaragua have reinforced their laws to protect wild parrots, but other South and Central American countries still have high levels of bird trade.

Regarding natural habitat, agricultural activity, large-scale logging, and other human activities are contributing to the parrots’ decline. Although the study estimates about 38 percent of the local species are threatened, the experts think the real numbers could be worse.

“It would be necessary to promote actions aimed at the effective preservation of habitats and preserved natural areas,” said researcher Juan Carlos Guix. “Moreover, it should be necessary to create social and educational programs with the people who live around the natural preserved areas, and provide security and the illegal trade audit with more resources.”

The study was conducted by an international team of 101 experts from 76 institutions and non-governmental organizations.

Nature, Science

The Dog Domestication Date Debate Has Been (Sort Of) Resolved

The dog domestication date debate may have been resolved, thanks to scientists from Cornell.
Photo: Shutterstock

You might not know this, but there are two distinct arguments about when dogs were domesticated. One group believes dogs were domesticated in the Paleolithic age (more than 17,000 years ago), and another believes dogs were domesticated much later, in the Neolithic age (17,000 to 7,000 years ago).

So, when exactly were dogs domesticated?

A team of researchers from Cornell University set out to find out which camp is right. They used 3-D scans of fossils to help determine the difference between wolves and dogs by studying ancient fossil canid mandibles (jaw bones) to determine if they were dogs or wolves.

How does mandible evolution distinguish a dog from a wolf? Wolves have fairly straight mandibles, while those of dogs are curved. These features become evident in 3-D scans.

The researchers, led by Abby Grace Drake, a senior lecturer in Cornell’s Department of Ecology and Evolutionary Biology, found that in the early stages of domestication, canids’ skulls changed shape, but the evolution of the mandible lagged behind.

“A lot of the fossil evidence for the date of dog domestication is based on morpohological [structural] analysis of mandibles,” said Drake, the paper’s first author. “Our study shows that when you measure modern dog mandibles and wolf mandibles using 3-D measurements you can distinguish them, and yet when we looked at these fossil mandibles, they don’t look like dogs or wolves.”

Although the team could distinguish 99.5 percent of modern dogs’ mandibles from those of wolves, a lot of the fossil mandibles couldn’t be classified as either dog or wolf. However, other data proved that the fossils were dog remains.

Other evidence from two Russian sites showed that the canid remains were found with human dwellings, and there were marks that revealed butchery—meaning that the dogs were eaten. In addition, isotope analysis of canid and human remains at both sites indicates that canids and humans both ate fish, and that humans were feeding the canids.

Drake said that since mandibles don’t appear to evolve as rapidly as the skull, they are not reliable for identifying early dog fossils.

However, 3-D analysis of canid skulls uses landmarks across the skull—differences in the angle of the muzzle, snout, and eye orbits—provides more evidence of dogs’ domestication time.

“The earliest dogs I’ve seen in my analysis were from 7,000 to 9,000 years ago,” Drake said.

Climate Change, Conservation, Nature

Old Nautical Charts Reveal Coral Loss

British navigation charts from the 1800s show us how much coral has disappeared.
British navigation charts from the 1800s show us how much coral has disappeared. Photo: Shutterstock

Nautical charts mapped in the 18th century are showing modern researchers just how much coral has been lost around the world.

A new U.S. and Australian study has compared early British navigation charts to modern coral habitat maps to determine what changes have taken place over the past three centuries.

The study was led by Professor Loren McClenachan of Colby College in Waterville, Maine, with assistance from the University of Queensland (UQ) in Australia and the Australian Research Council Centre of Excellence in Coral Reef Studies.

Professor John Pandolfi of UQ said that the study used information from “surprisingly accurate” 18th century nautical charts and satellite data to understand coral loss in the Florida Keys.

Professor McClenachan said that more than half of the coral reef habitat mapped in the 1770s was no longer there. In some areas, coral loss was close to 90 percent.

“We found near the shore, entire sections of reef are gone, but in contrast, most coral mapped further from land is still coral reef habitat today,” McClenachan said.

This is one of the first studies where marine scientists have measured the loss of coral reef habitats over a large geographic area. Most studies look more closely at the loss of living coral from smaller sections of reefs.

“We found that reef used to exist in areas that today are not even classified as reef habitat anymore,” Pandolfi said. “When you add to this the 75 percent loss of living coral in the Keys at that finer scale, the magnitude of change is much greater than anyone thought.”

Dr. Benjamin Neal of the Bigelow Laboratory for Ocean Sciences in East Boothbay, Maine, said that the early maps were remarkably precise.

“They had the best technology and they used it to create new information that conferred a lot of power,” Neal said. “The maps were essential to expansion of the British Empire, and luckily for us, they also included a lot of useful ecological information.”

This research has important conservation implications. As the authors said, when large-scale changes like this were overlooked, scientists could miss out on information about past abundance.

“We tend to focus on known areas where we can measure change. That makes sense. Why would you look for coral where you never knew it was?” McClenachan said.

Climate Change, Environmental Hazards, Nature, Science

Was Hurricane Harvey Caused by Global Warming? Not Entirely

Was Hurricane Harvey caused by global warming? Not entirely.
Cars submerged by flooding in the wake of Hurricane Harvey. Photo: michelmond / Shutterstock.com

Climate change is responsible for a lot of things, but it may not be directly responsible for Hurricane Harvey.

Harvey is not the first hurricane to hit the Texas coast.  A deadly hurricane struck Galveston in 1900, and that storm caused thousands to lose their lives, primarily due to the lack of warning. Meteorology was not an advanced science at that time, and there were no satellites to track the storms as they moved across the Atlantic Ocean.

However, climate change is almost certainly responsible for the epic rainfall and catastrophic flooding endured by the cities struck by Hurricane Harvey.

“This is they type of event, in terms of extreme rainfall, that we would expect to see more of in a warming climate,” Dr. Friederike Otto from the University of Oxford told the BBC.

In fact, the rainfall was so extreme that the National Weather Service had to add new colors to its rainfall maps to account for the intensity of Harvey’s rains.

There’s a physical law called the Clausius-Claperyon equation, which says that a hotter atmosphere holds more moisture. For every degree Celsius in warming, the atmosphere can hold 7 percent more water, which makes rainfall events more extreme.

The temperature of the seas also contributes to the strength of hurricanes.

“The waters of the Gulf of Mexico are about 1.5 degrees warmer than they were from 1980 to 2010,” Sir Brian Hoskins of the Grantham Institute for Climate Change told the BBC. “This is very significant because it means the potential for a stronger storm is there, and the contribution of global warming to the warmer waters in the Gulf, it’s almost inevitable that there was a contribution to that.”

Although there have been slow-moving storms over Texas in the past, some scientists still attribute the intensity of Harvey to climate change.

Professor Stefan Rahmstorf from the Potsdam Institute for Climate Impact Research says that a general slowdown in atmospheric circulation in the earth’s middle latitudes could be a result of changing climate in other parts of the world.

“This is a consequence of the disproportionately strong warming in the Arctic,” Rahmstorf said. “It can make weather systems move less and stay longer in a given location—which can significantly enhance the impacts of rainfall extremes.”

Other scientists think it’s a stretch to believe that the slowly moving nature of the storm is caused by climate change. “I don’t think we should speculate on these more difficult and complex links like melting in the Arctic without looking into these effects in a dedicated study,” said Dr. Otto.

In addition to the damage caused by the flooding, pollution is causing the floodwaters to become a toxic stew of sewage, garbage, chemicals from more than 20 Superfund sites in the Houston area, oil and petrochemicals from damaged refineries, and much more, are causing concern.

“There’s no need to test [the water],” Houston Health Department spokesman Porfirio Villareal told the New York Times. “It’s contaminated. There’s millions of contaminants.”

Climate Change, Nature, Science

Galápagos Seabird Population May Shrink Due to Global Warming

Nazca boobies and other animals are in jeopardy as water warms around the Galápagos Islands.
A Nazca booby guards her egg. Photo via Pixabay

The Galápagos Islands are the home of thousands of unique species. In fact, those islands were where Charles Darwin began writing about his findings on evolution. But at least one of these species is in jeopardy because of warming ocean temperatures.

Within the next century, rising ocean temperatures around the Galápagos Islands are expected to make the water too warm for sardines to tolerate.

Why is that important? Sardines are a key prey species for many seabirds including the Nazca booby.

Wake Forest University biologists published a study in the August 23 issue of the journal PLOS ONE about this phenomenon. They used decades of data on the diet and breeding of the Nazca booby to understand how the absence of sardines could affect the booby population.

They studied the diet, breeding, and survival of Nazca boobies as part of their study at Isla Españnola in the Galápagos Islands for more than 30 years. In 1997, halfway through their study, sardines disappeared from Nazca booby diet samples, replaced by flying fish.

Flying fish are less nutritious than sardines, and as researcher Emily Tompkins, lead author of the study, said, as flying fish replaced sardines in the birds’ diet, “reproductive success was halved.”

“If the current links between diet and reproduction persist in the future, and rising ocean temperatures exclude sardines from the Galápagos, we forecast the Nazca booby population will decline,” Tompkins said.

David Anderson, a professor of biology and co-author of the study, said, “Few connections have been made between ocean warming and population effects in the tropics, making this study significant.”

But the Nazca booby isn’t the only creature that could be harmed by rising ocean temperatures. The study suggests that other Galápagos predators that do well when sardines are available will have to adjust to a new menu within the next 100 years.

So many species have gone extinct or become highly endangered due to global climate change—probably including species we never even discovered—that it behooves us to act to stop, or at least slow, climate change. Given the United States’ exit from the Paris Climate Agreement, it’s up to other nations, and states and cities within the U.S., to step up and do something about this increasing danger to the survival of all animals, including humans.