“These future droughts are not only going to be bad compared to what we’ve experienced over the historical period, but also really bad compared to the past millennium,” says Benjamin Cook, a drought researcher at NASA’s Goddard Institute for Space Studies in New York City, who led the work. “It’s going to be a pretty much fundamental shift.”
Much of North America has a long and detailed climate history, thanks to tree rings that preserve records of temperature and rainfall. Many scientists have used these to piece together the story of decades-long droughts, like one that gripped the US Southwest in the thirteenth century and probably contributed to the disappearance of ancient Pueblo peoples. Others have used global climate models to study the region’s future, and found that it may already be transitioning to a fundamentally drier state.
Cook’s team aimed to bridge past and present. The scientists compared 1,000 years of North American climate history with future projections from 17 different climate models — “as many as we could get our hands on that gave us the data we needed”, Cook says.
Among other metrics, the researchers looked at a measure known as the Palmer Drought Severity Index, which is an indicator of soil moisture. Some scientists criticize the Palmer index because it can overestimate future drying if it is calculated on the basis of temperature projections alone. To get around this problem, Cook’s team used a different method of calculating the index, one that incorporates humidity and energy from sunlight.
Kevin Anchukaitis, a palaeoclimatologist at the Woods Hole Oceanographic Institution in Massachusetts, says that the revised method gives a much more accurate projection of how dry things will really get. “This is the first convincing demonstration I’ve seen that it is both possible to seamlessly connect past, present and future, and to then be confident that they are on comparable scales,” he says.
At the rate things are going, the Earth in the coming decades could cease to be a “safe operating space” for human beings. That is the conclusion of a new paper published Thursday in the journal Science by 18 researchers trying to gauge the breaking points in the natural world.
The paper contends that we have already crossed four “planetary boundaries.” They are the extinction rate; deforestation; the level of carbon dioxide in the atmosphere; and the flow of nitrogen and phosphorous (used on land as fertilizer) into the ocean.
“What the science has shown is that human activities — economic growth, technology, consumption — are destabilizing the global environment,” said Will Steffen, who holds appointments at the Australian National University and the Stockholm Resilience Center and is the lead author of the paper.
These are not future problems, but rather urgent matters, according to Steffen, who said that the economic boom since 1950 and the globalized economy have accelerated the transgression of the boundaries. No one knows exactly when push will come to shove, but he said the possible destabilization of the “Earth System” as a whole could occur in a time frame of “decades out to a century.”
The researchers focused on nine separate planetary boundaries first identified by scientists in a 2009 paper. These boundaries set theoretical limits on changes to the environment, and include ozone depletion, freshwater use, ocean acidification, atmospheric aerosol pollution and the introduction of exotic chemicals and modified organisms.
Beyond each planetary boundary is a “zone of uncertainty.” This zone is meant to acknowledge the inherent uncertainties in the calculations, and to offer decision-makers a bit of a buffer, so that they can potentially take action before it’s too late to make a difference. Beyond that zone of uncertainty is the unknown — planetary conditions unfamiliar to us.
“The boundary is not like the edge of the cliff,” said Ray Pierrehumbert, an expert on Earth systems at the University of Chicago. “They’re a little bit more like danger warnings, like high-temperature gauges on your car.”
In a fit of pique and self-pity, Watson is selling his Nobel Prize medallion. He will become the first Nobel laureate in history to do so. He gave the Financial Times several reasons why, this Thursday, he will auction off the gold disk, symbol of the highest honor in science (expected price: up to $3.5 million). He claims that, even though he ran major research institutions and served on corporate boards until the age of 79, he needs the money. He might donate it to universities, he said, or buy a David Hockney painting. Oh, and he also mentioned to the FT that he’s selling the medal because he has become an “unperson,” and “no one really wants to admit I exist.”
This is not about the Hockney. Selling the medal is Watson’s way of sticking his tongue out at the scientific establishment, which has largely shunned him since 2007. Watson had been making racist and sexist remarks throughout his career, but he really outdid himself seven years ago when he told the Sunday Times that he was “inherently gloomy about the prospect of Africa” because “all our social policies are based on the fact that their intelligence is the same as ours—whereas all the testing says not really.” He further said that while we may wish intelligence to be equal across races, “people who have to deal with black employees find this not true.”
The community that epitomizes the pollution warehouses can bring is Mira Loma.“Our quality of life is in the tubes,” said Gene Proctor, 73, who has lived in Mira Loma Village for 43 years. “I wish people shopping in Tucson, Arizona, in other places, I wish they could see the little kids around here, their respiratory problems.” His great-granddaughter has asthma, and his 3-year-old great-grandson, he said, “coughs like a smoker.”
Population 21,000, Mira Loma is so small and poor it doesn’t have a movie theater, a community center, or even a moderately upscale restaurant. What it does have are 90 warehouses and a whole lot of big rigs: Trucks rumble through 15,000 times every day. In just half an hour on a recent afternoon, 269 trucks passed by the big plate glass window in the front of the Farmer Boys truck stop on Etiwanda Avenue.
That is more than one every seven seconds.
Avol, the professor at the USC Keck School of Medicine, began visiting the town in the early 1990s as part of a study of air pollution and children’s health across Southern California. Back then, he said, researchers chose Mira Loma because it sits at the “end of the tailpipe” of the Los Angeles basin, meaning the prevailing winds off the Pacific Ocean blow L.A.’s infamous smog east until much of it arrives in Mira Loma. So it was rural yet had a lot of ozone and smog. Other places in the study, such as Santa Barbara and Long Beach, were picked because they were thought to boast clean air or because they were in industrial areas.
When the study began, Mira Loma residents complained to researchers about the smell of dairy cows, herds of which clustered on vast pastures and cow yards. But in 1987, Riverside county supervisors revamped the general plan for Mira Loma, clearing the way for massive warehouse development.
“In the course of a few years, the dairies disappeared,” and what had been “open pasture became streets and warehouses, lined with trucks,” Avol said. “Mira Loma turned out to be a very interesting place to study.”
The trucks made the already bad air worse, bringing in diesel particulates, very small particles that can enter the lungs and travel to tissues throughout the body. They are associated with asthma, heart disease, neurological problems, and cancer.
In Mira Loma, children were found to be growing up with stunted lungs compared with children living in places with better air. Their lungs were growing at a rate that was 1 to 1.5% slower, Avol said, so that “after their teen years, they were about 10 to 12% lower in lung function than children who had grown up in cleaner places.”
He added: “We have no information at this point that supports the idea that they ever catch up.”
Studies from other Inland Empire communities are also dire. In a neighborhood near the BNSF rail yard in the city of San Bernardino, Loma Linda University researchers found that adults have more respiratory problems, and children alarmingly high rates of asthma, even when compared with other polluted communities.
There are several potential explanations for what’s going on here. The most likely is that some combination of increasingly infrequent summer snowstorms, wind-blown dust, microbial activity, and forest fire soot led to this year’s exceptionally dark ice. A more ominous possibility is that what we’re seeing is the start of a cascading feedback loop tied to global warming.
Box mentions this summer’s mysterious Siberian holes and offshore methane bubbles as evidence that the Arctic can quickly change in unpredictable ways.
This year, Greenland’s ice sheet was the darkest Box (or anyone else) has ever measured. Box gives the stunning stats: “In 2014 the ice sheet is precisely 5.6 percent darker, producing an additional absorption of energy equivalent with roughly twice the US annual electricity consumption.”
Perhaps coincidentally, 2014 will also be the year with the highest number of forest fires ever measured in Arctic.
Box ran these numbers exclusively for Slate, and what he found shocked him. Since comprehensive satellite measurements began in 2000, never before have Arctic wildfires been as powerful as this year. In fact, over the last two or three years, Box calculated that Arctic fires have been burning at a rate that’s double that of just a decade ago. Box felt this finding was so important that he didn’t want to wait for peer review, and instead decided to publish first on Slate. He’s planning on submitting these and other recent findings to a formal scientific journal later this year.
From the CBC