From an ancient Peruvian civilization comes this warning: Don’t chop down all your trees, or there will be hell to pay.
The Nazca people are famous for the enormous earthworks they carved into an arid plateau, in designs that range from simple geometrical forms to representations of animals like hummingbirds, lizards, and monkeys. They were previously known to have disappeared around A.D. 500, when massive floods powered by El Niño ravaged the valley where they made their home. Now, a new study that examined the pollen in buried layers of soil in order to trace the horticultural history of the land may have revealed why those floods were so devastating.
The Ica Valley, about 120 miles south of Lima, is barren today but was once a riverine oasis — a fertile landscape capable of supporting many people. The key to that fertility was a tree called the huarango [Los Angeles Times]. The huarango tree provided wood for building and fuel, and seed pods that can be ground up and used in flour or beer. Its branches caught the water in morning mists, and its roots stabilized the topsoil. Says lead researcher David Beresford-Jones: “These were very special forests…. It is the ecological keystone species in the desert zone enhancing soil fertility and moisture and underpinning the floodplain with one of the deepest root systems of any tree known” [BBC News].
Lord Nicholas Stern, the British economist who produced an influential report on the potential costs of global warming, is strongly urging the British public to go vegetarian in order to slow the accumulation of heat-trapping gases in our atmosphere. Said Stern: “Meat is a wasteful use of water and creates a lot of greenhouse gases. It puts enormous pressure on the world’s resources. A vegetarian diet is better” [The Times]. Stern also suggested that climate change legislation that makes it more expensive to generate greenhouse gases could soon force meat producers to raise prices, which might lower consumption.
In a 2006 report, the UN Food and Agriculture Organization (FAO) concluded that worldwide livestock farming generates 18% of the planet’s greenhouse gas emissions. By comparison, it said, all the world’s cars, trains, planes and boats accounted for a combined 13% of greenhouse gas emissions [BBC News]. The gases are produced by each step of livestock production. Take cows, for example. First forested land is cleared for cattle grazing or for agricultural operations that generate livestock feed, then there’s the methane emitted by burping cows and the nitrous oxide in their manure, and finally there are the energy costs associated with slaughtering the cows and transporting the meat.
Not everyone is calling for the drastic measure of eliminating meat entirely from our diets. Many experts agree that we could make a good start merely by dropping meat one day a week. This is what the citizens of the Belgian city of Ghent have been doing, voluntarily, all this year, without noticeable ill effects [The Times].
Scientists have used nanotechnology in some bizarre applications—nanotube speakers and glue are just two examples. Now carbon nanotubes may have a use as fertilizer, according to a new study. Plant biologist Mariya Khodakovskaya and nanotechnologist Alexandru Biris … planted tomato seeds in a growth medium that contained carbon nanotubes. They found that the seeds germinated sooner and seedlings grew faster than those in a non-treated medium [New Scientist]. After 12 days, 72 percent of the treated seeds had germinated compared with 30 percent of the untreated group. After four weeks, the nanotube-supplemented seeds were twice as tall and had twice the biomass. However, the root systems in both groups were roughly the same.
Similar findings have been reported previously, but until now nobody understood how nanotubes sped and enhanced plant growth. The new study, which recently appeared in the journal ACS Nano, proposes that nanotubes poke holes in the seeds, which allows water to seep in and speeds up germination. However, some researchers are skeptical that a complex process like germination can be enhanced simply by poking holes in the seed’s coating, and at least one researcher is suggesting that the nanotubes cause a hormonal imbalance in the plants.
Before nanotubes could become a commercial fertilizer, their effect on the environment would have to be studied, with close attention to how nanotubes move through the food chain. Some single-walled nanotubes are toxic to some insects; testing on mice has found multi-layer nanotubes (like the kind used in the study) have carcinogenic effects similar to those of asbestos [Popular Science].
In an ambitious attempt to assess how humans are doing as stewards of planet earth, 28 leading scientists have drawn up a list of nine “planetary boundaries” that must not be crossed if we want to avoid drastically changing the global environment and imperiling our own existence. The only problem is, we’ve already crossed three of those thresholds.
The paper, published in Nature (and available for free), aims to define a “safe operating space” for human life on the planet. It’s a first-draft users’ manual for an era that scientists dub the “anthropocene,” in which nearly seven billion resource-hungry humans have come to dominate ecological change on Earth [Wired.com]. What follows is a list of the nine environmental factors, and how we’re doing on living within each limit.
Norman E. Borlaug, a world-renowned American botanist, died this past Saturday at his home in Dallas from complications due to cancer. Borlaug, who was 95, won the Nobel Peace Prize in 1970 for starting the “Green Revolution” that dramatically increased food production in developing nations and saved countless people from starvation [Washington Post]. Borlaug pioneered high-yield agricultural techniques, using cross-bred crops and nitrogen fertilizers, which helped India, Mexico, and other nations combat hunger and become self-sufficient producers of grains.
“Civilization as it is known today could not have evolved, nor can it survive, without an adequate food supply,” said Borlaug during his Nobel Lecture in 1970. “Yet food is something that is taken for granted by most world leaders despite the fact that more than half of the population of the world is hungry. Man seems to insist on ignoring the lessons available from history.”
Meat may be tasty, but many people object to way that chickens, cows, and other animals are treated at so-called “factory farms,” which produce massive amounts of edible flesh. So could animals that have been genetically engineered to not feel pain (or at least not be bothered by the sensation) offer a solution to an ethical dilemma posed by these meat factories?
That’s what one philosopher asked in a paper published in the journal Neuroethics, concluding that we have an ethical duty to consider the option. “If we can’t do away with factory farming, we should at least take steps to minimise the amount of suffering that is caused” [New Scientist] by practices such as de-beaking chickens without anesthesia, says author Adam Shriver. But because pain serves as an important warning sign, these so-called “pain-free” animals would still be able to sense pain–they just wouldn’t be bothered by it. Researchers seek ways to eliminate the suffering caused by pain without tampering with the physical sensation [New Scientist].
Just a few days ago, we wrote that laughing gas, or nitrous oxide, has become today’s biggest threat to the ozone layer. So what’s the greatest source of nitrous oxide? Manure, according to new research published in Nature Geoscience.
Nitrous oxide, which also contributes to global warming, is produced naturally and through human activities like agriculture. Fertilizer is a recognized source of the gas, but until now, manure had been largely overlooked. Says researcher Eric Davidson: “[Fertilisers] are extremely important, but that’s only part of the story.” … He says nitrous oxide levels started increasing in the late 19th century “long before we started using nitrogen fertilisers in the 1960’s” [ABC Science]. And as a growing number of people around the globe consume meat, the manure that is an inevitable byproduct of meat production could pump an increasing amount of nitrous oxide into the atmosphere–or we could harness the power-producing potential of the waste.
Watermelons could do more than grace the tables at picnics across the land: They could also serve as a source of biofuel. Researchers fermented watermelon juice to produce ethanol, according to a study published in Biotechnology for Biofuels, and while the melons aren’t likely to become a primary biofuel crop, the process could help out farmers.
Nearly one-fifth of the watermelon crop grown in the United States is left in the fields after harvest because of defects on the melons’ rinds. “It’s not that there’s anything wrong with the melon on the inside, but our only method of judgment is the outside,” said [lead author] Wayne Fish [Greenwire]. Although farmers often till the abandoned melons into the soil, the value of the nutrients provided by this practice is much less than the overall cost to farmers of losing so much of their crop.
Scientists have long wondered what exactly is killing bees in hives afflicted by colony collapse disorder (CCD), and now they may have found a clue. Bees in collapsing hives showed evidence of damaged ribosomes, which are crucial to protein production, according to a study published in the journal Proceedings of the National Academy of Science. The researchers suggest that an onslaught of viruses may be responsible for the cellular damage.
The findings suggest that CCD, which has been blamed on everything from viruses to fungi to pesticides, may be linked to problems with protein production that could make bees more susceptible to these threats. “If your ribosome is compromised, then you can’t respond to pesticides, you can’t respond to fungal infections or bacteria or inadequate nutrition because the ribosome is central to the survival of any organism. You need proteins to survive” [AP], said lead researcher May Berenbaum.
The discovery of a pair of genes that prompt rice plants to grow extra-tall when submerged in water could potentially lead to new hardier varieties of rice that yield food even in flooded conditions, and could help out farmers in flood-prone nations like Thailand and Cambodia, according to a study published in Nature.
Researchers discovered a pair of genes known as SNORKEL, which spurs growth among the plants when they are completely submerged, allowing the plants to survive by keeping their leaf tops above the water. As water levels rise, accumulation of the plant hormone ethylene activates the SNORKEL genes, making stem growth more rapid. When the researchers introduced the genes into rice that does not normally survive in deep water, they were able to rescue the plants from drowning [AP].
The groundwater of northern India is being drained away by irrigation faster than it can be replenished by the annual monsoon rains, and new satellite data shows that the process is accelerating. In an area that’s home to about 10 percent of the world’s people, that could be a recipe for disaster, policy experts say. A growing population with an increasing standard of living will only boost the demand for groundwater, a trend that could eventually lead to a reduction in agricultural yields, shortages of potable water and an increase in societal unrest [Science News].
The Gravity Recovery and Climate Experiment (GRACE) is comprised of a pair of satellites that measure subtle variations in the Earth’s gravity, caused by the movement of water either in the oceans or under the ground. Most famously, GRACE has recorded the shrinking of ice sheets; it has also detected shifting ocean currents, the desiccation of droughts, and the draining of large lakes [ScienceNOW Daily News]. Now two new studies of GRACE’s data have revealed the loss of groundwater from northern India; once water is pumped up from the aquifers for use in irrigation, it either flows away from the region or evaporates.
Scientists have created genetically engineered corn plants that resist a root-destroying larvae by emitting a chemical call for help, summoning a parasite that preys on the larvae.
The larvae of the western corn rootworm (actually a beetle) is considered the most destructive corn pest in the United States and plagues parts of Europe as well. Known as the billion-dollar bug, the rootworm is said to be responsible for crop damage and pest-control spending valued at more than nine figures [National Geographic News]. To fight the larvae without the use of synthetic pesticides, researchers created corn plants that release a chemical compound into the soil, which calls forth parasitic nematodes to come and infest the beetle larvae.
An ancient Roman city that was the predecessor of Venice has been rediscovered beneath croplands near the Venetian lagoon using sophisticated aerial imagery and some clever analysis. Researchers say they’ve found the harbor city of Altinum, which was once one of the richest cities of the Roman empire. But terrified by the impending invasion of the fearsome Germanic Emperor Attila the Hun, its inhabitants cut their losses and fled in AD452, leaving behind a ghost town of theatres, temples and basilicas [Times Online].
Many of the city’s ancient buildings were dismantled and the stones were carted away in the Middle Ages. The remaining foundations sunk back into the marsh, which was drained and turned into agricultural land in the 19th century. The new study, published in Science, is a result of aerial images taken in unusually dry summer of 2007, when the crops were suffering from drought. When the visible light and near-infrared images were processed to tease out subtle variations in plant water stress, a buried metropolis emerged. The researchers discovered that the crops planted on the land were in different stages of ripening, thanks to differences in the amount of water in the soil [ScienceNOW Daily News].
The region today known as Iraq was once known as Mesopotamia, which means “Land Between the Rivers,” and since that ancient time the land between the Euphrates and Tigris rivers has been renowned for its fecund soil and thriving farms. But now the Mesopotamian cradle of civilisation seems to be returning to desert [New Scientist].
Decades of war and mismanagement, compounded by two years of drought, are wreaking havoc on Iraq’s ecosystem, drying up riverbeds and marshes, turning arable land into desert, killing trees and plants, and generally transforming what was once the region’s most fertile area into a wasteland…. “We’re talking about something that’s making the breadbasket of Iraq look like the Dust Bowl of Oklahoma in the early part of the 20th century” [Los Angeles Times], said Adam L. Silverman, a social scientist with the U.S. military.
The ancient civilization known as the Incan empire, which at its peak reached a population of 8 million people spread throughout South America, may owe its success at least in part to a warming climate, according to a study in the journal Climate of the Past. A rise in temperatures would have melted glaciers and allowed crops to grow further into the Andes mountains, fostering agricultural growth.
The study found that between 1100 and 1533 AD, temperatures increased several degrees, making it possible for the Incas to use new mountain land for agriculture. It also expanded the swath of land the empire occupied which, at its peak, spanned from the middle of Chile to the border shared by Ecuador and Colombia. This climate information came from an analysis of deeply buried sediment samples in the region the Incans once occupied. The researchers examined pollen and seeds buried in layers of mud on the floor of Lake Marcacocha in the Cuzco region of the Peruvian Andes. Similar to the rings in the trunk of a tree, each layer of sediment represents a fixed period of time. In the case of Lake Marcacocha, the researchers were able to analyze a 1,200-year-old sediment record [Discovery News].
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From an ancient Peruvian civilization comes this warning: Don’t chop down all your trees, or there will be hell to pay.
Lord Nicholas Stern, the British economist who produced an influential 
Scientists have used nanotechnology in some bizarre applications
In an ambitious attempt to assess how humans are doing as stewards of planet earth, 28 leading scientists have drawn up a list of nine “planetary boundaries” that must not be crossed if we want to avoid drastically changing the global environment and imperiling our own existence. The only problem is, we’ve already crossed three of those thresholds.
Norman E. Borlaug, a world-renowned American botanist, died this past Saturday at his home in Dallas from complications due to cancer. Borlaug, who was 95, won the Nobel Peace Prize in 1970 for starting the “Green Revolution” that dramatically increased food production in developing nations and saved countless people from starvation [
Meat may be tasty, but many people object to way that chickens, cows, and other animals are treated at so-called “factory farms,” which produce massive amounts of edible flesh. So could animals that have been genetically engineered to not feel pain (or at least not be bothered by the sensation) offer a solution to an ethical dilemma posed by these meat factories?
Just a few days ago, we wrote that laughing gas, or nitrous oxide, 
Watermelons could do more than grace the tables at picnics across the land: They could also serve as a source of 
Scientists have long wondered what exactly is killing 
The groundwater of northern India is being drained away by irrigation faster than it can be replenished by the annual monsoon rains, and new satellite data shows that the process is accelerating. In an area that’s home to about 10 percent of the world’s people, that could be a recipe for disaster, policy experts say. A growing population with an increasing standard of living will only boost the demand for groundwater, a trend that could eventually lead to a reduction in 
Scientists have created 
An ancient Roman city that was the predecessor of Venice has been rediscovered beneath croplands near the Venetian lagoon using sophisticated aerial imagery and some clever analysis. Researchers say they’ve found the harbor city of Altinum, which was once one of the richest cities of the Roman empire. But terrified by the impending invasion of the fearsome Germanic Emperor Attila the Hun, its inhabitants cut their losses and fled in AD452, leaving behind a ghost town of theatres, temples and basilicas [
The region today known as Iraq was once known as Mesopotamia, which means “Land Between the Rivers,” and since that ancient time the land between the Euphrates and Tigris 
The ancient civilization known as the Incan empire, which at its peak reached a population of 8 million people spread throughout South America, may owe its success at least in part to a warming climate, according to a 
