Wednesday, November 10th, 2010
There have been several critiques of geoengineering as a climate mitigation tool. Two of the most incisive, in my opinion, come from science and ethics.
The first is a 2007 paper in PNAS by Matthews and Caldeira showing that if we establish aerosol clouds or space reflectors while doing nothing to reduce carbon emissions, we run the risk of catastrophic rates of warming (2-4 degrees C per decade) if these systems were to fail.
The second is a recent piece in Slate by my colleague, Dale Jamieson, who argued that there is no moral and legal authority to know how and when to deploy geoengineering or by how much.
One proposed geoengineering tool is fertilizing the world’s oceans with iron. The premise behind this idea was developed by John Martin in 1990, who is often quoted as saying something like, “Give me a tanker of iron, and I’ll give you an ice age.” Micronutrients like iron and zinc are extremely limiting to phytoplankton growth in the open ocean—orders of magnitude moreso than nutrients we typically think of in common fertilizers, like nitrogen and phosphorus. Dumping iron into the oceans has been shown to stimulate algal blooms, and the creation of this biomass consumes CO2 from the surface waters and atmosphere, thereby helping to mitigate rising CO2 from fossil fuels. In theory, some of this biomass should sink to the deep ocean where it is sequestered for centuries, but this has yet to be shown definitively on a wide scale.
In a forthcoming paper in the Proceedings of the National Academy of Sciences, Mary Silver and colleagues show that there is another potential risk of geoengineering resulting from ocean iron fertilization…
Monday, November 8th, 2010
In a forthcoming article in the Proceedings of the National Academy of Sciences, Patric Allard and Monica Colaiácovo use a nemotode (round worm) system to explore how BPA damages genetic processes in animals.
BPA ranks among the highest production volume chemicals with a global annual production scale of ≈4 million metric tons. It is commonly used in the manufacture of several polymers, including polycarbonate and epoxy resins. Thus, BPA is found in a variety of items such as plastic bottles, the lining of both food and beverage cans, and dental sealants. Consistent with its widespread presence, urinary BPA is detected in >90% of the population in the United States. Higher levels of urinary BPA have been correlated with cardiovascular diseases and diabetes and may be associated with an increased risk for miscarriages.
Thursday, October 7th, 2010
There’s a new paper in this week’s issue of Science that suggests that growing a landscape mixed with genetically modified (GM) Bt corn and non-GM hybrid varieties of corn can be mutually beneficial to all corn farmers.
Why? They argue that the populations of GM corn knock down the populations of insect herbivores enough that, on a landscape scale, this effect spills over to nearby farmers growing non-GM corn, which raises yields and profits:
[W]e estimate that cumulative benefits for both Bt and non-Bt maize growers during the past 14 years were almost $6.9 billion in the five-state region (18.7 million ha in
2009)—more than $3.2 billion in Illinois, Minnesota, and Wisconsin, and $3.6 billion in Iowa and Nebraska. Of this $6.9 billion total, cumulative suppression benefits to non-Bt maize growers resulting from O. nubilalis [European corn borer] population suppression in non-Bt maize exceeded $4.3 billion—more than $2.4 billion in Illinois, Minnesota, and Wisconsin, and $1.9 billion in Iowa and Nebraska—or about 63% of the total benefits.
They suggest that the populations of non-GM corn also benefit the Bt corn farmers because the non-GM corn maintains a genetically diverse population of insects, helping prevent the evolution of herbivores resistant to Bt corn.
These results are interesting and —if they hold—could be an example of how GM crops bring environmental and social benefits. A good outcome for all.
However, there are a couple of important things to consider:
(1) The notion of mixing crop types to minimize herbivory is the one of the fundamental tenets of traditional agroecology and organic agriculture, but instead of relying on GM crops, it could be done with a mix of hybrid crop varieties that doesn’t risk the potential environmental side effects of Bt corn or other unexpected outcomes of GM crops. This is a major value judgment. Does having one GM crop and a few dominant corn varieties count as diversity when the Midwest becomes a giant sea of maize? As I explain in #2 below, probably not. Could we achieve the same kind of insect pest management using a diversity of non-GM crops? Yes—it happens all the time in midwestern organic farms. Multi-crop organic farming is often more labor intensive than industrial agriculture, making the food produced more expensive. But do we only care about cheap food?
(2) I’ve lived in southern Minnesota, where it’s a giant rotating monoculture of corn and soybeans. If you look at Figure 1 in this paper, you will see that 50-75% (or more) of the corn grown in many regions of states like Iowa, Nebraska, and Minnesota is Bt corn. When so much of your landscape is Bt corn, the evolution of resistance to Bt is most likely inevitable, as we saw in a previous post with the use of Roundup-ready crops like soybeans, which are often grown in rotation with Bt corn in these regions. Acknowledging this fact of life, EPA recommends mixing GM and non-GM corn in an effort to delay the evolution of resistance, not prevent it:
To delay evolution of resistance, the U.S. Environmental Protection Agency (EPA) mandated that a minimum 20 to 50% of total onfarm maize be planted as non-Bt maize within 0.8 km of Bt fields as a structured refuge for susceptible O. nubilalis. Use of non-Bt maize refugia is an important element of long-term insect resistance management.
…Sustained economic and environmental benefits of this technology, however, will depend on continued stewardship by producers to maintain non-Bt maize refugia to minimize the risk of evolution of Bt resistance in crop pest species, and also on the dynamics of Bt resistance evolution at low pest densities and for variable pest phenotypes.
Hutchison, W., Burkness, E., Mitchell, P., Moon, R., Leslie, T., Fleischer, S., Abrahamson, M., Hamilton, K., Steffey, K., Gray, M., Hellmich, R., Kaster, L., Hunt, T., Wright, R., Pecinovsky, K., Rabaey, T., Flood, B., & Raun, E. (2010). Areawide Suppression of European Corn Borer with Bt Maize Reaps Savings to Non-Bt Maize Growers Science, 330 (6001), 222-225 DOI: 10.1126/science.1190242
Photo credit: Ian Hayhurst
Sunday, September 19th, 2010
Laura Miller at Salon reviews a new book out this week by Judy Pasternak titled, “Yellow Dirt: An American Story of a Poisoned Land and a People Betrayed.” A few excerpts from Miller’s analysis:
In the summer of 1979, an earthen dam over the town of Church Rock, Utah, broke, flooding the arroyo below and then the bed of the Rio Puerco (an intermittent stream) on the southern border of the Navajo Nation. It was a small flood, but a dangerous one. It burned the feet of a boy who stepped into it, and caused sheep and crops along the banks to drop dead. That’s because the pond it came from had been used by a nearby uranium mine to store the tailings (residue) of its excavations — the water kept the radioactive dust from blowing away. The 93 million gallons of contaminated water that poured into the Rio Puerco remains the largest accidental release of radioactive material in U.S. history, bigger than the notorious Three Mile Island reactor meltdown that occurred 14 weeks later.
The Church Rock flood is only one incident among many in the “slow-motion disaster” investigative journalist Judy Pasternak comprehensively recounts in her chilling new book, “Yellow Dirt: An American Story of a Poisoned Land and a People Betrayed.” Based on a prize-winning four-part series she wrote for the Los Angeles Times, “Yellow Dirt” begins during World War II, when secretive government surveyors first appeared on the remote reservation, supposedly looking for deposits of an ore called vanadium, used to strengthen steel needed for the war effort. Uranium was the real prize, and after the bombings of Hiroshima and Nagasaki and the ramping up of the Cold War, the American demand for the radioactive substance boomed.
The Navajo Nation and the area around it contained some of the richest deposits of uranium ore in the world, and certainly the most conveniently located. For about a decade, various corporations and government agencies reaped 1.4 million tons of uranium ore from the Monument Valley region alone; Pasternak makes a single mine there, known as Monument No. 2, her primary focus. The mining operations were relatively rudimentary, and by ordination of the tribal government, worked almost entirely by Navajo men. Even the cheapest and most elementary safety practices, such as wetting down blast areas to keep the miners from breathing toxic dust, were neglected in the rush to satisfy the Atomic Energy Commission’s insatiable appetite for uranium.
By the 1960s, the need tapered off, and the mining companies blithely abandoned the sites, leaving piles of radioactive tailings lying around for Navajo kids to play on and their parents to scavenge for conveniently sized rocks with which to build houses, ovens and cisterns. The dust and gravel made seemingly excellent concrete for floors. Monument No. 2, once a mesa, had been nearly leveled, its uranium-laced innards exposed to the open air, reduced to what Pasternak characterizes as a “radioactive pit.” Old quarries filled up with rain- and groundwater, new “lakes” from which local residents watered their herds and gratefully drank.
The next boom, unsurprisingly, was in cancer rates (previously so low among the Navajo that they were thought to be miraculously immune to the disease), and in a birth defect, christened “Navajo neuropathy,” that caused children’s fingers to fuse together and curl into claws. Still, it took decades for the cause to be fully recognized and even longer for it to be addressed; it wasn’t until 2008 and under the lashing of Rep. Henry Waxman, that the federal government made serious efforts to clean up the mine sites, purify water supplies and relocate families living in houses built from radioactive materials.
Read the rest of the review here.
Photo Credit: Christopher Isherwood
Tuesday, June 1st, 2010
Two stories in today’s news:
(1) The Washington Post ran an article on the possible pesticide-child behavior link we examined in a previous post.
(2) CNN also picked up the recent report from the Environmental Working Group (video clip and printed story) on pesticide residues in produce:
The Dirty Dozen (may contain 47-67 pesticides per serving—EWG suggests buying or growing these organically)
The Clean 15 (contain fewer or no pesticides—EWG suggests you can buy these conventionally grown)
The EWG shopper’s guide.
Photo Credit: http://www.flickr.com/photos/maheshkhanna/786837829/
Sunday, May 30th, 2010
Now that hurricane season is upon us, we’re learning this week from forecasters that it’s supposed to be a bad one:
Weather Services International predicted 18 named storms, 10 hurricanes and five intense hurricanes, rated as Category 3 storm with winds of 110-130 mph, or greater.
NBC ran a segment (video clip) asking what impacts hurricanes might have on the oil spill. The clip mentions, among other things, that 2010 Atlantic sea surface temperatures are the warmest on record—not a good omen when it comes to hurricane intensity.
This is, potentially, a very serious situation for the Gulf states. If a Katrina-like storm surge were to push the oil plume onto land, we would be looking at possible oil contamination of all of the affected land areas. Imagine parking your car in your house and opening the oil pan drain plug, letting oil leak onto the floors and out onto your driveway, lawn, and streets. Now do that for every car and home along the Gulf Coast that could be impacted by storm surge where the oil plume is close to shore.
This has to be keeping people at EPA and the Gulf Coast up at night. It could be an environmental pollution disaster the likes of which we have never seen—Marshes, swamps, white-sand beaches, and coastal/vacation communities becoming a giant, oil-soaked, polluted brownfield.
One would think that witnessing this kind of unprecedented environmental disaster, and the potential for worse with the impending hurricane season, would help make the case for the transition to clean energy. Indeed, this week we have seen the oil spill mentioned by President Obama and some members of Congress as motivation for a long-term energy strategy.
Don’t hold your breath.
Even these events—as bad as they appear in real life— can be externalized from the day-to-day lives of most people in unaffected areas. Maybe that will change as this spill gets worse and we face the possibility of oil release for another few months, but right now, there is simply not enough outrage from the public demanding change in Washington, as Bob Herbert alluded to last week. And John Kerry is right, halting drilling on the Gulf Coast isn’t going to happen.
So where does all this leave us in terms of climate change, energy, and oil spills?
I’m pretty pessimistic these days. I’m not sure if anything short of a severe economic energy shock that hits ordinary people hard—similar to what we saw in 2006-2007—will bring us to a tipping point. If the U.S. returns to $4-5/gallon gasoline and home heating oil, we will start seeing environmentalists, security hawks, the energy independence crowd, green jobs advocates, and everyday citizens realign once again. Only then will there be a coalition large and loud enough to force Washington take on the political-economic might of the fossil fuel industry and their lobbyists.
If my guess is right, then we are probably still a few years away from seeing a serious move to clean energy—not until the economic recovery is further along, economies pick up speed, and the demand for oil and oil speculation kick back into high gear, causing oil prices to spike once more. Fortunately, this time around—unlike 2006-2007—we will have better technology, including electric cars, which will help make the leap easier and more sustained (provided that people can afford them).
The Gulf Coast is unfortunately poised to become collateral damage as we wait for more significant economic drivers to make the clean energy transition happen.
I’m lucky to have had the chance to travel along the coast from New Orleans to Tampa in the spring of 2005 before Katrina hit and now this oil spill happened. It’s a beautiful region. For our friends and all of the wildlife living there, let’s just hope this is a mild hurricane season and that most of the oil stays in the deep sea where it will hopefully get removed by hungry bacteria.
Photo credit: http://www.flickr.com/photos/joiseyshowaa/2392156164/
Saturday, May 22nd, 2010
Bob Herbert’s column in today’s Times forces us to look in the mirror not only with regards to the Gulf oil spill but to the political-economic foundation of social and environmental problems in general:
The response of the Obama administration and the general public to this latest outrage at the hands of a giant, politically connected corporation has been embarrassingly tepid. We take our whippings in stride in this country. We behave as though there is nothing we can do about it.
The fact that 11 human beings were killed in the Deepwater Horizon explosion (their bodies never found) has become, at best, an afterthought. BP counts its profits in the billions, and, therefore, it’s important. The 11 men working on the rig were no more important in the current American scheme of things than the oystermen losing their livelihoods along the gulf, or the wildlife doomed to die in an environment fouled by BP’s oil, or the waters that will be left unfit for ordinary families to swim and boat in.
This is the bitter reality of the American present, a period in which big business has cemented an unholy alliance with big government against the interests of ordinary Americans, who, of course, are the great majority of Americans. The great majority of Americans no longer matter.
No one knows how much of BP’s runaway oil will contaminate the gulf coast’s marshes and lakes and bayous and canals, destroying wildlife and fauna — and ruining the hopes and dreams of countless human families. What is known is that whatever oil gets in will be next to impossible to get out. It gets into the soil and the water and the plant life and can’t be scraped off the way you might be able to scrape the oil off of a beach.
It permeates and undermines the ecosystem in much the same way that big corporations have permeated and undermined our political system, with similarly devastating results.
Photo Credit: http://www.flickr.com/photos/chrisjman/3338514389/
Monday, May 17th, 2010
MSNBC is reporting today on new research suggesting that some pesticides may double the rate of ADHD (attention deficit hyperactivity disorder) in kids.
Youngsters with high levels of pesticide residue in their urine, particularly from widely used types of insecticide such as malathion, were more likely to have ADHD, the behavior disorder that often disrupts school and social life, scientists in the United States and Canada found.
Kids with higher-than-average levels of one pesticide marker were nearly twice as likely to be diagnosed with ADHD as children who showed no traces of the poison.
The take-home message for parents, according to Bouchard: “I would say buy organic as much as possible,” she said. “I would also recommend washing fruits and vegetables as much as possible.”
As discussed in a previous post “Do our daily routines put our health at risk?” here’s an easy to use shopping guide of which fruits and vegetables to buy organic.
Friday, March 19th, 2010
European bee populations are on the decline worldwide. Who cares? These bees are major pollinators of crops and therefore perform, for free, a vital ecological service worth about $U.S. 14 billion per year. Not to mention the many other species of non-crop flowering plants that reproduce with the help of insects like this.
The recent kind of decline is specific—only female worker bees disappear—and has been given the name colony collapse disorder (CCD). Nobody has figured out why this is happening. The potential list of culprits includes mites, viruses, synthetic chemicals, and other factors.
In an article this week in PLoS ONE, Christopher Mullin and colleagues explore further the potential link between pesticides and CCD.1
One third of honey bee colonies in the US were lost during each of the last three winters between ’06-’09. This alarming overwinter along with other losses of this primary pollinator, Apis mellifera L., as well as those of native pollinators, has been documented in North America and Europe. The most recent manifestation of this decline, Colony Collapse Disorder (CCD), has led to a significant collaborative effort involving several land grant universities, Departments of Agriculture and the USDA.
We have found 121 different pesticides and metabolites within 887 wax, pollen, bee and associated hive samples. Almost 60% of the 259 wax and 350 pollen samples contained at least one systemic pesticide, and over 47% had both in-hive acaricides fluvalinate and coumaphos, and chlorothalonil, a widely-used fungicide. In bee pollen were found chlorothalonil at levels up to 99 ppm and the insecticides aldicarb, carbaryl, chlorpyrifos and imidacloprid, fungicides boscalid, captan and myclobutanil, and herbicide pendimethalin at 1 ppm levels. Almost all comb and foundation wax samples (98%) were contaminated with up to 204 and 94 ppm, respectively, of fluvalinate and coumaphos, and lower amounts of amitraz degradates and chlorothalonil, with an average of 6 pesticide detections per sample and a high of 39. There were fewer pesticides found in adults and brood except for those linked with bee kills by permethrin (20 ppm) and fipronil (3.1 ppm).
The 98 pesticides and metabolites detected in mixtures up to 214 ppm in bee pollen alone represents a remarkably high level for toxicants in the brood and adult food of this primary pollinator. This represents over half of the maximum individual pesticide incidences ever reported for apiaries. While exposure to many of these neurotoxicants elicits acute and sublethal reductions in honey bee fitness, the effects of these materials in combinations and their direct association with CCD or declining bee health remains to be determined.
The high frequency of multiple pesticides in bee collected pollen and wax indicates that pesticide interactions need thorough investigation before their roles in decreasing bee health can be either supported or refuted. The large number of studies to date, are limited by being done on mostly one compound at a time, as well as using whole colonies where the timing of contaminated pollen intake and its utilization by the colony are difficult to interpret as a causal relationship. Laboratory studies have clearly indicated sublethal impacts on honey bee learning, immune system functioning, and synergism of insecticide toxicity by fungicides, yet combinations of herbicides with fungicides and insecticides in 3 or more component mixtures have not been studied.
The widespread occurrence of multiple residues, some at toxic levels for single compounds, and the lack of any scientific literature on the biological consequences of combinations of pesticides, argues strongly for urgent changes in regulatory policies regarding pesticide registration and monitoring procedures as they relate to pollinator safety. This further calls for emergency funding to address the myriad holes in our scientific understanding of pesticide consequences for pollinators. The relegation of bee toxicity for registered compounds to impact only label warnings, and the underestimation of systemic pesticide hazards to bees in the registration process may well have contributed to widespread pesticide contamination of pollen, the primary food source of our major pollinator. Is risking the $14 billion contribution of pollinators to our food system really worth lack of action?
1Christopher A. Mullin, Maryann Frazier, James L. Frazier, Sara Ashcraft, Roger Simonds, Dennis vanEngelsdorp, Jeffery S. Pettis (2010). High Levels of Miticides and Agrochemicals in North American Apiaries: Implications for Honey Bee Health PLoS ONE
Monday, March 1st, 2010
How do you turn a male frog into a female frog that breeds with other male frogs? Expose them to herbicides that are routinely sprayed on agricultural fields worldwide.
Last year, Tyrone Hayes from UC Berkeley gave a talk at Bowdoin about his career’s work studying the impacts of endocrine-disrupting chemicals on amphibian development.
This week’s Early Edition of the Proceedings of the National Academy of Sciences features some of this research.1
Atrazine is one of the most widely used pesticides in the world. Approximately 80 million pounds are applied annually in the United States alone, and atrazine is the most common pesticide contaminant of ground and surface water. Atrazine can be transported more than 1,000 km from the point of application via rainfall and, as a result, contaminates otherwise pristine habitats, even in remote areas where it is not used. In fact, more than a half million pounds of atrazine are precipitated in rainfall each year in the United States.
In addition to its persistence, mobility, and widespread contamination of water, atrazine is also a concern because several studies have shown that atrazine is a potent endocrine disruptor active in the ppb (parts per billion) range in fish, amphibians, reptiles, and human cell lines, and at higher doses (ppm) in reptiles, birds, and laboratory rodents. Atrazine seems to be most potent in amphibians, where it is active at levels as low as 0.1 ppb. Although a few studies suggest that atrazine has no effect on amphibians under certain laboratory conditions, in other studies, atrazine reduces testicular volume; reduces germ cell and Sertoli cell numbers; induces hermaphroditism; reduces testosterone; and induces testicular oogenesis. Furthermore, atrazine contamination is associated with demasculinization and feminization of amphibians in agricultural areas where atrazine is used and directly correlated with atrazine contamination in the wild.
Using an experiment where his team exposed frogs to a 2.5 parts per billion atrizine solution, here’s what they found:
Atrazine-exposed males were both demasculinized (chemically castrated) and completely feminized as adults. Ten percent of the exposed genetic males developed into functional females that copulated with unexposed males and produced viable eggs. Atrazine exposed males suffered from depressed testosterone, decreased breeding gland size, demasculinized/feminized laryngeal development, suppressed mating behavior, reduced spermatogenesis, and decreased fertility. These data are consistent with effects of atrazine observed in other vertebrate classes. The present findings exemplify the role that atrazine and other endocrine-disrupting pesticides likely play in global amphibian declines.
The main implication of this chemically induced sex switching is that it has the potential to disrupt breeding and contribute to the amphibian declines observed worldwide:
Although many studies have focused on death from disease and its role in global amphibian declines and sudden enigmatic disappearances of populations, virtually no attention has been paid to the slow gradual loss of amphibian populations due to failed recruitment. The present study suggests several ways that exposure to endocrine disruptors such as atrazine may lead to population level effects in the wild and contribute to amphibian declines. Certainly, the inability to compete for females and the significant decline in fertility in exposed males, as reported in the present study, will have a direct impact on exposed populations.
1Hayes, T. et al (2010) Atrazine induces complete feminization and chemical castration in male African clawed frogs (Xenopus laevis). Proceedings of the National Academy of Sciences. doi:10.1073/pnas.0909519107