Category Archives: Human Ecology

Cell Phones and Microwaves

Devra Davis, of the University of Pittsburgh's Center for Environmental Oncology, has an interesting piece posted on YouTube on the possible health risks of cell phone use.  A health scare about cell phone use seems to appear every couple of years but changes no one's actual behavior as far as I can tell.  What is interesting about this short video is how sensibly it incorporates a discussion of risk into the question of the safety of cell phones. Should we stop using cell phones altogether?  No.  Should we think about the potential consequences of long-term microwave exposure to developing brains.  You bet.   

 

Food for thought, particularly on the subject of the appropriateness of cell phone use by children and adolescents.

More on Salmonella

The first produce to positively match the Salmonella serotype Saintpaul was announced today.  A jalapeño chile, grown in México and processed at an unnamed plant in McAllen, Texas, tested positive for the strain of Salmonella that has sickened at least 1237 people since April.  This is the first time that the bug has actually shown up on a sample of fresh produce.  Perhaps it wasn't tomatoes after all, but it is a nice demonstration of confounding in epidemiological inference (tomatoes and jalapeños are commonly served together in the form of salsa, making it difficult to determine which is the actual vehicle for infection if both are implicated). Now the question is where along the production chain the contamination took place and how we can make sure that we bring an end to this outbreak.  All of the news stories and government reports on this topic can be found on the ProMedMail website.  

WALL-E, the Anthropocene, and the Future of Humanity

My kids are away for the month and my wife is in the hospital, recovering from a recent surgery.  So what do I do with my first free Saturday night in, say, ten years?  I go see a children's movie.  Having read the rave review by A. O. Scott in the New York Times and heard the similarly glowing review by David Edelstein on Fresh Air, I didn't think that I could wait until my kids come back from a month of camp and grandparents. Somehow, the idea of a story set on a post ecological-apocalyptic Earth seemed to resonate with my my mood.

The movie was, indeed, terrific.  The narrative is very straightforward and sweet.  Robot meets robot. Robot falls in love with robot.  Robots take off for distant nebula where they undergo a series of trials and tribulations in an effort to save the descendants of humanity and Earth.  You know...

It's the backdrop of the movie that is so stunning.  The bleak vision of a dead Earth, strewn with the detritus of a decadent consumer society, where toxic dust storms ravage the deadened landscape and a lone mutant cockroach appears to be the extent of life.  And when we meet what has become of humans... In just 25 generations, humans have evolved to become passive, obese, infantile receptacles of mindless consumption.  Deriving all nutriment from Big Gulps. Too fat and weak to even walk, they scoot around (seemingly endlessly) on floating sleds, interacting with the world only through the video screens constantly in front of their faces.  Hmmm, a distorting mirror for our society that my recent travels up and down American highways suggests is not all that distorting.

And yet, there is hope in the movie.  Athletic physiques may be extinct in the 28th century, but not the human spirit.  All it takes is a little robot in love to jump start a new communitarian will to power.

About the time I went to see WALL-E, a reference to this article appeared in my inbox.  Mike Davis, author of City of Quartz: Excavating the Future in Los Angeles, writes a dark essay on the state of our planet.  I don't always agree with Davis, but there is little doubt that he is a provocative and compelling writer who makes you think. In this essay, Davis describes the recent suggestion by the The Geological Society of London that human agency has led to the dawning of the newest geological epoch, The Anthropocene.

The term "Anthropocene" was coined by Dutch Nobel Laureate Paul Crutzen and has been used casually for a number of years now.  Recent work, however, has suggested that there might truly be scientific utility to the term.  Zalasiewicz and colleagues ask in the Geological Society of America's publication, GSA Today, Are We Now Living in the Anthropocene? In a recent issue of the journal Ambio, Steffen and colleagues describe the Anthropocene in terms of trends in atmospheric carbon dioxide.  This work suggests that humans have changed the environment to such an extent that it is geologically durable. Future geologists (perhaps from another planet?) could recognize the human ecological footprint in Earth's stratigraphy. In the words of Zalasiewicz et al., 

Earth has endured changes sufficient to leave a global stratigraphic signature distinct from that of the Holocene or of previous Pleistocene interglacial phases, encompassing novel biotic, sedimentary, and geochemical change. These changes, although likely only in their initial phases, are sufficiently distinct and robustly established for suggestions of a Holocene–Anthropocene boundary in the recent historical past to be geologically reasonable.

The untimely passing of the Holocene may seem an obscure and uninteresting event, but it is troubling when you think that everything that has happened in human civilization has happened in -- and because of -- the Holocene, a period of warmth and climatic stability otherwise not seen in the recent geological history of Earth.  You know, little things like the origin of agriculture, complex societies, writing, the Red Sox.  All because of the stability of the Holocene.

So the Anthropocene may bring with it increased climatic volatility and create a potentially more hostile world, less buffered to further perturbations.  But just as global warming doesn't mean that all places on Earth get noticeably warmer, so too, the environmental sequelae of the Anthropocene will not be felt equally by all.  Once again, the poor are likely to lose.  And if we really manage to bring upon ourselves the environmental apocalypse envisioned in WALL-E?

This question bugged me as I basked in the glow of WALL-E. Are there non-Americans on the Axiom, the space cruise ship that is the home away from home for humanity?  Did the Buy N Large Corporation, which seems to have taken over the world when humanity bugs out, see fit to bring poor people from, say, Sub-Saharan Africa or Central Asia to space?  Everyone on Axiom seems pretty American in their accent, gluttony, and shape.  But who knows?  It emphasizes the likelihood that in the Anthropocene world of potentially increasing climatic instability, differences between those who have and those who don't will be magnified.  As Davis writes,

But global warming is not War of the Worlds, where invading Martians are dedicated to annihilating all of humanity without distinction. Climate change, instead, will initially produce dramatically unequal impacts across regions and social classes. It will reinforce, not diminish, geopolitical inequality and conflict.

If we foul our home to the point that our only option is to emigrate to space, who will be invited to the party?  Let's hope that we never need to actually answer that question.  You see, the ability to transport all of humanity to a space ship to wait out the environmental end-of-days is not really an option.  In his book, How Many People Can the Earth Support?, Rockefeller University demographer Joel Cohen writes about the space option for dealing with over-population and resulting ecological collapse.  Cohen's simple calculations show how spectacularly out-of-the-question the space colonization solution is, even if the technology that would allow space colonization existed.

So I guess we had better take care of our home.  We're stuck here. Let's hope that we can galvanize some of that enduring human spirit that shows itself in WALL-E to change the potentially disastrous path we have set out for ourselves.  Davis is clearly right when he rails against the pie-in-the-sky "Spontaneous Decarbonization" that is implicit in most climate change scenarios.  Checking global warming will require active, politically difficult, interventions to be undertaken.  I'm not exactly overflowing with confidence that we can pull this off, but then again, life can take hold in the most unlikely of places.

Salmonella Outbreak: Is It Really Tomatoes?

An outbreak of Salmonella serotype Saintpaul has sickened 943 people since April.  Nearly 14% of these cases required hospitalization. It has been hypothesized that tomatoes have been the vehicle for this food-borne infection.  Here in Palo Alto, certain types of tomatoes (e.g., Roma and beefsteak) were taken off store shelves for a while.  The latest report from CDC suggests that tomatoes may not, in fact, be the culprit.  CDC epidemiologists are expanding their investigations to include food items that are "commonly consumed with tomatoes."

Epidemiological evidence indicates that while people of just about any age can contract the infection (age range of cases is <1-99 years), the most likely age group to contract the infection are 20-29 year-olds.  The least likely age classes are 10-19 year-olds and people over 80.  What food do young adults commonly eat with raw tomatoes that is less commonly eaten by the young or very old?  I'd say salad greens but if that were the case, I'd expect a sex bias in infections.  50% of the infections are women and my informed guess (based on my experience with largely middle-class college students) is that 20-29 year-old women eat more salad than 20-29 year-old men.  

So what is it if it's not tomatoes?  Something having to do with consumption of alcohol? Some salsa ingredient like jalapeños or scallions? (note: another thing consumed in bars)

Biofuels Place Price Pressure on Food

A recent story in The Guardian reports on an unpublished World Bank study that suggests the conversion of food crops to biofuels, and the resulting economic pressures entailed in this process, is responsible for most of the steep price increases in food this year.  The World Bank report has not been published, though it was completed in April, and speculation is that the delay is meant to avoid embarrassing the Bush administration, who maintains that biofuels have had only a minor impact on food prices. For example, the report contradicts statements by US Agriculture Secretary Ed Schafer and Energy Secretary Samuel Bodman made in a letter sent to the Senate Energy Committee last month.  The World Bank report attributes fully 75% of the increase in food prices to biofuels in contrast to the official US estimates of just 3%.

Biofuel development distorts food markets in three ways, one of them obvious, the other two less so: (1) it diverts grain production for food to the production of biofuels, (2) it creates incentives for farmers to set aside more land for biofuel crop development, and (3) it induces speculation on the commodities market, driving up grain prices.

The results of this report (at least as reported in The Guardian) resonate well with my own intuitions about biofuels. It seems like a very bad idea to me to make fuel for SUVs out of food.  It's all too easy for people in the developing world, where the leading dietary problem is obesity, to forget that a substantial portion of the world (somewhere in the vicinity of 800 million) is still regularly hungry. I remain open to the idea of generating biofuels from organic waste, but the consequences of growing grain and other basic foodstuffs for biofuels on commodity prices, and therefore the price that people pay for food, should be obvious to anyone who has taken an introductory economics class. Price increases with demand and decreases with supply, remember? Given that world population is still growing and that some formerly poor parts of the world are rapidly developing (and therefore increasing their demand for grain both directly and indirectly through increased demand for meat), there is no way that demand for grain as food is going to decrease.  This can only mean that increasing crop production for biofuel is bound to decrease supply for food in the absence of large expansions of crop land.  Generating demand for biofuels through legislation requiring a certain proportion of biofuel use (as is the case in the EU) or marketing ethanol-burning SUVs as somehow environmentally friendly is similarly going to increase demand for biofuels.  This means that prices for grains (and substitutable commodities) are bound to increase. Or am I missing something here?

Smoky Palo Alto

The other day I woke up and the house smelled intensely of wood smoke.  When I went outside, the smell was almost overwhelming.  A low haze hung over the area and my eyes and throat burned after running.  The last time this happened was during the Summit Fire in Santa Cruz this May.

 
It is, of course, well known that over a thousand wildfires were sparked throughout Northern California by dry lightning storms last week. What I couldn't understand about the past week is that there are no nearby fires, yet the smoky haze has been far worse over the past week than it was at the height of the Summit Fire.  So where is all the smoke coming from?  Looking at the MODIS site, I found an answer. This is the picture of the day from 29 June and it is pretty stunning.  The smoke from the Napa, Shasta, and Mendocino County fires was just funneling down through the the San Francisco Bay Area.  Yikes. 

Things have been a bit better over the last couple days but it is still disturbingly overcast and hazy. I fear it is going to be a very long summer...

West Nile Virus Activity, Spring 2008

I don't want to jump to conclusions about global warming, but the extremely early start to the 2008 West Nile Virus season in the Western United States is extremely troubling. Earlier this week, a Maricopa County, Arizona man became the first human case of WNV this year.  The report of a WNV infected bird this week in Bakersfield, California means that WNV has appeared 2 months earlier than last year in Kern County, a place that saw 140 human cases and 4 deaths last year.  There are a number of possible ecological explanations for why WNV activity could be off to such an early start this year.  One set of possibilities  involve warming temperatures. There is real concern that global warming will expand the range of a variety of vector-borne diseases.  Let's hope that dengue and malaria don't manage to invade California too.

High Rice Prices Affect Nearly Three Billion

Nearly half the world's population relies on rice as its primary food staple.  In the last three months, the trading price of rice on international markets has nearly doubled.  This is bad news for poor people in Asia and, especially, parts of urban West Africa. One contributor to this dramatic increase in price is the reduced growth in production in places like Vietnam because of viral infections such as grassy stunt virus and tungro and other crop infestations such as brown planthopper.  So far, the infestations have not spilled over into China, the worlds largest rice producer, but one worries about the proximity and borders that are notoriously permeable to the smuggling of agricultural products