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Diary of a Tree Stump

Something lighter:                                    

  “I would vote for a tree stump if it could beat Donald Trump”

   [Timothy Egan, in his Nov. 8, 201...

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Winds of Change
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Afterword to the softbound edition.


The Octopus and the Orangutan
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The Future In Plain Sight
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Silent Partners
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Affluence and Discontent
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GLOBALFEVER

CLIMATE CHANGE THREATENS MORE THAN MEGASTORMS, FLOODS AND DROUGHTS. THE REAL PERIL MAY BE DISEASE
BY EUGENE LINDEN


Monday, Jul. 08, 1996
Floods. Droughts. Hurricanes. Twisters. Are all the bizarre weather extremes we've been having lately normal fluctuations in the planet's atmospheric systems? Or are they a precursor of the kind of climactic upheavals that can be expected from the global warming caused by the continued buildup of CO2 and the other so-called greenhouse gases? Scientists are still not sure. But one of the effects of the unusual stretch of weather over the past 15 years has been to alert researchers to a new and perhaps even more immediate threat of the warming trend: the rapid spread of disease-bearing bugs and pests.

Climate change, whether natural or man-made, may already be spreading disease and pestilence, according to a host of new studies, including a major report being prepared by the World Health Organization and other international institutions for release this summer. Malaria, for example, has been flourishing in recent years owing to unusually hot weather. Similarly, climate disruptions may be giving new life to such ancient scourges as yellow fever, meningitis and cholera, while fostering the spread of emerging diseases like hantavirus.

Underlying all these outbreaks is the same Darwinian mechanism: unusual weather such as dry spells in wet areas or torrential rains in normally dry spots tends to favor so-called opportunistic pests--rodents, insects, bacteria, protozoa, viruses--while making life more difficult for the predators that usually control them. Episodes of extreme weather are routinely followed by outbreaks of plagues, both old and new. Among the most recent examples:

CHOLERA. In 1991 a freighter coming from South Asia emptied its bilges off the coast of Peru. Along with the wastewater came a strain of cholera that found a home in huge algal blooms stimulated by unusually warm ocean waters and abundant pollution. The microbe then made its way into shellfish and humans. So far, the epidemic has infected over half a million people and killed at least 5,000.

HANTAVIRUS. In 1993 a six-year drought followed by heavy rains produced a tenfold increase in the population of deer mice in the American Southwest, leading to an outbreak of a deadly form of pulmonary hantavirus. The disease, which first appeared on a Navajo reservation, has since spread to 20 states and killed 45 people, nearly half of those infected.

PLAGUE. In 1994 a long monsoon in northern India followed by 90 consecutive days of 100[degrees]F heat drove rats into the cities. In Surat, they caused an outbreak of pneumonic plague. The ensuing panic killed 63 people and ultimately cost India $2 billion.

DENGUE FEVER. The coastal mountain ranges of Costa Rica had long confined dengue fever, a mosquito-borne disease accompanied by incapacitating bone pain, to the country's Pacific shore. But in 1995 rising temperatures allowed Aedes aegypti mosquitoes to breach the coastal barrier and invade the rest of the country. Dengue also advanced elsewhere in Latin America, reaching as far north as the Texas border. By September the epidemic had killed 4,000 of the 140,000 people infected.

Of all the infectious diseases humans will have to contend with as the world gets warmer, malaria may be the worst. Malaria is already the world's most widespread mosquito-borne illness. Rising temperatures will not only expand the range of Anopheles mosquitoes, but make them more active biters as well. Paul Epstein, an epidemiologist with the Harvard School of Public Health, notes that a temperature rise of 4 [degrees] F would more than double mosquito metabolism, forcing them to feed more often. A 4 [degrees] F rise in global temperatures could also expand malaria's domain from 42% to 60% of the planet. When temperatures rise above 104 [degrees] F, mosquitoes begin to die off--but at those temperatures, so do people and the crops on which they live.

Humans often make matters worse for themselves by the changes they make in their local environments. Unusually warm waters played an important role in the cholera epidemic that hit Latin America in 1991, but the outbreak was also exacerbated by sewage poured into the waters off Asia and Latin America, the destruction of pollution-filtering mangroves in the Bay of Bengal and overcrowding in the cities.

The same synergies that empower microbes also weaken our defenses against them. Heat, increased ultraviolet radiation resulting from ozone depletion, and pollutants like chlorinated hydrocarbons all suppress the disease-battling immune systems--both for humans and for other animals. Epstein, who is one of the principal authors of the upcoming WHO study, notes that in recent years variants of the class of viruses that includes measles have killed seals in the North Sea, lions in the Serengeti and horses in Australia--three very different animals widely scattered around the globe.

A common denominator in each case: abnormal weather had caused malnutrition, weakened animal immune systems and spurred the reproduction of viruses. Epstein also notes that once ordinarily benign microbes invade weakened animals, they can become sufficiently deadly to invade healthy populations. The real threat for people, says Epstein, may not be a single disease, but armies of emergent microbes raising havoc among a host of creatures. "The message I take home," he says, "is that diseases afflicting plants and animals can send ripples through economies and societies no less disastrous than those affecting humans."

A small but persistent group of critics, many of them supported by the oil and coal industries, still don't buy it. S. Fred Singer, president of the industry-funded Science and Environment Policy Project, argues that Epstein and his colleagues fail to note the positive health benefits of warmer nights and winters. Others, like John Shlaes, executive director of the Global Climate Coalition, suggest that when the world is faced with the pressing health problems stemming from overcrowded cities and the collapse of sanitation systems, the threat of disease caused by climate change may seem like a minor concern.

No one disputes the role of poverty and overpopulation in spreading disease. That is no reason to ignore the warnings sounded by Epstein and his colleagues, however. Scientists first raised alarms about climate change in the late 1980s, but the international community has taken few concrete steps to address the problem. The world is gambling, in effect, that problems in the future will not be serious enough to warrant inconvenience in the present. With each passing year, the future gets closer and that bet gets bigger.

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Short Take

THOUGHTS ON WHY THE EARLY IPCC ASSESSMENTS UNDERSTATED THE CLIMATE THREAT

 

An oped involves extreme compression, and so I thought I’d expand on why I think the initial IPCC reports so underestimated the threat. Make no mistake, the consensus in the summaries for policy makers in the first two assessments did underestimate the threat. The consensus was that permafrost would be stable for the next 100 years and also that the ice sheets would remain stable (there was even a strong sentiment at that time that the East Antarctic sheet would gain mass). Moreover, in 1990, the concept of rapid climate change was at the periphery of mainstream scientific opinion. All these things turned out to be wrong

Of course, there were scientists at that time who raised alarms about the possibility of rapid climate change, collapse of the ice sheets, and nightmare scenarios of melting permafrost, but, fairly or not, the IPCC summary for policy makers was and is taken to represent the consensus of scientific thinking.

In my opinion such documents will always take a more conservative (less dramatic) position than what scientists feel is justified. For one thing the IPCC included policy makers, most of whom were more incentivized to downplay the threats. For another, many of the national governments that were the customers for these assessments barely tolerated the exercise and gave strong signals that they didn’t want to see anything that called for dramatic action, and this being the UN, there was a strong push to present a document that as many governments as possible would accept.

And then there is the nature of science and the state of climate science at that point. There is an inherent structural lag built in to the nature of science. For instance, the 1980’s were marked by the rapid development of proxies to see past climate changes with ever more precision. By the mid-late 80’s the proxies and siting had been refined sufficiently that the GISP and GRIP projects could confidently get ice cores from Greenland that they felt represented a true climate record and by then they also had the proxies with the resolution to see the rapid changes that had taken place in the past. Given the nature of data collection, interpretation, peer-review and publishing, it wasn’t until 1993 that these results were published.

It took nearly another decade for this new, alarming, paradigm about how rapidly global climate can change to percolate through the scientific community, and, even today, much of the public is unaware that climate can change on a dime.

As for the ice sheets, when I was on the West Antarctic Ice Sheet in 1996, there was talk about the acceleratio of  ice streams feeding the Thwaites and Pine Island glaciers, but the notion that there might be a significant increase in runoff from the ice sheet over the next hundred years was still very much a fringe idea.

With permafrost, the problem was a sparsity of data in the 80s and early 90s and it is understandable that scientists didn’t want to venture beyond the data.

The problem for society as a whole was that the muted consensus on the scale of the threat diminished any sense of urgency about dealing with the problem. Perhaps the best example of this was the early work of William Nordhaus. Working from the IPCC best estimates in the early 1990s Nordhaus published one paper in which he predicted the hit to the US GDP from climate change in 2100 would be about ½ of 1%. Nobody is going to jump out of their chair and demand action if the hit to the economy was going to be 0.5% of GPD a hundred years laterLibertarians such as William Niskanen seized on this and testified before Congress that there was plenty of time to deal with global warming if it was a threat at all.  

And then there was the disinformation campaign of industry, particularly fossil fuel lobbyists, as well as pressure from unions (the UAW in particular) and the financial community. These highly motivated, deep-pocketed interests seized on scientific caution to suggest deep divisions among scientists and that the threat was overplayed. Little wonder then that the public failed to appreciate that this was a looming crisis that demanded immediate, concerted action.

 



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