Daily Archives: February 3, 2014

ENSO dynamics dominate terrestrial water cycle

Diego G. Miralles, Martinus J. van den Berg, John H. Gash, Robert M. Parinussa, Richard A. M. de Jeu, Hylke E. Beck, Thomas R. H. Holmes, Carlos Jiménez, Niko E. C. Verhoest, Wouter A. Dorigo, Adriaan J. Teuling, A. Johannes Dolman. El Niño–La Niña cycle and recent trends in continental evaporation. Nature Climate Change 4, 122–126 (2014) doi:10.1038/nclimate2068

The hydrological cycle is expected to intensify in response to global warming. Yet, little unequivocal evidence of such an acceleration has been found on a global scale. This holds in particular for terrestrial evaporation, the crucial return flow of water from land to atmosphere. Here we use satellite observations to reveal that continental evaporation has increased in northern latitudes, at rates consistent with expectations derived from temperature trends. However, at the global scale, the dynamics of the El Niño/Southern Oscillation (ENSO) have dominated the multi-decadal variability. During El Niño, limitations in terrestrial moisture supply result in vegetation water stress and reduced evaporation in eastern and central Australia, southern Africa and eastern South America. The opposite situation occurs during La Niña. Our results suggest that recent multi-year declines in global average continental evaporation reflect transitions to El Niño conditions, and are not the consequence of a persistent reorganization of the terrestrial water cycle. Future changes in continental evaporation will be determined by the response of ENSO to changes in global radiative forcing, which still remains highly uncertain.

Click here for full paper (fee).

Economic comparison of green, white, and black roofs

Julian Sproul, Man Pun Wan, Benjamin H. Mandel, Arthur H. Rosenfeld. Economic comparison of white, green, and black flat roofs in the United States. Volume 71, March 2014, Pages 20–27

White and “green” (vegetated) roofs have begun replacing conventional black (dark-colored) roofs to mitigate the adverse effects of dark impervious urban surfaces. This paper presents an economic perspective on roof color choice using a 50-year life-cycle cost analysis (LCCA). We find that relative to black roofs, white roofs provide a 50-year net savings (NS) of $25/m2 ($2.40/ft2) and green roofs have a negative NS of $71/m2 ($6.60/ft2). Despite lasting at least twice as long as white or black roofs, green roofs cannot compensate for their installation cost premium. However, while the 50-year NS of white roofs compared to green roofs is $96/m2 ($8.90/ft2), the annualized cost premium is just $3.20/m2-year ($0.30/ft2-year). This annual difference is sufficiently small that the choice between a white and green roof should be based on preferences of the building owner. Owners concerned with global warming should choose white roofs, which are three times more effective than green roofs at cooling the globe. Owners concerned with local environmental benefits should choose green roofs, which offer built-in stormwater management and a “natural” urban landscape esthetic. We strongly recommend building code policies that phase out dark-colored roofs in warm climates to protect against their adverse public health externalities.

Click here for full paper (Open Source).

Israel to end water fluoridation in 2014, good choice

NEW YORK, Aug. 8, 2013 /PRNewswire-USNewswire/ — On July 29, 2013, the Supreme Court of Israel ruled that new regulations require Israel to stop adding fluoride chemicals into public water supplies in one year, reports the Fluoride Action Network (FAN).

Izun Hozer Association for Dissemination of Health Education and Yaacov Gurman petitioned Israel’s highest court, November 12, 2012, demanding that the Ministry of Health order the cessation of fluoridation because it presents health dangers and its benefits are no longer widely accepted.

A 1974 regulation mandated fluoridation throughout Israel. But in April 2013, the Minister of Health, Yael German, created a new regulation removing that mandate.

“It must be known to you that fluoridation can cause harm to the health of the chronically ill,” including “people who suffer from thyroid problems,” German wrote in a letter addressed to doctors opposed to ending fluoridation.

The court ruled that the new regulations will not only bring an end to mandatory fluoridation in Israel in 2014 but will also put an end to any fluoridation – mandatory or voluntary. See translation of the Court’s ruling at: http://www.fluoridealert.org/uploads/israel_supreme_ct_july2013.pdf

Paul Connett, PhD, FAN Executive Director, says, “Zealous fluoridation promoters try to convince the American public that ‘everyone drinks fluoridated water.’ But the opposite is true. An overwhelming number of countries do not fluoridate, including 97% of the European population. In fact, over half the people in the world drinking fluoridated water live in the US. We are the odd ones out.”

“Fluoridation is an outdated, unscientific, failed public health blunder,” says Connett. “What I find remarkable here is that Health Minister German has been able to escape the unscientific belief system on fluoridation that traps so many public health bureaucracies in fluoridated countries.”

Many communities, over the last few years, stopped fluoridation in the US, Canada, New Zealand and Australia. Recently, both Wichita, Kansas and Portland, Oregon rejected fluoridation 60% to 40%. Hamilton, NZ, councilors voted 7-1 to stop 50 years of fluoridation after councilors listened to several days of testimony from those for and against fluoridation.

Windsor, Ontario, stopped 51 years of fluoridation. Sixteen regional councils have halted or rejected fluoridation in Queensland since mandatory fluoridation was dropped there in Nov. 2012.

Meanwhile, New York City Council Member Peter Vallone, Jr. continues in his effort to halt fluoridation in NYC.

Research published in peer-reviewed scientific journals indicates that fluoride ingestion is ineffective at reducing tooth decay and harmful to health. See http://www.FluorideAction.Net/issues/health.

SOURCE Fluoride Action Network

Source: PR Newswire US, 08/08/2013
Item: 201308081810PR.NEWS.USPR.DC61637