CHINA SUFFERS FROM SEVERE WATER POL-
lution, primarily resulting from substantial
discharge of wastewater. In 2011, China gen-
erated 65.21 billion tons of wastewater (1),
and the total amount is expected to continue
growing as a result of rapid urbanization and
industrialization, reaching 78.4 billion tons
by 2015 based on an annual increase rate of
On 6 August, China issued the Twelfth
Five-Year Plan of Energy Conservation
and Emission Reduction (2011 to 2015),
in which the importance of wastewater
treatment is addressed (3). The plan sets a
goal: By 2015, the municipal wastewater
treatment rate (wastewater treated divided
by wastewater generated) and wastewater
recycle rate (wastewater recycled divided
by wastewater treated) should reach 85 and
The 85% target will be difficult to meet if
rural areas are taken into account. Currently,
national statistics for wastewater treatment
rate in China only include urban areas and
industrial sectors. If the wastewater treatment
conditions in rural areas, which make up
more than 50% of total population in China,
are factored in, the wastewater treatment rate
[currently 82.3% (2)] would drop dramati-
cally. Most villages (96%) do not have drain-
age or wastewater treatment systems, and the
remaining 4% treat wastewater with simple
technologies such as septic tanks (4).
1. Ministry of Environmental Protection of the People’s
Republic of China, National Report on Environmental
Quality of 2011 ( http://jcs.mep.gov.cn/hjzl/
zkgb/2011zkgb/) [in Chinese].
2. Ministry of Environmental Protection of the People’s
Republic of China, National Report on Environmental
Statistics of 2010 ( http://zls.mep.gov.cn/hjtj/nb/)
3. The State Council, The Twelfth Five-Year Plan of Energy
Conservation and Emission Reduction ( www.gov.cn/
zwgk/2012-08/21/ content_2207867.htm) [in Chinese].
4. J. Li, Application of Decentralized Wastewater Treatment
in Small Towns and Villages of China (Chalmers Univ. of
Technology, Gothenburg, Sweden, 2010).
5. Innovation Center Denmark, Shanghai, “Wastewater
Treatment in China” (2009).
6. Y. L. Liu, Recycle rate of wastewater reaches
8.5% in China (2010); http://info.water.hc360.
com/2010/04/ 160933182857.shtml [in Chinese].
7. L. Guo, Science 317, 1166 (2007).
8. R. Stone, Science 333, 1210 (2011).
9. M. Yang et al., Science 319, 158 (2008).
CORRECTIONS AND CLARIFICATIONS
Letters: “Friends in fungi” by G. D. A. Werner and E. T. Kiers (21 September, p. 1452). The
image of the rare ericoid mycorrhizal fungus was misleading. The Letter’s discussion applies
more closely to arbuscular mycorrhizal fungi. The image has been replaced in the HTML and
PDF versions online. The caption has been changed to “Arbuscular mycorrhizal fungi” and
the credit has been changed to Jan Jansa.
This Week in Science: “Modulating the clock” (31 August, p. 1017). The image with this
description should have been placed with the description below: “Keeping DNA flexible.”
The placement has been corrected in the HTML and PDF versions online.
Perspectives: “Walking on solid ground” by B. F. Dickey (24 August, p. 924). In panel A of
the figure, the path of the mucus (going up the trachea, making a turn, and going down
the esophagus) should have been indicated in dark blue. The H TML and PDF versions online
have been corrected.
News Focus: “Stopping Alzheimer’s before it starts” by G. Miller (17 August, p. 790).
Matthew Reiswig should have been referred to as Matt throughout the story. Also, in the
family portrait caption, Matt and his brother were misidentified. Matt is the second adult
from the left, and his brother Marty is in the red shirt just right of center. The HTML and PDF
versions online have been corrected.
Review: “Valorization of biomass:
deriving more value from Waste” by
C. O. Tuck et al. (special section on
Working with Waste, 10 August, p.
695). In Fig. 3, the bracketed por-
tion of the cyanophycin structure
should have shown an amide, rather
than an amine. The complete figure
has been corrected in the HTML version online. The corrected structure is shown here.
Perspectives: “Recycling of the #5 polymer” by M. Xanthos (special section on Working
with Waste, 10 August, p. 700). The figure credit was omitted. It should be the following:
Photo collage by L. Blizard; Thinkstock; iStockphoto; Shutterstock; Wikimedia Commons.
The credit is correct in the HTML version online.
News Focus: “An evolutionary theory of dentistry” by A. Gibbons (25 May, p. 973). The
article implied that both European countries and the United States added fluoride to their
drinking water in the 1970s. In fact, water in most European nations was not fluoridated.
However, European improvements in public dental health from the 1970s to the present
have matched or even exceeded those of the United States. Reasons include fluoridated
toothpastes, which became widely available in the 1970s, and changing criteria for diag-
nosing caries. See T. M. Marthaler, Caries Res. 38, 173 (2004).
TECHNICAL COMMENT ABSTRACTS
Comment on “Multiyear Prediction of Monthly Mean
Atlantic Meridional Overturning Circulation at 26.5°N”
Gabriel A. Vecchi, Rym Msadek, Thomas L. Delworth, Keith W. Dixon,
Matei et al. (Reports, 6 January 2012, p. 76) claim to show skillful multiyear predictions of
Eric Guilyardi, Ed Hawkins, Alicia R. Karspeck, Juliette Mignot, Jon
Robson, Anthony Rosati, Rong Zhang
the Atlantic Meridional Overturning Circulation (AMOC). However, these claims are not jus-
tified primarily because the predictions of AMOC transport do not outperform simple refer-
ence forecasts based on climatological annual cycles. Accordingly, there is no justification
for the “confident” prediction of a stable AMOC through 2014.
Full text at http://dx.doi.org/10.1126/science.1222566
Response to Comment on “Multiyear Prediction
of Monthly Mean Atlantic Meridional Overturning
Circulation at 26.5°N”
Daniela Matei, Johanna Baehr, Johann H. Jungclaus, Helmuth Haak,
Vecchi et al. question the skill of our initialized multiyear predictions of Atlantic Meridi-
Wolfgang A. Müller, Jochem Marotzke
onal Overturning Circulation (AMOC), arguing that our predictions do not outperform their
suggested climatological reference forecast—using a single measure of skill. We show that
our initialized AMOC predictions do outperform the climatological reference forecast, using
both measures of hindcast performance that were presented in our original paper.
Full text at http://dx.doi.org/10.1126/science.1223200
2 NOVEMBER 2012 VOL 338 SCIENCE www.sciencemag.org