NATURE
1. An age difference of
two billion years between a metal-rich and a metal-poor globular cluster
B.
M. S. Hansen, J. S. Kalirai, J. Anderson, A. Dotter, H. B. Richer, R. M. Rich,
M. M. Shara, G. G. Fahlman, J. R. Hurley, I. R. King, D. Reitzel & P. B.
Stetson
Nature 500, 51–53 (01 August 2013) doi:10.1038/nature12334
An
absolute age of about ten billion years is determined for the globular cluster
47 Tucanae, which is about two billion years younger than the cluster NGC 6397
is thought to be, suggesting that metal-rich clusters like 47 Tucanae formed
later than metal-poor clusters like NGC 6397.
2. Seasonal sea surface
cooling in the equatorial Pacific cold tongue controlled by ocean mixing
James
N. Moum, Alexander Perlin, Jonathan D. Nash & Michael J. McPhaden
Nature 500, 64–67 (01 August 2013) doi:10.1038/nature12363
In
the tropics, a strong seasonal cycle in sea surface temperature exists despite
comparatively constant radiation inputs; turbulent mixing from below is now
shown to control the cooling phase of the seasonal cycle in the equatorial
Pacific ‘cold tongue’ at 140° W.
3. Feeding andesitic
eruptions with a high-speed connection from the mantle
Philipp
Ruprecht & Terry Plank
Nature 500, 68–72 (01 August 2013) doi:10.1038/nature12342
Diffusion
modelling of nickel in mantle melts beneath a volcano reveals the short
timescales of magma movement from the base of the crust to the surface in the
months to years before an eruption.
4. Reward research
outreach in Japan
Amane
Koizumi, Yuko Morita & Shishin Kawamoto
Nature 500, 29 (01 August 2013) doi:10.1038/500029a
Only
64% of almost 9,000 surveyed Japanese scientists communicate results outside
the scientific community. This is because researcher performance in Japan is
evaluated solely on the number of journal publications, so time and effort
spent on science communication will not help scientists to secure funding,
promotion or employment. Since 2010, the government has urged the researchers
it funds to improve communication with the tax-paying public.
5. The milk revolution
Andrew
Curry
Nature 500, 20–22 (01 August 2013) doi:10.1038/500020a
When
a single genetic mutation first let ancient Europeans drink milk, it set the
stage for a continental upheaval.
6. Pilot projects bury
carbon dioxide in basalt
Jeff
Tollefson
Nature 500, 18 (01 August 2013) doi:10.1038/500018a
Two
experiments test viability of sequestering emissions in porous layers of hard
rock.
SCIENCE
SPECIAL ISSUE ON CLIMATE CHANGE
7. How a Fickle Climate
Made Us Human
Ann
Gibbons
Science
2 August 2013:
Vol.
341 no. 6145 pp. 474-479, DOI: 10.1126/science.341.6145.474
Many
researchers agree that shifts in climate and environment shaped human
evolution, but there has been little direct evidence about exactly how. Now
researchers are drilling cores to gather geological data in the African
landscapes where human ancestors once lived. Such localized data may help test
ideas such as the savanna hypothesis, which proposes that the rise of grasses
accompanied the birth of hominins.
8. Out of the Kenyan
Mud, an Ancient Climate Record
Elizabeth
Pennisi
Science
2 August 2013:
Vol.
341 no. 6145 pp. 476-479, DOI: 10.1126/science.341.6145.476
Scientists
gather for a first look at a fresh sediment core, hoping that it will offer
hard data linking environmental change to human evolution.
9. Can Coastal Marshes
Rise Above It All?
Eli
Kintisch
Science
2 August 2013:
Vol.
341 no. 6145 pp. 480-481, DOI: 10.1126/science.341.6145.480
There's
wide agreement that salt marshes are among the ecosystems most vulnerable to
rapid sea-level rise. But few researchers are ready to predict the fate of
specific marshes; there's still too much to learn, they say. Now, wetlands
scientists are mobilizing to reduce the uncertainty and hope to identify
practical steps to protect marshes.
10. a) Worth a Thousand
Words
Elizabeth
Pennisi
Science
2 August 2013:
Vol.
341 no. 6145 p. 482, DOI: 10.1126/science.341.6145.482-a
By
comparing historic images with modern photos snapped at the very same spots,
researchers are documenting biological change that might be otherwise invisible
in Ethiopia, China, Sweden, and the Arctic. Photo comparisons have yielded
numerous insights and a few surprises. In this article, Science takes a look at
a few projects that use photos to go back in time.
10. b) Advancing
Seasons in China
Elizabeth
Pennisi
Science
2 August 2013:
Vol.
341 no. 6145 pp. 482-483, DOI: 10.1126/science.341.6145.482-b
10. c) Tundra in
Turmoil
Elizabeth
Pennisi
Science
2 August 2013:
Vol.
341 no. 6145 pp. 483-484, DOI: 10.1126/science.341.6145.483
10. d) Tree Line Shifts
Elizabeth
Pennisi
Science
2 August 2013:
Vol.
341 no. 6145 p. 484, DOI: 10.1126/science.341.6145.484
10. e) Humans Greening
a Landscape
Elizabeth
Pennisi
Science
2 August 2013:
Vol.
341 no. 6145 p. 485, DOI: 10.1126/science.341.6145.485
Reviews:
11. Changes in
Ecologically Critical Terrestrial Climate Conditions
Noah
S. Diffenbaugh, Christopher B. Field
Science
2 August 2013
Vol.
341 no. 6145 pp. 486-492, DOI: 10.1126/science.1237123
Terrestrial
ecosystems have encountered substantial warming over the past century, with
temperatures increasing about twice as rapidly over land as over the oceans.
Here, we review the likelihood of continued changes in terrestrial climate.
12. Marine Ecosystem
Responses to Cenozoic Global Change
Science
2 August 2013:
Vol.
341 no. 6145 pp. 492-498, DOI: 10.1126/science.1240543
The
future impacts of anthropogenic global change on marine ecosystems are highly
uncertain, but insights can be gained from past intervals of high atmospheric
carbon dioxide partial pressure. The long-term geological record reveals an
early Cenozoic warm climate that supported smaller polar ecosystems, few
coral-algal reefs, expanded shallow-water platforms, longer food chains with
less energy for top predators, and a less oxygenated ocean than today.
13. Climate Change and
the Past, Present, and Future of Biotic Interactions
Science
2 August 2013:
Vol.
341 no. 6145 pp. 499-504, DOI: 10.1126/science.1237184
Biotic
interactions drive key ecological and evolutionary processes and mediate
ecosystem responses to climate change. We highlight episodes of climate change
that have disrupted ecosystems and trophic interactions and identify knowledge
gaps and fruitful areas for research that will further our understanding of the
effects of climate change on ecosystems.
14. The Future of
Species Under Climate Change: Resilience or Decline?
Science
2 August 2013:
Vol.
341 no. 6145 pp. 504-508, DOI: 10.1126/science.1237190
As
climates change across already stressed ecosystems, there is no doubt that
species will be affected, but to what extent and which will be most vulnerable
remain uncertain. The fossil record suggests that most species persisted
through past climate change, whereas forecasts of future impacts predict
large-scale range reduction and extinction.
15. Climate Change
Impacts on Global Food Security
Science
2 August 2013:
Vol.
341 no. 6145 pp. 508-513, DOI: 10.1126/science.1239402
Climate
change could potentially interrupt progress toward a world without hunger. The
evidence supports the need for considerable investment in adaptation and
mitigation actions toward a “climate-smart food system” that is more resilient
to climate change influences on food security.
16. Climate Change and
Infectious Diseases: From Evidence to a Predictive Framework
Science
2 August 2013:
Vol.
341 no. 6145 pp. 514-519, DOI: 10.1126/science.1239401
Climate
change has already increased the occurrence of diseases in some natural and
agricultural systems. We highlight research progress and gaps that have emerged
during the past decade and develop a predictive framework that integrates
knowledge from ecophysiology and community ecology with modeling approaches.
17. Ecological
Consequences of Sea-Ice Decline
Eric Post, Uma S. Bhatt, Cecilia M. Bitz, Jedediah F. Brodie, Tara L. Fulton, Mark Hebblewhite, Jeffrey Kerby, Susan J. Kutz, Ian Stirling, Donald A. Walker
Science
2 August 2013:
Vol.
341 no. 6145 pp. 519-524, DOI: 10.1126/science.1235225
After
a decade with nine of the lowest arctic sea-ice minima on record, including the
historically low minimum in 2012, we synthesize recent developments in the
study of ecological responses to sea-ice decline.
SCIENCE
18. Study Links Climate
Change and Violence, Battle Ensues
Science
2 August 2013:
Vol.
341 no. 6145 pp. 444-445
DOI:
10.1126/science.341.6145.444
In
many cities, violence spikes with the temperature. Some social scientists say
that the same could be true globally, proposing that climate change could lead
to escalating violence. Now, a study published online this week in Science
tries to quantify the increase.
19. Efficient
Generation of H2 by Splitting Water with an Isothermal Redox Cycle
Christopher L. Muhich, Brian W. Evanko, Kayla C. Weston, Paul Lichty, Xinhua Liang, Janna Martinek, Charles B. Musgrave, Alan W. Weimer
Science
2 August 2013:
Vol.
341 no. 6145 pp. 540-542
DOI:
10.1126/science.1239454
Solar
thermal water-splitting (STWS) cycles have long been recognized as a desirable
means of generating hydrogen gas (H2) from water and s unlight.
Two-step, metal oxide–based STWS cycles generate H2 by sequential
high-temperature reduction and water reoxidation of a metal oxide. We show that
these temperature swings are unnecessary.
20. Is There Social
RNA?
Science
2 August 2013:
Vol.
341 no. 6145 pp. 467-468, DOI: 10.1126/science.1243175
Our
understanding of the forms, functions, and movement of RNA continues to expand.
Not only can RNA control gene expression by multiple mechanisms within a cell,
it appears to travel outside the cell within an organism as well. This raises
the interesting question of whether the RNA world extends beyond the boundaries
of the organism. Can RNA traffic integrate an organism into its environment—is
there “social RNA”? Examining the mechanism of RNA interference (RNAi) may be a
good route for seeking the answer.
PNAS
21. Rapid accumulation
of committed sea-level rise from global warming
Benjamin
H. Strauss
PNAS
2013 ; published ahead of print July 29, 2013, doi:10.1073/pnas.1312464110
22. Dynamic model constraints
on oxygen-17 depletion in atmospheric O2 after a snowball Earth
Xiaobin
Cao and Huiming Bao
PNAS
2013 ; published ahead of print July 29, 2013, doi:10.1073/pnas.1302972110
A
large perturbation in atmospheric CO2 and O2 or bioproductivity will result in
a drastic pulse of 17O change in atmospheric O2, as seen in the Marinoan
Oxygen-17 Depletion (MOSD) event in the immediate aftermath of a global
deglaciation 635 Mya. A snowball Earth is a precondition for the observed MOSD
event.
23. Mass support for
global climate agreements depends on institutional design
Michael
M. Bechtel and Kenneth F. Scheve
PNAS
2013 ; published ahead of print July 25, 2013, doi:10.1073/pnas.1306374110
Effective
climate mitigation requires international cooperation, and these global efforts
need broad public support to be sustainable over the long run. We provide
estimates of public support for different types of climate agreements in
France, Germany, the United Kingdom, and the United States.
24. Variations in
atmospheric CO2 growth rates coupled with tropical temperature
Weile
Wang, Philippe Ciais, Ramakrishna R. Nemani, Josep G. Canadell, Shilong Piao,
Stephen Sitch, Michael A. White, Hirofumi Hashimoto, Cristina Milesi, and Ranga
B. Myneni
PNAS
2013 ; published ahead of print July 24, 2013, doi:10.1073/pnas.1219683110
Previous
studies have highlighted the occurrence and intensity of El Niño–Southern
Oscillation as important drivers of the interannual variability of the
atmospheric CO2 growth rate, but the underlying biogeophysical mechanisms
governing such connections remain unclear. Here we show a strong and persistent
coupling (r2 ≈ 0.50) between interannual variations of the CO2 growth
rate and tropical land–surface air temperature during 1959 to 2011.
NATURE
GEOSCIENCE
25. Troubling milestone
for CO2
Nicola
Jones
Nature Geoscience 6, 589 (2013) doi:10.1038/ngeo1900
Published
online 30 July 2013
On
9 May 2013, the daily average concentration of CO2 in our planet's atmosphere,
measured at the famous Mauna Loa Observatory in Hawaii, crept above 400 parts
per million for the first time since humans walked the Earth.
26. Acidification and
acclimation
Anna
Armstrong
Nature Geoscience 6, 590 (2013) doi:10.1038/ngeo1913
Continued
acidification of the global ocean as a result of rising concentrations of
atmospheric carbon dioxide reduces the formation of calcium carbonate in the
oceans and could therefore impair the growth of carbonate coral skeletons.
Corals that occur in naturally acidic waters near the Yucatan Peninsula show
decreased levels of calcification, according to a morphological analysis of
corals in the region.
27. Miocene melt-down
Alicia
Newton
Nature Geoscience 6, 590 (2013) doi:10.1038/ngeo1915
Published
online 30 July 2013
About
23 million years ago, ice sheets on Antarctica temporarily expanded to
near-modern volumes. An analysis of marine sediments suggests that this
expansion was accompanied by cooling of deep waters and increased burial of
organic carbon.
28. Extinction promoted
fire
Beverly
Johnson
Nature Geoscience 6, 595–596 (2013) doi:10.1038/ngeo1907
Published
online 30 July 2013
The
extinction of megafauna in Australia roughly coincided with shifts in
vegetation and fire regimes. Sediment geochemistry shows that the vegetation
shift followed the extinction, indicating that the loss of browsers promoted
fire and altered plant composition.
29. Imprint of Southern
Ocean eddies on winds, clouds and rainfall
I.
Frenger, N. Gruber, R. Knutti & M. Münnich
Nature Geoscience 6, 608–612 (2013) doi:10.1038/ngeo1863
Owing
to the turbulent nature of the ocean, mesoscale eddies are omnipresent. An
analysis of atmospheric conditions associated with several hundred thousand
eddies in the Southern Ocean suggests that the transitory sea surface
temperature fronts associated with these eddies alter near-surface winds,
clouds and rainfall.
30. Limits in detecting
acceleration of ice sheet mass loss due to climate variability
Nature Geoscience 6, 613–616 (2013) doi:10.1038/ngeo1874
Received
26 July 2012 Accepted 05 June 2013 Published online 14 July 2013
The
Greenland and Antarctic ice sheets have been reported to be losing mass at
accelerating rates. Comparison of mass loss trends over the past decade with
reconstructions of past mass loss indicates that the existing satellite record
is too short to separate long-term mass loss trends from natural variability.
31. Variable North Pacific influence on drought in southwestern North
America since AD 854
Staryl McCabe-Glynn, Kathleen R. Johnson, Courtenay
Strong, Max Berkelhammer, Ashish Sinha, Hai Cheng & R. Lawrence Edwards
Nature Geoscience 6, 617–621 (2013) doi:10.1038/ngeo1862
Received 19 December 2012 Accepted 29 May 2013
Published online 07 July 2013
Over the twentieth century, droughts in
southwestern North America have been linked to sea surface temperature
variability in the North Pacific Ocean. Speleothem data from southern
California suggest that links between the North Pacific and drought were less
pronounced during the past millennium.
32. Transient
stratification as the cause of the North Pacific productivity spike during
deglaciation
Phoebe
J. Lam, Laura F. Robinson, Jerzy Blusztajn, Camille Li, Mea S. Cook, Jerry F.
McManus & Lloyd D. Keigwin
Nature Geoscience 6, 622–626 (2013) doi:10.1038/ngeo1873
Received
15 March 2013 Accepted 04 June 2013 Published online 14 July 2013
During
the last deglaciation, the North Pacific Ocean was characterized by a spike in
primary productivity, which has been attributed to iron input. Marine sediment
analyses suggest that, instead, the productivity may have been fuelled by deep
convection and subsequent stratification.
33. Abrupt vegetation
change after the Late Quaternary megafaunal extinction in southeastern
Australia
Raquel
A. Lopes dos Santos, Patrick De Deckker, Ellen C. Hopmans, John W. Magee,
Anchelique Mets, Jaap S. Sinninghe Damsté & Stefan Schouten
Nature Geoscience 6, 627–631 (2013) doi:10.1038/ngeo1856
The
extinction of megafauna in Australia about 43,000 years ago has been linked to
both human arrival and vegetation change. Marine sediment analyses from the
east coast of Australia suggest that vegetation change was a result, rather
than cause, of the extinction.
34. Subduction zone
earthquake as potential trigger of submarine hydrocarbon seepage
David
Fischer, José M. Mogollón, Michael Strasser, Thomas Pape, Gerhard Bohrmann,
Noemi Fekete, Volkhard Spiess & Sabine Kasten
Nature Geoscience 6, 647–651 (2013) doi:10.1038/ngeo1886
Received
31 March 2013 Accepted 12 June 2013 Published online 28 July
Methane
is abundant in marine sediments. Analysis of sediment cores and seismic images
of marine sediments obtained off the coast of Pakistan show fracturing of gas
hydrates and an increase in upward methane flux in the decades following a
large earthquake in the Arabian Sea in 1945, suggesting that quakes can trigger
hydrocarbon seepage.
35. Low simulated
radiation limit for runaway greenhouse climates
Colin
Goldblatt, Tyler D. Robinson, Kevin J. Zahnle & David Crisp
Nature Geoscience 6, 661–667 (2013) doi:10.1038/ngeo1892
As
a moist atmosphere warms, it will reach a limit after which it is unable to
radiate incoming solar radiation back to space, and a runaway greenhouse will
occur. Calculations suggest that this limit is lower than previously thought
and, for a water-saturated atmosphere, a runaway greenhouse can occur under
present-day solar radiation.
36. Lithium isotope
evidence for enhanced weathering during Oceanic Anoxic Event 2
Philip
A. E. Pogge von Strandmann, Hugh C. Jenkyns & Richard G. Woodfine
Nature Geoscience 6, 668–672 (2013) doi:10.1038/ngeo1875
Received
16 April 2013 Accepted 05 June 2013 Published online 07 July 2013
Ocean
Anoxic Event 2 was marked by rapid global warming and loss of O2
from the ocean. Lithium isotope data suggest that the warming was accompanied
by enhanced silicate weathering, which stimulated marine productivity and
helped stabilize atmospheric CO2 levels.
NATURE COMMUNICATIONS
37. Tertiary structural
elements determine the extent and specificity of messenger RNA editing
Leila
E. Rieder, Cynthia J. Staber, Barry Hoopengardner & Robert A. Reenan
Nature Communications 4, Article number: 2232
doi:10.1038/ncomms3232
The
specificity and extent of RNA editing by ADAR enzymes is determined largely by
local primary sequence and secondary structural imperfections in duplex RNA.
Our results demonstrate that complex RNA tertiary structures, which may be
difficult to predict computationally, form in vivo and can regulate
RNA-editing events.
38. Nitrate formation
from atmospheric nitrogen and oxygen photocatalysed by nano-sized titanium
dioxide
Shi-Jie
Yuan, Jie-Jie Chen, Zhi-Qi Lin, Wen-Wei Li, Guo-Ping Sheng & Han-Qing Yu
Nature Communications 4, Article number: 2249
doi:10.1038/ncomms3249
The
concentration of nitrate in aquatic systems is rising with the development of
modern industry and agriculture, causing a cascade of environmental problems.
Given the expanding use of titanium dioxide worldwide, such a titanium
dioxide-mediated photocatalysis process may reveal a potentially underestimated
source of nitrate in the environment, which on one hand may lead to an
increasing environmental pollution concern, and on the other hand may provide
an alternative, gentle and cost-effective method for nitrate production.
39. The effects of
carbon dioxide and temperature on microRNA expression in Arabidopsis
development
Patrick
May, Will Liao, Yijin Wu, Bin Shuai, W. Richard McCombie, Michael Q. Zhang
& Qiong A. Liu
Nature Communications 4, Article number: 2145
doi:10.1038/ncomms3145
Elevated
levels of CO2 and temperature can both affect plant growth and development, but
the signalling pathways regulating these processes are still obscure. Here we
identify, using the small RNA-sequencing method, microRNAs that change
significantly in expression by either doubling the atmospheric CO2
concentration or by increasing temperature 3–6 °C. Notably, nearly all
CO2-influenced microRNAs are affected inversely by elevated temperature.
