Journal Review 9 – 6 May 2014 (Nature, Science, Nature Geoscience)

NATURE

1. No magic fix for carbon

Nature 509, 7 (01 May 2014) doi: 10.1038/509007a

Carbon sequestration has been seen as a viable option in reducing anthropogenic carbon input into the atmosphere by many policymakers. However, a lot of work needs to be done in order to ensure it works to keep carbon stored in the long term.

2. Conservation: Former Iron Curtain safeguards wildlife

Bernhard Jank & Johannes Rath

Nature 509, 33 (01 May 2014) doi: 10.1038/509033d

New, unstable countries do not protect biodiversity and habitat as well as nations that have strong governance structures. Conservation efforts in regions with a history of strife should seek to emulate the European Green Belt, which has been converting former cold-war territory into protected reserves.

3. North Atlantic forcing of tropical Indian Ocean climate

Mahyar Mohtadi, Matthias Prange, Delia W. Oppo, Ricardo de Pol-Holz, Ute Merkel, Xiao Zhang, Stephan Steinke & Andreas Luckge

Nature 509, 76-80 (01 May 2014) doi: 10.1038/13196

Mohtadi et al. show that slowdowns of the Atlantic meridional overturning circulation during Heinrich stadials and the Younger Dryas stadial affected the tropical Indian Ocean hydroclimate through changes to the Hadley circulation including a southward shift in the rising branch and an overall weakening over the southern Indian Ocean. They use high-resolution sea surface temperature and seawater oxygen isotope records of sedimentary archives from the tropical eastern Indian Ocean for the past 45 000 years, combined with climate model simulations of Atlantic circulation slowdown under Marine Isotope Stages 2 and 3 boundary conditions, in order to do this.

4. Electrical conductivity during incipient melting in the oceanic low-velocity zone

David Sifre, Emmanuel Cardes, Malcolm massuyeau, Leila Hashim, Saswata Hier-Majumder & Fabrice Gaillard

Nature 509, 81-85 (01 May 2014) doi: 10.1038/nature13245

Sifre et al. calculated conductivity profiles across the asthenosphere for various tectonic plate ages to determine the electrical conductivity of carbon-dioxide-rich and water-rich melts. Several electrical discontinuities are predicted and match geophysical observations.

SCIENCE

5. Drones Flying High as New Tool for Field Biologists

Richard Schiffman

Vol. 344 no. 6183 p. 459 doi:10.1126/science.344.6183.459

Field biologists are using drones, also known as unmanned aerial vehicles (UAVs), to track and manage wildlife. These also act well as deterrents against poachers.

6. Seafloor Mining Plan Advances, Worrying Critics

Carolyn Gramling

Vol. 344 no. 6183 p. 463 doi: 10.1126/science.344.6183.463

The first ever commercial deep-sea mine may begin operating in 2016, raising issues about its long-term effects on marine ecosystems.

7. Tolerance for Predatory Wildlife

Adrian Treves, Jeremy Bruskotter

Vol. 344 no. 6183 pp. 476-477 doi: 10.1126/science.1252690

Promoting human tolerance is critical to success of predator conservation efforts. Economic incentives may help, but social factors play a large part as well.

8. Planetary Science: Forming Terrestrial Planets

John Chambers

Vol. 344 no. 6183 pp. 479-480 doi: 10.1126/science.1252257

Izidoro et al. has created a simulation model which accounts for Mars’ stunted growth as compared with the other terrestrial planet. The planet was modeled to form around 1 AU and was gravitationally scattered into the depleted region of the solar nebula, where the reduction of planestesimals near its current orbit caused its small size.

9. Multiple Dimensions of Climate Change and Their Implications for Biodiversity

Raquel A. Garcia, Mar Cabeza, Carsten Rahbek, Miguel B. Araujo

Vol. 344 no. 6183 doi: 10.1126/science.1247579

Raquel et al. analysed different measurements of climate change and linked the metrics to their implications on biodiversity by creating a conceptual framework that classifies them into common currencies of threat and opportunity.

10. Faster Decomposition Under Increased Atmospheric CO­­₂ Limits Soil Carbon Storage

Kees Jan van Groenigen, Xuan Qi, Craig W. Osenberg, Yiqi Luo, Bruce A. Hungate

Vol. 344 no. 6183 pp. 508-509 doi: 10.1126/science.1249534

Rising atmospheric CO₂ is expected to stimulate plant growth and soil C input but may also alter microbrial decomposition. Groenigen et al. show that atmospheric CO­₂ enrichment results in lower equilibrium soil C stocks than expected from the rise in soil C input alone, indicating a general mechanism limits C accumulation in soil.

NATURE GEOSCIENCE

11. Biogeochemistry: Lake carbon

Anna Armstrong

Nature Geoscience 7, 328 (2014) doi: 10.1038/ngeo2159

Glob. Change Biol. http://doi.org/r85 (2014)

A positive correlation between lake carbon burial and phosphorus levels indicates that lake eutrophication may cause an increase in carbon burial. If the burial rates collected by Anderson et al. from 90 European lowland lakes apply to other European lakes, the sum total of sequestered carbon may be more than previously thought.

12. Climate change: Walker uncertainty

Alicia Newton

Nature Geoscience 7, 328 (2014) doi: 10.1038/ngeo2160

Clim. Dyn. http://doi.org/r86 (2014)

Recent observations show the Walker atmospheric circulation cell strengthening and shifting to the west instead of weakening and moving eastwards as forecasted. This behaviour may be the result of the recent predominance of La-Niña-like conditions in the Pacific region.

13. Geochemistry: A piece of the deep carbon puzzle

Craig E. Manning

Nature Geoscience 7, 333-334 (2014) doi: 10.1038/ngeo2152

Ague and Nicolescu show that significant amounts of carbonate minerals are dissolved from subducting slabs by infiltrating fluids, aiding the transfer of carbon back to Earth’s surface. This may balance carbon dioxide emissions at arc volcanoes, which was previously thought to be much more than the carbon loss from subducting slabs.

14. Climate warming during Antarctic ice sheet expansion at the Middle Miocene transition

Gregor Knorr & Gerrit Lohmann

Nature Geoscience 7, 376-381 (2014) doi: 10.1038/ngeo2119

The authors use a coupled atmosphere-ocean model to assess the relative effects of changes in atmospheric CO₂ concentration and ice sheet growth on regional and global temperatures during the Middle Miocene climate transition. Paradoxically, the expansion of the ice sheet occurred while the surface waters of the Southern Ocean were warming. The simulations showed the changes were due to a complex interplay between wind field, ocean circulation and the sea-ice system.

15. Carbon sequestration during the Palaeocene-Eocene Thermal Maximum by an efficient biological pump

Zhongwu Ma, Ellen Gray, Ellen Thomas, Brandon Murphy, James Zachos & Adina Paytan

Nature Geoscience 7, 382-388 (2014) doi: 10.1038/ngeo2139

Ma et al. present records of marine barite accumulation rates that show distinct peaks during the PETM, suggesting a general increase in oceanic export productivity. They propose that changes in marine ecosystems, resulting from high atmospheric partial pressure of CO­₂ and ocean acidification, led to enhanced carbon export from the photic zone to depth, thereby increasing the efficiency of the biological pump.