Volume 3 Issue 3, March 2013

Clothing containing recycled bottles and food industry by-products is a funky alternative now available in shopping malls. But it may generate only minor environmental benefits.

After recent events in Japan and the Indian Ocean, the world is alert to the risk posed by earthquake-generated tsunamis. A team of scientists are now seeking to understand a rarer type of tsunami caused by huge underwater landslides, and determine whether climate change might affect their frequency. Project leader Peter Talling, of the National Oceanography Centre, talks to Nature Climate Change.

Policymakers must make it worthwhile for businesses to invest in resource-efficient product design, as Sonja van Renssen explains.

Phytoplankton support most marine food webs, but little is known about their intraspecific diversity. Research shows the strains that are most responsive to changes in CO₂ concentration may outcompete less flexible types in an acidifying ocean.

Increased concentrations of carbon dioxide in the atmosphere support greater plant biomass in grasslands, but this response is constrained in the long term by soil nitrogen availability.

Earthworms play an essential part in determining the greenhouse-gas balance of soils worldwide but whether their activity moves soils towards being a net source or sink remains controversial. This Review of the overall effect of earthworms on the greenhouse-gas balance of soils suggests that although beneficial to fertility, earthworms tend to increase the net soil emissions of such gases.

An increasingly ice-free Arctic Ocean could have significant implications for greenhouse-gas sources and sinks in the Northern high latitudes. In this Review, the impact of diminishing sea-ice extent on greenhouse-gas exchange in both marine and terrestrial Arctic environments is synthesised and discussed.

European forests are threatened by climate change with impacts on the distribution of tree species. Previous discussions on the consequences of biome shifts have concentrated only on ecological issues; however, research now shows that under forecasted changes in temperature and precipitation there could be a decline of economically valuable species, which would lead to a loss in the value of European forest land.

Soybean hosts the symbiotic nitrogen-fixing soil bacterium Bradyrhizobium japonicum, that can produce the greenhouse gas nitrous oxide. This study shows that nitrous oxide emissions from soybean ecosystems can be biologically mitigated at a field scale by inoculation with strains of B. japonicum that have increased nitrous oxide reductase activity.

Shifts in evapotranspiration are investigated for non-irrigated agriculture and hydropower, and compared to irrigated agriculture and deforestation, as used predominantly in previous studies. The increase in evapotranspiration from the combined results highlights the need for models to include different human uses of water as anthropogenic drivers of hydroclimatic change.

Climate change is known to influence insect-induced tree mortality. Research now reveals knock-on implications for municipal water quality in Colorado, USA. Significantly higher levels of harmful disinfection by-products and total organic carbon were found in treatment facilities using water from mountain pine beetle-infested basins compared with unaffected watersheds.

Climatic changes could transform rivers as drought becomes more frequent with potentially severe, but largely unknown, consequences at multispecies levels of organization. Now research shows experimentally how the intensification of drought may alter the underlying structure and functioning of freshwater food webs.

Future aquatic ecosystems will be impacted synergistically by large-scale environmental changes, such as climate change and increased humic content. Now research shows that community responses are determined by food-chain length and that the top trophic level, and every second level below that, can be expected to benefit from climate change, whereas trophic levels in between are likely to suffer.

Climate change scenarios predict an average sea surface temperature rise of 1–6 °C by 2100. Now, a study investigating the potential effect of these changes on the distribution and diversity of marine top predators finds that, based on data from electronic tags on 23 marine species, a change in core habitat range of up to 35% is possible for some species by 2100.

Species are largely predicted to shift polewards as global temperatures increase. Now research—based on historical changes in the distribution of Australian birds—shows that if only poleward shifts in distribution are considered, the fingerprint of climate change is underestimated by an average of 26% in temperate regions and 95% in tropical regions.

There is concern that species may not adapt fast enough to keep up with the changing climate. This study shows that in the past fifteen years, the hatching date of a moth species has genetically changed at a rate predicted by a model, sufficient to keep up with predicted rates of climatic change.

Understorey plants perform an important role in forest ecosystems but their sensitivity to climate change remains largely unexplored. Now research points to a substantial climate-mediated reduction in the distributional ranges of three dominant bamboo species in the Qinling Mountains over the twenty-first century; plants that comprise almost the entire diet of the panda population in the region.

In the ocean, biological responses to climate change include altered distribution, phenology and productivity. A modelling study into the integrated effects of these various changes on fish body size suggests that averaged maximum body weight could fall by 14–24% globally by 2050. About half of the decline is accounted for by changes in distribution and abundance, with the remainder being physiological.

Understanding the factors that influence coral susceptibility to thermally induced bleaching may aid reef management efforts. Now corals with high symbiont cell densities are shown to be more susceptible to bleaching, indicating that environmental conditions which increase symbiont densities—such as nutrient pollution—could exacerbate climate-induced coral bleaching.

Climate change is threatening marine biodiversity in two ways—temperature increases and acidification. This study demonstrates that from 1960 to 2009 North Atlantic calcifying plankton primarily responded to temperature changes. Plankton communities showed an abrupt shift circa 1996, a time of a substantial temperature increase, and some taxa exhibited a poleward movement in agreement with expected biogeographical changes under ocean warming. Although acidification may become a serious threat to marine calcifiers, over the study period the primary driver of spatial distribution was ocean temperature.

Wave-resistant algal rims—chiefly composed of carbonate from crustose coralline algae—form critical structures for the survival of many shallow coral reefs, raising concerns about the susceptibility of these protective structures to ocean acidification. Research now shows that dolomite-rich frameworks—common in shallow coral reefs globally—are likely to persist as carbon dioxide increases.

Peatlands are important sinks for carbon dioxide, but how their biogeochemistry will be affected by climate warming is poorly understood. This study compares sites along an altitudinal gradient, simulating a natural gradient in soil temperature to elucidate plant–soil microbe feedback in response to a climate-induced change in vegetation.

The stimulation of plant growth by increased atmospheric CO₂ concentrations could function as a negative feedback damping the future rate of climate change. Results from a rare long-term (13 year) grassland experiment demonstrate that nitrogen supply can act to constrain the extent of CO₂ fertilization. Such interactions are not yet incorporated into Earth system models.

Indonesia accounts for a large proportion of the oil palm plantation expansion occurring globally. However, Indonesia’s mixed forests (and associated carbon stocks) complicate estimation of the contribution of oil palm agriculture to global carbon budgets. Remotely sensed land-cover classification combined with carbon flux estimates are now used to develop high-resolution estimates of carbon flux from Kalimantan plantations for the period 1990–2010.

Rice cultivation is one of the largest anthropogenic sources of the greenhouse gas methane. Now a meta-analysis shows that increased atmospheric CO₂ (550–743 ppmV) and climate warming (+0.8 °C to +6 °C) can be expected to significantly increase the yield-scaled greenhouse-gas emissions of rice.

As the global climate changes, drought is expected to reduce productivity and tree survival across many forests; however, the relative influence of climate variables on forest decline remains poorly understood. A drought-stress index based on tree-ring data—newly developed for the southwestern United States—is found to be equally influenced by evaporation (primarily temperature driven) and precipitation and may serve as a holistic forest-vigour indicator in water-limited forests.

A survey shows that variation in responses to ocean acidification among ecotypes of a widely distributed picoplankton species is similar to that found between different genera. The findings should also help to predict evolutionary change within species and how the composition of phytoplankton communities will change in a high-CO₂ world.