Research articles

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.

Under global warming, arid subtropical regions are expected to get drier and expand polewards. This study uses model simulations to examine changes in hydrological parameters for the southwestern United States. The predictions for 2021–2040 show declines in surface-water availability, resulting in reduced soil moisture and runoff.

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.

Research based on a survey across 89 countries demonstrates that individuals who live in places with rising average temperatures are more likely than others to perceive local warming. The study also suggests that personal experience of the impacts of climate change may shift public opinion about the reality of global warming.

A relatively wide range of emissions in 2020 could keep open the option of limiting long-term temperature increase to below 2 °C; however, a shortfall in critical technologies would narrow that range or eliminate it altogether. Reduced emissions in 2020 would hedge against this uncertainty.

In 1990 the First Assessment Report of the Intergovernmental Panel on Climate Change was produced. It contained a prediction of the global-mean-temperature trend for 1990–2030 which, halfway through that period, appears accurate. This is remarkable in hindsight, considering a number of important external forcings were not included. This study concludes the greenhouse-gas-induced warming is largely overwhelming the other forcings.

Environmental campaigns often promote energy conservation by appealing to economic rather than environmental concerns, assuming self-interest drives people’s behaviour. New research discredits such conventional wisdom and shows that, at least in some cases, it is more effective to call on people’s interest in protecting the biosphere to encourage behavioural changes.

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.

Understanding public engagement with climate change in developing countries is critical for the success of local adaptation strategies. A study in Indonesia shows that nearly one-third of the population has observed and perceived risks of climate change—contrary to previous research suggesting low levels of awareness—but has not taken action to address it.

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.

Research in America finds that observable climate impacts increase people’s certainty about global warming and that prior certainty shapes people’s perceptions of the impacts. The first process happens frequently among people less engaged in the issue of climate change whereas the second process is typical of people already convinced about it.

A survey conducted in England and Ireland after a major flooding event shows that perceptions of individual responsibility for protection depend on the specific social and policy context. Perception of future risk, in the case of people directly affected by the flooding, also depends on the context. Expectations about the state’s responsibility for climate protection are critical in promoting longer-term adaptation to the changing climate.

Most lakes are net sources of CO₂; conventionally the CO₂ in lake waters is attributed to in-lake oxidation of terrestrially-produced dissolved organic carbon. Now research indicates that CO₂ in lakes may be delivered directly via inflowing streams. These findings suggest that future CO₂ emissions from lakes will be strongly related to productivity in the lake catchment.

Predictions of climate warming raise concerns about food security. However, the extent to which adaptation can offset heat-related yield losses remains unclear. Now research that used spatial adaptation of US maize crops as a surrogate for future adaptation finds that the yield reduction resulting from warming of 2 °C above pre-industrial levels can be approximately halved using existing management practices.

Snow accumulation is critical for water availability in the Northern Hemisphere. Model projections show a shift towards low snow years, with areas of western North America, northeastern Europe and the Greater Himalayas showing the strongest decline. Many snow-dependent regions are likely to experience increasing stress from low snow years if global warming exceeds 2° above the pre-industrial baseline.

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.

Sea-level rise brings the risk of coastal flooding from marine waters. This study looks at how rising sea level will affect groundwater balance, which may also cause coastal plain flooding. Taking groundwater into consideration shows that sea-level rise may cause twice the flooding expected from marine waters alone.

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.

Recharge sustains groundwater resources that are depended on globally for drinking water and irrigated agriculture. A newly compiled 55-year record of groundwater-level observations in an aquifer in central Tanzania reveals the highly episodic occurrence of recharge resulting from anomalously intense seasonal rainfall. Model projections show a shift towards more intense monthly rainfall, which favours groundwater recharge, suggesting it may be a viable adaptation water source in the future.

Political and media debate on the existence and causes of climate change often rests on claims about what most citizens really think. New research demonstrates that people overestimate how common their own opinion is, and when they do they are less likely to change their view. People also overestimate how many reject the existence of climate change.