Research articles

A warming world poses challenges for species with temperature-dependent sex determination. The implications of increasingly skewed sex ratios for an important marine turtle rookery have been assessed. This study has identified how offspring sex ratio translates into future operational sex ratios and population size-up, and should help to guide conservation efforts.

The IPCC uses probabilistic statements to describe uncertainty in the projections of models. Now a multinational study, across 17 languages, shows that people interpret IPCC statements as implying probabilities closer to 50% than intended by the IPCC authors. If numerical ranges are included, interpretations better reflect the IPCC guidelines.

The Greenland ice sheet is a large contributor to sea-level rise primarily because of the increased speed of its glaciers in the southeast and northwest. This study looks at a previously stable ice stream in northeast Greenland, and finds that it is thinning due to regional warming. This region drains 16% of the ice sheet but has not figured in model projections of sea-level rise, indicating an under-estimation of Greenland contributions.

The slowdown in global average surface warming has recently been linked to sea surface cooling in the eastern Pacific Ocean. This work shows that strengthening trade winds caused a reduction in the 2012 global average surface air temperature of 0.1–0.2 °C. This may account for much of the warming hiatus and is a result of increased subsurface ocean heat uptake.

Little is known about how temperature anomalies affect people’s views about climate change. Research now shows that available information about today’s temperature, even though less relevant than evidence of global patterns, is used to formulate opinions. With experience of abnormal temperatures, people overestimate the frequency of similar past events and belief in global warming increases.

The tropical monsoon is thought to play a key role in glacier change in High Asia. The mass balance of a glacier in the southern Tibetan Plateau is found to be due to May/June precipitation, which is controlled by mid-latitude climate and the tropical monsoon. Further attention should be paid to mid-latitude climate to understand glacier changes.

Will networks of protected areas remain effective as the climate changes? Research into the response of bird populations to climate variance and change attempts to shed light on this issue. Results suggest that despite projected declines in many of the species investigated, most sites that are designated as EU Special Protection Areas in the UK can be expected to retain their conservation value and legal status.

Climate extremes are on the increase. Research into mortality from extremes of heat in Stockholm now shows that during the period 1980–2009 mortality was double that likely to have occurred without climate change. Moreover, the frequency of cold extremes also increased slightly, despite higher average winter temperatures, contributing to a small increase in mortality during the winter months.

The severity of the ecological threat posed by ocean acidification remains poorly understood. Now analysis of the sensitivities of five animal groups to a wide range of CO₂ concentrations finds a variety of responses within and between taxa, indicating that acidification will drive substantial changes in ocean ecosystems this century.

There is no single correct procedure for the attribution of responsibility for growth in atmospheric CO₂ concentrations because results are closely dependant on how carbon sinks are accounted for and linked to emissions. Now research that uses two different approaches—one assuming geographically constrained sinks and the other unconstrained—unambiguously attributes the largest share of the historical increase in CO₂ to developed countries.

Communities of boreal species are spreading northwards as tundra communities recede under climate change in the Arctic. Concurrently, human activities in the Arctic are increasing. This study takes a multidisclinary approach to investigate the potential future distribution of tundra species and to relate the location of refugial areas to disparate land-use practices in northern Alaska.

Climate change has the potential to disrupt marine habitats and food webs. Targeted multidisciplinary research reveals how this is likely to affect the contributions of fisheries and aquaculture to the food security and economies of Pacific islands.

There is a widespread assumption that changes in reported anthropogenic global CO₂ emissions are indicative of changes in climate and ocean chemistry. However, examination of atmospheric CO₂ measurements from the past two decades challenges this idea. A new study develops and advocates use of CO₂ measurement practices that reduce uncertainty in atmospheric verification of emissions, and identifies modelling inadequacies.

Climate mitigation policies are rarely assessed in terms of the proportion of climate impacts they can avoid both regionally and globally. Research shows that policies with a 50% chance of remaining below a 2 °C rise in temperature may reduce the impacts of climate change by 20–65% by 2100, relative to pathways with a temperature rise of 4 °C.

This study uses a formalized pooling of expert views on uncertainties in the future contributions of melting ice sheets to sea-level rise, using a structured elicitation approach. The median estimate obtained is substantially larger than that found by previous studies. Expert opinion is shown to be both very uncertain and undecided on the key issue of whether recent ice-sheet behaviour is a long-term trend or due to natural variability.

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.

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.

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.

Public concern about anthropogenic global warming has been declining despite the scientific consensus on the issue. It is still unknown whether experts’ consensus determines people’s beliefs, and it is not clear if public perception of consensus overrides worldviews known to foster rejection of anthropogenic climate change. New research shows that information about scientific consensus increases acceptance of anthropogenic global warming and neutralizes the effect of worldviews.

The South Pacific Convergence Zone is the largest rainband in the Southern Hemisphere, and its response to global warming is still undetermined. In this study a hierarchy of climate models show that the uncertainty in rainfall projections in the South Pacific Convergence Zone is the result of two competing mechanisms.