Letters in 2012

Climate-induced range shifts have been detected in a number of European species for which long-term survey data are available. In North America, well-organized long-term data needed to document such shifts are much less common. Now observations made by ‘citizen scientists’ help to demonstrate that a major, climate-induced shift of North American butterflies is underway.

Few studies have considered the effects of changes in climatic variability on disease incidence. Now research based on laboratory experiments and field data from Latin America shows that frog susceptibility to the pathogenic chytrid fungus is influenced by temperature variation and predictability through effects on host and parasite acclimation.

Regional climates can be modified by urban development affecting the radiation and hydrological balances. This study looks at the expanding megapolitan area in the Sun Corridor, Arizona, USA, and models local climate change in line with urban development.

Emissions from landscape fires affect both climate and air quality. This study uses satellite-derived fire estimates and atmospheric modelling to quantify the effects on health from fire emissions in southeast Asia from 1997 to 2006. Strong El Nino years are found to increase the incidence of fires, in addition to those caused by anthropogenic land use change, leading to an additional 200 days per year when the WHO atmospheric particle target is exceeded and increase adult mortality by 2%. Reducing regional deforestation and degradation, and thereby forest fires caused by land use change would therefore improve public health.

Campaigns to promote pro-environmental behaviour usually emphasize self-interested reasons for engaging with a self-transcendent cause such as protecting the environment. However, psychological evidence suggests that this approach may fail to stimulate other, different, environmental behaviours. Research shows that communicating self-transcending motives for car-sharing increases recycling rates, whereas presenting self-interested reasons alone, or combined with self-transcending motives, does not.

Grasslands have always experienced drought, but future drought conditions are likely to be more severe and frequent as climates change. This study shows that many of the world’s grasslands probably have drought-tolerant grasses that can maintain ecosystem functions, and the resilience of grasslands globally requires the maintenance of grass diversity.

Historical records show increased aridity over many land areas since 1950. This study looks at observations and model projections from 1923 to 2010, to test the ability of models to predict future drought conditions. Models are able to capture the greenhouse-gas forcing and El Niño–Southern Oscillation mode for historical periods, which inspires confidence in their projections of drought.

Understanding the response of evapotranspiration to global warming should help to predict surface climate, including heatwaves and droughts. This study shows that increasing atmospheric concentrations of greenhouse gases and decreasing loadings of anthropogenic (and volcanic) aerosols have led to enhanced evapotranspiration in mid and high latitudes over recent decades.

Increasing Eurasian Arctic river discharges and climate model projections show an increased wetting trend in northern high latitudes in coming years. Now a study finds that the increase in river discharge has accelerated in the past decade and that enhancement of poleward atmospheric moisture transport decisively contributes to this increase.

There is increasing concern about the potential role of climate change in facilitating the spread of bacterial waterborne infectious diseases to new areas. Now research supports these concerns by finding an association between long-term environmental changes observed in the Baltic area and the recent emergence of Vibrio infections in the region.

In 2011 the waters along the west coast of Australia—a global hotspot of biodiversity—experienced an unprecedented (in recorded times) warming event with warming anomalies of 2–4 °C that persisted for more than ten weeks. Now research shows that biodiversity patterns of temperate seaweeds, invertebrates and fishes were significantly different following the warming event.

Glacial melting in the Tibetan Plateau affects the water resources of millions of people. This study finds that—partly owing to changes in atmospheric circulations and precipitation patterns—the most intensive glacier shrinkage is in the Himalayan region, whereas glacial retreat in the Pamir Plateau region is less apparent.

Future greenhouse-gas emissions need to deviate from a fossil-fuel intensive scenario to avoid dangerous climate change, and this implies feedback links between climate change and societal actions. Research shows that the global growth of new renewable energy post-1990 represents an annual climate–society feedback of ∼ 0.25% per degree increase in global mean temperature.

This study describes the development of a multi-species model used to explore the integrated eco-evolutionary responses to climate change. The results should help to understand and predict the responses of biological diversity, ecosystems, and ecological services to changing climate.

Increasing ocean temperatures are impacting the health of coral reef ecosystems, but understanding how the response of corals varies spatially remains important for conservation efforts. Now research shows that skeletal extension within forereef colonies of the coral Siderastrea siderea declined with increasing seawater temperature, whereas extension rates of backreef and nearshore colonies were not impacted.

Evidence is presented that climate change-induced lake warming may cause the same undesired effects as have formerly emerged from excess nutrients (eutrophication). Stronger thermal stratification and reduced mixing has favoured blooming of a toxic cyanobacterium in a large temperate lake previously thought to be successfully ‘restored’ after decades of pollution.

South of Africa, the Agulhas ocean current system transports warm, salty water from the Indian Ocean to the Atlantic Ocean. This study shows that the mesoscale variability of the Agulhas system has intensified over recent decades, apparently owing to enhanced trade winds over the tropical Indian Ocean.

Based on an analysis of maximum latewood density data from northern Scandinavia, along with published dendrochronological records, this study finds evidence that previous tree-ring-reliant reconstructions of large-scale near-surface air temperature underestimated long-term pre-industrial warmth during Medieval and Roman times.

Using models and ecological data, this study shows that the eastern Pacific Ocean population of leatherback sea turtles could well face extirpation owing to climate change. However, the findings indicate that it may be possible to sustain a viable nesting population in Costa Rica throughout this century by cooling nests.

This study uses satellite data to study snow grain size–albedo relationships over the whole Antarctic Plateau. The findings suggest that increased precipitation resulting from climate change will effectively compensate for the decreased albedo that should have resulted from warming, thereby inhibiting the expected ice–albedo feedback.