Research articles

A study using a newly developed framework shows how future peak temperature is related to cumulative emissions of long-lived greenhouse gases such as carbon dioxide and sustained emissions of shorter-lived species such as methane, and suggests an approach for limiting future warming to 2 °C above pre-industrial levels.

Rising carbon dioxide concentrations in oceanic waters is conventionally expected to stimulate marine primary productivity, as long as sufficient light is available. Now research shows that the combination of increased carbon dioxide and increased light exposure can negatively impact photosynthesis in marine primary producers; an effect with the potential to cause widespread declines in future marine primary productivity.

The discovery of an apparently universal function describing the frequency distribution for 24-h precipitation leads to a formula relating heavy precipitation to the mean amounts and the number of days when it rains. The formula has been validated using more than 30,000 daily rain-gauge records from around the world.

By combining satellite observations with global climate models, this study provides evidence that a few key equatorial islands and coral atolls could be spared the brunt of previously predicted tropical ocean warming and productivity decline, potentially providing crucial refuges for marine biodiversity amid global climate change.

There is increasing interest in the possible impacts of wind farms on regional weather and climate. Focusing on three large wind farms located in Texas, USA, this study finds evidence for a significant warming trend at night-time and also a small warming effect at daytime over wind farms.

Several factors can either increase or buffer the effects of climate change on the volatility of grain prices. A study shows that US corn price volatility is more sensitive to near-term climate change than to energy policy or agriculture–energy market integration. A biofuels mandate increases price sensitivity to climate change by more than 50%.

Ocean pH is expected to drop by 0.3 units by 2100, but it remains unclear how plankton might respond. Now research shows that pH and carbonate chemistry at the exterior surface of marine organisms deviates increasingly from those of bulk sea water as organism metabolic activity and size increases. Understanding of such deviations is important for predicting ecological response.

Feedbacks can modulate the way plants respond to warming, but difficulties in detecting long-acting feedbacks complicate understanding of the climatic effects on community structure and function beyond initial responses. Now a mesocosm experiment shows that although warming initially increased aboveground net primary productivity in grassland ecosystems, the response diminished progressively over time.

Satellite data suggest that contemporary climate warming has already resulted in increased productivity and shrub biomass over much of the Arctic, but plot-level evidence for vegetation transformation remains sparse. Now research provides plot-scale evidence linking changes in vascular plant abundance to local summer warming in widely dispersed tundra locations across the globe.

Comparison of global-scale measurements of subsurface ocean temperature taken during the epic voyage of HMS Challenger (1872–1876) with data collected by the Argo Programme over the past eight years shows that oceans have been warming at least since the late-nineteenth/early-twentieth century.

This study provides a quantitative approach that predicts the response of coral calcification to the combined effects of ocean acidification and global warming. The analysis suggests that warm-water aragonitic corals are more resilient to climate change than previously thought, whereas marine organisms that precipitate calcitic skeletons are particularly vulnerable.

Analysts implicitily assume that increasing renewable-energy generation by one unit displaces conventional energy by the same amount. Research now shows that, owing to the complexity of our socio–economic systems, each unit of total national non-fossil-fuel energy use displaced less than one-quarter of a unit of fossil-fuel energy use over the past 50 years.

How effective are protected areas for conserving biodiversity in a rapidly changing world? A study shows that the network of protected areas in Mexico’s cloud forests—a biome with high species richness and a large fraction of endemics—is almost completely redundant in a changing climate.

This study addresses the importance of systematic biases in regional and global climate models. Simulations for the central Mediterranean region show that, unless a bias-correction method is applied, individual models significantly overestimate regional amplification of global warming.

In many regions climate change is reducing the glacial meltwater contribution to river flow, but the effect of these changes on specialized glacier-fed river communities is poorly quantified. Now research demonstrates quantitatively not only the vulnerability of local biodiversity hotspots but also that the number of species lost is likely to be much higher than the few specialist species found only in glacier-fed rivers.

Despite 20 years of concern about human migration in response to environmental pressure, estimates of the numbers likely to move as a result of climate change remain, at best, guesswork. Now computer simulations reveal complex interactions in the way that climate and demographic changes combine to influence migration, suggesting that we should expect some surprises.

A comprehensive stability analysis shows that the critical global temperature rise that leads to collapse of the Greenland ice sheet is only 1–2 °C above the pre-industrial climate state, which is significantly lower than previously believed.

Feedbacks between the living and non-living components of the terrestrial carbon cycle present a major source of uncertainty in climate predictions. Now research using materially closed soil-vegetation-atmosphere chamber experiments with carbon amounts proportional to the main terrestrial carbon pools suggests that short-term biotic responses could potentially buffer a temperature increase of 2.3 °C without significant positive feedbacks to atmospheric carbon dioxide.

This paper reports results from a laboratory experiment designed to quantify the reduction of snow albedo by black carbon. The study aims to test models of radiative transfer in snow and the parameterizations from them that are used in climate models.

A modelling study shows how global temperatures would change if all greenhouse-gas and aerosol emissions were eliminated. The researchers estimate the committed future climate warming associated with past anthropogenic emissions, and provide a critical baseline against which to measure the effect of future emissions.