Research articles

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.

Urban climate policies interact with socio–economic policy goals. These interactions can lead to trade-offs or synergies, but have been rarely analysed. Now research provides a quantification of these trade-offs and synergies, and suggests that stand-alone adaptation and mitigation policies are unlikely to be politically acceptable, emphasizing the need to mainstream climate policy within urban planning.

This study documents the effects of warming on cyanobacterial mats from the Arctic and Antarctica. It describes toxin production in such mats and provides experimental evidence that increased temperatures could shift mat cyanobacterial species diversity from cold-loving species towards predominance of cold-tolerant and toxin-producing species.

Trends in phenological phases associated with climate change are widely reported, yet attribution remains rare. Attribution analysis of trends in wine-grape maturity in Australia indicates that two climate variables—warming and declines in soil water content—are driving a major portion of the earlier-ripening trend. Crop-yield reductions and evolving management practices have also contributed.

This modelling study shows that chemical weathering of continental surfaces—which removes carbon dioxide from the atmosphere—is highly sensitive to a carbon dioxide doubling for the Mackenzie River Basin, the most important Arctic watershed. The findings highlight the potential role of chemical weathering processes in mitigating global warming.

There are concerns that sea-level rise resulting from climate change could lead to saltwater intrusion into coastal aquifers. However, a study shows that groundwater extraction is the main driver of saltwater intrusion in the United States, highlighting the importance of sustainable water management.

A comparison of specimens collected from the same locations but nearly a century apart shows that an alpine chipmunk has suffered reduced genetic diversity and gene flow as a result of climate-driven habitat loss in Yosemite National Park, USA. This study highlights one important impact of climate change on biodiversity

Focusing on New York City, this study investigates the impact of climate change on hurricane storm surges. The analysis shows that the frequency of surge-flooding events is likely to increase greatly owing to the combined effects of storm-climatology change and sea-level rise.

Assessments of tropical cyclone risk trends are typically based on reported losses, which are biased by improvements in information access. Now research based on thousands of physically observed events and contextual factors shows that, despite projected reductions in tropical cyclone frequency, projected increases in demographic pressure and tropical cyclone intensity can be expected to exacerbate disaster risk.

There has been concern that climate change may cause increases in harmful algal blooms (HABs). Research now shows that previously abundant HAB and non-HAB dinoflagellates have decreased since 2006, whereas common diatoms, including both HAB and non-HAB species, have recently increased in abundance.

It is unclear how global warming will affect the El Niño/Southern Oscillation (ENSO), in part because the instrumental record is too short to understand how ENSO has changed in the past. Now a 700-year-long tree-ring record indicates that ENSO-related climate variability may increase in New Zealand with continued warming.

A study shows that regional atmospheric change driven by land-cover change contributes little to glacier mass loss on Tanzania’s Mount Kilimanjaro. More generally, this finding suggests that local land-cover change may have limited impact on mountain glaciers in the tropics and elsewhere, compared with that of global climate change.

Reducing Emissions from Deforestation and forest Degradation (REDD) has been widely discussed as a way of mitigating climate change while concurrently benefitting biodiversity. This study combines a global land-use model and spatial data on species distributions to quantify the potential impacts of REDD in avoiding global species extinctions.

Models and scenarios on which climate projection are based vary between IPCC reports. To facilitate meaningful comparison, this study provides probabilistic climate projections for different scenarios in a single consistent framework, incorporating the overall consensus understanding of the uncertainty in climate sensitivity, and constrained by the observed historical warming.