Volume 2 Issue 6, June 2012
In This Issue
Brazil takes centre stage
Brazil's hosting of the much anticipated Rio+20 United Nations Conference on Sustainable Development this month will put the country in the climate change spotlight.
Rio+20 and Brazil's policy on climate change
As host to the Rio+20 United Nations Conference on Sustainable Development, Brazil will draw international attention to its policy on climate change, but the measures announced so far are not commensurate with the recently set reduction goal.
Shortcomings in wheat yield predictions
Predictions of a 40–140% increase in wheat yield by 2050, reported in the UK Climate Change Risk Assessment, are based on a simplistic approach that ignores key factors affecting yields and hence are seriously misleading.
Greenhouse-gas emissions from tropical dams
Emissions from tropical hydropower are often underestimated and can exceed those of fossil fuel for decades.
Shale gas can be a double-edged sword for climate change
Shale gas can be a powerful tool in combating climate change. However, its exploitation may also lead to undesired environmental effects that can conversely worsen climate change.
Waste not want not
Industrial symbiosis — the sharing of by-product resources among diverse industries — can reduce costs and improve the environment. But despite its benefits, it is no panacea.
Saving EU climate policy
Market-based mechanisms to tackle climate change have many advocates, but economic conditions are making emissions trading schemes hard to implement and sustain, explains Sonja van Renssen.
News & Views
Future of the Greenland ice sheet
Ice-sheet loss is a likely effect of human interference with the climate system. Research shows that the disintegration of the Greenland ice sheet could occur close to, or even below, the target of limiting warming to 2 °C above pre-industrial levels.
Future impact of today's choices
Climate change is now occurring, but few people consider how long the effects may last. A study emphasizes the long-term climate effects of present-day emissions.
Analysing fossil-fuel displacement
It is commonly assumed that fossil fuels can be replaced by alternative forms of energy. Now research challenges this assumption, and highlights the role of non-technological solutions to reduce fossil-fuel consumption.
The drivers of human migration
Warnings about torrents of forced migrations owing to climate change make headlines. Now research shows that this is an oversimplification.
Flooding and the scale of migration
Immobility rather than mobility should be the focus of concern for policymakers worried about the impact of climate-related natural hazards on the livelihoods of rural populations.
Quantifying future climate change
This Perspective describes techniques for quantifying uncertainties in climate projections in terms of a common framework, whereby models are used to explore relationships between past climate and climate change and future projections.
Global agriculture and nitrous oxide emissions
This Review discusses current knowledge regarding agriculture as a source for nitrous oxide — a major greenhouse gas. It offers an outlook on future developments about the consequences of increasing use of biofuels and the potential importance of aquaculture, as well as options for mitigation.
135 years of global ocean warming between the Challenger expedition and the Argo Programme
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.
Multistability and critical thresholds of the Greenland ice sheet
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.
Overestimation of Mediterranean summer temperature projections due to model deficiencies
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.
Black-carbon reduction of snow albedo
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.
Do alternative energy sources displace fossil fuels?
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.
Emerging migration flows in a changing climate in dryland Africa
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.
Vulnerability of cloud forest reserves in Mexico to climate change
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.
Plot-scale evidence of tundra vegetation change and links to recent summer warming
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.
Biogeochemical and ecological feedbacks in grassland responses to warming
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.
Physically based assessment of hurricane surge threat under climate change
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.
Environmental social scientist Lindsay C. Stringer worked with ecologists, soil and climate scientists, economists, and livelihood and policy experts to examine carbon storage, livelihoods and ecosystem services in subSaharan Africa's drylands.