Perspectives in 2013

Recent studies have produced conflicting results about the impacts of climate change on drought. In this Perspective, a commonly used drought index and observational data are examined to identify the cause of these discrepancies. The authors indicate that improvements in the quality and coverage of precipitation data and quantification of natural variability are necessary to provide a better understanding of how drought is changing.

This Perspective considers the extent to which early action to reduce emissions of short-lived climate pollutants, such as methane and black carbon, would help to limit global warming. Although decreasing emissions of these pollutants would have short-term benefits, simultaneous CO₂ reductions are urgently required to mitigate the risk of dangerous climate change in the longer term.

Recent reports of a lower climate sensitivity to CO₂ emissions have been used to suggest that the need for mitigation is not as urgent as previously thought. This Perspective investigates how quickly committed peak warming would increase ifmitigation is delayed. Peak warming is found to increase in line with cumulative CO₂ emissions, faster than current observed warming.

Trees can provide a multitude of ecosystem services. The current push to plant trees, motivated by the goal of sequestering carbon, raises the question of how tree diversity affects carbon sequestration and other services offered by afforestation/reforestation projects. This Perspective examines the potential benefits of mixed tree planting over a monoculture approach.

Climate change poses both practical and theoretical problems for coastal managers, who have to make and implement plans that cope with a highly uncertain, and therefore inherently risky, future. This Perspective uses three examples of ecological engineering — marshes, mangroves, and oyster reefs — to illustrate the synergistic effects and benefits of this approach.

Since the 1950s—after centuries of stock decline and deforestation—European forests started to recover, becoming a persistent carbon sink. The effect was projected to continue for decades, however there are early signs that the sink is saturating. This Perspective calls for a timely reaction from policymakers and forest managers to sustain European forests and thus the carbon sink.

China, already the largest generator of hydroelectricity, plans to accelerate dam construction. This has led to warnings that increased emissions of greenhouse gases, particularly methane, from Chinese reservoirs could constitute a 'global warming time-bomb'. A review of evidence on emissions from the Three Gorges Reservoir — the world's largest — indicates that such fears are probably misplaced.

Much climate change education research is now being funded in the USA. This Perspective argues that university-level climate change education may promote interdisciplinary, keep talented young people in the science, technology, engineering and mathematics pipeline, and help all students enhance their scientific, quantitative and climate literacies.

Increased use of IT services can contribute to reducing carbon emissions, given the improvements in efficiency of IT devices and data-centre operations. However, credible metrics to reward the data centres for minimizing carbon emissions are still lacking. This Perspective identifies the characteristics of low-carbon data centres and the factors that govern carbon performance.

The use of land, energy and water can contribute to climate change, which, in turn, affects the systems that provide those resources. Efficient resource management can limit climate impacts and support adaption practices. An approach integrating resource assessments and policy-making is proposed to manage land, energy and water effectively.

Access to timely climate information is critical for empowering proactive decision-making to absorb climate shocks that would otherwise lead to large-scale humanitarian crises. The value of Rainwatch — a prototype geographical information system designed to increase interactions between local climate information users, their providers and supporting groups — is illustrated in the case of the unfavourable West African 2011 monsoon.

Anthropology can offer valuable insights into the science, impacts and policy of climate change thanks to its fieldwork methodology, holistic view of society and engagement in society–environment interactions. Yet the discipline's voice in climate change debates remains marginal. This Perspective sheds light on how anthropological research can contribute to the understanding of climate change.

Two important aims of mitigation policy are to maintain land carbon stocks and reduce terrestrial ecosystem-based emissions. This Perspective discusses the scientific issues involved, argues that current negotiations under the United Nations Framework Convention on Climate Change are not solidly grounded in science, and proposes some ways forward.

Reliable measurements of changes in wetland surface elevation are necessary to understand and predict the probable impact of sea-level rise on vulnerable coastal ecosystems and for science-informed management, adaptation and mitigation. A simple, inexpensive and low-technology device called the 'rod surface elevation table' could be used to monitor threatened coastal wetlands around the world.

The first public engagement study on the acceptability of stratospheric aerosol technology and a proposed field trial of an aerosol deployment mechanism shows that almost all participants were willing to allow the trial to proceed. However, very few were comfortable with using stratospheric aerosols.

Climate change studies rarely yield consensus on the probability distribution of exposure, vulnerability, or possible outcomes, and therefore the evaluation of alternative policy strategies is difficult. This Perspective highlights the importance of decision-making tools designed for situations where generally agreed-upon probability distributions are not available and stakeholders show different degrees of risk tolerance.

At Rio+20, the United Nations established global targets for energy access, renewable energy and energy efficiency in the context of sustainable development and eradication of poverty, as well as climate risk mitigation. This Perspective discusses the consistency of these targets with the overarching goal of limiting global temperature increase to below 2 °C.