Understanding and responding to danger from climate change: the role of key risks in the IPCC AR5

Abstract

The IPCC's Fifth Assessment Report (AR5) identifies key risks in a changing climate to inform judgments about danger from climate change and to empower responses. In this article, we introduce the innovations and implications of its approach, which extends analysis across sectors and regions, and consider relevance for future research and assessment. Across key risks in the AR5, we analyze the changing risk levels and potential for risk reduction over the next few decades, an era with some further committed warming, and in the second half of the 21st century and beyond, a longer-term era of climate options determined by the ambition of global mitigation. The key risk assessment underpins the IPCC's conclusion that increasing magnitudes of warming increase the likelihood of severe, pervasive, and irreversible impacts. Here, we emphasize central challenges in understanding and communicating risks. These features include the importance of complex interactions in shaping risks, the need for rigorous expert judgment in evaluating risks, and the centrality of values, perceptions, and goals in determining both risks and responses.Anthropogenic interference with the climate system is occurring (IPCC 2013). The impacts of climate changes that have already occurred are widespread and consequential, and with continued high emissions or even with ambitious mitigation, large and uncertain consequences will play out over long timeframes (IPCC 2014c). These conclusions are deeply rooted in scientific understanding assessed comprehensively by the IPCC. They also propel us to an assessment frontier: how can we inform solutions through innovative conceptualizations of the climate challenge in assessment?In this article, we provide an overview of one response to this question: the key risk approach applied across the Working Group II contribution to the IPCC's AR5 (WGII AR5). We discuss why the key risk approach was developed, how it works, and what it implies across sectors and regions, informing both research and assessment.

Advances in risk assessment for climate change adaptation policy

“…At the level of global public concern, the Intergovernmental Panel on Climate Change (IPCC) have described the advantages of a risk-based approach in terms of improved understanding of both the dynamic interactions of risk factors (spatial and temporal) that lead to specific climate change impacts, and the role of adaptation initiatives in managing these risk factors. Both the Special Report on Extreme Events [21] and the Fifth Assessment Report [22] sought to characterize key global risks linked to current policy responses to provide recommendations for further intergovernmental action [23]. Similarly, risk assessment has also been highlighted as a key procedure at national scale to facilitate targeted adaptation strategies and coordinated risk governance (e.g.…”

Using fuzzy logic to determine the vulnerability of marine species to climate change

“…In this paper, we developed a vulnerability assessment that drew on principles and approaches adopted by the IPCC (Field et al, 2014;Mach, Mastrandrea, Bilir & Field, 2016). We developed a fuzzy logic expert system adapted from the framework used by Cheung et al (2005) that aimed to evaluate the intrinsic extinction vulnerability of marine fishes to fishing.…”

Future Meteorological Droughts in Ecuador: Decreasing Trends and Associated Spatio-Temporal Features Derived From CMIP5 Models

“…The last century increase of the global mean temperature is unprecedented in scales from decades to centuries (Mora et al, 2014). Such a temperature increase has produced generalized changes in spatio-temporal precipitation patterns, sea salinity (Heuzé et al, 2015), wind patterns, heat waves, and more intensity in tropical cyclones and droughts (Dai, 2013); all these phenomena are attributed to climate change (CC) (Allen and Ingram, 2002;Mach et al, 2016). Despite that several studies link CC with the increase of droughts' severity and occurrence, it is acknowledged that the impacts of CC are diverse and even contrasting depending on the specific region of study.…”