Strategies to mitigate anthropogenic climate change recognize that carbon sequestration in the terrestrial biosphere can reduce the build-up of carbon dioxide in the Earth’s atmosphere. However, climate mitigation policies do not generally incorporate the effects of these changes in the land surface on the surface albedo, the fluxes of sensible and latent heat to the atmosphere, and the distribution of energy within the climate system. Changes in these components of the surface energy budget can affect the local, regional, and global climate. Given the goal of mitigating climate change, it is important to consider all of the effects of changes in terrestrial vegetation and to work toward a better understanding of the full climate system. Acknowledging the importance of land surface change as a component of climate change makes it more challenging to create a system of credits and debits wherein emission or sequestration of carbon in the biosphere is equated with emission of carbon from fossil fuels. Recognition of the complexity of human-caused changes in climate does not, however, weaken the importance of actions that would seek to minimize our disturbance of the Earth’s environmental system and that would reduce societal and ecological vulnerability to environmental change and variability. 相似文献
Where policy and science intersect, there are always issues of ambiguous and conflicting lines of evidence. Combining disparate information sources is mathematically complex; common heuristics based on simple statistical models easily lead us astray. Here, we use Bayesian Nets (BNs) to illustrate the complexity in reasoning under uncertainty. Data from joint research at Resources for the Future and NASA Langley are used to populate a BN for predicting equilibrium climate sensitivity (ECS). The information sources consist of measuring the rate of decadal temperature rise (DTR) and measuring the rate of percentage change in cloud radiative forcing (CRF), with both the existing configuration of satellites and with a proposed enhanced measuring system. The goal of all measurements is to reduce uncertainty in equilibrium climate sensitivity. Subtle aspects of probabilistic reasoning with concordant and discordant measurements are illustrated. Relative to the current prior distribution on ECS, we show that after 30 years of observing with the current systems, the 2σ uncertainty band for ECS would be shrunk on average to 73% of its current value. With the enhanced systems over the same time, it would be shrunk to 32% of its current value. The actual shrinkage depends on the values actually observed. These results are based on models recommended by the Social Cost of Carbon methodology and assume a Business as Usual emissions path. 相似文献
The latest iteration of Intergovernmental Panel on Climate Change (IPCC) uncertainty guidance is simpler and easier to use
than the previous version. However, its primary focus remains assessing “what is at risk” under climate change, thus is most
suitable for dealing with the scientific uncertainties in Working Group I and part of Working Group II findings. I distinguish
between tame and complex risks, arguing that the guidance is most suited to assessing tame risks. Climate change is a complex
risk, and as such as can be divided into idealized, calculated and perceived risks. While science has claims to objectivity,
risk has a specific value component: when measuring gain and loss, calculated risks compete with risky options to manage those
risks. The IPCC is charged with calculating risk (IPCC 2007, p22) but the communication of key findings takes place in an environment of competing perceived risks. Recommendations for
managing this complex environment include separating scientific and risk-based findings, treating uncertainties for each separately;
strengthening the philosophical basis of uncertainty management; application of a methodical scientific research program;
clearly communicating competing findings, especially in the social sciences; and application of multiple frame to policy-relevant
findings as reflected in the literature. 相似文献
Authors of the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) received guidance on reporting
understanding, certainty and/or confidence in findings using a common language, to better communicate with decision makers.
However, a review of the IPCC conducted by the InterAcademy Council (2010) found that “the guidance was not consistently followed in AR4, leading to unnecessary errors . . . the guidance was often
applied to statements that are so vague they cannot be falsified. In these cases the impression was often left, quite incorrectly,
that a substantive finding was being presented.” Our comprehensive and quantitative analysis of findings and associated uncertainty
in the AR4 supports the IAC findings and suggests opportunities for improvement in future assessments. 相似文献
ABSTRACTAs increasing evidence shows that the risks of climate change are mounting, there is a call for further climate action (both reducing global emissions, and adaptation to better manage the risks of climate change). To promote and enable adaptation, governments have introduced, or are considering introducing, reporting on climate risks and efforts being taken to address those risks. This paper reports on an analysis of the first two rounds of such reports submitted under the UK Climate Change Act (2008) Adaptation Reporting Power. It highlights benefits and challenges for reporting authorities and policymakers receiving the reports that could also inform other countries considering such reporting. For reporting authorities, benefits arise from the reporting process and resulting reports. These benefits include elevating climate risks and adaptation to the corporate level and with stakeholders, alongside facilitating alignment and integration of actions within existing risk management and governance structures. For policymakers, reporting provides enhanced understanding of climate risks and actions from a bottom-up perspective that can be integrated into national-level assessments and adaptation planning processes. The identified challenges are those related to capacity and process. These include limited risk and adaptation assessment capacities; relevance of climate change risks and adaptation in the context of other urgent risks and actions; reporting process effectiveness and robustness; and the provision of effective and sufficiently comprehensive support, including feedback.Key policy insights
Effective adaptation reporting needs to be designed and delivered so as to enhance the value of the reporting process and resulting reports both for those reporting and those receiving the reports, as well as from the broader policy perspective.
Providing a positive and supportive reporting environment is critical to encourage participation and facilitating contiuous learning and improvement, while also facilitating delivery of policy-relevant adaptation reports.
Contributions of adaptation reporting can be enhanced by an inclusive reporting requirement involving a broader organizational mix that enables more effective risk management and reporting that reflects associated (inter)dependencies and consistency with the more comprehensive post-2015 resilience agenda (Paris Agreement, Sendai Framework for DRR and UN Agenda 2030 SDGs).
Abstract In the construction of global primitive equation models, based on the spherical harmonic method, two forms of truncation are in general use. Theoretical considerations suggest the triangular truncation method is superior, but the easily coded rhomboidal truncation is more commonly used. A verification experiment employing the Canadian Operational Spectral Model has been performed to determine if the theoretical superiority of the triangular truncation can be realized in practice. It was found that at least in the restricted case of extra‐tropical forecasts of less than 48 h, that the two truncation methods produced forecasts of equivalent accuracy. 相似文献
This paper discusses the role and relevance of the shared socioeconomic pathways (SSPs) and the new scenarios that combine SSPs with representative concentration pathways (RCPs) for climate change impacts, adaptation, and vulnerability (IAV) research. It first provides an overview of uses of social–environmental scenarios in IAV studies and identifies the main shortcomings of earlier such scenarios. Second, the paper elaborates on two aspects of the SSPs and new scenarios that would improve their usefulness for IAV studies compared to earlier scenario sets: (i) enhancing their applicability while retaining coherence across spatial scales, and (ii) adding indicators of importance for projecting vulnerability. The paper therefore presents an agenda for future research, recommending that SSPs incorporate not only the standard variables of population and gross domestic product, but also indicators such as income distribution, spatial population, human health and governance. 相似文献