Consortium on Risk in the Environment: Diagnostic, Integration, Benchmarking, Learning and Elicitation (CREDIBLE)

自然灾害事件每年夺走数千人的生命，经济损失高达数十亿美元。由于自然灾害而损失财富的风险现在正在以超过财富创造速度的速度增加。因此，自然灾害风险管理者有可能通过知情的行动，显著减少社会影响和保护经济资产。推而广之，环境科学通过告知风险管理者的行动，可以利用数百万美元的研究投资，产生以数十亿计的经常性社会和经济效益。然而，为了真正有效地发挥这一作用，环境科学必须明确认识到风险评估中不确定性的存在和影响。不确定性在自然灾害中普遍存在，这既源于灾害事件本身的固有不可预测性，也源于这些事件与环境和人之间相互作用的复杂方式。它也非常复杂，具有空间和时间结构(例如风暴集群)，测量数据稀疏，特别是对于大型事件，损失通常是危险级别的高度非线性函数。自然灾害科学家和风险经理(如保险公司的精算师)的趋势是明确地评估“简单”的不确定性，并将其余的分配给较大的误差范围。我们项目的第一个目标是引入统计技术，允许将一些不确定性从误差范围移回显式表示，这将极大地提高不确定性和风险评估的透明度和防御性。这方面的明显候选者是安装在以前事件目录上的危险模型(我们可以引入关于模型参数和模型类别的不确定性)，以及模型中关于危险对环境的“足迹”的限制，以及危险事件之后的损失。第二个目标是开发方法，使我们能够评估不确定性的较少可量化的方面，例如与未来情景(例如温室气体排放情景或人口增长预测)相关的概率。第三个目标是改善不确定性和风险的可视化和沟通，以促进对行动之间选择的共同所有权，并弥合行动意图(例如，修建堤坝或重新安置生活在高风险地区的一群人)与完成行动之间的差距。在自然灾害中，这一差距可能很大，因为该法案的成本很高，许多人可能会受到影响，该法案可能需要几年时间才能完成。最终，每个人都从更好的自然灾害风险管理中受益，尽管受益的性质将取决于地点。例如，在英国，主要危险是洪水，这是一个特别不确定的领域，因为降雨和沿海风暴潮可能会受到气候变化的影响。第二个危害是干旱，导致高温压力和水资源短缺。我们的项目对内陆洪水、风暴和干旱有明确的了解。世界其他地区受火山或地震的影响更大，我们的项目包括火山灰、火山喷发中发现的泥石流(即火山喷发；雪崩相似)和地震。未来，可能会出现新的危险，例如空间天气对通信的影响。我们项目的一个关键部分是开发跨当前和新出现的危害的通用方法。

Natural hazard events claim thousands of lives every year, and financial losses amount to billions of dollars. The risk of losing wealth through natural hazard events is now increasing at a rate that exceeds the rate of wealth creation. Therefore natural hazards risk managers have the potential, through well-informed actions, to significantly reduce social impacts and to conserve economic assets. By extension, environmental science, through informing the risk manager's actions, can leverage research investment in the low millions into recurring social and economic benefits measured in billions. However, to be truly effective in this role, environmental science must explicitly recognize the presence and implications of uncertainty in risk assessment.Uncertainty is ubiquitous in natural hazards, arising both from the inherent unpredictability of the hazard events themselves, and from the complex way in which these events interact with their environment, and with people. It is also very complicated, with structure in space and time (e.g. the clustering of storms), measurements that are sparse especially for large-magnitude events, and losses that are typically highly non-linear functions of hazard magnitude. The tendency among natural hazard scientists and risk managers (eg actuaries in insurance companies) is to assess the 'simple' uncertainty explicitly, and assign the rest to a large margin for error.The first objective of our project is to introduce statistical techniques that allow some of the uncertainty to be moved out of the margin for error and back into an explicit representation, which will substantially improve the transparency and defensibility of uncertainty and risk assessment. Obvious candidates for this are hazard models fitted on a catalogue of previous events (for which we can introduce uncertainty about model parameters, and about the model class), and limitations in the model of the 'footprint' of the hazard on the environment, and the losses that follow from a hazard event.The second objective is to develop methods that allow us to assess less quantifiable aspects of uncertainty, such as probabilities attached to future scenarios (eg greenhouse gas emissions scenarios, or population growth projections). The third objective is to improve the visualisation and communication of uncertainty and risk, in order to promote a shared ownership of choices between actions, and close the gap between the intention to act (eg, to build a levee, or relocate a group of people living in a high-risk zone) and the completion of the act. In natural hazards this gap can be large, because the cost of the act is high, many people may be affected, and the act may take several years to complete.Ultimately, everyone benefits from better risk management for natural hazards, although the nature of the benefits will depend on location. In the UK, for example, the primary hazard is flooding, and this is an area of particular uncertainty, as rainfall and coastal storm surges are likely to be affected by changes in the climate. A second hazard is drought, leading to heat stress and water shortages. Our project has explicit strands on inland flooding, wind-storms, and droughts. Other parts of the world are more affected by volcanoes or by earthquakes, and our project has strands on volcanic ash, debris flows as found in volcanic eruptions (ie lahars; avalanches are similar), and earthquakes. In the future, new hazards might emerge, such as the effect of space weather on communications. A key part of our project is to develop generic methods that work across hazards, both current and emerging.