TEDx Talks - How to calculate risk in a changing climate | Mel Reasoner | TEDxSelkirk College
The speaker outlines two main strategies for addressing climate change: mitigation and adaptation. Mitigation involves reducing greenhouse gas emissions, while adaptation focuses on anticipating and minimizing the impacts of climate changes. Despite global efforts, such as the Kyoto Protocol and the Paris Agreement, emissions and Earth's energy imbalance continue to rise, necessitating effective adaptation strategies. The approach discussed involves quantifying the probabilities of exceeding specific climate thresholds critical for infrastructure and natural systems. This information aids planners, asset managers, and engineers in making informed decisions to prevent costly failures. For example, understanding temperature thresholds can help modify bridge expansion joints to prevent catastrophic failures. The presentation also highlights a case study of a ski area in Canada, where probability analysis informed decisions about relocating to higher elevations for better snow conditions. Overall, the approach provides a framework for prioritizing adaptation measures and designing infrastructure to withstand future climate conditions with a specified level of confidence.
Key Points:
- Mitigation and adaptation are key strategies for climate change; adaptation is crucial due to insufficient mitigation progress.
- Quantifying probabilities of exceeding climate thresholds helps in planning and risk management for infrastructure.
- Understanding temperature thresholds can prevent infrastructure failures, such as bridge collapses.
- Probability analysis aids in decision-making for relocating assets, as shown in the ski area case study.
- The approach provides a framework for prioritizing adaptation measures and designing resilient infrastructure.
Details:
1. 🌍 Climate Change Approaches: Mitigation vs Adaptation
- There are two general approaches for dealing with climate change: mitigation and adaptation.
- Effective mitigation requires the rapid reduction of greenhouse gas emissions into the atmosphere, such as transitioning to renewable energy sources, improving energy efficiency, and adopting sustainable transportation.
- Adaptation involves anticipating climate changes and adjusting strategies accordingly, such as developing climate-resilient infrastructure, altering agricultural practices to withstand changing weather patterns, and enhancing water management systems.
2. 📉 Global Mitigation Efforts and Challenges
- Global emissions curve has begun to bend in the right direction, but this is insufficient as it should be decreasing rapidly.
- The Earth's energy imbalance, the best metric for global warming, has been increasing at an increasing rate since 2000.
- Despite efforts like the Kyoto Protocol, Copenhagen Accord, Paris Agreement, and 24 COP meetings, the Earth's energy imbalance continues in the wrong direction.
- The scientific community emphasizes the need to consider worst-case scenarios until the energy imbalance curve is bent in the right direction.
3. 🔍 Identifying and Quantifying Climate Thresholds
- Understanding and quantifying climate thresholds is crucial for effective adaptation measures, as it helps planners and engineers anticipate changes and prevent failures.
- Quantifying probabilities of exceeding climate thresholds is essential for infrastructure resilience against climate impacts.
- A specific example of the importance of identifying climate thresholds is the potential failure of one in four US steel bridges by 2040 due to climate changes.
- Bridge expansion joints are vulnerable to failure when high-temperature thresholds are exceeded, highlighting the need for proactive measures.
- In Nelson, BC, the all-time temperature record of 40.7 degrees set in 2021 illustrates the relevance of monitoring climate thresholds, with a critical threshold example being 41.5 degrees.
- Proactive adjustments to infrastructure, such as modifying bridge expansion joints, can prevent costly failures and enhance resilience.
4. 📈 Projections and Planning for Infrastructure Resilience
- Climate events previously considered as one-in-100-year occurrences are now more frequent due to climate change, necessitating revised planning strategies.
- The annual exceedance probability for a 41.5-degree event is currently 1%, projected to rise to 10% by 2050, impacting systems like ski area snow conditions and annual budget-related climate indices.
- Cumulative probability curves are essential for understanding long-term risks, particularly for planning against catastrophic failures, by assessing the likelihood of exceeding thresholds over time.
- The analogy of rolling a die helps differentiate between annual exceedance and cumulative probability, stressing the need for comprehensive risk assessment over time.
- Incorporating these probability assessments into planning tools can enhance infrastructure resilience by preparing for increased frequency and severity of climate events.
5. 🌡️ Temperature Thresholds and Asset Management
- The probability of exceeding a 41.5°C threshold in Nelson over the next 25 years is over 70%, while the risk tolerance for such an event is only 20%. This indicates a significant gap between risk and tolerance, necessitating immediate action.
- By 2031, the probability of reaching this temperature threshold will exceed acceptable risk levels, which compels asset managers to implement measures to increase the temperature threshold for assets.
- For more valuable assets in Nelson with a higher threshold of 43.5°C, the probability of exceeding this threshold by 2050 is over 35%, with a risk tolerance of only 10%. This necessitates strategic interventions by 2035 to prevent asset failure.
- Reverse calculations indicate that for 95% confidence in asset stability by 2050 in Nelson, assets should be designed to withstand 46.7°C, highlighting the need for future-proofing infrastructure.
- A Risk Index for assets is calculated as the cost of failure times the probability of failure, which prioritizes high-risk assets for adaptation measures, ensuring efficient allocation of resources.
- A real-world example involved a CrossCountry ski area in western Canada considering relocation due to climate change concerns, illustrating the practical applications of temperature threshold management.
6. 🏔️ Real-World Applications: Ski Area Analysis
- The average maximum temperature for January, February, and March correlates with the length of the ski season. Higher temperatures (around 4°C) result in longer seasons, while lower temperatures (around -0.5°C) lead to shorter seasons.
- Indicators such as groomers' logs show that good snow conditions correlate with longer ski seasons. Red dots indicate years with poor snow quality and short seasons, while green circles indicate good snow conditions and longer seasons.
- Despite a warming climate, historically there have been more good years than bad, prompting discussions on resource investment in higher elevation facilities versus maintaining valley bottom locations.
- A probability analysis indicates that by 2050, one in four years will be a bad year (exceeding 4°C). By 2070, over 40% of years will be bad. Conversely, the probability of a good year (not exceeding -0.5°C) drops to 12% by 2030 and less than 7% by 2050.
- These findings are critical for decision-making regarding resource allocation to higher elevation sites with potentially better snow conditions.
7. 🔄 Conclusion and Future Outlook on Climate Adaptation Efforts
- The approach focuses on quantifying probabilities of exceeding critical thresholds relevant for built and natural systems, aiding planners in comparing these probabilities with their risk tolerance.
- Provides design threshold information on temperature and precipitation that infrastructure can tolerate without failure, within a planning time frame.
- Offers a method to prioritize adaptation measures for numerous assets.
- Acknowledges poor global mitigation efforts and the potential for regression in progress due to the political climate, but emphasizes the necessity of reducing emissions as the primary solution.
- Highlights the importance of understanding forthcoming climate changes to enhance adaptation measures effectively.