Climatic Change最新文献

The Topical Collection “Accrual of Climate Change Risk in Six Vulnerable Countries” provides a harmonised assessment of risks to human and natural systems due to global warming of 1.5–4 °C in six countries (China, Brazil, Egypt, Ethiopia, Ghana, and India) using a consistent set of climate change and socioeconomic scenarios. It compares risks in 2100 if warming has reached 3 °C, broadly corresponding to current global greenhouse gas emission reduction policies, including countries’ National Determined Contributions, rather than the Paris Agreement goal of limiting warming to ‘well below’ 2 °C and ‘pursuing efforts’ to limit to 1.5 °C. Global population is assumed either constant at year 2000 levels or to increase to 9.2 billion by 2100. In either case, greater warming is projected to lead, in all six countries, to greater exposure of land and people to drought and fluvial flood hazard, greater declines in biodiversity, and greater reductions in the yield of maize and wheat. Limiting global warming to 1.5 °C, compared with ~ 3 °C, is projected to deliver large benefits for all six countries, including reduced economic damages due to fluvial flooding. The greatest projected benefits are the avoidance of a large increase in exposure of agricultural land to severe drought, which is 61%, 43%, 18%, and 21% lower in Ethiopia, China, Ghana, and India at 1.5 °C than at 3 °C, whilst avoided increases in human exposure to severe drought are 20–80% lower at 1.5 °C than 3 °C across the six countries. Climate refugia for plants are largely preserved at 1.5 °C warming in Ghana, China, and Ethiopia, but refugia shrink in areal extent by a factor of 2, 3, 3, 4, and 10 in Ghana, China, India, Ethiopia, and Brazil, respectively, if warming reaches 3 °C. Economic damages associated with sea-level rise are projected to increase in coastal nations, but more slowly if warming were limited to 1.5 °C. Actual benefits on the ground will also depend on national and local contexts and the extent of future investment in adaptation.

Today, a major challenge for climate science is to overcome what is called the “usability gap” between the projections derived fromclimate models and the needs of the end-users. Regional Climate Models (RCMs) are expected to provide usable information concerning a variety of impacts and for a wide range of end-users. It is often assumed that the development of more accurate, more complex RCMs with higher spatial resolution should bring process understanding and better local projections, thus overcoming the usability gap. In this paper, I rather assume that the credibility of climate information should be pursued together with two other criteria of usability, which are salience and legitimacy. Based on the Swiss climate change scenarios, I study the attempts at meeting the needs of end-users and outline the trade-off modellers and users have to face with respect to the cascade of uncertainty. A conclusion of this paper is that the trade-off between salience and credibility sets the conditions under which RCMs can be deemed adequate for the purposes of addressing the needs of end-users and gearing the communication of the projections toward direct use and action.

We present the results from a new framework providing an assessment of how climate change risks to natural capital accrue with warming of 1.5–4 °C in six countries (China, Brazil, Egypt, Ethiopia, Ghana, and India). Unlike typical biodiversity and climate change studies, this assessment also considers landcover and population changes across a range of 17 ecosystem services. The potential impacts of climate change (alone) on natural capital at 1.5 °C is greatest in Brazil and least in Ghana. However, when population and landcover change are included, areas projected to be at high natural capital risk begin to accrue by 1.5 °C in all countries. By 2 °C, Ethiopia and Ghana show increasing areas at high risk, even though they are at low risk owing to climate alone. Thus, current impacts to biodiversity and ecosystem services and changes in potential demand coupled with warming exceed changes projected by climate alone. However, this also indicates that there is adaptation potential, especially with warming of < 2 °C, to reduce risk through restoring habitat. At lower levels of warming, targeted restoration of marginal agricultural habitats would increase the bank of natural capital for use by people and provide support for remaining agricultural lands. By 3 °C, the adaptation potential from restoration is substantially less: < 1% in Brazil, India and Egypt; 7–8% in China and Ethiopia; but still 26% in Ghana. This indicates that restoration as an adaptation option for biodiversity, and thus, natural capital, rapidly decreases with increasing temperatures. By 2100, factoring in population change (SSP2), current ecological footprint, and current landcover, even with only 1.5 °C warming, large parts of Brazil, eastern China, most of Egypt, much of Ethiopia, southwestern Ghana (except for protected areas), and most of India are at high to extreme natural capital risk with an adaptation deficit potentially equating to a soft adaptation limit.

In response to the catastrophic flooding that occurred in British Columbia, Canada in November 2021, the City of Merritt is facing a difficult decision about whether to rebuild or not. The developing situation in Merritt provided a unique opportunity to explore the different types of adaptations (i.e., investments in climate resilient infrastructure, rebuilding, construction of structural mitigation, zoning, and buyouts) considered by policymakers in advance of official municipal decisions. Through qualitative mixed methods (e.g., interviews, open houses, town council meetings), the study explored preliminary discussions among decision makers surrounding long term risk reduction options including rebuild and retreat strategies, perceptions of flood risk, recovery challenges faced by small-scale municipalities, the development of the community’s flood mitigation plan, and recommendations for post-disaster transitional supports. The results indicated that communities in the post-disaster recovery phase are considering the use of buyouts as a risk reduction tool amongst broader flood mitigation strategies, however policy constraints and a lack of funding are impeding the implementation of a flood mitigation plan that includes buyouts. The findings suggest that decisions about post disaster recovery are often independent of broader municipal climate change adaptation plans instead focusing on short-term risk reduction mechanisms. Additionally, transitional supports including interim housing need to be accounted for in recovery planning. Governments in Canada can capitalize on the policy windows during the post-disaster recovery stage and learn from municipalities about the challenges and opportunities in the design and implementation of flood mitigation plans that can help to improve disaster policy.

Abstract

Climate change is contributing to the rapid warming of mountain environments, resulting in glacial retreat, diminished snowpacks, and permafrost thaw. Such rapid changes have transformed the riskscape of mountaineering routes, altering climbing conditions and increasing objective hazards. In response, this study used a mixed methods approach that combines statistical climatological analysis with archival content analysis and semi-structured interviews with mountain guides to explore the relationship between climate change, route conditions, hazards, and adaptations in the Abbot Pass area of Banff National Park (Canada). Results revealed that long-term climatic shifts contributed to change in climbing conditions and objective hazards across all routes, creating a typology of climate-driven route evolution based on the original route characteristics. Mountaineers adapted to such change by employing spatial/activity and temporal substitutions to mitigate risks and exploit emergent opportunities. However, the use of such strategies was influenced by demographic (i.e., age, years of experience) and socio-cultural factors (i.e., place attachment, risk tolerance) and limited by hard limits to adaptation. Given the projected trajectory of climate change, our findings highlight the potential inevitability of mountaineers encountering such limits, resulting in forced transformations and significant loss and damages. Therefore, it is imperative to examine both the economic and non-economic consequences of these shifts and evaluate the ability of mountaineers and tourism providers to navigate a significantly transformed climate future in mountainous areas. While focused on a Canadian context, the findings and methodologies developed herein are relevant to other mountain geographies, where climate change is rapidly transforming environments frequented by mountaineers and represents a call to action for more research in field of climate change, adaptation, and mountaineering.

How will the increased frequency of coastal inundation events induced by sea level rise impact residential insurance premiums, and when would insurance contracts be withdrawn? We model the contribution of localised sea level rise to the increased frequency of coastal inundation events. Examining four Aotearoa New Zealand cities, we combine historical tide-gauge extremes with geo-located property data to estimate the annual expected loss from this hazard, for each property, in order to establish when insurance retreat is likely to occur. We find that as sea level rise changes the frequency of inundation events, 99% of properties currently within 1% AEP coastal inundation zones can expect at least partial insurance retreat within a decade (with less than 10 cm of sea level rise). Our modelling predicts that full insurance retreat is likely within 20–25 years, with timing dependent on the property’s elevation and distance from the coast, and less intuitively, on the tidal range in each location.

The Nile basin is the second largest basin in Africa and one of the regions experiencing high climatic diversity with variability of precipitation and deteriorating water resources. As climate change is affecting most of the hydroclimatic variables across the world, this study assesses whether historical changes in river flow and sediment loads at selected gauges in the Nile basin can be attributed to climate change. An impact attribution approach is employed by constraining a process-based model with a set of factual and counterfactual climate forcing data for 69 years (1951–2019), from the impact attribution setup of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP3a). To quantify the role of climate change, we use the non-parametric Mann-Kendall test to identify trends and calculate the differences in long-term mean annual river flow and sediment load simulations between a model setup using factual and counterfactual climate forcing data. Results for selected river stations in the Lake Victoria basin show reasonable evidence of a long-term historical increase in river flows (two stations) and sediment load (one station), largely attributed to changes in climate. In contrast, within the Blue Nile and Main Nile basins, there is a slight decrease of river flows at four selected stations under factual climate, which can be attributed to climate change, but no significant changes in sediment load (one station). These findings show spatial differences in the impacts of climate change on river flows and sediment load in the study area for the historical period.

Abstract

The 2006 United Nations report “Livestock’s Long Shadow” provided the first global estimate of the livestock sector’s contribution to anthropogenic climate change and warned of dire environmental consequences if business as usual continued. In the subsequent 17 years, numerous studies have attributed significant climate change impacts to livestock. In the USA, one of the largest consumers and producers of meat and dairy products, livestock greenhouse gas emissions remain effectively unregulated. What might explain this? Similar to fossil fuel companies, US animal agriculture companies responded to evidence that their products cause climate change by minimizing their role in the climate crisis and shaping policymaking in their favor. Here, we show that the industry has done so with the help of university experts. The beef industry awarded funding to Dr. Frank Mitloehner from the University of California, Davis, to assess “Livestock’s Long Shadow,” and his work was used to claim that cows should not be blamed for climate change. The animal agriculture industry is now involved in multiple multi-million-dollar efforts with universities to obstruct unfavorable policies as well as influence climate change policy and discourse. Here, we traced how these efforts have downplayed the livestock sector’s contributions to the climate crisis, minimized the need for emission regulations and other policies aimed at internalizing the costs of the industry’s emissions, and promoted industry-led climate “solutions” that maintain production. We studied this phenomenon by examining the origins, funding sources, activities, and political significance of two prominent academic centers, the CLEAR Center at UC Davis, established in 2018, and AgNext at Colorado State University, established in 2020, as well as the influence and industry ties of the programs’ directors, Dr. Mitloehner and Dr. Kimberly Stackhouse-Lawson. We developed 20 questions to evaluate the nature, extent, and societal impacts of the relationship between individual researchers and industry groups. Using publicly available evidence, we documented how the ties between these professors, centers, and the animal agriculture industry have helped maintain the livestock industry’s social license to operate not only by generating industry-supported research, but also by supporting public relations and policy advocacy.

We propose a comprehensive methodological approach to address uncertainties in building energy simulation (BES) studies within a climate change context. Drawing upon expertise from the climate community, our approach aims to improve the reliability of climate-dependent BES for sustainable building design studies. The methodology focuses on creating weather files that accurately retain the climate variability from CORDEX high-frequency climate data, and performing multiple BES (conducted with climatologies from various climate models and emissions scenarios) while removing the climate models biases. The robustness of the results is assessed through statistical analysis, and an uncertainty range is attributed to future energy demand estimations. This approach is illustrated using a representative prototype of a social house located in central-eastern Argentina. The evaluation specifically focuses on assessing the influence of climate change projections on cooling and heating energy demand. We systematically assessed uncertainties related to climate scenarios, seasonality, and building design sensitivity. Our exercise highlight that uncertainty levels rise with higher emissions scenarios. Within our case study, the cooling (heating) energy demand exhibits substantial variations, ranging from 27-37 (303-330) MJ/m² in a moderate emissions context to 51-70 (266-326) MJ/m² in a high emissions scenario. Notably, improvements in building efficiency correlate with reduced uncertainty and, in the context of higher emissions, the projected energy demand can range between 24-37 (201-243) MJ/m². Finally, a discussion is provided on the added value of the proposed methodology compared to solely utilizing a single climate projection file in BES, when uncertainties within climate projections remain unassessed.

Higher education institutions have a mandate to serve the public good, yet in many cases fail to adequately respond to the global climate crisis. The inability of academic institutions to commit to purposeful climate action through targeted research, education, outreach, and policy is due in large part to “capture” by special interests. Capture involves powerful minority interests that exert influence and derive benefits at the expense of a larger group or purpose. This paper makes a conceptual contribution to advance a framework of “academic capture” applied to the climate crisis in higher education institutions. Academic capture is the result of the three contributing factors of increasing financialization issues, influence of the fossil fuel industry, and reticence of university employees to challenge the status quo. The framework guides an empirical assessment evaluating eight activities and related indices of transparency and participation based on principles of climate justice and the growing democracy-climate nexus. The framework can be a helpful tool for citizens and academics to assess the potential for academic capture and capacity for more just and democratic methods of climate action in higher education. We conclude with a series of recommendations on how to refine and apply our framework and assessment in academic settings. Our goal is to further the discussion on academic capture and continue to develop tools that transform higher education institutions to places of deep democracy and innovative climate education, research, and outreach to meet the challenges of the Anthropocene.