Abstract:
Climate Change is one of the most important environmental phenomenon in the current century. Located in an arid and semi-arid region of the world, Iran has already faced a water crisis and increasing temperatures, so the country is vulnerable to the climate change impacts. Due to the development of climate change studies and it’s impacts on different aspects of human’s life especially the economic sector, it appears that the lack of an indicator reflecting the state of climate change is felt in this context. While in the field, most of studies focus on analyzing the effects of climate change on the economy using only temperature and precipitation variables, however this multidimensional phenomenon is more than merely daily temperature and precipitation changes. Due to the complex nature of climate change, the study introduces and develops a composite index for climate change in provinces of Iran for 33 years (1991-2023) and examines it’s trends. The study applies Principal Component Analysis (PCA) method for weighing based on 25 climate change indices from World Meteorological Organization. The results show that in the most provinces the composite index deteriorated over the study period and this situation is more concerning in arid and semi-arid provinces like Fars. It is worth pointing out that this composite index can be useful for interdisciplinary studies and policy making specially in agricultural sector studies which is the most susceptible economic sector.
Extended Abstract:
Introduction:
Iran is located in the Middle East, an arid and semi-arid region in the world. It has already faced a water crisis and increasing temperatures, so the country is unsafe from climate change and its impacts. While in the field of environmental and climate change studies, most of them focus on analyzing the effects of climate change on the economy using only two variables (temperature and precipitation), this study aims to take into account a wide range of climate change variables by using core indices of climate change in order to provide a more comprehensive and precise description of the situation. Due to the development of composite indicators in economics studies, the study introduces and develops a composite index for climate change trends in provinces of Iran for 33 years. This composite index can simplify the complexity of this phenomenon, and then we can more easily analyze, compare, and track the trend of this multi-dimensional concept. It is noteworthy to mention that this composite index can be useful for studies and policy making in an agricultural sector which is the most vulnerable economic sector.
Methodology:
The study estimated a composite climate change index for 23 provinces in Iran by using proper methods and 25 climate change core indices from 1991 to 2023. This comprehensive study covers a broad geographic region of the country. Since all indices do not have negative impacts as they increase, the study classifies indices into two groups. The first group contains 16 indices, and their increase is expected to be harmful and negatively impact the social and economic sectors. On the other hand, the second group contains 9 indices, and their increase is expected to be welcome and have positive impacts. Weighing is the most crucial step in the composite index process. There are different methods to assign weight to the indicators; each has advantages and disadvantages. Meanwhile, principal components analysis (PCA) is one of the most used methods, and it will also be applied in this study. This method is commonly employed, especially when a linear relationship between variables is assumed. It is selected in this study because principal component analysis (PCA) serves as an effective tool to reveal patterns of similarity and difference within the data. Once those patterns are identified, PCA facilitates to reduce the number of dimensions without losing important information in the original data.
Discussion:
As demonstrated both indices had unpleasant trends, especially in the last 20 years. This trend is worse in provinces located in arid and semi-arid regions of the country, but as we have seen in the results, all provinces will face the challenges of climate change, and none of them is safe. For index 1, high values and increasing trends are expected to be harmful. Province like Fars have more critical situations, which is expected to worsen without proper action. Index 2 will negatively affect different sectors of the country as it declines. Provinces in arid regions are on the frontline of the impacts of the changes in the second index. Bushehr has a critical condition from the perspective of the second index. However, this province has a share of more than 5 percent of Iran's GDP. This trend can decrease the province's GDP. It is worth mentioning that the indices' deterioration can negatively impact economic-social sectors.
Conclusion:
Creating a composite climate change index is crucial for decision-making and policy-making processes to consider environmental aspects. Instead of dealing with numerous individual indicators, policymakers will have a composite index that covers all dimensions of climate change, allowing them to address every aspect of this issue. This will help not to eliminate any dimensions of climate change phenomenon. Similar to other applied indices such as the Climate Vulnerability Index (CVI), which is widely used by many countries to analyze vulnerability at the regional level, this index offers a robust framework for evaluation. Built upon a comprehensive set of standardized ETCCDI climate indices and employing a two-dimensional approach that categorizes indicators into favorable and unfavorable components, the proposed index can function on a level comparable to or even exceeding that of traditional vulnerability indices, which often focus solely on socio-economic variables. Due to its emphasis on key standard climatic variables, this index enables long-term trend analysis across different geographic scales and can be integrated with social and economic indicators.
While the findings highlight the worsening of climatic conditions across most provinces, it is essential to distinguish between the study’s comprehensive analytical approach and the descriptive reporting of index values. The primary aim of this research is to establish a coherent, integrated framework for analyzing climate change at the national level. This purpose extends beyond regional assessments of index fluctuations and can serve as a basis for interdisciplinary applications in economic, social, and policy-making domains.