In light of the prevailing urbanization trends observed not only in Kazakhstan but most parts of the world, it becomes increasingly important to prioritize the study and incorporation of urban climate considerations within regional policies and urban planning strategies. The primary focus of urban climate assessment lies in its ability to analyze climate conditions on smaller, local, and microclimate scales. However, when assessing climate change risks at regional and local levels, it is essential to begin with a broader perspective encompassing larger-scale climatic trends in Central Asia and Kazakhstan. According to the climate risk assessment conducted by the World Bank Group and Asian Development Bank in 2021 for Kazakhstan, it is projected that temperatures will rise at a faster rate in Kazakhstan over the coming decades compared to the global average relative to the 1986-2005 baselines. This upward trend is expected to have significant consequences, including a gradual reduction in glaciers across the region. This reduction will, in turn, lead to a substantial decrease in river flow and the availability of freshwater resources by the mid-21st century. These developments pose substantial threats to both water security and the economy, not only in Kazakhstan but also throughout Central Asia (WBG and ADB, 2021). However, one of the most important points made in the climate outlook for Kazakhstan within the scope of the urban climate is that climate change would lead to more frequent extreme weather events primarily expressed in both low and high temperatures. Interestingly, it is the extreme weather events that people in Kazakhstan tend to associate with climate change (Makhanov, 2021).
Currently, around 58% of Kazakhstan’s population resides in urban areas, a statistic that aligns consistently with the nation’s profile as a developing country. More than half of the world’s population is nowadays believed to be living in urban areas and projections indicate a further accelerating increase in the share of the urban population in Kazakhstan as well as worldwide in decades to come (UN-HABITAT, 2016). For instance, by 2050 around 68.4% of the global population and 69.1% of the population of Kazakhstan are expected to be living in urban areas (UN DESA, 2023). Based on different scenarios of urbanization, the projections suggest the largest increment in urban land to take place in areas where the current urbanization rate is relatively low (Gao and O’Neill, 2019), which is relevant for most developing countries. Considering these facts, firstly, it’s evident that, primarily, the urban climate will increasingly be the environment to which the majority of people are exposed, rather than the broader climate in general. This is one of the most compelling arguments advocating for the significance of urban climatology as a crucial research field deserving of dedicated resources.
Secondly, it should be borne in mind though that the proportion of the population living in cities varies a lot from country to country and generally tends to be larger in high-income countries with developed economies. In contrast, it is mainly low-income developing countries where rural populations outnumber urban residents by high margins and therefore it is where the bulk of future urbanization increment is expected to come from. A rough revision of future urbanization projections should give us an idea of the climatic profile of future hotspots of urban climate issues. In general, it would be rather accurate to say that it is the part of the world referred to as the “Global South” or developing nations that would be the primary source of future urbanization and challenges in urban climatology. According to the most recent global population projections of the UN, the urban population of the Global South is projected to increase by about two-thirds (66.9%) relative to the current levels whereas that of the rest of the world (Global North), would only add another 13.3% to its current urban population size (UN DESA, 2023). The world’s urban population is expected to adjust to these trends accordingly weighting towards the Global South. In these two groups of countries, Kazakhstan is closer to the former group of developing nations because it is expected to have a fairly large increase (46.5%) in the size of its current urban population by the mid-21st century. In other words, Kazakhstan is projected to witness an increase of over 5 million urban inhabitants by the year 2050 (UN DESA, 2023).
When discussing urban climate, it is essential to clarify the concept known as the Urban Heat Island (UHI). The UHI is an additional heat leading to a detectable temperature difference in urban areas compared to their rural surroundings due to non-natural land cover and human activity (Howard, 1818). This effect is due to multiple factors that are present in urban areas such as artificial surface, air pollution, urban geometry and characteristics of urban architecture, traffic congestion, etc. The UHI effect tends to be positively correlated with the size of a city and its population density and tends to be more pronounced in large cities. For instance, the UHI effect grows stronger with the size of the city and in cities with over one million population it can generate up to 5°C of additional heat. Besides generating the UHI effect, urbanization can modify the rainfall, enhancing the precipitation by 16% over the city (Liu and Niyogi, 2019). With the increasing urbanization and rapid industrialization in many parts of the world, it is expected that the mean global urban temperature around the world will increase significantly (Jones et al., 1990 and Marcotullio et al., 2021). The economic growth, especially in developing nations, unfortunately, would inevitably contribute to stronger and more detrimental urban climate effects. For instance, it has been noted that China used more cement in just three years from 2011 to 2013 than the U.S. did in the entire 20th century (Gatesnotes.com, 2014). Obviously, this extensive quantity of cement was predominantly utilized as a surface material within Chinese urban areas, which played a significant role in amplifying the Urban Heat Island (UHI) phenomenon.
As it was already mentioned, the urban climate issues are relevant for Kazakhstan primarily because of its growing urban population. Another factor that makes this issue relevant is the distribution of the urban population between the cities. Notably, over the past three decades, urban population growth in Kazakhstan has been concentrated largely within a handful of major urban centers. For instance, in 1990, the top three largest cities accounted for nearly 23% of the country’s total urban population. In contrast, as of 2023, these top three cities are now home to over 40% of the country’s urban population. Their combined population size and land areas have more than doubled since then and so did land their areas. Given that the effects of urban climate are correlated with population growth, it is evident that the overall influence of urban climate on human populations has intensified in Kazakhstan over the recent decades, resulting in greater exposure of more people to these effects.
Despite growing concerns, urban climatology is largely understudied and climate research is mostly done outside local and urban contexts in Kazakhstan. The available studies, although limited in number, provide compelling evidence of significant UHI effects and the presence of more extreme temperatures in Kazakhstan’s major urban centers compared to surrounding rural lands. Astana, as a focal point in urban climate research, gains significant interest due to its remarkable population growth, expansion in urban land area, and profound surface transformation. Since 1997, its population has nearly quadrupled, with the majority of this growth being accomplished by the conversion of previously rural and vacant lands on the left bank of the Ishim River. These conditions make Astana an almost ideal case for studying how significant transformations of unused rural land into urban areas can impact the local urban climate. The existing studies present robust evidence of a strong UHI effect in the city of Astana (Konstantinov, 2015; Berlessova and Konstantinov, 2020; Askar et al., 2021). Moreover, some of the research findings appear to be interesting and hold practical implications. For example, it was discovered that compact high-rise and mid-rise buildings notably amplify the existing UHI effect, with the most pronounced impact observed during the summer months (Berlessova and Konstantinov, 2020). In another study, it was found that the extensive urban expansion of Astana over the past four decades led to significant shifts in annual average maximum and minimum temperatures, as well as the daily temperature range. These changes can be directly attributed to the city’s urban development (Askar et al., 2021).
It can be said that urban climate studies are not extensive in developing countries. There is a strong geographical bias towards cities in western countries and Kazakhstan is not an outlier in this trend. Articles studying urban climate in these parts of the world are quite numerous so they are highly disproportionate to their share of the global population (Lamb et al., 2019). This geographic inconsistency can come as a result of various reasons. Usually, it is countries of the West that have sufficient resources to sustain good research activity on various issues including urban climate. Apparently, countries with very limited scientific resources cannot compete with countries in the wealthiest part of the world, which leads to huge inequalities in areas of research in urban climate case studies. Moreover, in most cases, research funding comes from public sources, which makes research institutions accountable to local authorities who are mostly interested in local issues.
In addition to regional and urban planning, the field of urban climatology in Kazakhstan should be seamlessly integrated into broader climate studies, primarily for reasons related to security and disaster prevention. According to major climate projections, one of the most pertinent risks posed by climate change to Kazakhstan and the Central Asian region is the heightened frequency and severity of adverse weather events, predominantly linked to extreme temperatures and shifts in precipitation patterns. Demographic factors play a significant role, with increasing urbanization and the concentration of large populations in a few major urban centers escalating the anticipated costs associated with these extreme weather events. Recent floods in cities like Astana and other major urban areas in northern Kazakhstan have vividly demonstrated the substantial and far-reaching consequences of such events. In this context, the development of resilience strategies against the adverse effects of local and urban climate conditions should be considered an essential component of comprehensive climate studies.
References
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Note: The views expressed in this blog are the author’s own and do not necessarily reflect the Institute’s editorial policy.