Climate change was conceived as a “risk multiplier” that could exacerbate security risks and conflicts in fragile regions and hotspots where poverty, violence, injustice, and social insecurity are prevalent. The linkages have been most extensively studied for the African continent, which is affected by both climate change and violent conflict. Together with other drivers, climate change can undermine human security and livelihoods of vulnerable communities in Africa through different pathways. These include variability in temperature and precipitation; weather extremes and natural disasters, such as floods and droughts; resource problems through water scarcity, land degradation, and food insecurity; forced migration and farmer–herder conflict; and infrastructure for transport, water, and energy supply. Through these channels, climate change may contribute to humanitarian crises and conflict, subject to local conditions for the different regions of Africa. While a number of statistical studies find no significant link between reduced precipitation and violent conflict in Africa, several studies do detect such a link, mostly in interaction with other issues. The effects of climate change on resource conflicts are often indirect, complex, and linked to political, economic, and social conflict factors, including social inequalities, low economic development, and ineffective institutions. Regions dependent on rainfed agriculture are more sensitive to civil conflict following droughts. Rising food prices can contribute to food insecurity and violence. Water scarcity and competition in river basins are partly associated with low-level conflicts, depending on socioeconomic variables and management practices. Another conflict factor in sub-Saharan Africa are shifting migration routes of herders who need grazing land to avoid livestock losses, while farmers depend on land for growing their harvest. Empirical findings reach no consensus on how climate vulnerability and violence interact with environmental migration, which also could be seen as an adaptation measure strengthening community resilience. Countries with a low human development index (HDI) are particularly vulnerable to the double exposure to natural disasters and armed conflict. Road and water infrastructures influence the social and political consequences of climate stress. The high vulnerabilities and low adaptive capacities of many African countries may increase the probability of violent conflicts related to climate change impacts.
Climate and Conflict in Africa
Jürgen Scheffran, Peter Michael Link, and Janpeter Schilling
Catastrophic Droughts and Their Economic Consequences
Farnaz Pourzand and Ilan Noy
The effect of climate change on hydrology and water resources is possibly one of the most important current environmental challenges, and it will be important for the rest of the 21st century. Climate change is anticipated to intensify the hydrological cycle and to change the temporal and spatial distribution patterns of water resources. It is predicted to increase the frequency and intensity of extreme hydrological events, such as heavy rainfall and floods, but in some locations also droughts. Water-related hazards occur due to complex interactions between atmospheric and hydrological systems. These events can then cause economic disasters, societal disturbances, and environmental impacts, which can pose a major threat to lives and livelihoods if they happen in places that are exposed and vulnerable to them. The economic impacts of extreme hydrological events can be separated into direct damage and indirect losses. Direct damage includes the damages to fixed assets and capital; losses of raw materials, crops, and extractable natural resources; and, most importantly, mortality, morbidity, and population displacement. All can be a direct consequence of the extreme hydrological event. Indirect losses are reductions in economic activity, particularly the production of goods and services—which will be greatly decreased after the disaster and because of it. Possibly the most damaging hydro-meteorological hazard, drought, is also the one that is least understood and the most difficult to quantify—even its onset is often difficult to identify. Drought is recognized as being associated with some of the most high-profile humanitarian disasters of past years, threatening the lives and livelihoods of millions of people, particularly those living in semi-arid and arid regions. Drought impacts depend on a set of weather parameters—high temperatures, low humidity, the timing of rain, and the intensity and duration of precipitation, as well as its onset and termination—and they depend on the population and assets and their vulnerabilities. While drought has wide-ranging effects on many economic sectors, the agricultural sector bears much of the impact, as it is very dependent on precipitation and evapotranspiration. Approximately 1.3 billion people rely on agriculture as their main source of income. In developing countries, the agriculture sector absorbs up to 80% of all direct damages from droughts. Droughts may be the biggest threat to food security and rural livelihoods globally, and they can increase local poverty, displace large numbers of people, and hinder the already fragile progress that has been made toward the achievement of Sustainable Development Goals (SDGs). As such, understanding droughts’ impacts, identifying ways to prevent or ameliorate them, and preventing further deterioration in the climatic conditions and social vulnerabilities that are their root causes are all of utmost importance.
Heavy Rainfall and Flash Flooding
Russ S. Schumacher
Heavy precipitation, which in many contexts is welcomed because it provides the water necessary for agriculture and human use, in other situations is responsible for deadly and destructive flash flooding. Over the 30-year period from 1986 to 2015, floods were responsible for more fatalities in the United States than any other convective weather hazard (www.nws.noaa.gov/om/hazstats.shtml), and similar findings are true in other regions of the world. Although scientific understanding of the processes responsible for heavy rainfall continues to advance, there are still many challenges associated with predicting where, when, and how much precipitation will occur. Common ingredients are required for heavy rainfall to occur, but there are vastly different ways in which the atmosphere brings the ingredients together in different parts of the world. Heavy precipitation often occurs on very small spatial scales in association with deep convection (thunderstorms), factors that limit the ability of numerical models to represent or predict the location and intensity of rainfall. Furthermore, because flash floods are dependent not only on precipitation but also on the characteristics of the underlying land surface, there are fundamental difficulties in accurately representing these coupled processes. Areas of active current research on heavy rainfall and flash flooding include investigating the storm-scale atmospheric processes that promote extreme precipitation, analyzing the reasons that some rainfall predictions are very accurate while others fail, improving the understanding and prediction of the flooding response to heavy precipitation, and determining how heavy rainfall and floods have changed and may continue to change in a changing climate.
Climate Change Communication in Turkey
Mehmet Ali Uzelgun and Ümit Şahin
The case of Turkey provides some insight into the socio-political and communicative processes taking place at the periphery of global climate governance efforts. Turkey’s 12-year delayed entry into the United Nations Framework Convention on Climate Change regime (in 2004) and its being one of the last signatories to the Kyoto Protocol (in 2009) has hampered climate-relevant efforts in the country in many ways. This includes institutionalization at national and local levels, the development of relevant national policies, and communication activities. Climate change communication activities in Turkey can be divided into two major categories: the earlier advocacy activities, and the period of mass communication. The earlier activist or advocacy group communication efforts began around 2000, and have contributed significantly to mainstreaming climate change. Paralleling the government’s position towards the issue in many ways, the national-level media activities have remained nominal until 2007, when escalating local weather extremes were widely associated with climate change. Research in climate change communication in Turkey commenced only recently. Although the studies are limited both in scope and quantity, existing evidence suggests that 2007 was crucial in setting the terms of the debate in the country. Mobilizations at both international and national levels in 2009 made that year another landmark for climate change communication and policy in Turkey. International organizations and governance agencies have also taken active roles in both communication and research activities, and in the translation of governance tools developed at the international level to the national level. A review of the above-mentioned efforts suggests that a bottom-up direction of climate change communication efforts, and a minority-influence framework—in which minor advocacy and expert groups are supported by global policy norms and scientific knowledge in taking the issue to the national agenda—may be useful in understanding the dynamics taking place in industrializing countries such as Turkey.
Impacts of Climate Warming on Alpine Lakes
Martin T. Dokulil
Climate warming has impacted Alpine lakes at all altitudes. The European Alps are particularly affected because the mean temperature increment is twice as high as the global average. Depending on the reduction of greenhouse gases realized in the near future, by the end of the 21st century, Alpine lakes will have warmed above the current temperature by 2–6°C. Extreme weather situations such as heatwaves, droughts, heavy precipitation, and storms are expected to further increase, impacting Alpine regions and lakes worldwide. The expected increase in temperature and the associated impacts on almost all aspects of the ecosystem, together with increasing greenhouse gases and extreme climatic events, will negatively affect Alpine lakes throughout the world.
The History and Science of Hurricanes in the Greater Caribbean
The Caribbean’s most emblematic weather symbol is the hurricane, a large rotating storm that can bring destructive winds, coastal and inland flooding, and torrential rain. A hurricane begins as a tropical depression, an area of low atmospheric pressure that produces clouds and thunderstorms. Hurricane season in the Caribbean runs from June 1 through November 30, although there have been infrequent storms that formed outside these dates. Hurricanes are classified according to their maximum wind speed, and when a tropical system reaches the wind speed of a tropical storm (35 mph), it is given a name. Lists of names, which are rotated periodically, are specific to certain regions. If a named storm is responsible for causing a significant number of deaths or property damage, the name is retired and replaced with another. Most deaths in a storm came from drowning, from storm surge along the coast or from flooding or mudslides in the interior. Storm-related deaths also occur when structures collapse or when victims are struck by flying debris. One important and underestimated cause of death after the passage of a storm is disease. Even if the destruction is not immediate, the passage of a hurricane can leave significant ecological damage along the coast and in the interior. Hurricanes can have a devastating effect on a community that takes a direct hit. Repeated hurricane strikes can leave a sense of helplessness and hopelessness, “hurricane fatigue.” Conversely, survivors of a disaster are often left with a feeling of confidence that, since they have endured the effects of at least one deadly hurricane, they can do so again. Until the last half of the 18th century, meteorology remained primitive, but the Age of Enlightenment brought scientific and ideological advances. Major beneficiaries were royal navies whose navigation manuals and nautical charts became increasingly more accurate. In 1821, William C. Redfield established the circular nature of storms and their counterclockwise rotation, while other scientists showed how wind currents within the storms moved upward. Once the coiled structure of hurricanes were established by mid-century, the term “cyclone” was applied, based upon the Greek word for the coils of a snake. After the mid-19th century, scientists moved from information gathering to attempts to predict hurricane strikes. Technology, in the form of the telegraph, was a key component in creating a forecasting system aided by organizations such as the Colegio de Belén, in Havana, Cuba. Later in the century, governments worldwide created official observation networks in which weather reports were radiotelegraphed from ships at sea to stations on land. The 20th century experienced advances, such as the use of kites and balloons, and the introduction of weather reconnaissance aircraft during World War II. In April 1960, the first satellite was launched to observe weather patterns, and by the early 1980s, ocean buoys and sophisticated radar systems made forecasts increasingly more accurate.
Health Problems in the European Alps Under Climate Change
Lisbeth Weitensfelder, Hans-Peter Hutter, Kathrin Lemmerer, Michael Poteser, Peter Wallner, and Hanns Moshammer
The Alpine region in Central Europe and its populations in principle face the same types of threats to their health due to climate change as those in other parts of the world. But special geographical and climatic aspects of that region warrant closer and special examination of the connections between health and climate change in the Alps. These include small-scale variation, in some instances steep mountain slopes, and, above all, a larger-than-average increase in near-surface temperatures. To that end, there are main pathways between climate change and health: “Direct effects” describe rather short-term health effects of extreme weather events. Such events have occurred in the past, and therefore ample epidemiological evidence is available for the assessment of their impact. With climate change, such extreme events are predicted to change in frequency and intensity. “Indirect effects” refer to a more complex pathway where long-term changes of various natural and anthropogenic systems in reaction or adaptation to climate change exert adverse or sometimes also beneficial impacts on health. Such systems include ecosystems in which, for example, the prevalence of disease vectors or the allergenicity of pollen will change. But agriculture and forestry or the built environment are also affected by climate change and in turn affect the health of people. “Distant effects” are also rather indirect in nature. But in this pathway, changes due to climate change in other parts of the world affect the health in the Alpine region. Increasing migration into the Alpine region and changing migration patterns are important examples of this pathway. In some instances, most importantly regarding mental health, there is still a need for more studies focusing on the Alpine environments. But apart from these especially understudied topics, as the climate crisis evolves, there is generally a need for continuous research on the health effects of climate change and the potential of health promotion to create co-benefits.
Meteorology in Vietnam, Pre-1850
The emergence of meteorology in Vietnam did not begin in 1898–1899, with the French installation of a central meteorological observatory in Phù Liễn, near Hải Phòng, and a network of meteorological stations across Indochina. Prior to the colonial time, the ethnic Vietnamese, as well as other ethnic groups such as the Cham, Muong, and Tay-Thai, developed their own knowledge of meteorological phenomena that functioned within their farming practices and cultural frameworks. While further research concerning traditional meteorological knowledge of minority groups in Vietnam is needed, substantial evidence allows a preliminary survey on the practices of the ethnic Vietnamese. Between 1000 and the 1850s, the Vietnamese expanded outwards from their original homeland in the lowlands of north and north-central Vietnam. They adopted the written language, thought systems, and technologies of imperial China, which predisposed them to an enduring Chinese-style meteorological ideology. The Vietnamese viewed weather extremes and other natural anomalies not merely as natural processes. Because meteorological phenomena were “Heaven-sent” warnings of cosmological disasters, Vietnamese dynastic rulers, as well as local farmers and rice producers, interpreted these signs as a demand for moral change. Redressing the authorities’ governance, according to their view, helped rehabilitate the equilibrium of the cosmos. Hence, the records of weather events in Vietnamese historical documents do not simply describe the conditions of past weather, but more importantly, the situations in which the cosmos was no longer in balance. One need not assume that premodern meteorology lacked material grounds. In Vietnam, meteorological knowledge and practices were strongly associated with wet rice cultivation. Vietnamese authorities maintained official agencies to produce yearly calendars that traced proper timing for rice crops, while the populace accumulated experience-based knowledge about seasonal rainfall. Intellectuals, too, expanded their interests to include meteorological knowledge because the subject enriched their philosophy of nature, as in the case of Confucian thinker Lê Quý Đôn (1726–1784), or their medical practices, as in the case of physician Lê Hữu Trác (1720–1791). The advances of Southeast Asian paleoclimate reconstruction since the beginning of the 21st century have added new ideas and methodologies to the study of premodern meteorology in Vietnam. A stronger partnership between climate scientists and historians will therefore facilitate more sophisticated investigations into the knowledge and practices that the Vietnamese developed to respond to weather and climate dynamics.
Terrestrial Processes and Their Roles in Climate Change
Nathalie de Noblet-Ducoudré and Andrew J. Pitman
The land surface is where humans live and where they source their water and food. The land surface plays an important role in climate and anthropogenic climate change both as a driver of change and as a system that responds to change. Soils and vegetation influence the exchanges of water, energy and carbon between the land and the overlying atmosphere and thus contribute to the variability and the evolution of climate. But the role of the land in climate is scale dependent which means different processes matter on different timescales and over different spatial scales. Climate change alters the functioning of the land with changes in the seasonal cycle of ecosystem growth, in the extent of forests, the melt of permafrost, the magnitude and frequency of disturbances such as fire, drought, … Those changes feedback into climate at both the global and the regional scales. In addition, humans perturb the land conditions via deforestation, irrigation, urbanization, … and this directly affects climatic conditions at the local to regional scales with also sometimes global consequences via the release of greenhouse gases. Not accounting for land surface processes in climate modelling, whatever the spatial scale, will result in biases in the climate simulations.
Climate Change Impacts on Cities in the Baltic Sea Region
While not all projected climate change impacts are affecting especially and directly at all the cities of the Baltic Sea region (bsr), including its basin, those cities expect very different direct as well as indirect impacts of climate change. The impacts are also a matter of location, if the city with its built structures and concentration of population is located in the northern or southern part of this basin, or more inland or directly at the coast. As there are many different definitions in use trying to determine what a city is, also in the different national contexts of the bsr, here it is cities in the sense of being human-dominated densely populated areas, which are also characterized by higher concentrations of built-up areas, infrastructure, and soil-sealing as well as socioeconomic roles than rural settlements are. Those characteristics render cities also especially vulnerable to climate change impacts while there are some opportunities arising too. There are many studies on climate change impacts on the Baltic Sea itself as well as on the various ecosystems, but the studies on the observed as well as potential future impacts of climate change on cities are disperse, many are also of a national character or concentrating on a small number of cases, leaving some cities not well studied at all. This renders an all-encompassing picture on the cities within the bsr difficult and even more complicated as every city provides a mix of built-up and open structures, of socioeconomic structure and role in a region, nation-state, or even on an international level, and further characteristics. Their urban development is dependent on manifold various interdependencies as well as climatic and nonclimatic drivers, such as, to name just a few diverse examples, urban to international governance processes, or topography and location, or also different socioeconomic vulnerabilities within the Baltic Sea basin. Accordingly every urban society and structure provides specific exposure, vulnerabilities, and adaptive capacity. Generally, the cities of the bsr have to deal with the impacts of temperature rise, natural hazards, and extreme events, and, depending on location and topography, with sea-level rise. With reference to temperature rise and the increase of heat waves, it is important to consider that cities of a certain size within the Baltic Sea basin contribute to their own urban climatic conditions and provide already urban heat islands. Also, urban planning and building facilitated by local political decisions contribute to the extent of urban floods as well as their damage, as these are regulating, for example, the sealing of soils or new built-up areas in flood-prone zones.
Impacts of Aerosols on Climate and Weather in the Hindu-Kush-Himalayas-Gangetic Region
William K. M. Lau
Situated at the southern edge of the Tibetan Plateau (TP), the Hindu-Kush-Himalayas-Gangetic (HKHG) region is under the clear and present danger of climate change. Flash-flood, landslide, and debris flow caused by extreme precipitation, as well as rapidly melting glaciers, threaten the water resources and livelihood of more than 1.2 billion people living in the region. Rapid industrialization and increased populations in recent decades have resulted in severe atmospheric and environmental pollution in the region. Because of its unique topography and dense population, the HKHG is not only a major source of pollution aerosol emissions, but also a major receptor of large quantities of natural dust aerosols transported from the deserts of West Asia and the Middle East during the premonsoon and early monsoon season (April–June). The dust aerosols, combined with local emissions of light-absorbing aerosols, that is, black carbon (BC), organic carbon (OC), and mineral dust, can (a) provide additional powerful heating to the atmosphere and (b) allow more sunlight to penetrate the snow layer by darkening the snow surface. Both effects will lead to accelerated melting of snowpack and glaciers in the HKHG region, amplifying the greenhouse warming effect. In addition, these light-absorbing aerosols can interact with monsoon winds and precipitation, affecting extreme precipitation events in the HKHG, as well as weather variability and climate change over the TP and the greater Asian monsoon region.