Part 1: Introductory Concepts in Planetary Health

4 Introduction to Climate Change

Climate Change

Authors: Wang, X., Kınay, P., Farooque, A.

Learner Outcomes

After reading this chapter students should be able to:

  • Understand the main causes of climate change
  • List the direct and indirect impacts of climate change on human societies and ecosystems
  • List the potential solutions for climate change mitigation and adaptation
  • Describe the relationship between climate change and human health


The important keywords for this chapter are:

  • Climate change, impacts, mitigation, adaptation, human health


4.1. Fundamentals of Climate Change

Concepts, Definitions & General Explanations

Climate change refers to any significant change in climate measures, such as temperature, precipitation, or wind, lasting for an extended period (decades or longer) [1]. Climate change may result from:

• natural factors, such as changes in the sun’s intensity or slow changes in the Earth’s orbit around the sun.

• natural processes within the climate system, such as changes in ocean circulation.

• human activities, such as burning fossil fuels, can change the atmosphere’s composition and the land surface, such as deforestation, urbanization, and desertification [2].

Although the terms “climate change” and “global warming” are frequently used interchangeably, “climate change” covers that there are more changes besides temperature increases. These modifications could be caused by natural processes, such as variations in the solar cycle. But since the 1800s, human activities have been the main driver of climate change, primarily due to the burning of fossil fuels like coal, oil, and gas, according to the Intergovernmental Panel on Climate Change (IPCC) [3]. The influence of humans on the climate now far outweighs the effects of known changes in natural processes, such as solar variations and volcanic eruptions.

The Difference Between Weather, Climate, Climate Variability, And Climate Change

Weather is the temperature, humidity, precipitation, cloudiness, and wind we experience in the atmosphere at a given time in a specific location. Climate is the average weather over a long period (30–50 years). A systematic change in the atmosphere’s long-term state over several decades or longer is referred as climate change. In the same way that clinical trials employ statistical tests to examine if a favourable reaction to therapy is likely to have happened by chance, scientists use statistical tests to determine the likelihood that climatic changes fall within the range of natural variability. For example, there is a less than 1% chance that the warming of the atmosphere since 1950 could be the result of natural climate variability. Before explaining the causes and effects in depth, there are two important terms to look at. Following sections will introduce two essential terms: climate prediction and projection, and the differences in between.

Climate Prediction

A climate prediction or forecast is a statement about how the climate system will evolve in the future, considering both internal variability and changes caused by GHG emissions [4]. Climate predictions do not seek to predict the system’s fundamental day-to-day changes. Rather, they attempt to forecast whether seasonal, yearly, or decadal averages or extremes will be higher, lower, or equal to climatological averages. While seasonal forecasts are frequently produced in many places, longer-term (decadal) climate predictions are now more of a research endeavor, however, operational systems are being advanced, for example within the CMIP6 (Coupled Model Intercomparison Program 6) climate modeling community [5, 6].

Climate Projection (Scenario)

In contrast to predictions, projections are not started with current-situation observations. They usually begin their simulations in the past, from pre-industrial to 1950, or even more recently [7]. The forecasts are derived by forcing the climate models with scenarios for future GHG emissions or concentrations. At the same time, the historical simulations are driven (or forced) by estimates of past human-induced and natural climate forcing agents (concentrations of GHGs). A climate projection simulates the climate system’s response to various greenhouse gas scenarios, frequently based on climate model simulations [7, 8]. Climate projections are distinguished from climate predictions to emphasize that climate projections are dependent on the emission/concentration/radiative forcing scenario used, which is based on assumptions that may or may not be realized, and thus is subject to substantial uncertainty unrelated to the climate system [9]. Climate scenario and climate projection are often used interchangeably. Climate projections often simulate the future climate until 2100 or even beyond (Figure 1).

Figure 1. Time-horizon of climate predictions and projections
Figure 1. Time-horizon of climate predictions and projections.
Difference Between Predictions and ProjectionsThe most likely future occurrences in a specific location or area are foreseen through forecasts or predictions. Depending on the site, the validity of model-based weather forecasts may be restricted beyond a week due to the atmosphere’s intrinsic dynamic nature. Because the environment is so dynamic, even little adjustments to the observed beginning conditions, which are continuously fed into the model, might give radically different weather predictions for the coming week.Climate variables are generated for each day in a climate projection, but the output for a given day cannot be trusted to be accurate so far in the future. Instead, it is indeed critical to determine whether long-term data is reliable for a particular location and/or season. This is independent of the simulation’s initial conditions; it is dependent on the model’s parameters as well as the provided forcings, such as GHGs.Causes of Climate ChangeClimate change has many consequences for the physical environment, ecosystems, and human societies [10]. How countries reduce greenhouse gas emissions and adapt to climate change will determine the future impact of climate change [11]. The loss of sea ice, rapid sea-level rise, and longer, more extreme heat waves that scientists anticipated in the past are already happening [12]. Climate change is projected to be unevenly distributed across the globe. Land areas change faster than oceans, and high northern latitudes change faster than tropics. Melting glaciers, modifying the hydrological cycle (evaporation and precipitation), and changing currents in the sea are three primary ways global warming may alter regional climate [13].Extreme weather, glacier retreat, sea-level rise, Arctic sea ice decreases, and changes in the timing of seasonal occurrences are all physical changes [14]. Climate change has harmed the environment by boosting temperatures, drying soils, and increasing the risk of wildfires. The latest IPCC report highlights different climate futures and emphasizes the warming impact (1.5 degree Celsius temperature rise) [10]. Recent warming has had a significant impact on natural biological systems. Species are migrating poleward to colder climates around the world. On land, species migrate to higher elevations, whereas marine species migrate to deeper depths to find colder water. Climate change has been estimated to put between 1% and 50% of land-based species at risk of extinction [15]. The causes of climate change can be increased energy use, agricultural practices, deforestation, mass production, increasing pollution, changes in land use, and solar radiation (Figure 2). In the following sections, these causes will be introduced briefly.

Figure 2. Cause-effect relationship of climate change.
Energy Use

Energy use is by far the main source of greenhouse gas emissions from human activities on a global scale [16, 17]. Burning fossil fuels for energy for heating, power, transportation, and industry accounts for almost two-thirds of worldwide greenhouse gas emissions [18]. Our energy use and production have a significant impact on the climate[19]. Climate change could modify our energy generation capacity as well as our energy requirements [20]. Changes in the water cycle, for example, have an impact on hydropower; warmer temperatures increase the energy demand for cooling in the summer while decreasing the need in the winter.

Agricultural Practices

Agriculture both causes and is affected by climate change [21, 22]. To combat climate change, nations must reduce agricultural greenhouse gas emissions and modify their food production methods [23]. However, there are many other factors besides climate change that have an impact on agriculture. To fulfill the growing global demand and maintain resource competitiveness, food production and consumption must be considered in a broader context that integrates agriculture, energy, and food security [24, 25]. The food supply releases greenhouse gases at every level into the atmosphere [26]. Farming produces significant amounts of the potent greenhouse gases methane and nitrous oxide. Belching is the method that allows livestock to release methane after digestion due to enteric fermentation [27, 28]. It can also escape from landfills where organic waste and manure are dumped, causing more agricultural GHGs.


Tropical forest trees employ photosynthesis, like other green plants, to absorb carbon dioxide from the atmosphere and release oxygen [29]. But as forests expand, photosynthesis outpaces respiration, and the extra carbon is stored in the soil, tree roots, and tree trunks. They also do the opposite process known as respiration. When trees are cut down, a significant amount of the carbon they have stored is released as CO2 back into the atmosphere [30]. This is how climate change and global warming are impacted by deforestation and forest degradation. Deforestation is one of the primary human drivers of climate change. Removing trees reduces a vital carbon “sink” that absorbs CO2 from the atmosphere. Large-scale deforestation also causes extreme warming [31]. It is evident that greener areas can foster cooling impact [32, 33]Changes in the Land UseChanges in land use are responsible for an increase in human population, deforestation, food types, and the demand for energy and fiber [24]. While deforestation and rapid population increase are two factors that affect the environment, unpredictable heavy rainfall and warming temperatures are two factors that affect land usage [34, 35]. Changes in land usage and strategies for efficient land management are indicators of how climate change is affecting land use. For instance, the climatic change affects crop output, which alters how land is used. The two driving force adjustments are different in time and space. Land-use change (LUC) is a crucial element of global adjustment that directly impacts climate change [36-38].

Solar Radiation

The primary source of energy for life on Earth is the Sun, which also greatly influences the climatic conditions of our habitats. The amount of solar energy that reaches the surface is an important factor in the surface energy balance [39]. It controls a wide range of surface processes, including evaporation and related hydrological components, snow and glacier melt, plant photosynthesis and associated terrestrial carbon uptake, as well as the diurnal and seasonal patterns of surface temperatures [40]. Major practical ramifications include those for solar energy technologies and agricultural productivity, for instance. Therefore, changes in the amount of solar radiation reaching the Earth’s surface may significantly affect the environment, society, and the economy. Over the course of the next century, the Earth keep warming due to the imbalance between thermal radiation from the sun and that from the sun’s atmosphere [41]. This warming will hasten the melting of the polar ice caps, raise sea levels, and increase the likelihood of more extreme weather patterns exacerbated by climate change [42].

4.2. Direct and Indirect Impacts of Climate Change

Climate change impacts can manifest in various ways [21, 43-45]. In recent years, heatwaves and other extreme events such as wildfires and flooding have been evident around the globe [46, 47]. There is, however an explanation for all these events happening and why and how they are exacerbated by climate change. This section will explain the links between climate change indicators and provide some examples (Figure 3).

Figure 3. Direct and indirect impacts of climate change


Direct Impacts of Climate Change


An extended stretch of unseasonably high temperatures and oppressive humidity is referred as a heatwave. Climate change is increasing the amount of heat that people experience [48]. On a worldwide scale, extreme temperature occurrences appear to get more often, longer, and more severe [46, 47, 49]. The ground loses more moisture on warm days, which dries out the vegetation. The consequences include damage to agriculture, larger, more intense wildfires, and a longer fire season. Heatwaves have an impact on human health and are the leading cause of fatal natural disasters [46]. Heat waves also impact our environment, agriculture, infrastructure, and services [21, 26]. Increases in heat and humidity would undoubtedly reduce worker output since they put a burden on people’s tolerance levels and make it difficult for outdoor workers to stay cool, and healthy. Continuous heat waves have more disastrous effects than severe temperatures on a single day. There is no doubt that sustained extreme temperatures are linked to excessive human morbidity and mortality rates and as climate change manifests these links are becoming more evident [49, 50].


Water accumulation over typically dry land causes flooding [51]. It results from inland waters (rivers and streams) overflowing, tidal waters, or an extraordinary water buildup from sources like torrential rains, dams, or levee failures [51, 52]. Floods are one of the most frequent and deadly natural disasters worldwide [53, 54]. In almost every county, they have caused destruction, and in many places, they are getting worse. A variety of sources can cause a flood. River flooding, inland flooding, and coastal flooding are a few examples of flooding types [55]. A flood can be brought on by weather-related factors (heavy or protracted rainfall, storm surges, abrupt snowmelt). Still, there are also human-driven factors, such as the way we manage our waterways (via dams, levees, and reservoirs), as well as the changes we make to the land [56]. For instance, increased urbanization results in more paving and other impermeable surfaces, changes to natural drainage systems, and frequently more housing construction on floodplains [57, 58]. Urban flooding can result from poorly maintained infrastructure in cities [59]. Flooding-related concerns are increasingly being connected to climate change. Numerous weather- and human-related factors influence whether a flood occurs, and the lack of data on historical floods makes it challenging to compare them to current flood trends that are affected by climate change [60]. However, it is becoming more evident that climate change “has detectably altered” numerous of the water-related factors that cause floods, such as rainfall and snowmelt, as the IPCC (Intergovernmental Panel on Climate Change) stated in its special report on extremes [61].


A lack of precipitation over a lengthy period (often a season or more), resulting in a water deficit, is referred as a drought [62, 63]. Precipitation, temperature, streamflow, ground and reservoir water levels, soil moisture, and snowpack are all drought indicators [64]. The likelihood of droughts worsening in many places of the world rises with climate change [65]. Droughts are becoming more likely in many parts of the world because of climate change [61]. Evaporation is accelerated by warmer temperatures, which decrease surface water and dry out soils and vegetation. Because of this, dry spells last longer than they would in the past decades [66]. The timing of when water is available is also changing due to climate change [63]. Snowmelt, which provides cold water for organisms like salmon, is essential to some ecosystems [67]. Snowmelt, which provides cold water for organisms like salmon, is vital to some ecosystems [68, 69]. Reduced snow cover raises surface temperatures because snow acts as a reflective surface, worsening drought conditions [70]. According to some climate models, warming increases precipitation variability, so more spells of excessive precipitation and drought will occur [71]. In drought years, this necessitates additional water storage, and during periods of exceptionally heavy precipitation, it increases the risk of flooding and dam failure.


Wildfire risk and size have increased in some areas because of climate change [72]. Temperature, soil moisture, and the availability of trees, bushes, and other possible fuel sources are some variables that affect the danger of wildfires [73]. These elements are strongly related to climatic variability and climate change, either directly or indirectly. The likelihood of hot, dry weather, prone to start wildfires, is increasing due to climate change [74]. Numerous research showed that climate change results in warmer and drier situations [75, 76]. These increases in wildfire risk are fueled by increased drought and a more extended fire season. The growth of dangerous insects that can weaken or destroy trees, adding to the fuels in a forest, is another effect of warmer, drier weather [77]. Wildfire risk is also influenced by land use and forest management [36]. As a result of climate change, extreme fire weather conditions, such as increased lightning and strong winds, are now occurring more frequently. In addition to these causes, climate change is predicted to continue to expand the region affected by wildfires [74].

Coastal Erosions

Climate change threatens coastal areas, which are already stressed by human activity, pollution, invasive species, and storms [78]. Sea level rise could erode and inundate coastal ecosystems and eliminate wetlands [79, 80]. Warmer and more acidic oceans are likely to disrupt coastal and marine ecosystems [81]. As cliffs regress or beaches and dunes “migrate,” coastal erosion causes the shoreline to shift landward (change location) [82]. Dunes and salt marshes may completely vanish in some areas, while new depositional features (such as beaches and spits) may develop in other areas [80]. Along with other elements, including variations in sea level, input from rivers, and tectonic activity (movements beneath the earth’s surface), both processes have long formed the shoreline. However, the shoreline’s tendency to shift inland frequently creates issues for human endeavours because it puts the roads, structures, and other coastal infrastructure at risk that support transit, agriculture, and the fishing industries [83]. Additionally, it might cause a change in habitat (e.g., through the loss of areas of marsh, lagoons, or sand dunes) [84].

Indirect Impacts of Climate Change

An increase in food and water insecurity, particularly in developing nations, is one of the indirect effects of climate change that directly affects us humans and our environment [85]. Forest fires and floods pose a hazard to people’s lives, health hazards brought on by a rise in the frequency and severity of heatwaves or economic effects of dealing with climate change-related secondary damage and related migration could also be counted among the indirect impacts of climate change [86, 87]. Also, the loss of biodiversity as a result of poor adaptation to the rapidity of flora and fauna, ocean acidification brought on by rising bicarbonate (HCO3) levels in the water as a result of rising CO2 levels and the necessity of adaptation in every context (e.g., agriculture, forestry, energy, infrastructure, tourism, etc.) could be considered as indirect impacts of climate change [88-90].

4.3. Climate Change Mitigation and Adaptation

Anticipating the adverse effects of climate change and acting appropriately to prevent or minimize the harm they can bring, or seizing opportunities that may present themselves, is what adaptation means [91]. Examples of adaptation strategies include extensive infrastructure modifications, such as the construction of sea-level rise fortifications, and behavioural changes, such as people cutting back on food waste [92]. Adjusting to the present and future effects of climate change can be viewed as the essence of adaptation [92]. By preventing or limiting the production of greenhouse gases (GHG) into the atmosphere, mitigation refers to lessening the severity of the effects of climate change [93, 94]. Mitigation can be accomplished by either reducing the sources of these gases, such as by increasing the proportion of renewable energies or implementing a cleaner transportation system or by improving the storage of these gases, such as by expanding forests [95]. In a nutshell, mitigation is human action that lowers GHG emission sources and improves sinks. Mitigating climate change entails preventing and reducing emissions of heat-trapping greenhouse gases into the atmosphere to prevent the planet from experiencing increasingly harsh temperatures [96]. While neither adaptation nor mitigation measures can completely halt the effects of climate change, they can greatly lower risks when implemented together. While adaptation is crucial to lowering such losses, mitigation is essential to reducing the irreversible losses brought on by climate change.

Adaptation and mitigation can be addressed with a single set of policies and procedures [97]. For instance, the likelihood of localized flooding in metropolitan areas may increase due to the expected increasing frequency and intensity of rainstorms due to climate change [98]. Governments can take the step of planting street trees to lessen stormwater runoff (adaptation) and boost carbon storage (mitigation) [99]. In other situations, there can be a contradiction between the goals of adaptation and mitigation that can only be resolved within a larger framework of community priorities and risk tolerance.

Mitigating Strategies

Mitigation strategies include retrofitting buildings to make them more energy efficient; adopting renewable energy sources like solar, wind, and small hydro; helping cities develop more sustainable transport such as bus rapid transit, electric vehicles, and biofuels; and promoting more sustainable uses of land and forests [21, 100]. The mitigation strategies can include:

enhancing energy efficiency and choosing renewable energy sources over fossil fuels [101, 102],

encouraging the use of public transportation and sustainable mobility by increasing the number of bicycle trips inside cities, decreasing the number of flights, and increasing the use of trains and shared vehicles [103, 104],

promoting the 3Rs rule, sustainable food production, ecological industry, agriculture, fishing, and animal farming (reduce, reuse, recycle) [105],

through levying fees on carbon markets and the consumption of fossil fuels [106].

Adaptive Strategies

To adapt means to modify the current or predicted future environment. The objective is to lessen our susceptibility to the negative impacts of climate change (like sea-level encroachment, more intense extreme weather events or food insecurity) [107, 108]. Adaptation strategies can include:

developing more sustainable and secure structures and infrastructure [109],

planting new trees and mending ecosystems [110, 111],

crop diversification will improve their ability to respond to climate change [112, 113],

investigating and creating novel ways to control and avert natural disasters [114],

creating plans of action for climate emergencies [115].
Figure 4 Goes Here
Figure 4. Mitigative and adaptive strategies.
4.4. Climate Change and Human Health

As mentioned in the above sections, the impacts of climate change include warming temperatures, changes in precipitation, increases in the frequency or intensity of extreme weather events, and rising sea levels [116, 117]. These impacts threaten our health by affecting the food we eat, the water we drink, the air we breathe, and the weather we experience [118, 119]. The disruption of food systems, rise in zoonoses and food-, water-, and vector-borne diseases, as well as mental health problems are all already effects of climate change on health. Extreme weather events like heatwaves, storms, and floods are among the many ways that climate change is already having an impact on health [61, 120]. Human health consequences of climate change include:

respiratory diseases [121-123],

cancer [124-126],

cardiovascular disease and stroke [127, 128],

mortality and morbidity affected by weather [129, 130],

nutritional issues and foodborne illnesses [131, 132],

heat-related morbidity and mortality [133],

mental health and stress-related disorders [134-136],

vectorborne and zoonotic diseases [137],

waterborne diseases [43, 133, 138].

Respiratory Diseases

Increased human exposure to pollen (due to altered growing seasons), mold (due to extreme or more frequent precipitation), air pollution, and aerosolized marine toxins (due to increased temperature, coastal runoff, and humidity), as well as dust, may lead to an increase in respiratory allergies and diseases (from droughts) [86, 139]. Adaptation and mitigation strategies may significantly reduce these hazards. It is clear that there is a connection between the composition of air pollutant mixes and climate change (e.g., how changed pollen counts and other climate change effects affect the severity of asthma) [140, 141]. Such methods help scientists evaluate illness risks, and as a result, they are a crucial part of creating effective risk communication and directing the messaging to at-risk groups.

Cardiovascular Diseases and Stroke

Climate change may exacerbate already existing cardiovascular disease by increasing heat stress, raising the body load of airborne particles, and altering the distribution of zoonotic vectors that transmit infectious diseases associated with cardiovascular disease [142, 143]. This new knowledge should be applied to developing health risk assessment models, early warning systems, health communication strategies aimed at vulnerable populations, land-use decisions, and strategies to meet air quality goals related to climate change [12, 142]. The science that addresses the cardiovascular effects of higher temperatures, heat waves, extreme weather, and changes in air quality on health is required. In some regions, the risks of cardiovascular disease and stroke brought on by climate change may be lessened by the air pollution decreases brought on by climate change mitigation [21].

Weather-Related Morbidity and Mortality

Increases in the frequency and severity of extreme weather events like hurricanes, floods, droughts, and wildfires could negatively impact people’s health during and after the events [49]. To make sure that risks are understood, and that ideal measures are created, communicated, and executed, research is required to enhance the capacity of healthcare and emergency services to address disaster planning and management [144, 145]. Climate change is projected to increase heat and cold-related illnesses and fatalities. However, proactive public health measures like heat wave response plans and health alert warning systems can reduce morbidity and mortality [144, 146]. By defining environmental risk factors, identifying susceptible people, and creating efficient risk communication and prevention measures, other science should concentrate on developing and expanding these tools in various geographic regions [49, 147-149]. Heat exposure can aggravate a variety of medical issues in addition to causing heat exhaustion and heat stroke [150]. Extreme heat increases morbidity and death in vulnerable groups, including the elderly, children, outdoor workers, some racial and ethnic groupings, those with chronic illnesses, and those who are socially or physically isolated. In addition to the outside temperature, air pollution, high humidity, and a lack of air conditioning all contribute to the health risks associated with the heat [151].


The environmental effects of carbon emissions and climate change may result in a rise in cancer mortality rates, disturbances in cancer treatment, and an increase in cancer risk [152]. Although there are many known direct consequences of climate change on cancer risks, such as increased ultraviolet (UV) radiation duration and intensity, future research is needed to determine whether there may also be indirect effects on chemical and toxin exposure pathways [124-126, 153]. Advanced health and environmental research are required advantages of alternative fuels, new battery and voltaic cell technologies, and other technologies, as well as potential negative risks from exposure to their components and wastes. This will allow the best strategies to be developed and implemented [154].

Food-borne Disease and Nutrition

Malnutrition, food contamination, and shortages of staple foods may all be correlated with climate change [155]. There is a need for scientific study in this area to identify and map complex food webs and sentinel species that may be vulnerable to climate change, as well as to understand better how changes in agriculture and fisheries may affect food supply and nutrition [62]. This investigation could be utilized to design more efficient outreach to impacted areas and prepare the public health and healthcare sectors for new diseases, evolving monitoring requirements, rising disease incidence, and more [156]. Undernutrition during pregnancy and the early years of life brought on by scarcities in food supplies and exposure to harmful pollutants and biotoxins as a result of severe weather events, increased use of pesticides in agricultural production, and an increase in toxic algal blooms in public areas are all possible effects of climate change that would have an impact on how humans usually develop [157]. Future health research should examine the relationship between human development and climate change adaptations, including changes to agriculture and fisheries that may affect food availability, increased pesticide use to combat spreading disease vector ranges, and prevention of toxic waste sites leaching into floodwaters during extreme weather events, to avoid adverse developmental effects [158, 159].

Mental Health and Stress Disorders

Climate change may cause or contribute to extreme weather events, leading to population displacement (migration, relocation), property damage, loss of loved ones, and chronic stress, all of which can be detrimental to mental health (Figure 5) [135, 160]. To help assure the provision of proper health care support, research is needed to identify significant mental health consequences, vulnerable groups, and migration monitoring networks [161-163]. The prevalence of neurological problems and diseases in humans may arise due to climate change, as well as mitigation and adaptation measures [32, 163]. Acknowledging the processes and effects of human exposure to neurological hazards such as metals (found in new battery technologies and compact fluorescent lights), pesticides (used in response to changes in agriculture), harmful algal blooms, and biotoxins (from harmful algal blooms), as well as the potential exacerbating effects of malnutrition and stress, is crucial [164]. Vulnerable populations to mental health burdens include Indigenous peoples, women, children, and older adults [165].

Vectorborne and Zoonotic Diseases

Warmer temperatures, up to an optimal temperature over which transmission decreases, accelerate the transmission of vector-borne diseases [166]. Varying mosquitoes have different temperature tolerances, much as they do in terms of the diseases they transmit [167]. For example, dengue fever and the Zika virus danger will arise when global temperatures and weather patterns change as a result of climate change [168]. Due to linked expansions in vector ranges, shortened incubation times for pathogens, and disruption and movement of sizable human populations, disease risk may rise due to climate change [137]. Improving the infrastructure for controlling pathogens and their vectors, including the identification of vectors and hosts, the integration of human and other terrestrial and aquatic animal health surveillance systems, the use of ecological studies to improve predictive models, and the strategies for risk communication and prevention must be prioritized by environmental and health researchers [169].

Waterborne Diseases

Water-borne infections will probably increase in frequency as climate change continues. This is due to an increase in precipitation, storm surges, and sea temperatures brought on by climate change [170]. These environmental variables can cause runoff and flooding, which spreads disease agents, pollutants, and sewage. The likelihood of water contamination with dangerous pathogens and chemicals, leading to greater human exposure, could increase as a result of increases in water temperature, precipitation frequency and intensity, evaporation-transpiration rates, and changes in the health of coastal ecosystems [44, 171]. What food sources may become contaminated, where changes in water flow will occur, how water will interact with sewage in surface and underground water supplies as well as drinking water distribution systems, where changes in water flow will happen, and how to better predict and prevent human exposure to waterborne and ocean-related pathogens and biotoxins should all be the focus of future research [138, 172].waterborne and ocean-related pathogens and biotoxins should all be the focus of future research [138, 172].
Figure 5. Goes Here
Figure 5. Health impacts of climate change.

In addition to the research needs identified in the individual research categories, there are cross-cutting issues relevant to preventing or avoiding many of the potential health impacts of climate change, including identifying susceptible, vulnerable, underrepresented, and displaced populations [173]; enhancing public health and health care infrastructure; developing capacities and skills in modeling and prediction; and improving risk communication and public health education [164, 174]. Such research will lead to more effective early warning systems and greater public awareness of an individual’s or community’s health risk from climate change, which should translate into more successful mitigation and adaptation strategies [175-177]. For example, health communications research is needed to properly implement health alert warning systems for extreme heat events and air pollution that primarily affect people with existing conditions such as cardiovascular disease [178-181]. Such risk communication pilot project might demonstrate effective communication practices in multiple areas and contribute to a comprehensive strategy for addressing various health risks simultaneously with different populations and in different regions. For example, health communications research is needed to properly implement health alert warning systems for extreme heat events and air pollution that primarily affect people with existing conditions such as cardiovascular disease [178-181]. Such risk communication pilot project might demonstrate effective communication practices in multiple areas and contribute to a comprehensive strategy for addressing various health risks simultaneously with different populations and in different regions.

Page Break


This chapter briefly introduced the concept of climate change, how it is brought about, and its consequences. In addition, the chapter discussed contexts for mitigation and adaptation and provided examples of mitigation and adaptation approaches. The primary focus of this chapter was on the relationship between climate change and human health because these links are evident. The risks associated with climate change to the population’s mental and physical health should be further investigated. Although climate change has an influence on human health, it is still difficult to predict the scope and severity of many climate-sensitive health hazards. But as science progresses, we can increasingly link an uptick in sickness and mortality to human-caused global warming and assess the severity of these health problems more precisely. The sensitivity of individuals, their resilience to the current rate of climate change, and the breadth and pace of adaptation will all significantly impact the health implications of climate change. The environmental impacts of climate change will become more severe, frequent, and intense in the future. The long-term outcomes will have a more significant impact on how far-reaching action is taken now to decrease emissions and stop the breaching of dangerous temperature thresholds and possibly irreversible tipping points. Interdisciplinary research should be conducted in these areas, emphasizing how government policy is implemented to lessen the danger of climate change.

References included in Back Matter


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