Natural Disasters

Natural disasterNatural disasters, also referred to as natural hazards, are extreme, sudden events caused by environmental factors such as storms, floods, droughts, fires and heatwaves. Natural disasters are now occurring with increasing severity, scope and impact. When we explore natural disasters in the context of planetary health, we are utilizing a systems-thinking approach to grasp the complexities and anthropogenic drivers relating a given disaster to causes and effects. 

Globally, twice as many people were affected by natural disasters in the 1990s vs. in the 1980s, and global annual economic losses from extreme events increased 10-fold over the past four decades. Heat waves, droughts, fires, floods, tropical storms, and other natural disasters pose long-term health consequences. For example, particulate matter from fires reduces air quality and causes morbidity and mortality from cardiorespiratory disease; flooding can cause biological contamination of water supplies, displacement and trauma; more intense coastal storms, combined with sea level rise and loss of coastal barrier systems (mangrove forests, vegetated dunes, coral reefs, and wetlands), generate a “triple threat” for inhabitants of low-lying coastal areas. Survivors of natural disasters face serious, yet poorly understood, physical and mental health impacts. It must be a priority to investigate trends in exposure to natural hazards, which populations are most vulnerable, and effective practices for reducing vulnerability.

Learning Objectives

  • L1: To identify and explain the anthropogenic drivers of increasingly severe natural disasters.
  • L2: To relate the potential direct and indirect impacts of different disasters, assessing the different settings and scales in which they occur.
  • L3: To examine local, regional and global actions that perpetuate or exacerbate disasters and understand the facilitating policy framework.
  • L4: To recognize cross-disciplinary areas for research and innovation in disaster resilience, spanning across the traditionally environmental or medically-focused efforts. 
  •  
  • 1 of 2
  • »
Hikichi H, Sawada Y, Tsuboya T, Aida J, Kondo K, Koyama S, Kawachi I. Residential relocation and change in social capital: A natural experiment from the 2011 Great East Japan Earthquake and Tsunami. Science Advances [Internet]. 2017;3 (7). Publisher's VersionAbstract

Social connections in the community (“social capital”) represent an important source of resilience in the aftermath of major disasters. However, little is known about how residential relocation due to housing destruction affects survivors’ social capital. We examined changes in social capital among survivors of the 2011 Great East Japan Earthquake and Tsunami. People who lost their homes were resettled to new locations by two primary means: (i) group relocation to public temporary trailer housing or (ii) individual relocation, in which victims moved into government-provided housing by lottery or arranged for their own accommodation (market rental housing or private purchase/new construction). The baseline for our natural experiment was established 7 months before the 11 March 2011 disaster, when we conducted a survey of older community-dwelling adults who lived 80-km west of the earthquake epicenter. Approximately 2.5 years after the disaster, the follow-up survey gathered information about personal experiences of disaster as well as health status and social capital. Among 3421 people in our study, 79 people moved via group relocation to public temporary trailer housing, whereas 96 people moved on their own. The individual fixed-effects model showed that group relocation was associated with improved informal socializing and social participation (β coefficient = 0.053, 95% confidence interval: 0.011 to 0.095). In contrast, individual relocation was associated with declining informal socializing and social participation (β coefficient = −0.039, 95% confidence interval: −0.074 to −0.003). Group relocation, as compared to individual relocation, appeared to preserve social participation and informal socializing in the community.

Bodmer R, Mayor P, Antunez M, Chota K, Fang T, Puertas P, Pittet M, Kirkland M, Walkey M, Rios C, et al. Major shifts in amazon wildlife populations from recent climatic intensification. Conservation Biology [Internet]. 2017. Publisher's VersionAbstract

In the western Amazon basin, recent intensification of river level cycles has increased flooding during the wet seasons and decreased precipitation during the dry season. Greater than normal floods occurred in 2009 and in all years from 2011–2015 during high water seasons, and a drought occurred during the 2010 low water season. During these years, we surveyed populations of terrestrial, arboreal and aquatic wildlife in a seasonally flooded Amazonian forest to study the consequences of intensification of climatic fluctuations to wildlife populations and in turn resource use by traditional people. Intensive floods and droughts have recently resulted in shifts in fish and terrestrial mammal populations in flooded forests, a major landscape in western Amazonia that make up 99,780 km2 of the Loreto region in Peru. The intensive floods caused terrestrial mammal populations to decrease by 95% with ungulates, terrestrial rodents and terrestrial edentates having increased mortality because they were forced onto small patches of land during peak flood pulses, and drowning during the historically high floods of 2012 and 2015. In contrast, fish increased and benefited from longer access to inundated forests, resulting in healthy populations of waterfowl, dolphins, otters and caimans. Arboreal species, including, macaws, game birds, primates, felids and other arboreal mammals had stable populations and were not affected directly by high floods. The drought of 2010 had the opposite consequences with decreases in fish, waterfowl and dolphin populations, and stable populations of terrestrial and arboreal species. Ungulates and large rodents are important wildmeat species for local people and their dramatic decline has shifted resource use of people living in the flooded forests with less reliance on hunting and greater use of fish.

Galvani AP, Bauch CT, Anand M, Singer BH, Levin SA. Human–environment interactions in population and ecosystem health. PNAS [Internet]. 2016;113 (51) :14502–14506. Publisher's VersionAbstract

As the global human population continues to grow, so too does our impact on the environment. The ingenuity with which our species has harnessed natural resources to fulfill our needs is dazzling. Even as we tighten our grip on the environment, however, the escalating extent of anthropogenic actions destabilizes long-standing ecological balances (12). The dangers of mining, refining, and fossil fuel consumption now extend beyond occupational or proximate risks to global climate change (3). Among a plethora of environmental problems, extreme climate events are intensifying (45). Storms, droughts, and floods cause direct destruction, but also have pervasive repercussions on food security, infectious disease transmission, and economic stability that take their toll for many years. For example, within weeks of the catastrophic wind and flood damage from the 2016 Hurricane Matthew in Haiti, there was a dramatic surge in cholera, among other devastating repercussions (67). In a world where 1% of the population possesses 50% of the wealth (8), those worst affected by extreme climatic events and the aftermath are also the least able to rebound.

Bronen R. Climate-induced community relocations: using integrated social-ecological assessments to foster adaptation and resilience . Ecology and Society. 2015;20 (3) :36.Abstract

Extreme weather events coupled with sea level rise and erosion will cause coastal and riverine areas where people live and maintain livelihoods to disappear permanently. Adaptation to these environmental changes, including the permanent relocation of millions of people, requires new governance tools. In the USA, local governments, often with state-level and national-level support, will be primarily responsible for protecting residents from climate-change impacts and implementing policies needed to protect their welfare. Government agencies have a variety of tools to facilitate protection in place and managed coastal retreat but have very limited tools to facilitate community relocation. In addition, no institutional mechanism currently exists to determine whether and when preventive relocation needs to occur to protect people from climate change impacts. Based on research involving four Alaska Native communities threatened by climate-induced environmental impacts, I propose the design and implementation of an adaptive governance framework to respond to the need to relocate populations. In this context, adaptive governance means the ability of institutions to dynamically respond to climate change impacts. A component of this adaptive governance framework is a social-ecological monitoring and assessment tool that can facilitate collaborative knowledge production by community residents and governance institutions to guide sustainable adaptation strategies and determine whether and when relocation needs to occur. The framework, including the monitoring and assessment tool, has not been systematically tested. However, the potential use of this tool is discussed by drawing on empirical examples of Alaskan communities faced with accelerating rates of erosion.

Almada AA, Golden CD, Osofsky SA, Myers SS. A case for Planetary Health/Geohealth. GeoHealth [Internet]. 2017;1 (2) :75-78. Publisher's VersionAbstract

Concern has been spreading across scientific disciplines that the pervasive human transformation of Earth's natural systems is an urgent threat to human health. The simultaneous emergence of “GeoHealth” and “Planetary Health” signals recognition that developing a new relationship between humanity and our natural systems is becoming an urgent global health priority—if we are to prevent a backsliding from the past century's great public health gains. Achieving meaningful progress will require collaboration across a broad swath of scientific disciplines as well as with policy makers, natural resource managers, members of faith communities, and movement builders around the world in order to build a rigorous evidence base of scientific understanding as the foundation for more robust policy and resource management decisions that incorporate both environmental and human health outcomes.

Licensing & Fair Use Agreement

All of the content in the collection is licensed for sharing and modification under a Creative Commons license (CC BY 4.0). If you are involved in education on planetary health topics and would like to share teaching materials, please enrich our community! By sharing materials you agree to the terms and conditions outlined in our legal framework. You can share materials here