Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (727 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
Calamities producing great damage, loss of life, and distress. They include results of natural phenomena and man-made phenomena. Normal conditions of existence are disrupted and the level of impact exceeds the capacity of the hazard-affected community.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Where it fits in the MeSH classification
- Broader topics
- Environment
- Narrower topics
- Disaster Planning; Emergencies; Emergency Shelter; Mass Casualty Incidents; Medical Countermeasures; Natural Disasters; Relief Work; Rescue Work
- See also
- Relief Work
Research landscape
PubMed indexes 126,082 records tagged with the MeSH heading “Disasters” (counts retrieved 2026-10-31). 32,123 of them (25.5%) were published from 2020 onward, and the busiest period so far is 2010-2019 with 38,900 records.
Reviews account for 12,909 records (10.2%) and meta-analyses for 445. Randomized controlled trials number 939 (0.7%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 31,340 |
| 2000-2009 | 23,719 |
| 2010-2019 | 38,900 |
| 2020 onward | 32,123 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 12,909 | 10.2% |
| Meta-analyses | 445 | 0.4% |
| Randomized controlled trials | 939 | 0.7% |
Method: PubMed query "Disasters"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-31.
Reading the evidence in public health and nutrition
Population and nutrition studies mostly observe what people eat, breathe or are exposed to and then look for links with health, which shows association and not proof of cause. Self-reported diet is imprecise, people who eat or live differently also differ in other ways, and effects measured across a population may not apply to one person. Check the study design, how exposure was measured, what else was accounted for and the size of the effect, not only whether it was statistically significant.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Biodiversity effects under climate extremes intensify with aridity in grasslands but not forests | 2026 | Research article Design not recorded in structured metadata | 3 | cc by PMID 42457981 · DOI · PMC13441892 |
| Recent high-severity wildfires in a dry-conifer landscape are unprecedented over five centuries and foretell future forest loss | 2026 | Research article Design not recorded in structured metadata | 2 | cc by PMID 42673462 · DOI · PMC13552868 |
| Cardiopulmonary hospitalization risks from wildfire-specific and non-wildfire PM2.5 in 20 US states | 2026 | Research article Design not recorded in structured metadata | 1 | cc by PMID 42754610 · DOI · PMC13586224 |
| Innovative humanitarian finance: examining the promises and realities of impact bonds in humanitarian and refugee response | 2027 | Research article Design not recorded in structured metadata | 0 | cc by PMID 42946533 · DOI · PMC13713432 |
Biodiversity effects under climate extremes intensify with aridity in grasslands but not forests [1]
Abstract reading summary — source excerpts
- Opening excerpt
- Biodiversity generally enhances ecosystem productivity, but whether such effects persist or intensify during climate extremes is unclear.
- Closing excerpt
- Our synthesis identifies when and where plant diversity most strongly enhances productivity, showing that its effects are the greatest under extreme drought in more arid grasslands.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (156 words)
Biodiversity generally enhances ecosystem productivity, but whether such effects persist or intensify during climate extremes is unclear. Here we synthesized data from 75 biodiversity experiments across grasslands and forests to assess how aridity and soil nutrients modulate plant diversity effects under drought and heat extremes. Biodiversity most strongly enhanced productivity under extreme drought in more arid grasslands but had limited effects in forests under such conditions. More arid grasslands showed enhanced complementarity effects under extreme drought, whereas less arid grasslands favoured selection effects driven by productive species. Heat extremes did not produce comparable context-dependent changes in plant diversity effects across ecosystem types or aridity gradients. Soil nutrients did not have any detectable influence under either drought or heat extremes, suggesting that as climatic stress intensifies, hydric limitations override edaphic constraints. Our synthesis identifies when and where plant diversity most strongly enhances productivity, showing that its effects are the greatest under extreme drought in more arid grasslands.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42457981 · DOI · PMC13441892
Recent high-severity wildfires in a dry-conifer landscape are unprecedented over five centuries and foretell future forest loss [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Dry forests of the western United States evolved with frequent, spatially extensive, low-severity fires, followed by a century of fire exclusion.
- Closing excerpt
- Modern high-severity fire regimes appear incompatible with dry-conifer forest persistence.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (243 words)
Dry forests of the western United States evolved with frequent, spatially extensive, low-severity fires, followed by a century of fire exclusion. Recently, these same forests have experienced large and increasingly severe fires causing widespread forest loss. To what extent do modern high-severity fires depart from pre-1900 fire regimes, and how do these departures affect the future persistence of dry-conifer forests? We address these questions using a multiscalar approach that combines the largest landscape-scale tree-ring fire-scar network in North America with neutral landscape model simulations in the Jemez Mountains of northern New Mexico. Fire scars recorded a continuous 400-y history (ca. 1500-1900 CE) of frequent, low-severity fires across individual sites, landscapes, and centuries. We evaluated whether forests exhibiting this record could plausibly persist if they had historically burned under modern patterns of high-severity fire. Across the 240,000-ha Jemez landscape, high-severity fires from 1995-2024 burned 32% of fire-scar sites and 25% of dry-conifer forests. Within the Las Conchas Fire perimeter-a 61,000 ha area reburned by multiple fires-66% of fire-scar sites and 71% of forests were burned at high severity, erasing multiple centuries of forest and fire history. Simulations indicate that the probability of the observed fire-scar network persisting under modern high-severity fire rates is near-zero (P < 0.001). Projecting these dynamics forward indicates rapid loss of both dry-conifer forests and tree-ring fire histories-50% of modern dry-conifer forest will remain by 2055, and 24% by 2115. Modern high-severity fire regimes appear incompatible with dry-conifer forest persistence.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42673462 · DOI · PMC13552868
Cardiopulmonary hospitalization risks from wildfire-specific and non-wildfire PM2.5 in 20 US states [3]
Abstract reading summary — source excerpts
- Opening excerpt
- Increasing wildfire activity in the US has made wildfire-specific fine particulate matter (PM2.
- Closing excerpt
- 5, underscoring wildfire smoke as a growing public health threat that requires targeted mitigation alongside conventional air quality control strategies.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (177 words)
Increasing wildfire activity in the US has made wildfire-specific fine particulate matter (PM2.5) an important and growing source of air pollution, yet its long-term health impacts and relative toxicity compared with non-wildfire PM2.5 remain unclear. Using a self-controlled design, we examine associations between 2-year average wildfire-specific and non-wildfire PM2.5 and cardiopulmonary hospitalization risks across 20 US states during 2006-2019. Per 1 µg/m3 increase, wildfire-specific PM2.5 is associated with significantly higher hospitalization risks for all cardiopulmonary diseases, with relative risks ranging from 10% for heart failure to 16% for asthma. In contrast, a 1-µg/m3 increase in non-wildfire PM2.5 is associated with smaller risk elevations, ranging from 4.7% for chronic obstructive pulmonary disease to 8.5% for hypertension. Stronger associations for both wildfire-specific and non-wildfire PM2.5 are observed among minorities, metropolitan residents, those with fewer years of education, and more deprived communities. Overall, at an equivalent concentration increase, long-term exposure to wildfire-specific PM2.5 poses greater cardiopulmonary hospitalization risks than non-wildfire PM2.5, underscoring wildfire smoke as a growing public health threat that requires targeted mitigation alongside conventional air quality control strategies.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42754610 · DOI · PMC13586224
Innovative humanitarian finance: examining the promises and realities of impact bonds in humanitarian and refugee response [4]
Abstract reading summary — source excerpts
- Opening excerpt
- This article contributes to scholarship on innovative humanitarian finance by examining the application of impact bonds-an outcome-based financing mechanism where investors fund projects upfront and are repaid with interest if they succeed.
- Closing excerpt
- The article therefore underscores the need for a rigorous evaluation of new financing mechanisms before adoption.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (151 words)
This article contributes to scholarship on innovative humanitarian finance by examining the application of impact bonds-an outcome-based financing mechanism where investors fund projects upfront and are repaid with interest if they succeed. Amid consistent funding shortfalls, impact bonds were framed as a radical transformation in how aid can be financed and delivered. By sharing financial risk with investors and linking payment to results, they were meant to attract private capital and enhance aid effectiveness. However, this study reveals a gap between the expectations and realities of impact bonds through case studies of two pilots: the Humanitarian Impact Bond (International Committee of the Red Cross); and the Refugee Impact Bond (Near East Foundation). In practice, impact bonds did not generate additional funds for the humanitarian sector, transfer significant risk to investors, or outperform traditionally financed programmes. The article therefore underscores the need for a rigorous evaluation of new financing mechanisms before adoption.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42946533 · DOI · PMC13713432
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Variable influenza vaccine effectiveness by subtype: a systematic review and meta-analysis of test-negative design studies [5]
- Research article Meta-analysis reveals that hydraulic traits explain cross-species patterns of drought-induced tree mortality across the globe [6]
- Research article Rescuers at risk: a systematic review and meta-regression analysis of the worldwide current prevalence and correlates of PTSD in rescue workers [7]
- Research article Drought effect on plant nitrogen and phosphorus: a meta-analysis [8]
- Research article Psychological impairment in the wake of disaster: the disaster-psychopathology relationship [9]
- Research article The bystander-effect: a meta-analytic review on bystander intervention in dangerous and non-dangerous emergencies [10]
References
- Sasaki T, Hoss D, Huang Y, Iwachido Y, Zheng L, Abdala-Roberts L, et al.. Biodiversity effects under climate extremes intensify with aridity in grasslands but not forests. . 2026. PMID 42457981 · DOI · PMC13441892
- Wion AP, Stevens JT, Coop JD, Farris CA, Parks SA, Allen CD, et al.. Recent high-severity wildfires in a dry-conifer landscape are unprecedented over five centuries and foretell future forest loss. . 2026. PMID 42673462 · DOI · PMC13552868
- Zhang M, Castro E, Qiu M, Danesh Yazdi M, Li B, Wright RJ, et al.. Cardiopulmonary hospitalization risks from wildfire-specific and non-wildfire PM2.5 in 20 US states. . 2026. PMID 42754610 · DOI · PMC13586224
- Zulkaphil L. Innovative humanitarian finance: examining the promises and realities of impact bonds in humanitarian and refugee response. . 2027. PMID 42946533 · DOI · PMC13713432
- Belongia EA, Simpson MD, King JP, Sundaram ME, Kelley NS, Osterholm MT, et al.. Variable influenza vaccine effectiveness by subtype: a systematic review and meta-analysis of test-negative design studies. Lancet Infect Dis. 2016. PMID 27061888 · DOI
- Anderegg WR, Klein T, Bartlett M, Sack L, Pellegrini AF, Choat B, et al.. Meta-analysis reveals that hydraulic traits explain cross-species patterns of drought-induced tree mortality across the globe. Proc Natl Acad Sci U S A. 2016. PMID 27091965 · DOI · PMC4983847
- Berger W, Coutinho ES, Figueira I, Marques-Portella C, Luz MP, Neylan TC, et al.. Rescuers at risk: a systematic review and meta-regression analysis of the worldwide current prevalence and correlates of PTSD in rescue workers. Soc Psychiatry Psychiatr Epidemiol. 2012. PMID 21681455 · DOI · PMC3974968
- He M, Dijkstra FA. Drought effect on plant nitrogen and phosphorus: a meta-analysis. New Phytol. 2014. PMID 25130263 · DOI
- Rubonis AV, Bickman L. Psychological impairment in the wake of disaster: the disaster-psychopathology relationship. Psychol Bull. 1991. PMID 1829536 · DOI
- Fischer P, Krueger JI, Greitemeyer T, Vogrincic C, Kastenmüller A, Frey D, et al.. The bystander-effect: a meta-analytic review on bystander intervention in dangerous and non-dangerous emergencies. Psychol Bull. 2011. PMID 21534650 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-11-04; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-11-04.
See how EvidenceLib is built. Spotted an error? Email support@evidencehelix.com.
Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.