Bibliography

This bibliography is still a work in progress.  Below are over 1200 references compiled from multiple different sources. We plan to remove some that are only tangentially related to planetary health and then constantly update them via a combination of automated searches followed by evaluation by a staff member of the PHA for relevance. The bibliography will be searchable by topic, author, or date to facilitate quick capture of relevant literature for a particular project or question. 

If you are aware of a reference related to planetary health that you have noticed is missing, please bring it to our attention. Contact: pha@harvard.edu.

Bell MD, Phelan J, Blett TF, Landers D, Nahlik AM, Houtven GV, Davis C, Clark CM, Hewitt J. A framework to quantify the strength of ecological links between an environmental stressor and final ecosystem services . Ecosphere [Internet]. 2017;8 (5). Publisher's VersionAbstract

Anthropogenic stressors such as climate change, increased fire frequency, and pollution drive shifts in ecosystem function and resilience. Scientists generally rely on biological indicators of these stressors to signal that ecosystem conditions have been altered. However, these biological indicators are not always capable of being directly related to ecosystem components that provide benefits to humans and/or can be used to evaluate the cost-benefit of a change in health of the component (ecosystem services). Therefore, we developed the STEPS (Stressor–Ecological Production function–final ecosystem Services) Framework to link changes in a biological indicator of a stressor to final ecosystem services. The STEPS Framework produces “chains” of ecological components that explore the breadth of impacts resulting from the change in a stressor. Chains are comprised of the biological indicator, the ecological production function (EPF, which uses ecological components to link the biological indicator to a final ecosystem service), and the user group who directly uses, appreciates, or values the component. The framework uses a qualitative score (high, medium, low) to describe the strength of science (SOS) for the relationship between each component in the EPF. We tested the STEPS Framework within a workshop setting using the exceedance of critical loads of air pollution as a model stressor and the Final Ecosystem Goods and Services Classification System (FEGS-CS) to describe final ecosystem services. We identified chains for four modes of ecological response to deposition: aquatic acidification, aquatic eutrophication, terrestrial acidification, and terrestrial eutrophication. The workshop participants identified 183 unique EPFs linking a change in a biological indicator to a FEGS; when accounting for the multiple beneficiaries, we ended with 1104 chains. The SOS scores were effective in identifying chains with the highest confidence ranking as well as those where more research is needed. The STEPS Framework could be adapted to any system in which a stressor is modifying a biological component. The results of the analysis can be used by the social science community to apply valuation measures to multiple or selected chains, providing a comprehensive analysis of the effects of anthropogenic stressors on measures of human well-being.

Guerra CA, Snow RW, Hay SI. A global assessment of closed forests, deforestation and malaria risk. Ann Trop Med Parasitol [Internet]. 2006;100 :189-204. Publisher's VersionAbstract

Global environmental change is expected to affect profoundly the transmission of the parasites that cause human malaria. Amongst the anthropogenic drivers of change, deforestation is arguably the most conspicuous, and its rate is projected to increase in the coming decades. The canonical epidemiological understanding is that deforestation increases malaria risk in Africa and the Americas and diminishes it in South-east Asia. Partial support for this position is provided here, through a systematic review of the published literature on deforestation, malaria and the relevant vector bionomics. By using recently updated boundaries for the spatial limits of malaria and remotely-sensed estimates of tree cover, it has been possible to determine the population at risk of malaria in closed forest, at least for those malaria-endemic countries that lie within the main blocks of tropical forest. Closed forests within areas of malaria risk cover approximately 1.5 million km2 in the Amazon region, 1.4 million km2 in Central Africa, 1.2 million km2 in the Western Pacific, and 0.7 million km2 in South-east Asia. The corresponding human populations at risk of malaria within these forests total 11.7 million, 18.7 million, 35.1 million and 70.1 million, respectively. By coupling these numbers with the country-specific rates of deforestation, it has been possible to rank malaria-endemic countries according to their potential for change in the population at risk of malaria, as the result of deforestation. The on-going research aimed at evaluating these relationships more quantitatively, through the Malaria Atlas Project (MAP), is highlighted.

Oldekop JA, Holmes G, Harris WE, Evans KL. A Global Assessment of the Social and Conservation Outcomes of Protected Areas. Conservation Biology [Internet]. 2015. Publisher's VersionAbstract

Protected areas (PAs) are a key strategy for protecting biological resources, but they vary considerably in their effectiveness, and are frequently reported as having negative impacts on local people. This has contributed to a divisive and unresolved debate concerning the compatibility of environmental and socioeconomic development goals. Elucidating the relationship between positive and negative social impacts and conservation outcomes of PAs is key for the development of more effective and socially just conservation. Here, we conduct a global analysis of how PAs affect the wellbeing of local people, the factors associated with these impacts, and crucially the relationship between PAs’ conservation and socioeconomic outcomes. Our results show that PAs reporting positive socioeconomic outcomes are more likely to report positive conservation outcomes. We find positive conservation and socioeconomic outcomes are more likely to occur when PAs adopt co-management regimes, empower local people, reduce economic inequalities and maintain cultural and livelihood benefits. While the strictest regimes of PA management attempt to exclude anthropogenic influences to achieve biological conservation objectives, our study provides evidence that PAs that explicitly integrate local people as stakeholders tend to be more effective at achieving joint biological conservation and socioeconomic development outcomes. Strict protection may be needed in some circumstances, yet our results demonstrate that conservation and development objectives can be synergistic and highlight management strategies that increase the probability of achieving win-win scenarios that maximize conservation performance and development outcomes of PAs. 

Patz JA. A Human Disease Indicator for the Effects of Recent Global Climate Change. Proc Natl Acad Sci [Internet]. 2002;99 :12506-12508. Publisher's VersionAbstract

With new concerns about global warming, accompanied by greater climate variability, recent studies have focused on disease fluctuations related to shortterm or inter-annual climate oscillations (e.g., from weather extremes driven by El Niño). The question remains as to whether or not there has been any documented change in human disease trends in response to long-term climate change, since warming has already occurred over the last century. This study provides evidence that warming trends over the last century are affecting human disease. This summary is not an official abstract. Users should refer to the original published version of the material for the full abstract

Miller LV, Krebs NF, Hambidge MK. A mathematical model of zinc absorption in humans as a function of dietary zinc and phytate. The Journal of Nutrition [Internet]. 2007;137 :135-141. Publisher's VersionAbstract

The quantities of zinc and phytate in the diet are the primary factors determining zinc absorption. A mathematical model of zinc absorption as a function of dietary zinc and phytate can be used to predict dietary zinc requirements and, potentially, enhance our understanding of zinc absorption. Our goal was to develop a model of practical and informative value based on fundamental knowledge of the zinc absorption process and then fit the model to selected published data to assess its validity and estimate parameter values. A model of moderate mathematical complexity relating total zinc absorption to total dietary zinc and total dietary phytate was derived and fit to 21 mean data from whole day absorption studies using nonlinear regression analysis. Model validity, goodness of fit, satisfaction of regression assumptions, and quality of the parameter estimates were evaluated using standard statistical criteria. The fit had an R(2) of 0.82. The residuals were found to exhibit a normal distribution, constant variance, and independence. The parameters of the model, A(MAX), K(R), and K(P), were estimated to have values of 0.13, 0.10, and 1.2 mmol/d, respectively. Several of these estimates had wide CI attributable in part to the small number and the scatter of the data. The model was judged to be valid and of immediate value for studying and predicting absorption. A version of the model incorporating a passive absorption mechanism was not supported by the available data.

Winfree R, Aguilar R, Vázquez DP, LeBuhn G, Aizen MA. A meta-analysis of bees' responses to anthropogenic disturbance. Ecology [Internet]. 2009;90 (8) :2068-76. Publisher's VersionAbstract

Pollinators may be declining globally, a matter of concern because animal pollination is required by most of the world's plant species, including many crop plants. Human land use and the loss of native habitats is thought to be an important driver of decline for wild, native pollinators, yet the findings of published studies on this topic have never been quantitatively synthesized. Here we use meta-analysis to synthesize the literature on how bees, the most important group of pollinators, are affected by human disturbances such as habitat loss, grazing, logging, and agriculture. We obtained 130 effect sizes from 54 published studies recording bee abundance and/or species richness as a function of human disturbance. Both bee abundance and species richness were significantly, negatively affected by disturbance. However, the magnitude of the effects was not large. Furthermore, the only disturbance type showing a significant negative effect, habitat loss and fragmentation, was statistically significant only in systems where very little natural habitat remains. Therefore, it would be premature to draw conclusions about habitat loss having caused global pollinator decline without first assessing the extent to which the existing studies represent the status of global ecosystems. Future pollinator declines seem likely given forecasts of increasing land-use change.

Challinor AJ, Watson J, Lobell DB, Howden SM, Smith DR, Chhetri N. A meta-analysis of crop yield under climate change and adaptation. Nature Climate Change [Internet]. 2014;4 (4) :287-291. Publisher's VersionAbstract

Feeding a growing global population in a changing climate presents a significant challenge to society(1,2). The projected yields of crops under a range of agricultural and climatic scenarios are needed to assess food security prospects. Previous meta-analyses(3) have summarized climate change impacts and adaptive potential as a function of temperature, but have not examined uncertainty, the timing of impacts, or the quantitative effectiveness of adaptation. Here we develop a new data set of more than 1,700 published simulations to evaluate yield impacts of climate change and adaptation. Without adaptation, losses in aggregate production are expected for wheat, rice and maize in both temperate and tropical regions by 2 degrees C of local warming. Crop-level adaptations increase simulated yields by an average of 7-15%, with adaptations more effective for wheat and rice than maize. Yield losses are greater in magnitude for the second half of the century than for the first. Consensus on yield decreases in the second half of the century is stronger in tropical than temperate regions, yet even moderate warming may reduce temperate crop yields in many locations. Although less is known about interannual variability than mean yields, the available data indicate that increases in yield variability are likely.

Curtis PS, Wang X. A meta-analysis of elevated CO2 effects on woody plant mass, form, and physiology. Oecologia [Internet]. 1998;113 :299-313. Publisher's VersionAbstract

Quantitative integration of the literature on the effect of elevated CO2 on woody plants is important to aid our understanding of forest health in coming decades and to better predict terrestrial feedbacks on the global carbon cycle. We used meta-analytic methods to summarize and interpret more than 500 reports of effects of elevated CO2 on woody plant biomass accumulation and partitioning, gas exchange, and leaf nitrogen and starch content. The CO2 effect size metric we used was the log-transformed ratio of elevated compared to ambient response means weighted by the inverse of the variance of the log ratio. Variation in effect size among studies was partitioned according to the presence of interacting stress factors, length of CO2 exposure, functional group status, pot size, and type of CO2 exposure facility. Both total biomass (W T) and net CO2assimilation (A) increased significantly at about twice ambient CO2, regardless of growth conditions. Low soil nutrient availability reduced the CO2 stimulation of W T by half, from +31% under optimal conditions to +16%, while low light increased the response to +52%. We found no significant shifts in biomass allocation under high CO2. Interacting stress factors had no effect on the magnitude of responses of A to CO2, although plants grown in growth chambers had significantly lower responses (+19%) than those grown in greenhouses or in open-top chambers (+54%). We found no consistent evidence for photosynthetic acclimation to CO2 enrichment except in trees grown in pots <0.5 l (−36%) and no significant CO2 effect on stomatal conductance. Both leaf dark respiration and leaf nitrogen were significantly reduced under elevated CO2 (−18% and −16% respectively, data expressed on a leaf mass basis), while leaf starch content increased significantly except in low nutrient grown gymnosperms. Our results provide robust, statistically defensible estimates of elevated CO2 effect sizes against which new results may be compared or for use in forest and climate model parameterization.

Feng Z, Kobayashi K, Wang X. A meta-analysis of responses of wheat yield formation to elevated ozone concentration. Chinese Science Bulletin [Internet]. 2009;54 (2) :249-255. Publisher's VersionAbstract

The meta-analysis method was applied to quantitatively investigate effects of the elevated ozone concentration ([O-3]) on chlorophyll concentration, gas exchange and yield components of wheat. There were 39 effective references through Web of Science (ISI, USA) and Chinese journal full-text database (CNKI, China). The results of meta-analysis indicated that elevated [O-3] decreased grain yield, grain weight, grain number per ear, ear number per plant and harvest index by 26%, 18%, 11%, 5% and 11%, respectively, relative to ambient air. The decrease in leaf physiological characters was much greater than that in yield when wheat was expose to elevated [O-3], while light-saturated photosynthetic rate (Asat), stomatal conductance (Gs) and chlorophyll content (Chl) decreased by 40%, 31%, and 46%, respectively. The responses to elevated [O-3] between spring wheat and winter wheat were similar. Most of the variables showed a linear decrease trend with an increase of [O-3]. The most significant decrease for Asat, Gs and Chl was found in grain filling stage. Elevated [CO2] could significantly ameliorated or offset the detrimental effects caused by elevated [O-3].