The effects on public health of climate change adaptation responses: a systematic review of evidence from low- and middle-income countries

Climate change adaptation responses are being developed and delivered in many parts of the world in the absence of detailed knowledge of their effects on public health. Here we present the results of a systematic review of peer-reviewed literature reporting the effects on health of climate change adaptation responses in low- and middle-income countries (LMICs). The review used the 'Global Adaptation Mapping Initiative' database (comprising 1682 publications related to climate change adaptation responses) that was constructed through systematic literature searches in Scopus, Web of Science and Google Scholar (2013–2020). For this study, further screening was performed to identify studies from LMICs reporting the effects on human health of climate change adaptation responses. Studies were categorised by study design and data were extracted on geographic region, population under investigation, type of adaptation response and reported health effects. The review identified 99 studies (1117 reported outcomes), reporting evidence from 66 LMICs. Only two studies were ex ante formal evaluations of climate change adaptation responses. Papers reported adaptation responses related to flooding, rainfall, drought and extreme heat, predominantly through behaviour change, and infrastructural and technological improvements. Reported (direct and intermediate) health outcomes included reduction in infectious disease incidence, improved access to water/sanitation and improved food security. All-cause mortality was rarely reported, and no papers were identified reporting on maternal and child health. Reported maladaptations were predominantly related to widening of inequalities and unforeseen co-harms. Reporting and publication-bias seems likely with only 3.5% of all 1117 health outcomes reported to be negative. Our review identified some evidence that climate change adaptation responses may have benefits for human health but the overall paucity of evidence is concerning and represents a major missed opportunity for learning. There is an urgent need for greater focus on the funding, design, evaluation and standardised reporting of the effects on health of climate change adaptation responses to enable evidence-based policy action

Potential impact on prevalence of obesity in the UK of a 20% price increase in high sugar snacks: modelling study

OBJECTIVE:To estimate the potential impact on body mass index (BMI) and prevalence of obesity of a 20% price increase in high sugar snacks. DESIGN:Modelling study. SETTING:General adult population of the United Kingdom. PARTICIPANTS:36 324 households with data on product level household expenditure from UK Kantar FMCG (fast moving consumer goods) panel for January 2012 to December 2013. Data were used to estimate changes in energy (kcal, 1 kcal=4.18 kJ=0.00418 MJ) purchase associated with a 20% price increase in high sugar snacks. Data for 2544 adults from waves 5 to 8 of the National Diet and Nutrition Survey (2012-16) were used to estimate resulting changes in BMI and prevalence of obesity. MAIN OUTCOME MEASURES:The effect on per person take home energy purchases of a 20% price increase for three categories of high sugar snacks: confectionery (including chocolate), biscuits, and cakes. Health outcomes resulting from the price increase were measured as changes in weight, BMI (not overweight (BMI <25), overweight (BMI ≥25 and <30), and obese (BMI ≥30)), and prevalence of obesity. Results were stratified by household income and BMI. RESULTS:For income groups combined, the average reduction in energy consumption for a 20% price increase in high sugar snacks was estimated to be 8.9×103 kcal (95% confidence interval -13.1×103 to -4.2×103 kcal). Using a static weight loss model, BMI was estimated to decrease by 0.53 (95% confidence interval -1.01 to -0.06) on average across all categories and income groups. This change could reduce the UK prevalence of obesity by 2.7 percentage points (95% confidence interval -3.7 to -1.7 percentage points) after one year. The impact of a 20% price increase in high sugar snacks on energy purchase was largest in low income households classified as obese and smallest in high income households classified as not overweight. CONCLUSIONS:Increasing the price of high sugar snacks by 20% could reduce energy intake, BMI, and prevalence of obesity. This finding was in a UK context and was double that modelled for a similar price increase in sugar sweetened beverages

The effects of crop diversity and crop species on biological diversity in agricultural landscapes: a systematic review protocol [version 1; peer review: 1 approved, 2 approved with reservations]

Agricultural intensification is a well-known driver of biodiversity loss. Diversity of crop production over space and time reduces land use intensity and may mitigate impacts on biodiversity while contributing to growing demand for human food and nutrition resources. Crop species are also known to have independent impacts on biodiversity. To date, reviews synthesising our knowledge of crop species and crop diversity-biodiversity links are missing. We will therefore conduct a systematic review by searching multiple agriculture, ecology and environmental science databases (e.g. Web of Science, Geobase, Agris, AGRICOLA, GreenFILE) to identify studies reporting the impacts of crop diversity and crop species on the biological diversity of fauna, flora and microbes in agricultural landscapes. Outcomes will include metrics of species richness, abundance, assemblage, community composition and species rarity. Screening, data coding and data extraction will be carried out by one reviewer and a proportion will be independently conducted by a second reviewer. Study quality and risk of bias will be assessed. Evidence will first be mapped by species/taxa then assessed for further narrative or statistical synthesis based on comparability of results and likely robustness. Gaps in the evidence base will also be identified with a view toward future research and policy directions for nutrition, food systems and ecology

The effects of crop diversity and crop type on biological diversity in agricultural landscapes: a systematic review protocol [version 2; peer review: 1 approved, 2 approved with reservations]

Agricultural intensification is a well-known driver of biodiversity loss. Crop diversity and its changes over space and time drive land use intensity and impact biodiversity of agricultural landscapes, while meeting the growing demand for human food and nutrition resources. Loss of biodiversity in agricultural landscapes reduces primary productivity and soil health and erodes a range of other ecosystem services. At present, while having partial understanding of many processes, we lack a general synthesis of our knowledge of the links between crop diversity and biodiversity. We will therefore conduct a systematic review by searching multiple agriculture, ecology and environmental science databases (e.g. Web of Science, Geobase, Agris, AGRICOLA, GreenFILE) to identify studies reporting the impacts of crop diversity and crop type on the biological diversity of fauna and flora in agricultural landscapes. Response variables will include metrics of species richness, abundance, assemblage, community composition and species rarity. Screening, data coding and data extraction will be carried out by one researcher and a subset will be independently carried out by a second researcher for quality control. Study quality and risk of bias will be assessed. Evidence will first be mapped to species/taxa then assessed for further narrative or statistical synthesis based on comparability of results and likely robustness. Gaps in the evidence base will also be identified with a view toward future research and policy directions for nutrition, food systems and ecology

Trading water: virtual water flows through interstate cereal trade in India

Cereals are an important component of the Indian diet, providing 47% of the daily dietary energy intake. Dwindling groundwater reserves in India especially in major cereal-growing regions are an increasing challenge to national food supply. An improved understanding of interstate cereal trade can help to identify potential risks to national food security. Here, we quantify the trade between Indian states of five major cereals and the associated trade in virtual (or embedded) water. To do this, we modelled interstate trade of cereals using Indian government data on supply and demand; calculated virtual water use of domestic cereal production using state- and product-specific water footprints and state-level data on irrigation source; and incorporated virtual water used in the production of internationally-imported cereals using country-specific water footprints. We estimate that 40% (94 million tonnes) of total cereal food supply was traded between Indian states in 2011–12, corresponding to a trade of 54.0 km3 of embedded blue water, and 99.4 km3 of embedded green water. Of the cereals traded within India, 41% were produced in states with over-exploited groundwater reserves (defined according to the Central Ground Water Board) and a further 21% in states with critically depleting groundwater reserves. Our analysis indicates a high dependency of Indian cereal consumption on production in states with stressed groundwater reserves. Substantial changes in agricultural practices and land use may be required to secure future production, trade and availability of cereals in India. Diversifying production systems could increase the resilience of India's food system