Mapping the effectiveness of nature-based solutions for climate change adaptation.

Nature-based solutions (NbS) to climate change currently have considerable political traction. However, national intentions to deploy NbS have yet to be fully translated into evidence-based targets and action on the ground. To enable NbS policy and practice to be better informed by science, we produced the first global systematic map of evidence on the effectiveness of nature-based interventions for addressing the impacts of climate change and hydrometeorological hazards on people. Most of the interventions in natural or semi-natural ecosystems were reported to have ameliorated adverse climate impacts. Conversely, interventions involving created ecosystems (e.g., afforestation) were associated with trade-offs; such studies primarily reported reduced soil erosion or increased vegetation cover but lower water availability, although this evidence was geographically restricted. Overall, studies reported more synergies than trade-offs between reduced climate impacts and broader ecological, social, and climate change mitigation outcomes. In addition, nature-based interventions were most often shown to be as effective or more so than alternative interventions for addressing climate impacts. However, there were substantial gaps in the evidence base. Notably, there were few studies of the cost-effectiveness of interventions compared to alternatives and few integrated assessments considering broader social and ecological outcomes. There was also a bias in evidence toward the Global North, despite communities in the Global South being generally more vulnerable to climate impacts. To build resilience to climate change worldwide, it is imperative that we protect and harness the benefits that nature can provide, which can only be done effectively if informed by a strengthened evidence base.

Measles outbreaks in the UK, is it when and where, rather than if? A database cohort study of childhood population susceptibility in Liverpool, UK.

OBJECTIVES: There was a large outbreak of measles in Liverpool, UK, in 2012-2013, despite measles, mumps and rubella (MMR) immunisation uptake rates that were higher than the national average. We estimated measles susceptibility of a cohort of children born in Liverpool between 1995 and 2012 to understand whether there was a change in susceptibility before and after the outbreak and to inform vaccination strategy. DESIGN: Retrospective cohort study. SETTING: The city of Liverpool, North West UK. PARTICIPANTS: All children born in Liverpool (72 101) between 1995 and 2012 inclusive who were identified using the Child Health Information System (CHIS) and were still resident within Liverpool in 2014. PRIMARY AND SECONDARY OUTCOME MEASURES: We estimated cohort age-disaggregated and neighbourhood-disaggregated measles susceptibility according to WHO thresholds before and after the outbreak for children aged 1-17 years. RESULTS: Susceptibility to measles was above WHO elimination thresholds before and after the measles outbreak in the 10+ age group. The proportion of children susceptible before and after outbreak, respectively: age 1-4 years 15.0% before and 14.9% after; age 5-9 years 9.9% before and 7.7% after; age 10+ years 8.6% before and 8.5% after. Despite an intensive MMR immunisation catch-up campaign after the 2012-2013 measles outbreak, the overall proportion of children with no MMR remains high at 6.1% (4390/72 351). Across all age groups and before and after the outbreak, measles susceptibility was clustered by neighbourhood, with deprived areas having the greatest proportion of susceptible children. CONCLUSIONS: The risk of sustained measles outbreaks remains, especially as large pools of susceptible older children will start leaving secondary education and continue to aggregate in higher education, employment and other community settings and institutions resulting in the potential for a propagated measles outbreak.