These positive examples in recent years must not mask the dangerous consequences of failing to meet the Paris Agreement, the past two decades of relative inaction, the economies and sectors currently lagging behind, and the enormity of the task ahead, which leave achieving the Agreement's aims in a precarious position. Indeed, much of the data presented should serve as a wake-up call to national governments, businesses, civil society, and the health profession. However, as this report demonstrates, the world has already begun to embark on a path to a lowcarbon and healthier world. Whilst the pace of action must greatly accelerate, the direction of travel is set.

Decreasing labour productivity, increased capacity for the transmission of diseases such as dengue fever, malaria, and cholera, and threats to food security provide early warning of compounding negative health and nutrition effects if temperatures continue to rise. Adaptation, planning, and resilience for health Global inertia in adapting to climate change persists, with a mixed response from national governments since the signing of the Paris Agreement in 2015. More than half of global cities surveyed expect climate change to seriously compromise public health infrastructure, either directly, with extremes of weather disrupting crucial services, or indirectly, through the overwhelming of existing services with increased burdens of disease (indicator 2.2). Globally, spending for climate change adaptation remains well below the $100 billion per year commitment made under the Paris Agreement. Within this annual spending, only 3•8% of total development spending committed through formal UN Framework Convention on Climate Change (UNFCCC) mechanisms is dedicated to human health (indicator 2.8). This low investment in Panel 1: Progress towards the recommendations of the 2015 Lancet Commission on health and climate change In 2015, the Lancet Commission made ten policy recommendations. Of these ten recommendations, the Lancet Countdown is measuring progress on the following: Recommendation 1: invest in climate change and public health research Since 2007, the number of published articles on health and climate change in scientific journals has increased by 182% (indicator 5.2). Recommendation 2: scale up financing for climate-resilient health systems Spending on direct health adaptation as a proportion of total adaptation spending increased in 2017 to 4•8% (£11•68 billion), which is an increase in absolute and relative terms from the previous year (indicator 2.7). Health-related adaptation spending (including disaster response and food and agriculture) was estimated at 15•2% of total adaptation spend. Although this national-level spending is increasing, climate financing for mitigation and adaptation remains well below the US$100 billion per year committed in the Paris Agreement (indicator 2.8). Recommendation 3: phase out coal-fired power Coal consumption remains high, but continued to decline in 2017, a trend which is largely driven by China's decreased reliance and continued investment in renewable energy (indicators 3.2 and 3.3). The Powering Past Coal Alliance (an alliance of 23 countries including the UK, Italy, Canada, and France) was launched at the 23rd Conference of the Parties to the UN Framework Convention on Climate Change (UNFCCC) in December, 2017 (COP23), committing to phase out coal use by 2030 or earlier. Recommendation 4: encourage city-level low-carbon transition to reduce urban pollution In 2017, a new milestone was reached, with more than 2 million electric vehicles on the road, and with global per-capita electricity consumption for road transport increasing by 13% from 2013 to 2015 (indicator 3.6). C...

BackgroundIncreasing active travel (primarily walking and cycling) has been widely advocated for reducing obesity levels and achieving other population health benefits. However, the strength of evidence underpinning this strategy is unclear. This study aimed to assess the evidence that active travel has significant health benefits.MethodsThe study design was a systematic review of (i) non-randomised and randomised controlled trials, and (ii) prospective observational studies examining either (a) the effects of interventions to promote active travel or (b) the association between active travel and health outcomes. Reports of studies were identified by searching 11 electronic databases, websites, reference lists and papers identified by experts in the field. Prospective observational and intervention studies measuring any health outcome of active travel in the general population were included. Studies of patient groups were excluded.ResultsTwenty-four studies from 12 countries were included, of which six were studies conducted with children. Five studies evaluated active travel interventions. Nineteen were prospective cohort studies which did not evaluate the impact of a specific intervention. No studies were identified with obesity as an outcome in adults; one of five prospective cohort studies in children found an association between obesity and active travel. Small positive effects on other health outcomes were found in five intervention studies, but these were all at risk of selection bias. Modest benefits for other health outcomes were identified in five prospective studies. There is suggestive evidence that active travel may have a positive effect on diabetes prevention, which may be an important area for future research.ConclusionsActive travel may have positive effects on health outcomes, but there is little robust evidence to date of the effectiveness of active transport interventions for reducing obesity. Future evaluations of such interventions should include an assessment of their impacts on obesity and other health outcomes.