The World Meteorological Organization anticipates that 2016 will be the hottest year on record. This represents a major on-going threat to global health.
Over the past half century, there have been significant health improvements globally. Some notable achievements include reducing maternal and child mortality, tackling hunger, increasing access to basic sanitation and making significant progress with many of the Millennium Development Goals (MDGs). Just some of the MDG achievements in health include:
• The number of people living in extreme poverty has reduced by more than half, from 1.9 billion in 1990 to 836 million in 2015 (most of this decline has occurred since 2000).
• The proportion of undernourished people in developing countries has fallen from 23.3% (1990-1999) to 12.9% (2014-2016).
• Global under-five mortality reduced from 90 to 43 deaths per 1000 live births between 1990 and 2015.
• Over 6.2 million malaria deaths have been prevented between 2000 and 2015.
• Ozone-depleting substances have been virtually eliminated.
• In 2015, 91% of the world's population used an improved drinking water facility, compared with 76% in 1990.
These health improvements are largely thanks to international development efforts and initiatives such as the MDGs, which has since been followed up with the Sustainable Development Goals (SDGs) to continue this work in improving global health. Both of these UN-led initiatives have worked to identify key issues in global health and indicators that will effectively monitor these. This helps provide tangible means of examining changes in key health metrics within and between countries.
Beyond this, such indicators support countries in evaluating changes in public health; identifying key health problems that need addressing; and helping inform how these health problems can be reduced. Whilst there are still huge health challenges across the world, and of course most especially among the poorest and most vulnerable populations, the overall improvements observed in global health over the last 50 years are testament to the effectiveness of using indicators to monitor and improve health. Yet during these 50 years, there has been another growing threat that could undermine the progress made in global health: climate change.
The Threat to Progress
Already, climatic changes are estimated to result in around 150,000 deaths annually. Estimations for the future health effects associated with climate change are even more severe, with 250,000 deaths expected to be caused by climate change every year between 2030 and 2050, and health costs due to climate change being as high as US$ 2-4 billion per year by 2030. Further, existing health problems will be exacerbated by climate change and so too will existing health inequalities. Despite having contributed least to climate change, the most vulnerable populations will be most heavily affected and have the lowest capacity to adapt. The most effective way to improve the health resilience of many of these groups is by improving basic health facilities, but this in itself is no mean feat in many parts of the world. Yet whilst climate change presents a huge challenge, tackling the problem now also presents a huge opportunity to improve public health. Indeed, the 2015 Lancet Commission concluded that "tackling climate change could be the greatest global health opportunity of the 21st century".
Interventions to reduce the risks faced by climate change also hold significant benefits for human wellbeing, by improving our air quality, encouraging healthier diets, and creating communities that promote more physical activity. What's more, these strategies are often cost-effective and can result in immediate benefits for health. For example, short-lived climate pollutants can have significant and adverse impacts on human health and also in terms of global warming. Yet emissions of short-lived climate pollutants can be reduced relatively fast and, owing to their short life span, the benefits of doing so are felt quite quickly.
For example, a key health opportunity associated with short-lived climate pollutants is indoor air pollution. Globally, 3 billion people still use biomass (including wood, animal dung and crop waste) and coal to cook and heat their homes. Burning these traditional fuels emits short-lived climate pollutants, such as black carbon and methane. In confined spaces, these emissions become concentrated to dangerous levels. Consequently, over 4 million premature deaths occur every year as a result of exposure to indoor air pollution. Many of these deaths, and also additional health problems, could be prevented if these populations using traditional fuels in their homes had other means of cooking and heating their homes. Having access to electric stoves would be a significant improvement; this has been achieved in many places by using decentralised solar systems in homes to provide electricity for these stoves. This also has important co-benefits in terms of climate change, as black carbon and methane are two of the major greenhouse gases emitted from burning biomass and coal. Both of these are significant contributors to global warming; black carbon is the second most important human emission behind carbon dioxide and methane has 21 times the global warming potential of carbon dioxide over a 100 year period.
This example highlights the importance of understanding the relationship between climate change and health, and exemplifies the need to monitor the progress being made in tackling these issues. The existing frameworks of the WHO Health and Climate Change Country Profiles are an invaluable resource for monitoring improvements in global health and identifying where issues remain. To complement this process, the Lancet Countdown: Tracking Progress on Health and Climate Change will launch with the aim of tracking the world's progress on tackling climate change and harnessing human health.
Tracking Impacts and Progress
Launching this week, The Lancet Countdown: Tracking Progress on Health and Climate Change, a new international, multi-disciplinary research collaboration, will report annually in The Lancet (from now until 2030) on a number of indicators monitoring health and climate change. The Lancet Countdown will complement existing initiatives, such as the SDGs, to track the impacts of climate change on global health and also the progress being made in addressing these challenges. When working to improve global health, a long-term view must be taken; this cannot be done without considering climate change. By focussing on health and climate change together, the Lancet Countdown will therefore provide vital information alongside existing indicator processes, by highlighting where and how health improvements are being undermined by climate change now, and how they could be threatened further in future. It will also demonstrate that addressing climate change offers tangible, immediate and significant benefits to public health.
Beyond this, it is important to understand where and how progress in health and climate change is being made globally, in order to be able to independently hold governments to account. Governments around the world have made ground-breaking commitments to address both global health and climate change, through the SDGs and Paris Agreement. These commitments should be supported and applauded, but also should not be unduly over-praised until governments walk the walk, as well as talk the talk. It is therefore vital to monitor progress in health and climate change globally, to report on governments' progress and determine whether or not their actions match their commitments.