Extreme heat kills roughly half a million people worldwide each year, but at the current rate of global warming, it could be close to five times as deadly by 2050. Then there are the indirect health risks of climate change: chaotic weather and higher temperatures generate deadly natural disasters , bring diseases into new areas , and drive up economic insecurity and poor mental health. Governments need to act, and the Lancet Countdown—an international research collaboration that tracks how health is being impacted—is giving decision-makers undeniable evidence that change is needed right now. “When we talk about climate change, we’re not talking about the future. The cost of inaction is that we pay with people’s lives,” says Marina Romanello, the organization’s executive director. But, she says, we shouldn’t see this just as a doomsday scenario. “Much of tackling climate change is what we need to do to have a better quality of life,” Romanello says. The byproducts of action are greener cities, cleaner air, and healthier, more affordable diets. Ahead of speaking at WIRED Health this month, Romanello sat down with WIRED to talk about what we do and don’t know about the health risks of inaction, and why acting now is for the good of everyone. This interview has been edited for length and clarity. How is climate change impacting health right now? Each year, the impacts of climate change on health are getting worse, across every single indicator we measure. We're seeing extreme heat events, extreme storms, floods, and droughts increasingly affecting people's health, both through direct harm but also indirectly— they impact food systems, water quality, and the transmission of infectious diseases like dengue and malaria, which are spreading into new parts of the world. Climate change also influences socio-economic conditions. Heat exposure lowers labor productivity, which undermines many people's incomes and in turn their ability to sustain good mental and physical health. That’s a lot. How are you keeping track of all of that? We monitor over 50 indicators, using different techniques, tools, and models according to the type of risk that we're monitoring. Sometimes we’re monitoring changing environmental hazards—so the changing occurrence, frequency, and intensity of extreme events that threaten people's health. WIRED Health showcases the most exciting and thought-provoking disruptors, scientists, and practitioners making a positive change in how we provide and access health care. Find out more. We also measure some indirect health impacts of climate change. For example, we monitor self-reported food insecurity. And then sometimes, we combine measures together. For instance, we’ve been able to link self-reported food insecurity to the increased frequency of heat waves, to show that 127 million more people reported food insecurity in 2022 compared to the 1990s average, because of climate change. How are these impacts distributed? Are there any parts of the world where climate change isn’t affecting health? No part of the world is safe, but hazards and effects aren't evenly distributed. Europe, for example, is warming rapidly, and because it has a large elderly population and a high incidence of non-communicable diseases, it has the highest rate of death from extreme heat in the world. Elsewhere, extreme droughts are affecting people, for example in the Horn of Africa, where it’s causing acute hunger. Then in South America, dengue is spreading. In parts of Africa and Asia more areas are becoming suitable for malaria transmission. So the impacts of climate change are being felt everywhere but in different ways. Generally, those that have contributed the least to global emissions are disproportionately affected due to their extreme vulnerability. Almost without exception, countries that are lower on the Human Development Index are lagging in adapting and building resilience to climate risks, largely because of a lack of finances. Climate change is amplifying historical inequities. What sort of things are needed that aren’t happening in these highly vulnerable places? In general, developing countries need more resilient health systems. But also, they need more resilient food systems, water systems, and sanitation. When something like a
Hurricane or extreme flood hits, it can affect infrastructure at the same time. Not only does demand for health care soar, but often then you have a health system that can’t work, because the hospital has flooded or some essential infrastructure has been destroyed. Many countries are also really lagging in the adoption of things like early warning systems on climate-sensitive health risks, or early response systems that allow health systems to respond quickly to those affected by an environmental hazard. Even on things like the international health regulations , which are legally mandated and designed to help countries better respond to an international hazard—for example, a global pandemic—many countries are still lagging on adopting them. This leaves most countries unprotected and unprepared to cope in the event of a health emergency, whether it’s triggered by climate change or not. So being better prepared for the health impacts of climate change would also help with other health crises—disease outbreaks, epidemics, things like that? Exactly. Especially as health threats don’t happen in isolation. Direct climate impacts compound with other crises. We've seen that during the pandemic and can see it right now with dengue in South America. All of this really requires health systems to have better capacity, more resilience, stronger infrastructure. Where are the gaps in our data? Our understanding of the risks posed by climate change is quite good—we know roughly how they are changing and increasing. However, there are enormous gaps in our knowledge of how the impacts of these risks are changing, and that’s largely because countries very rarely report this health impact data. We have less understanding of how effectively health systems are protecting people or how effective adaptation efforts are. That means we don’t really know if we’re responding adequately to protect health or how well prepared we are to cope with emerging health hazards. There's also a lot to be done on identifying who and where the vulnerable populations are specifically. Climate change generally affects the most underserved communities in each country—those that lack reliable access to health care and whose socio-economic conditions are more frail. But data is rarely reported that’s disaggregated by socio-economic status, ethnicity, race, religion, gender, so we still have enormous gaps in understanding how the really vulnerable in a given country are being harmed. Are any countries adapting well to climate change? Many are undertaking very successful initiatives. When we look at middle-income countries, many in South America are stepping up to the challenge. Colombia has made enormous progress in moving away from fossil fuels and promoting better health care, for example. But I don't think we can say that any country is a role model, because their hazards are different. Is climate change driving up rates of conflict and migration, and do you measure those as climate-related health impacts? Climate migration is growing rapidly. It's very difficult to measure, because there's no good international monitoring, or much internal monitoring—and most movement is actually within country boundaries. Migration can be a very effective adaptation measure if planned and done with support. It’s one option that many countries—particularly small island developing states—are considering. Are there any climate-related health issues that you think don’t get enough attention? Probably the fact it’s a compound problem—climate change creates multiple health hazards that happen together. Supporting systems have to deal with a perfect storm of rising heart, lung, and kidney disease, heat stress and heat stroke, lost labor capacity, infectious diseases, and food insecurity at the same time. We are not yet very good at assessing the compound impact of climate change on our health, social, and economic systems. The health effects of climate change are much worse than what we can directly attribute to it because of the complexity of these systems. At an individual level, what can someone do to lessen these health risks? Most actions to tackle climate change directly are also very sensible health-protecting measures, so people should try to adopt these. These include choosing healthier diets, with less meat and more plants, or choosing to walk more. And many of the impacts on our health we can avoid through behavioral changes. In a heat wave, stay away from extreme heat. Your self-protection lessens the demand on your country’s health system. Ultimately, the biggest thing is to support those that are in power and demand that they take action, because they will respond to us in
Democratic countries. We have the capacity to drive what they do. Hear Marina Romanello speak at the 10th anniversary of WIRED Health on March 19 at Kings Place,
London. Get tickets at health.wired.com .