H5N1

Compound mortality impacts from extreme temperatures and the COVID-19 pandemic

Via Nature Communications: Compound mortality impacts from extreme temperatures and the COVID-19 pandemic. The abstract:

Extreme weather and coronavirus-type pandemics are both leading global health concerns. Until now, no study has quantified the compound health consequences of the co-occurrence of them. We estimate the mortality attributable to extreme heat and cold events, which dominate the UK health burden from weather hazards, in England and Wales in the period 2020-2022, during which the COVID-19 pandemic peaked in terms of mortality. 

We show that temperature-related mortality exceeded COVID-19 mortality by 8% in South West England. Combined, extreme temperatures and COVID-19 led to 19 (95% confidence interval: 16–22 in North West England) to 24 (95% confidence interval: 20–29 in Wales) excess deaths per 100,000 population during heatwaves, and 80 (95% confidence interval: 75–86 in Yorkshire and the Humber) to 127 (95% confidence interval: 123–132 in East of England) excess deaths per 100,000 population during cold snaps. 

These numbers are at least ~2 times higher than the previous decade. Society must increase preparedness for compound health crises such as extreme weather coinciding with pandemics.

‘Deadliest outbreak ever seen’: Climate crisis fuels Bangladesh’s worst dengue epidemic

Via The Guardian: ‘Deadliest outbreak ever seen’: climate crisis fuels Bangladesh’s worst dengue epidemic. Excerpt:

In a small, dimly lit control room at the Directorate General of Health Services (DGHS) in Dhaka, data on Bangladesh’s dengue outbreak flashes across multiple computer screens. Government analysts here have been busy collecting and monitoring the impact of the disease across the country since cases were first reported last April.  

In 2023, the total reported cases of dengue numbered 321,179, with 1,705 deaths recorded, a massive jump from the year before, when 62,000 people were known to have had the virus, and 281 died. It was the highest number of annual deaths caused by the mosquito-transmitted disease ever recorded in Bangladesh.

The deaths last year included at least 113 children. According to Save the Children, the majority of these deaths were of children under the age of 10, with 38 deaths among those under five.  

“Children make up around 30% of all dengue cases in Bangladesh and are particularly vulnerable to the virus because of underdeveloped immune systems,” says Dr Shamim Jahan, Bangladesh director of Save the Children. “Those under five are particularly at risk from developing severe symptoms, such as dehydration and shock.”  

Over the past few months, the surge in cases has pushed Bangladesh’s health system to the limit, with hospital corridors overflowing with patients as wards run out of beds.  

“It’s been the deadliest outbreak of dengue the country has ever seen,” says Dr Mohammad Shafiul Alam, a scientist at the ICDDR,B health research centre in Dhaka.  

The high death toll has continued into the new year. As of Wednesday, the outbreak had affected 756 people so far this month, resulting in 10 deaths, compared with 424 cases and three deaths this time last year.  

However, the official figures may not give a true indication of the scale of the outbreak. “These reported figures are likely an underestimation of the actual burden,” says Alam. “Numerous healthcare facilities in Bangladesh operate beyond the reporting framework. This underscores the likelihood that the actual figures could be several times higher.”

The 2023 report of the Lancet Countdown on health and climate change: The imperative for a health-centred response in a world facing irreversible harms

Via The Lancet, a major report: The 2023 report of the Lancet Countdown on health and climate change: the imperative for a health-centred response in a world facing irreversible harms. An excerpt from the executive summary:

The Lancet Countdown is an international research collaboration that independently monitors the evolving impacts of climate change on health, and the emerging health opportunities of climate action. In its eighth iteration, this 2023 report draws on the expertise of 114 scientists and health practitioners from 52 research institutions and UN agencies worldwide to provide its most comprehensive assessment yet.  

In 2022, the Lancet Countdown warned that people's health is at the mercy of fossil fuels and stressed the transformative opportunity of jointly tackling the concurrent climate change, energy, cost-of-living, and health crises for human health and wellbeing. This year's report finds few signs of such progress. At the current 10-year mean heating of 1·14°C above pre-industrial levels, climate change is increasingly impacting the health and survival of people worldwide, and projections show these risks could worsen steeply with further inaction. However, with health matters gaining prominence in climate change negotiations, this report highlights new opportunities to deliver health-promoting climate change action and a safe and thriving future for all.

The rising health toll of a changing climate

In 2023, the world saw the highest global temperatures in over 100 000 years, and heat records were broken in all continents through 2022. Adults older than 65 years and infants younger than 1 year, for whom extreme heat can be particularly life-threatening, are now exposed to twice as many heatwave days as they would have experienced in 1986–2005 (indicator 1.1.2). Harnessing the rapidly advancing science of detection and attribution, new analysis shows that over 60% of the days that reached health-threatening high temperatures in 2020 were made more than twice as likely to occur due to anthropogenic climate change (indicator 1.1.5); and heat-related deaths of people older than 65 years increased by 85% compared with 1990–2000, substantially higher than the 38% increase that would have been expected had temperatures not changed (indicator 1.1.5).

 

Simultaneously, climate change is damaging the natural and human systems on which people rely for good health. The global land area affected by extreme drought increased from 18% in 1951–60 to 47% in 2013–22 (indicator 1.2.2), jeopardising water security, sanitation, and food production. A higher frequency of heatwaves and droughts in 2021 was associated with 127 million more people experiencing moderate or severe food insecurity compared with 1981–2010 (indicator 1.4), putting millions of people at risk of malnutrition and potentially irreversible health effects. The changing climatic conditions are also putting more populations at risk of life-threatening infectious diseases, such as dengue, malaria, vibriosis, and West Nile virus (indicator 1.3).

 

Compounding these direct health impacts, the economic losses associated with global heating increasingly harm livelihoods, limit resilience, and restrict the funds available to tackle climate change. Economic losses from extreme weather events increased by 23% between 2010–14 and 2018–22, amounting to US$264 billion in 2022 alone (indicator 4.1.1), whereas heat exposure led to global potential income losses worth $863 billion (indicators 1.1.4 and 4.1.3). Labour capacity loss resulting from heat exposure affected low and medium Human Development Index (HDI) countries the most, exacerbating global inequities, with potential income losses equivalent to 6·1% and 3·8% of their gross domestic product (GDP), respectively (indicator 4.1.3).

 

The multiple and simultaneously rising risks of climate change are amplifying global health inequities and threatening the very foundations of human health. Health systems are increasingly strained, and 27% of surveyed cities declared concerns over their health systems being overwhelmed by the impacts of climate change (indicator 2.1.3). Often due to scarce financial resources and low technical and human capacity, the countries most vulnerable to climate impacts also face the most challenges in achieving adaptation progress, reflecting the human risks of an unjust transition. Only 44% of low HDI countries and 54% of medium HDI countries reported high implementation of health emergency management capacities in 2022, compared with 85% of very high HDI countries (indicator 2.2.5). Additionally, low and medium HDI countries had the highest proportion of cities not intending to undertake a climate change risk assessment in 2021 (12%; indicator 2.1.3).

 

These inequalities are aggravated by the persistent failure of the wealthiest countries to deliver the promised modest annual sum of $100 billion to support climate action in those countries defined as developing within the UN Framework Convention on Climate Change. Consequently, those countries that have historically contributed the least to climate change are bearing the brunt of its health impacts—both a reflection and a direct consequence of the structural inequities that lie within the root causes of climate change.

The Lancet Commission on 21st-Century Global Health Threats

Via The Lancet, December 15, 2022: The Lancet Commission on 21st-Century Global Health Threats. 

The world has lived through an extraordinary global health threat, the COVID-19 pandemic, leading to nearly 20 million deaths, staggering economic losses, a generational decline in human capital, and the first decline in global life expectancy since 1950 (the first year when UN estimates were published). Another major threat, climate change, now has broad scientific, political, and social recognition. The spectre of nuclear confrontation has re-emerged as a serious threat during the ongoing Russian invasion of Ukraine. 

The three Cs—COVID-19, climate change, and conflict—highlight that the steady global health progress of the past 70 years will not necessarily continue in the next 70 years. But there are many other threats beyond the three Cs that threaten to undermine future global health progress, including rising antimicrobial resistance, increasing obesity, inverted population pyramids, eroding sexual and reproductive rights for women, food insecurity, and fraying multilateralism. How global health advances or retreats will depend crucially on the multiplicity of these threats and how they intersect. 

The global community and many nations have launched commissions, task forces, and panels to draw lessons from the COVID-19 pandemic. The Pan-European Commission on Health and Sustainable Development explored the post-pandemic world for Europe and made far-reaching recommendations based on a One Health lens. The Independent Panel for Pandemic Preparedness and Response and the G20 High Level Independent Panel on Financing the Global Commons for Pandemic Preparedness and Response called for the creation of new institutions and financing mechanisms to prepare the world for new pandemics and other threats. 

Multiple commissions, task forces, and panels have addressed climate change, including two Lancet Commissions, and the Intergovernmental Panel on Climate Change produces regular multistakeholder assessments. These global convenings have been mirrored by multiple national reviews. Although there are high-profile initiatives for pandemics and climate change, other threats have received less widespread attention or have been debated largely in academic subdisciplines.  

Governments, international organisations, and local communities will need to manage multiple threats at the same time. Many of these threats interact and lead to complex health, economic, social, and geopolitical consequences. Climate change, population growth, and political fragility may coincide leading to large-scale migration. Food systems can be designed to improve health, reduce poverty, and slow climate change, or the reverse.  

Specific and cross-cutting technologies and policies are needed to reduce the risk of emerging threats or to decrease the harms from threats as they unfold. The most important strategies for risk and harm reduction are unlikely to emerge if each threat is examined in isolation from the others.  

We have established the Lancet Commission on 21st-Century Global Health Threats to examine the broad set of threats facing the world over the rest of the century. This long perspective is needed since threats such as climate change, food systems, antimicrobial resistance, or inverted population pyramids require many decades for actions to alter future trajectories. The Sustainable Development Goal focus on 2030 is an important motivator for immediate policy action, but a longer-term perspective is needed to fully assess and respond to emerging threats.

This Commission's work will be informed by diverse expertise. The Commission members are drawn from many distinct groups: current and former heads of state, intergovernmental organisation leaders, leaders of public health institutions, global health funders, global health thought leaders, and civil society and youth organisations. The Commission represents a diverse group with gender parity and regional balance so that many perspectives are brought to bear on finding cross-cutting tools and solutions for future threats. The Commission will meet over the next 2 years to assess the evidence produced by various working groups and will release its analysis and recommendations by the end of 2024.

Next pandemic may come from melting glaciers, new data shows

Via The Guardian: Next pandemic may come from melting glaciers, new data shows. Excerpt:

The next pandemic may come not from bats or birds but from matter in melting ice, according to new data.  

Genetic analysis of soil and lake sediments from Lake Hazen, the largest high Arctic freshwater lake in the world, suggests the risk of viral spillover – where a virus infects a new host for the first time – may be higher close to melting glaciers.  

The findings imply that as global temperatures rise owing to climate change, it becomes more likely that viruses and bacteria locked up in glaciers and permafrost could reawaken and infect local wildlife, particularly as their range also shifts closer to the poles.  

For instance, in 2016 an outbreak of anthrax in northern Siberia that killed a child and infected at least seven other people was attributed to a heatwave that melted permafrost and exposed an infected reindeer carcass. Before this, the last outbreak in the region had been in 1941.  

To better understand the risk posed by frozen viruses, Stéphane Aris-Brosou and her colleagues at the University of Ottawa in Canada collected soil and sediment samples from Lake Hazen, close to where small, medium and large amounts of meltwater from local glaciers flowed in.  

Next, they sequenced RNA and DNA in these samples to identify signatures closely matching those of known viruses, as well as potential animal, plant or fungal hosts, and ran an algorithm that assessed the chance of these viruses infecting unrelated groups of organisms.  

The research, published in Proceedings of the Royal Society B, suggested that the risk of viruses spilling over to new hosts was higher at locations close to where large amounts of glacial meltwater flowed in – a situation that becomes more likely as the climate warms.  

The team did not quantify how many of the viruses they identified were previously unknown – something they plan to do in the coming months – nor did they assess whether these viruses were capable of triggering an infection.  

However, other recent research has suggested that unknown viruses can, and do, loiter in glacier ice. For instance, last year, researchers at Ohio State University in the US announced they had found genetic material from 33 viruses – 28 of them novel – in ice samples taken from the Tibetan plateau in China. Based on their location, the viruses were estimated to be approximately 15,000 years old.  

In 2014, scientists at France’s National Centre for Scientific Research in Aix-Marseille managed to revive a giant virus they isolated from Siberian permafrost, making it infectious again for the first time in 30,000 years. The study’s author, Jean-Michel Claverie, told the BBC at the time that exposing such ice layers could be “a recipe for disaster”. 

Even so, Aris-Brosou’s team cautioned that predicting a high risk of spillover was not the same as predicting actual spillovers or pandemics. “As long as viruses and their ‘bridge vectors’ are not simultaneously present in the environment, the likelihood of dramatic events probably remains low,” they wrote.  

On the other hand, climate change is predicted to alter the range of existing species, potentially bringing new hosts into contact with ancient viruses or bacteria.  

“The only take-home that we can confidently put forward is that as temperatures are rising, the risk of spillover in this particular environment is increasing,” said Aris-Brosou. “Will this lead to pandemics? We absolutely don’t know.”

Over half of known human pathogenic diseases can be aggravated by climate change

Via Nature Climate Change: Over half of known human pathogenic diseases can be aggravated by climate change. The abstract:

It is relatively well accepted that climate change can affect human pathogenic diseases; however, the full extent of this risk remains poorly quantified. Here we carried out a systematic search for empirical examples about the impacts of ten climatic hazards sensitive to greenhouse gas (GHG) emissions on each known human pathogenic disease. 

We found that 58% (that is, 218 out of 375) of infectious diseases confronted by humanity worldwide have been at some point aggravated by climatic hazards; 16% were at times diminished. Empirical cases revealed 1,006 unique pathways in which climatic hazards, via different transmission types, led to pathogenic diseases. 

The human pathogenic diseases and transmission pathways aggravated by climatic hazards are too numerous for comprehensive societal adaptations, highlighting the urgent need to work at the source of the problem: reducing GHG emissions.

Climate change increases cross-species viral transmission risk

Via Nature, an important new study: Climate change increases cross-species viral transmission risk. The abstract:

At least 10,000 virus species have the capacity to infect humans, but at present, the vast majority are circulating silently in wild mammals. However, climate and land use change will produce novel opportunities for viral sharing among previously geographically-isolated species of wildlife. In some cases, this will facilitate zoonotic spillover—a mechanistic link between global environmental change and disease emergence.  

 

Here, we simulate potential hotspots of future viral sharing, using a phylogeographic model of the mammal-virus network, and projections of geographic range shifts for 3,139 mammal species under climate change and land use scenarios for the year 2070.  

 

We predict that species will aggregate in new combinations at high elevations, in biodiversity hotspots, and in areas of high human population density in Asia and Africa, driving the novel cross-species transmission of their viruses an estimated 4,000 times.  

 

Because of their unique dispersal capacity, bats account for the majority of novel viral sharing, and are likely to share viruses along evolutionary pathways that will facilitate future emergence in humans. Surprisingly, we find that this ecological transition may already be underway, and holding warming under 2°C within the century will not reduce future viral sharing.  

 

Our findings highlight an urgent need to pair viral surveillance and discovery efforts with biodiversity surveys tracking species’ range shifts, especially in tropical regions that harbor the most zoonoses and are experiencing rapid warming.

Six unlearned lessons of the pandemic

The Tyee has published my article Six Unlearned Lessons of the Pandemic. Excerpt:

6. We’ll never go back to the ‘before times’  

The neoliberal world order established since the 1980s has been brutally shaken since New Year’s Eve 2019, exposing political failures ranging from worsening climate change to the migration crisis and systemic racism. Yet governments behave as if the pandemic scarcely exists. They play familiar Cold War games: Russia threatens Ukraine, China bullies its critics, the U.S. pretends it’s the leader of something called the “free world.”  

It’s understandable to yearn for a world without a pandemic. But the “before times” got us into this mess. If we did go back to before-times economies and social relations, we would soon face still more pandemics and social conflicts. Omicron’s Here.

As the pandemic continues, with occasional guest appearances by climate disasters like last summer’s heat dome and November’s floods, many of the world’s leading nations (and leaders) are hollowed-out remnants of what they once were. Internally divided, they pretend it’s business as usual. But they seem terrified of their own people and unable to define and carry out a consistent pandemic policy.  

So, having learned nothing from the pandemic, they continue as they began — unless and until we elect new governments that really have learned from the past two years.

Covid recovery poses dire climate, health risks: Lancet

Via The Times of India, an AFP report: Covid recovery poses dire climate, health risks: Lancet. Excerpt:

PARIS: Countries' fossil-fuel powered Covid-19 recoveries will have long-lasting consequences on human health and risk worsening the food and water insecurity, heatwaves and infectious diseases already threatening billions globally, a major assessment warned Thursday.  

The Lancet Countdown is the largest annual study of the impacts of climate change on human health.  

It found that up to 19 percent of Earth's land mass was affected by extreme drought in 2020 and warned that climate change posed a major threat to food security, which already affects more than two billion people.  

Compared with the historic average, the global population of over-65s lived through 3.1 billion additional extreme heat days last year, it found.  

Populations of 134 countries are now at greater threat from wildfires than at any time previously, and millions of farmers and construction workers are losing income because of the rising number of extremely hot days.  

And climate change is creating ideal conditions for infectious diseases such as dengue fever, Zika virus, cholera and malaria across a far larger span of the globe than just a few decades ago and including Europe, it said.  

"Climate change is here and we're already seeing it damaging human health across the world," said Anthony Costello, executive director of the Lancet Countdown.  

"As the Covid-19 crisis continues, every country is facing some aspect of the climate crisis too."  

The assessment found that the five years with the most areas affected by extreme drought have all occurred since 2015.  

Disruption to the water cycle due to global heating shortens the time in which plants reach maturity, resulting in small yields putting ever-greater stress on food production.  

The Lancet said that yield potential for maize -- a global staple -- had already declined 6 percent compared with 1981-2010 levels.  

Wheat has seen a 3-percent yield potential fall, and rice a 1.8-percent fall, it found.  

And the marine food upon which 3.3. billion people depend on for either sustinence or income is under "increasing threat", with average sea temperature rising in nearly 70 percent of territorial waters compared with just 15 years ago.  

The report also warned that nearly three quarters of countries surveyed said they believed they could not afford an integrated national health and climate strategy.  

"This year we saw people suffering intense heatwaves, deadly floods and wildfires," said lead author Maria Romanello.  

"These are grim warnings that, for every day that we delay our response to climate change, the situation gets more critical.  

"It's time to realise that no one is safe from the effects of climate change."  

In an editorial, the Lancet called on world leaders at the forthcoming COP26 summit to divert some of the trillions they are spending on Covid-19 recovery to reduce inequality and safeguard health.  

"This year's indicators give a bleak outlook: global inequities are increasing, and the direction of travel is worsening in all health outcomes."

Call for emergency action to limit global temperature increases, restore biodiversity, and protect health

Via The Lancet, but also published in 200 other health journals around the world: Call for emergency action to limit global temperature increases, restore biodiversity, and protect health.

The UN General Assembly in September, 2021, will bring countries together at a critical time for marshalling collective action to tackle the global environmental crisis. They will meet again at the biodiversity summit in Kunming, China, and the UN Climate Change Conference of the Parties (COP26) in Glasgow, UK. Ahead of these pivotal meetings, we—the editors of health journals worldwide—call for urgent action to keep average global temperature increases below 1·5°C, halt the destruction of nature, and protect health.  

Health is already being harmed by global temperature increases and the destruction of the natural world, a state of affairs health professionals have been bringing attention to for decades.1 The science is unequivocal; a global increase of 1·5°C above the pre-industrial average and the continued loss of biodiversity risk catastrophic harm to health that will be impossible to reverse. Despite the world's necessary preoccupation with COVID-19, we cannot wait for the pandemic to pass to rapidly reduce emissions.  

Reflecting the severity of the moment, this Comment appears in health journals across the world. We are united in recognising that only fundamental and equitable changes to societies will reverse our current trajectory.  

The risks to health of increases above 1·5°C are now well established. Indeed, no temperature rise is “safe”. In the past 20 years, heat-related mortality among people older than 65 years has increased by more than 50%. Higher temperatures have brought increased dehydration and renal function loss, dermatological malignancies, tropical infections, adverse mental health outcomes, pregnancy complications, allergies, and cardiovascular and pulmonary morbidity and mortality. Harms disproportionately affect the most vulnerable, including children, older populations, ethnic minorities, poorer communities, and those with underlying health problems.  

Global heating is also contributing to the decline in global yield potential for major crops, falling by 1·8–5·6% since 1981; this, together with the effects of extreme weather and soil depletion, is hampering efforts to reduce undernutrition. Thriving ecosystems are essential to human health, and the widespread destruction of nature, including habitats and species, is eroding water and food security and increasing the chance of pandemics.  

The consequences of the environmental crisis fall disproportionately on those countries and communities that have contributed least to the problem and are least able to mitigate the harms. Yet no country, no matter how wealthy, can shield itself from these impacts. Allowing the consequences to fall disproportionately on the most vulnerable will breed more conflict, food insecurity, forced displacement, and zoonotic disease—with severe implications for all countries and communities. As with the COVID-19 pandemic, we are globally as strong as our weakest member.  

Rises above 1·5°C increase the chance of reaching tipping points in natural systems that could lock the world into an acutely unstable state. This would critically impair our ability to mitigate harms and to prevent catastrophic, runaway environmental change.  

Encouragingly, many governments, financial institutions, and businesses are setting targets to reach net-zero emissions, including targets for 2030. The cost of renewable energy is dropping rapidly. Many countries are aiming to protect at least 30% of the world's land and oceans by 2030.  

These promises are not enough. Targets are easy to set and hard to achieve. They are yet to be matched with credible short-term and longer-term plans to accelerate cleaner technologies and transform societies. Emissions reduction plans do not adequately incorporate health considerations. Concern is growing that temperature rises above 1·5°C are beginning to be seen as inevitable, or even acceptable, to powerful members of the global community. Relatedly, current strategies for reducing emissions to net zero by the middle of the 21st century implausibly assume that the world will acquire great capabilities to remove greenhouse gases from the atmosphere.

This insufficient action means that temperature increases are likely to be well in excess of 2°C, a catastrophic outcome for health and environmental stability. Crucially, the destruction of nature does not have parity of esteem with the climate element of the crisis, and every single global target to restore biodiversity loss by 2020 was missed. This is an overall environmental crisis.

Health professionals are united with environmental scientists, businesses, and many others in rejecting that this outcome is inevitable. More can and must be done now—in Glasgow and Kunming—and in the immediate years that follow. We join health professionals worldwide who have already supported calls for rapid action.

Equity must be at the centre of the global response. Contributing a fair share to the global effort means that reduction commitments must account for the cumulative, historical contribution each country has made to emissions, as well as its current emissions and capacity to respond. Wealthier countries will have to cut emissions more quickly, making reductions by 2030 beyond those currently proposed and reaching net-zero emissions before 2050. Similar targets and emergency action are needed for biodiversity loss and the wider destruction of the natural world.

To achieve these targets, governments must make fundamental changes to how our societies and economies are organised and how we live. The current strategy of encouraging markets to swap dirty for cleaner technologies is not enough. Governments must intervene to support the redesign of transport systems, cities, production and distribution of food, markets for financial investments, health systems, and much more. Global coordination is needed to ensure that the rush for cleaner technologies does not come at the cost of more environmental destruction and human exploitation.

Many governments met the threat of the COVID-19 pandemic with unprecedented funding. The environmental crisis demands a similar emergency response. Huge investment will be needed, beyond what is being considered or delivered anywhere in the world. But such investments will produce huge positive health and economic outcomes. These include high quality jobs, reduced air pollution, increased physical activity, and improved housing and diet. Better air quality alone would realise health benefits that easily offset the global costs of emissions reductions.

These measures will also improve the social and economic determinants of health, the poor state of which may have made populations more vulnerable to the COVID-19 pandemic. But the changes cannot be achieved through a return to damaging austerity policies or the continuation of the large inequalities of wealth and power within and between countries.

In particular, countries that have disproportionately created the environmental crisis must do more to support low-income and middle-income countries to build cleaner, healthier, and more resilient societies. High-income countries must meet and go beyond their outstanding commitment to provide US$100 billion a year, making up for any shortfall in 2020 and increasing contributions to and beyond 2025. Funding must be equally split between mitigation and adaptation, including improving the resilience of health systems.

Financing should be through grants rather than loans, building local capabilities and truly empowering communities, and should come alongside forgiving large debts, which constrain the agency of so many low-income countries. Additional funding must be marshalled to compensate for inevitable loss and damage caused by the consequences of the environmental crisis.

As health professionals, we must do all we can to aid the transition to a sustainable, fairer, resilient, and healthier world. Alongside acting to reduce the harm from the environmental crisis, we should proactively contribute to global prevention of further damage and action on the root causes of the crisis. We must hold global leaders to account and continue to educate others about the health risks of the crisis. We must join in the work to achieve environmentally sustainable health systems before 2040, recognising that this will mean changing clinical practice. Health institutions have already divested more than $42 billion of assets from fossil fuels; others should join them.

The greatest threat to global public health is the continued failure of world leaders to keep the global temperature rise below 1·5°C and to restore nature. Urgent, society-wide changes must be made and will lead to a fairer and healthier world. We, as editors of health journals, call for governments and other leaders to act, marking 2021 as the year that the world finally changes course.