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Key Takeaways From the 2020 Lancet Countdown on Health and Climate Change

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No country — whether rich or poor — is immune from the health impacts of worsening climate change. Unless urgent action is taken, climate change will increasingly threaten global health, disrupt lives and livelihoods, and overwhelm healthcare systems, according to a new review published in the medical journal, The Lancet. The Lancet Countdown on Health and Climate Change tracks 43 indicators on links between health and climate change; it is designed to provide better information to public health professionals and policymakers and accelerate their response to key threats and opportunities presented by climate change.

This year’s countdown includes a country-by-country analysis and an accompanying policy brief specifically focused on the impact of climate change on health in the United States. The U.S. Countdown brief is led by Renee Salas, a Yerby Fellow at the Center for Climate, Health, and the Global Environment at the Harvard T.H. Chan School of Public Health, and Jeremy Hess, professor of environmental and occupational health sciences, global health and emergency medicine at the University of Washington.

The report and accompanying brief draw from experts at academic institutions across the country, including Melissa C. Lott, a senior research scholar at Columbia University’s Center on Global Energy Policy. Lott authored sections on the health co-benefits of climate change mitigation in the energy sector, both globally and in the United States. Her work provides new data and insights that show how climate change and air pollution from burning fossil fuels is already harming human health, and how the energy transition impacts people and communities.

Mitigating global carbon emissions would lead to cleaner skies and save millions of lives

According to the Countdown report, total deaths from ambient particulate pollution increased globally from 2.95 million in 2015 to 3.01 million in 2018.

“Climate change is already harming the health of communities around the globe and none of us are immune,” said Lott. “Without significant intervention, this new era will come to define the health of people at every stage of their lives, particularly children and other vulnerable people. The core of the challenge — and its solution — are our global energy systems.”

Existing datasets and research clearly show that the energy sector — including power plants, transportation, buildings, and industry — not only produces the majority of global greenhouse gas emissions, but also the vast majority of key air pollutants that damage our bodies, including particulate matter and nitrogen oxides. Exposure to this air pollution can lead to increasing instances of childhood asthma, heart disease, respiratory illness, cancers, and early death.

“The United States has already made incredible progress to reduce air pollution, but there’s still more work to do to continue to improve air quality and to reduce associated greenhouse gas emissions that contribute to climate change,” said Jason Bordoff, founding director of the Center on Global Energy Policy. “The Countdown report expresses in clear terms why it is critical that we move quickly — for the health of people and the planet, to address the increasing threats associated with climate change, and to strengthen our economy over the long-term.”

The Countdown report shows how the transition to cleaner sources of energy could be one of the world’s greatest public health opportunities. From 2016 to 2018, global carbon dioxide emissions from the energy sector grew by 2.6%. In the United States, after almost a decade of decline, air pollution rose from 2016 to 2018, leading to nearly 10,000 additional early deaths.

“According to this research, accelerating the transition to a zero-carbon energy sector will save lives and make us healthier by cleaning up the air we breathe and reducing the negative impacts of climate change ,” said Lott. “But we need to act quickly and effectively if we want to mitigate the damage to our health and give ourselves and our children a healthier future.”

illustration shows different organs impacted by air pollution
Credit: The Lancet

The COVID-19 pandemic and climate change crises converge

In this year’s Countdown report, the authors say that the recovery from the COVID-19 pandemic offers a key moment to act on climate change. Together, a joint response to converging crises offers the chance to improve public health, create a sustainable economy, and protect the environment.

“The pandemic has shown us that when health is threatened on a global scale, our economies and ways of life can come to a standstill,” says Ian Hamilton, executive director of the Lancet Countdown. “The threats to human health are multiplying and intensifying due to climate change, and unless we change course our healthcare systems are at risk of being overwhelmed in the future. This year’s devastating U.S. wildfires and tropical storms in the Caribbean and Pacific, coinciding with the pandemic, have tragically illustrated that the world doesn’t have the luxury of dealing with one crisis at a time.”

New evidence from the Countdown report shows that the last two decades have seen a 54% increase in heat-related deaths in older people, with a record 2.9 billion additional days of heatwave exposure affecting people over the age of 65 in 2019 — almost twice the previous high.

However, the 120 world-leading health and climate change academics and clinicians behind the new report say that if we take urgent action to tackle climate change — by implementing plans to deliver commitments of limiting global temperature increases to well below 2 degrees C — we can mitigate these shocks and achieve health and economic benefits instead. At the same time, these actions could reduce the risk of future pandemics, because the drivers of climate change can also drive the emergence of zoonotic diseases (infectious diseases such as COVID-19 that jump from non-human animals to humans).

The report — a collaboration between experts from more than 35 institutions including the World Health Organization (WHO), World Meteorological Organization, and University College London — published on the fifth anniversary of the Paris Agreement, when the world pledged to limit global warming to well below 2 degrees Celsius.

Wenjia Cai, director of the newly-launched Lancet Countdown Regional Centre for Asia, based within Tsinghua University in Beijing, China, said: “On the occasion of the fifth anniversary of the Paris Agreement, we must confront the worst outlook for public health our generation has seen. Failure to meet our climate commitments could take some key Sustainable Development Goals out of reach as well as our ability to limit warming.”

Climate-related health shocks globally and across the U.S.

From small islands to big cities, climate-related health shocks may arise in the future due to difficulties anticipating the impacts of extreme heat and finding successful ways to adapt.

Heat-related deaths among vulnerable people in all parts of the world are growing, with 296,000 lives claimed in 2018. Livelihoods are at risk, too, as heat is increasingly affecting people’s ability to work outdoors in developing regions, with significant economic implications. Last year saw a continued loss in productivity, with India accounting for 40% of the total 302 billion work hours lost.

The U.S., like Europe, is witnessing a worrying trend in heat-related mortality in people over 65, having seen the absolute number of deaths double in the last two decades to 19,000 in 2019 — a figure second only to Germany among high-income countries. In addition, the U.S. is experiencing different kinds of heat-related impacts; potential work hours lost due to heat exposure were 2 billion in 2019, a 63% increase since 2000.

Heat and drought are also driving sharp increases in exposure to wildfires, resulting in burns, heart and lung damage from smoke, and the displacement of communities. Some 128 countries have experienced an increase in population exposure to wildfires since the early 2000s, with the U.S. seeing one of the largest increases. By the end of the century, meanwhile, the report finds that projected sea level rise could threaten to displace up to 565 million people, exposing them to a wide range of health harms.

Professor Hugh Montgomery, Lancet Countdown co-chair and an intensive care doctor based at University College London, said: “Climate change drives a cruel wedge which widens existing health inequalities between and within countries. Our report shows that — just as for COVID-19 — older people are particularly vulnerable, and those with a range of pre-existing conditions including asthma and diabetes are at even greater risk.”

New data in the report highlight that healthcare capacity to deal with these future health shocks is still not enough, despite improvements. Only half of countries surveyed have drawn up national health and climate plans, with just four reporting adequate national funding, and less than half of countries have conducted vulnerability and adaptation assessments for health. Meanwhile, two thirds of global cities surveyed expect climate change to seriously compromise public health infrastructure.

Montgomery added, “The COVID-19 pandemic has thrown a spotlight on the current ability of healthcare and wider health systems to cope with the sorts of future health shocks that climate change may generate. Flames, floods and famine do not respect national borders or bank accounts: a nation’s wealth offers no protection against the health impacts of even a 1.2C global average temperature rise.”

Converging pandemic and climate crises

A Lancet editorial published alongside the new report highlights that climate change and zoonotic pandemic risk share common drivers, making them inextricably entwined so that they must be handled together. Climate change and its drivers damage the environment through urbanization, intensive agriculture and unsustainable food systems, air travel and tourism, trade, and lifestyles powered by fossil fuels, in turn creating conditions that encourage zoonoses.

Richard Horton, editor-in-chief of the Lancet, said: “If we wish to reduce the risk of future pandemics, we must prioritize action on the climate crisis — one of the most powerful forces driving zoonoses today. Now is the time for us all to take the environmental determinants of health more seriously — we must address the climate emergency, protect biodiversity, and strengthen the natural systems on which our civilization depends. This is a moment we cannot afford to ignore. Just as we have seen with COVID-19, delayed action will cause avoidable deaths.”

The report explains that climate change is also leading to more favorable conditions for the spread of deadly infectious diseases such as dengue fever, malaria, and vibriosis — putting at risk the decades of progress in tackling these diseases.

A green COVID-19 recovery

By limiting temperature increases to well below 2 degrees C, and aligning climate and pandemic recovery, the world can deliver near-term and long-term health benefits, according to the new report. Health gains could in turn deliver many billions in economic benefits, which could more than pay for the costs of mitigation and bolster the case for green stimulus measures.

The 7 million deaths per year from air pollution associated with the combustion of fossil fuels point to the potential of cleaner energy. In the WHO Europe region, modest steps to promote cleaner energy and transport sectors saw deaths from ambient PM2.5 air pollution fall from 62 per 100,000 in 2015 to 59 per 100,000 in 2018. Globally, deaths from ambient PM2.5 associated with coal fell by 50,000 in the same year. The European Union’s marginal air quality improvements from 2015 to 2018 could be worth an estimated US$8.8bn every year, if held constant. Stemming from the annual average reduction in years of life lost, the figure will grow with further improvements in air quality.

Given that food production is the source of a quarter of the world’s greenhouse gas emissions, the report suggests there is a similar opportunity to address some of the 9 million annual deaths linked to poor diet. With livestock being particularly emissions-intensive, the report examined deaths from excess eating of red meat. The authors found that mortality has risen 70% over the last 30 years, with the majority of the now almost 1 million annual deaths occurring in the regions of the Western Pacific and Europe.

“With trillions being invested globally in economic support and stimulus there is a genuine opportunity to align the responses to the pandemic and climate change to deliver a triple win — one that improves public health, creates a sustainable economy and protects the environment,” said Maria Neira, director of the Department of Environment, Climate Change and Health at the World Health Organization. “But time is short. Failure to tackle these converging crises in tandem will lock in huge amounts of fossil fuels, moving the world’s 1.5C target out of reach and condemning the world to a future of climate-induced health shocks.”

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Congratulations to our Columbia Climate School MA in Climate & Society Class of 2024! Learn about our May 10 Class Day celebration. #ColumbiaClimate2024

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