Intended for healthcare professionals

Observations Climate change

The most important global public health agreement of the century

BMJ 2015; 351 doi: (Published 17 December 2015) Cite this as: BMJ 2015;351:h6878
Infographic: Climate change health impacts
Click here to see an interactive graphic, summarising the impacts on health predicted by the Intergovernmental Panel on Climate Change.

  1. Josh Karliner, director, global projects, Health Care Without Harm, San Francisco, USA
  1. josh{at}

If fully implemented, the recent UN agreement to reduce climate change would reap health benefits

The new United Nations climate treaty recently agreed by representatives of 195 countries in Paris is far from perfect, but, by committing nearly every country’s government to lowering its greenhouse gas emissions, it takes a major step toward staving off the worst effects of climate change.

Not just about polar bears

This accord could become known as the greatest public health accomplishment of our time, forestalling what is widely acknowledged as the greatest public health threat this century. It has become increasingly clear that climate change is not just about polar bears but also about clean air. It’s not just about endangered species but also a growing burden of disease. Reversing climate change would protect everyone’s health.

Health leaders have also begun to see other opportunities in mitigating climate change. If we can move away from hazardous coal, oil, and gas—the biggest drivers of climate change—to clean, renewable energy such as solar and wind power, the health effects of air pollution and their related economic burden would be relieved too. This could save millions of lives and trillions of healthcare dollars.

When civilization changed course

The Paris moment may well be remembered as that instant in history when civilization changed course and took on perhaps its greatest existential threat by moving away from the barbaric practice of generating energy by fossil fuel combustion. That, of course, depends on how well the agreement is implemented and built on.

In the meantime, the negotiators have returned home from Paris to a world increasingly traumatized by the causes and consequences of climate change—a world beginning to experience the symptoms of what the Lancet has called a “global health emergency.”

For example, they went back to China, where last week the government issued a red alert in Beijing, aimed at protecting the public from air pollution that shrouded the city in a dark and deadly cloud for days. They went back to India, whose capital, Delhi, if judged by the same air quality standards, should have been under red alert for 29 days in the month of November and whose fifth largest city, Chennai, was devastated by the worst rains and flooding in 100 years during the Paris talks.

Rising seas lap higher

Negotiators also went back to small island states, many of them watching with increasing despair as rising seas lap higher and higher on their fragile shores. They went back to European capitals swamped by a refugee crisis that is putting huge pressure on many countries’ health systems, not to mention their political stability. This mass migration is due not only to Middle Eastern politics and militant fundamentalism but also to drought and displacement induced by climate change throughout northern Africa and in Syria.

And they went back to the United States—a country whose population has been battered in recent years by extreme storms, flood, drought, and wildfires, yet one where a political party that dominates both houses of Congress has many leaders who regularly deny the existence of climate change.

All of this prompts a question: is the Paris treaty up to the task of fostering the change necessary to protect human health and the ecological integrity of the planet?

For the treaty to work, it will need all sectors of all societies to step up to combat climate change. This means that health professionals and institutions around the world must jump into the climate arena with the same fervor as in campaigns to combat smoking or HIV/AIDS.

Paris provided a start

An unprecedented alliance of doctors, nurses, and others representing more than 1700 health organizations, 8200 hospitals, and 13 million health professionals came together in Paris to call on governments to reach a strong agreement that protects public health. And they committed to leading the way toward climate solutions by promoting low carbon healthcare, climate resilient health systems, and healthcare leadership to combat climate change.

Growing this health sector leadership—pressuring governments to implement the Paris treaty fully and go beyond it—will be essential in protecting public health from climate change.

Though seen in the past as an environmental or economic problem, climate change is also, at its core, a human health problem. In the words of Maria Neira, World Health Organization director of public health and the environment, this treaty may well become “the most important public health agreement of the century.”


Cite this as: BMJ 2015;351:h6878


  • Competing interests: I have read and understood the BMJ policy on declaration of interests and have no relevant interests to declare.

  • Provenance and peer review: Not commissioned; not externally peer reviewed.

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