Climate change's toll on global health increasingly getting attention

Heat waves that kill tens of thousands of people at once. Massive floods that not only destroy property but also spread typhoid and cholera. Mosquito-borne illnesses such as dengue fever and malaria, in areas that never saw such diseases before. A new pandemic far deadlier than COVID-19. These are just a few of the dramatic potential health effects of unstoppable climate change — and not 50 years or a century from now, but possibly within the next decade. Global summits routinely discuss the multifaceted dynamics of climate change — from the economic fallout of natural disasters to conflicts driven by precious resources — although the nexus between changing weather patterns and human health has not received as much attention. But the issue will be discussed at the upcoming World Economic Forum in Davos, a sign that policymakers are increasingly recognizing the growing body of evidence that climate change is already wreaking havoc on human health. Consider this: A recent study by researchers at the University of Hawaiʻi at Mānoa found that 58% of human diseases have already intensified due to increasing greenhouse gas emissions. Scientists analyzed over 70,000 scientific papers and discovered that 218 of 375 specific illnesses they considered were affected by climate change — most of them for the worse. That’s because warmer temperatures and more humid environments will cause mosquitoes, ticks, fleas, and birds to proliferate, thereby spreading everything from Lyme disease to yellow fever. And extreme weather events will also create millions of climate refugees, bringing them into contact with new pathogens through waterborne diseases while weakening their already vulnerable immune systems. “Given the extensive and pervasive consequences of the COVID-19 pandemic, it was truly scary to discover the massive health vulnerability resulting as a consequence of greenhouse gas emissions,” the study’s lead author, Camilo Mora, said in a statement to the media. “There are just too many diseases, and pathways of transmission, for us to think that we can truly adapt to climate change.” “Every country is now seeing some sort of impact from climate change.” --— Jeni Miller, executive director, Global Climate and Health Alliance It highlights the urgent need to reduce greenhouse gas emissions globally. Yet exactly the opposite is happening. ‘Zero progress’ on phasing out fossil fuels at COP 27 If emissions continue on this upward trend, the world’s remaining carbon sink that keeps warming below 1.5 degrees Celsius will disappear in only nine years — despite the lofty promises made at the recent United Nations climate change conference in Sharm el-Sheikh, Egypt, known as COP 27. “Absolutely zero progress was made on a commitment to fully phase out fossil fuels, and without tackling the major root cause of the climate crisis, we cannot fully protect health,” said Jeni Miller, executive director of the Global Climate and Health Alliance. “There wasn’t any progress made on that. They just repeated the same language as at COP 26.” Miller, interviewed by phone from San Francisco, said her 12-year-old alliance comprises 130 health professional associations, NGOs, and development agencies focused on health. In 2021, it issued a “Healthy Climate Prescription” letter endorsed by over 600 organizations representing 46 million health care workers demanding urgent action to limit global warming to 1.5 degrees Celsius. “Every country is now seeing some sort of impact from climate change,” she said. “We’re seeing extreme weather — both heat waves and extreme winter storms — and ramped-up hurricanes that produce much more rain over longer periods of time, as well as worsening droughts, and all the health consequences of people driven from their homes.” In the United States, the two leading causes of death — cardiovascular disease and cancer — will undoubtedly worsen as the mercury rises. In the past 20 years, according to a 2021 study in Translational Behavioral Medicine, heat-related mortality among people 65 years and older has jumped by more than 50%, with higher temperatures already having brought “increased dehydration and renal function loss, dermatological malignancies, tropical infections, adverse mental health outcomes, pregnancy complications, allergies, and cardiovascular and pulmonary morbidity.” Even so, the study warns, “current strategies for reducing emissions to net zero by the middle of the century implausibly assume 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 2C — a catastrophic outcome for health and environmental stability.” WHO taking climate change more seriously Meanwhile, the World Health Organization — long criticized for not having taken climate change seriously enough — is apparently waking up, albeit slowly. “It has made climate change a priority over the last couple of years,” Miller said. “WHO’s mandate comes from world governments and ministries of health. But for it to take a stronger position and be more effective, it needs resources and the mandates to keep doing that. I would love to see health ministries adopt a resolution that really gives WHO that mandate.” For now, WHO’s homepage — which is filled with stories about its work regarding COVID-19, monkeypox, the Ukraine humanitarian crisis, Africa’s Ebola outbreak, cervical cancer, and the dismal status of women in Afghanistan — doesn’t even mention climate change. Alan Dangour is the director of climate and health at Wellcome, a London-based charity that focuses on climate change, infectious disease, and mental health. He said that at COP 26 in Glasgow, his organization supported WHO’s pavilion, which was the only place where anyone was really talking about the health impact of climate change. One year later in Egypt, he said the conversation had changed notably. “What we saw at Sharm el-Sheikh was a significant increase in discussions on health,” said Dangour, whose foundation has a £38.2 billion ($40 billion) investment portfolio. “It was a real change to see that, and it demonstrates the value of pushing an agenda that says climate change will have a catastrophic effect on health. I think we’ve seen a huge amount of progress.” The health effects of extreme weather in 2022 A big part of the reason for the progress, perhaps, was the extreme weather events making headlines in 2022. These included epic flash floods that submerged a third of Pakistan, killing 1,700 people and displacing 32 million; powerful Hurricane Ian, which killed 114 people — making it Florida’s deadliest storm in 90 years; and a late July heat wave in the United Kingdom that saw the country’s highest temperature ever recorded: 40.3 degrees Celsius. It was so hot that train tracks buckled and an airport runway melted. And that came a year after normally temperate Canada set its highest temperature ever, 49.6 degrees Celsius, in Lytton, British Columbia, on June 29, 2021. Three days later, a wildfire sparked by the heat wave burned 90% of the town to the ground. “This past year, we saw enormous peaks in temperatures that we’ve never seen before, and 30% of heat-related mortality is attributed to climate change,” Dangour told Devex. “The fact that the planet is getting hotter is causing more people to die, but there’s also evidence of the impacts of heat on unborn children.” In fact, researchers from the London School of Hygiene and Tropical Medicine, or LSHTM, recently studied 92 pregnant women in Gambia. They concluded that every extra degree Celsius in extreme heat stress caused a 17% increase in strain on the fetus, specifically by raising fetal heart rate and slowing blood flow through the umbilical cord. Dr. Ana Bonell, a clinical research fellow at LSHTM who led the study, said she and her colleagues followed subsistence farmers ages 16 to 45 for more than a year in the Gambian district of Kiang West. They toiled in the fields where temperatures averaged 28 degrees Celsius but sometimes reached as high as 45 degrees Celsius. “Globally, we’ve seen an increasing duration and intensity of heat events. Not a single continent has been spared from that,” Bonell told Devex. “And we have pretty good evidence that when mothers are exposed to high temperatures, it increases the risk of having a baby born too soon, or stillborn, or of low birth weight. Simply asking women to rest is not enough.” A fossil fuel ‘non-profileration treaty’ The effects are not being seen just in Africa. Recently, Greece and Italy reported their first outbreaks in decades of dengue fever — a disease more associated with places like Brazil, Vietnam, Indonesia, and the Philippines. “As the environment becomes hotter and more humid, mosquitos thrive and spread incredibly dangerous diseases to parts of the world where we haven’t seen it before,” Dangour said. “In Europe, we have very good surveillance systems, but there’s very clear evidence showing that an extra 4 billion people on the planet will be at risk of malaria and dengue.” Dangour praised WHO Director-General Dr. Tedros Adhanom Ghebreyesus for listing the need to combat runaway climate change among his five top priorities. “He’s passionate about it, and he recognizes that unless we tackle climate change head-on, the health of the planet will deteriorate very quickly,” Dangour said, adding that despite the U.N. agency’s sometimes cumbersome bureaucracy, “we should also praise where praise is due.” Dangour also lauded WHO for signing a letter calling for a Fossil Fuel Non-Proliferation Treaty, making it the first U.N. agency ever to take that step. In doing so, it joins the Pacific island nations of Tuvalu and Vanuatu, as well as the European Parliament, 75 cities and subnational governments, and more than 550,000 individuals who are calling for a ban on all new oil and gas exploration and production. Loss and damage fund “What’s exciting is that the new generation recognizes much more clearly their responsibility and are willing to make changes,” Dangour said. “In the U.K., we’re seeing very clear evidence they’re shifting their diets in ways that reduce the environmental footprint and are more supportive of health. And the food industry is producing many more foods to meet that market.” While COP 27 didn’t mention phasing out oil or gas, delegates did finally hammer out an agreement to establish a so-called loss and damage fund for high-income nations to compensate vulnerable, low-income countries that did little to cause the climate crisis but are bearing the brunt of its effects. “This was a non-starter for many years, and finally at COP 27, they committed to establishing a fund. This is huge for people’s health,” said Miller, though no set amount for the fund has been determined. The first meeting of a transitional committee to recommend funding arrangements at this year’s COP 28 in Dubai is expected to take place in March. One more glimmer of hope, Miller said: The surprising Oct. 31 razor-thin election victory of 77-year-old populist politician Luiz Inácio Lula da Silva as president of Brazil. Newsweek reported that researchers at the University of Oxford, the International Institute for Applied System Analysis, and the National Institute for Space Research found that deforestation could fall by 89% by 2030 under Lula if he reinstates the policies introduced during his first term in office, saving 75,000 square kilometers of the Amazon rainforest — an area larger than Ireland. “I was very gratified to see those election results,” Miller told Devex. “We did a report in 2021 that looked at the significant health impact of smoke from fires set to clear land for farming. Globally, the Amazon is vitally important for helping the planet to stabilize, so it’s really great to see a leader back in place who’s ready to protect the Amazon.”