ORLANDO — It’s important for pediatricians not only to understand the causes and effects of climate change but also to know how to discuss this issue with families and make risk-based adjustments to their clinical practice based on the individual health and circumstances of each patient. That’s one of the key messages delivered on September 28 at the annual meeting of the American Academy of Pediatrics (AAP) by Elizabeth C. Matsui, MD, MHS, a professor of population health and pediatrics and director of the Center for Health and Environment Education and Research at the University of Texas at Austin Dell Medical School. 

“Even though climate change has been here and has been affecting health already for a while, it’s just really impossible to ignore right now,” she told attendees in a session focused on climate change impacts on allergies and asthma. “The challenge is connecting the dots between something that is much larger, or feels much larger, than the patient and the family that’s in front of you.” 

The reality, however, is that climate change is now impacting patients’ health on an individual level, and pediatricians have a responsibility to understand how that’s happening and to help their families prepare for it. 

“From the perspective of someone who went into medicine to practice and take care of the individual patient, I think it has been more difficult to connect those dots, and for the people in this room, it’s our job to connect those dots,” Matsui said. She also acknowledged that many of the solutions are frustratingly limited to the policy level and challenging to implement, “but it doesn’t mean that we can’t make a difference for the patients who are in front of us.” 

Charles Moon, MD, a pediatrician and Pediatric Environmental Health Fellow at the Children’s Environmental Health Center, Icahn School of Medicine at Mount Sinai, New York City, found the talk particularly helpful in providing information about both the broader issue and what it means on a local practice level. 

“The biggest takeaway is that more people and more pediatricians are tuning in to this issue and realizing the dangers,” Moon told Medscape Medical News. “It’s clear that a larger community is forming around this, and I think we are at the cusp where more and more people will be coming in. We are really focusing on taking all the data and trying to figure out solutions. I think the solutions orientation is the most important part.” 

Understanding the Big Picture

Matsui opened with a general discussion of the human causes of climate change and the effects on a global scale presently and in the future. For example, over the past 800,000 years, carbon dioxide levels have never been above 300 ppm, but they surpassed that threshold in 1911 and have reached 420 ppm today. The trapping of heat in Earth’s atmosphere caused by the increase in carbon dioxide and other greenhouse gases is leading to multiple phenomena that impact health, such as longer growing seasons; increased droughts, heat waves, and wildfire seasons; and higher temperatures. These changes, in turn, affect allergens and asthma.

Children are particularly vulnerable to climate change impacts because they have a higher risk for developing asthma, allergic disease, and infections, Matsui said. Childhood is a critical period for lung and immune development, and the Environmental Protection Agency’s 2023 Climate Change and Children’s Health and Well-Being report projects that an increase of 2 °C in global warming will result in an additional 34,500 pediatric asthma cases and 228,000 allergic rhinitis cases per year, driven largely by predicted increases in ozone and 2.5-µm particulate matter. The report also forecasts an increase in 6240 asthma emergency department visits and 332 additional respiratory hospitalizations per year. 

“We know that these associations that we see between climate change exposures and poor respiratory health outcomes in kids are biologically plausible,” Matsui said. “They’re not just correlation without causation. A lot of the mechanisms for how air pollution, allergies, and other factors directly affect the lungs of the airway epithelium have been worked out.” 

An Increase in Allergens and Viral Infections

Pediatricians should prepare for anticipated growth in allergens and viral infections. The longer growing seasons mean that pollen seasons will also lengthen. Meanwhile, higher concentrations of carbon dioxide cause individual plants to produce more pollen. 

“As the winters get warmer, mice that might not be able to survive during the winter are surviving, and mice reproduce at a very rapid rate,” she said. “The increase in moisture means that dust mites, which absorb their water — they drink by absorbing humidity that’s in the air — will be present in higher concentrations, and their range will expand.”

Fungal and mold exposures are also increasing, not just outdoors but also indoors, “and there are all sorts of allergic and respiratory health consequences of fungal exposure,” Matsui said. As hurricanes and flooding increase, storm damage can also make indoor environments more conducive to fungal and mold growth. 

Extreme weather from climate change also affects infrastructure. “When there’s healthcare infrastructure disruption and other infrastructure disruption, it adds to the challenge,” she said. “It compounds all the other threat to health from climate change, so this overall problem of climate change and health is multidimensional and very complicated.”

Then there’s the impact of climate change on respiratory viruses, which are a major driver of asthma exacerbations, Matsui said. The greater variability in daytime temperatures affects environmental reservoirs, transmission patterns, geographical ranges, and seasonality of various respiratory pathogens. The prevalence of respiratory syncytial virus infections, for example, increases during humid periods. 

“This is coupled with the fact that the projected increases in air pollution increase susceptibility to respiratory virus infections,” Matsui said. “In fact, climate change and air pollution are inextricably linked.” 

Climate Change and Air Pollution

Climate disruption creates extreme weather patterns that then lead to worsening air quality due to high temperatures; heavier precipitation; and more forest fires, droughts, dust storms, thunderstorms, hurricanes, stagnation events, and other extreme weather. Matsui shared a map showing the substantial increase in days with stagnant air since 1973. During stagnation events, air pollution builds up in the atmosphere because of a stable air mass that remains over a region for several days, with low-level winds and no precipitation. 

The pollutants can then contribute to rising temperatures. Black carbon particulate matter released from the burning of forests and other biomass absorbs more solar radiation, further contributing to temperature increases. Data from the National Bureau of Economic Research has shown that the US made big strides in reducing air pollution from 2009 through 2016, but it began to reverse in 2016 as severe weather events picked up. 

Pediatricians need to be cognizant of the synergistic effect of these different impacts as well. “We oftentimes talk about these problems in a silo, so we may talk about air pollution and health effects, or allergens and health effects, or heat and health effects, but all of these interact with each other and further compound the health effects,” compared to just one of them in isolation, Matsui said.

For example, air pollution increases sensitivity to allergen exposure and increases reaction severity, which disrupts the immune tolerance to allergens. “Heat and air pollution also interact, and the combination of the two is more deadly than either one alone,” she said. 

Air pollution from wildfire smoke is also more toxic to the lungs than air pollution from other sources, so if there’s wildfire-based air pollution, the impact on respiratory hospitalizations is significantly greater. Even in places that would not otherwise be at risk for wildfires, the threat remains of air pollution from more distant fires, as New York City experienced from Canadian wildfires last year. 

“This is a problem that is not just isolated to the parts of the world where the wildfires are located,” Matsui said.

Moon, who practices in New York City, said he really appreciated Matsui’s perspectives and nuanced advice as a subspecialist “because it’s obvious that the way we deliver healthcare is going to have to change based on climate change.” He hopes to see more subspecialists from other pediatric areas getting involved in looking at climate impacts and providing nuanced advice about changing clinical care similar to the examples Matsui provided. 

Air pollution can also be deadly, as a landmark case in the United Kingdom revealed a few years ago when the court ruled that a child’s death from an asthma attack was directly due to air pollution. In addition to causing worse asthma symptoms and exacerbations, air pollution also adds to the risk of developing asthma and impedes lung growth, all of which disproportionately affects disadvantaged and minoritized communities, she said. 

Greater Impact on Disadvantaged Populations

Matsui called attention to the equity implications of climate change impacts on health. 

“If you have a community that does not have the infrastructure and access to resources, and that same community has a prevalence of asthma that is double that of their more advantaged and white counterparts, then the impacts of climate change are going to be amplified even more,” she said.

For example, a 2019 study found that the biggest predictor of the location of ragweed plants has to do with vacant lots and demolition of housing. Ragweed plants being more common in neighborhoods with vacant lots will disproportionately affect disadvantaged neighborhoods, she said. Another study found in Baltimore that mouse allergens — specifically urine — were a bigger cause of asthma in low-income children than were cockroach allergens. 

“It’s important to consider context,” including age, gender and social and behavioral context, she said. “We as pediatricians know that children are particularly vulnerable, and what happens to them has an effect across the lifespan.” 

Furthermore, pediatricians are aware that disadvantaged and minoritized communities lack infrastructure; often live in areas with greater air pollution; often have heat islands in their communities without protection, such as tree canopy; and may be at greater flooding risk. “Poverty is also associated with increased vulnerability” because of poorer housing and infrastructure, less education, less access to care, more preexisting health conditions and greater discrimination, she said.

Three Cornerstone Interventions

Interventions fall into three main buckets, Matsui said: mitigation, adaption, and resilience. 

“Mitigation means reducing greenhouse gas and air pollution production and trying to enhance sinks for greenhouse gases,” she said. Mitigation strategies primarily occur at the policy level, with improved regulation, treaties, and market-based approaches, such as carbon tax and cap and trade. 

Adaptation includes actions that lessen the impact on health and environment, such as infrastructure changes and implementation of air conditioning. Examples of climate change adaptation strategies also mostly come from policy but largely at state and local levels, where individual pediatricians have a greater voice and influence. These can include changes in urban planning to address heat islands, flooding risk, and public transportation’s contribution to air pollution and climate change. It can also include changes in housing regulation and policy and investments in healthcare, such as expanded Medicaid and health insurance and investing in disaster planning and readiness. 

“Resilience is a more holistic concept,” Matsui said, “which advocates for system-wide, multilevel changes and involves a range of strategies to enhance social, human, natural, physical, and financial capacities.”

What Pediatricians Can Do

Pediatricians have an important role to play when it comes to climate change and health impacts. 

“The first step is sort of understanding the complexity of climate change in terms of its potential health effects, but also being prepared to talk with our patients and their families about it,” Matsui said. “The second step is advocacy.” 

She drew attention to the February policy statement in Pediatrics that discusses precisely the ways in which pediatricians can leverage their expertise and credibility. 

“Pediatricians are ideal advocates with whom to partner and uplift youth and community voices working to advance zero-carbon energy policy and climate justice,” she said. “There are many opportunities to advocate for climate solution policies at the local, state, national, and even international level.” 

These roles can include educating elected officials and health insurance entities about the risks that climate change poses to allergies, asthma, and child health more broadly, as well as the benefits of local solutions, including improved air quality, tree canopy, and green space. “There are lots of opportunities to engage with the community, including speaking at public hearings, serving as an expert testimony, and writing letters to the editor,” she said. 

The impact of these efforts can be further maximized by working with other healthcare professionals. Lori Byron, MD, a pediatrician from Red Lodge, Montana, who heads the AAP Chapter Climate Advocates program, noted during Q&A that every AAP chapter in the country has climate advocates. She added that the AAP is the first medical board to have climate modules in their maintenance of certification specifically designed to incorporate climate change education into well visits.

Adjusting Clinical Care

Meanwhile, in patient care, Matsui acknowledged it can be frustrating to think about what a massive impact climate has and simultaneously challenging to engage families in discussions about it. However, a wide range of resources are available that can be provided to patients. 

“For a patient in front of you, being informed and prepared to talk about it is the first step to being able to assess their climate change risk and provide tailored guidance,” she said. Tailored guidance takes into account the child’s specific health situation and the risks they’re most likely to encounter, such as wildfire smoke, air pollution, longer pollen seasons, environmental allergens, or disruption of infrastructure. 

“If I am seeing a patient with asthma who is allergic to a particular pollen, I can anticipate that that pollen may be present in higher levels of the future, and that the season for that pollen may be longer,” Matsui said. “So if I’m thinking about allergen immunotherapy for that patient, future risk may be something that would push the conversation and the shared decision-making” from possible consideration to more serious consideration, depending on the child’s age. 

“Another example is a patient with asthma, thinking about wildfire risk and having them prepared, because we know from data that wildfire air pollution is going to be worse for that child than pollution from other sources, and there are ways for them to be prepared,” Matsui said. For instance, having an HVAC system with a high-grade air filter (at least a MERV 13) will filter the air better if a wildfire causes smoke to descend over an area. Portable, less expensive HEPA filters are also an option if a family cannot upgrade their system, and wearing an N95 or N95-equivalent mask can also reduce the impact of high air pollution levels. 

An example of thinking about the impact of potential infrastructure disruption could be ensuring patients have enough of all their medications if they’re close to running out. “It’s important for them to always have think about their medications and get those refills ahead of a storm,” she said.

Additional Resources 

Understanding that pediatricians may not have time to discuss all these issues or have broader conversations about climate change during visits, Matsui highlighted the AAP website of resources on climate change. In addition to resources for pediatricians, such as a basic fact sheet about climate change impacts on children’s health and the technical report that informed the policy statement, the site has multiple resources for families: 

The following resources can also be helpful to pediatricians and/or families:

In some states, Medicaid will provide or cover the cost of air conditioning and/or air filters.

The presentation did not involve external funding. Matsui and Moon had no disclosures. 

Tara Haelle is a Dallas-based science journalist.

Our planet is changing. So is our journalism. This weekly newsletter is part of a CBC News initiative entitled “Our Changing Planet” to show and explain the effects of climate change. Keep up with the latest news on our Climate and Environment page.

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This week:

• How oceans could be used for carbon capture on a big scale
• Dam! Beavers pose a methane problem in the Arctic
• Humidity makes a sweltering apartment that much harder to live in

How oceans could be used for carbon capture on a big scale

Scientists have said we’re poised to overshoot the 1.5 C warming target enshrined in the Paris Agreement, and that in order to return to 1.5 C by 2100, we would need to remove vast amounts of carbon dioxide from the atmosphere.

Carbon capture from smokestacks or the air, using technology and tree planting, has received a lot of attention and funding. But last week, a few hundred scientists around the world argued that more attention should be paid to carbon capture in the ocean.

“The ocean’s carbon content is 50 times larger than what is in the atmosphere. Its sheer size also means that ocean-based climate solutions can be scaled to significantly mitigate climate risk,” they wrote in a letter posted on the web page of Ocean Visions, a non-profit umbrella group for universities and oceanographic institutions focused on ocean-climate restoration solutions.

The problem? Even scientists know little about the effectiveness, risks or impacts of ocean carbon capture solutions. 

Kate Moran, president and CEO of Ocean Networks Canada and a spokesperson for the scientists who wrote the letter, said more information is crucial for making policy decisions about ocean carbon capture.

“We do need to, as a collective community, get behind research needed to understand these issues, and it’s pretty urgent,” she said in an interview from the Canadian Coast Guard ship Tully off the coast of B.C., where she is doing some of that research.

The letter was signed by a number of scientists from the Canadian firm Planetary Technologies, including its chief ocean scientist, Will Burt. Planetary Technologies ran its first ocean tests of its carbon capture technology in Halifax harbour this week (see photo above).

Burt hopes the letter helps the public “build some confidence that what we’re doing is … widely believed scientifically to be worth exploring.”

WATCH | Scientists hope antacid could help relieve climate change

Scientists hope antacid could help relieve climate change

Halifax Harbour is getting a dose of Tums to see if that will help remove carbon from the atmosphere. Paul Withers has the story.

By now, you might be asking, “OK, but what kinds of solutions are we even talking about?” 

They fall into two main categories: biotic and abiotic.

Biotic ocean carbon removal is similar to planting trees on land to absorb CO2, except it involves marine or coastal ecosystems and plants. The carbon they store is called blue carbon, and it can involve:

Seaweed or “macroalgae” such as kelp. The carbon can later be sequestered — for example, by sinking it to the ocean floor. (That’s one of the solutions Moran was researching on the Tully last week.)

Microscopic organisms called microalgae or phytoplankton, encouraged to grow by fertilizing the ocean with nutrients such as iron.

Plants in coastal ecosystems, such as tidal salt marshes, mangrove forests or seagrass meadows. Restoring degraded coastal ecosystems doesn’t just store carbon, it also reduces emissions from sources like erosion.

Abiotic solutions include:

Ocean alkalinity enhancement. This is being tested by Planetary Technologies. It involves adding “antacids” made of rock dust, such as magnesium hydroxide, to the ocean to neutralize dissolved CO2. This converts the CO2 into stable minerals and salts, effectively removing it from the carbon cycle. Like a sponge that’s been squeezed out, the water regains the capacity to absorb more CO2 from the atmosphere. In the photo above, you can see Dalhousie University researchers taking measurements from a boat after the antacid was added to the water, along with a red dye that helps track how the antacid spreads. Burt says this technology should also reverse ocean acidification that harms coral reefs and shellfish.

Electrochemical ocean carbon dioxide removal. This technology uses electricity to separate seawater into acidic and alkaline solutions. Each of those solutions uses a different method to remove CO2 from seawater (one of them is very similar to ocean alkalinity enhancement). California-based Captura and Montreal-based Deep Sky plan to test this technology in eastern Quebec in 2024.

Planetary Technologies’ Burt said that while reducing emissions is by far the best tool for tackling climate change, “we’re going to need more than that.” 

Ocean carbon capture “could be a really key player.” 

— Emily Chung

Old issues of What on Earth? are here. The CBC News climate page is here. 

Check out our radio show and podcast. This week, meet the people doing the dirty work of planting millions of trees, one by one, across Canada. What On Earth airs on Sundays at 11 a.m. ET, 11:30 a.m. in Newfoundland and Labrador. Subscribe on your favourite podcast app or hear it on demand at CBC Listen.

Watch the CBC video series Planet Wonder featuring our colleague Johanna Wagstaffe here.

Reader feedback

Gaille Musgrove responded to last week’s story on invasive species: 

“I live north of Toronto in a township called Adjala-Tosorontio. I love it here. Unfortunately, I have invasions of all kinds of plant species that I have never seen before. Something called ground clover (no relation to real clover) has spread all over my property. It choked out my grass and is invading my gardens. We also have something called dog strangling vine, which has pulled down a fence and killed many trees. 

“In the 46 years that we have lived here, we have lost all of our butternut trees, all of our beautiful beech trees and now something is eating our spruce trees. It is very distressful.”

Write us at whatonearth@cbc.ca. 

Have a compelling personal story about climate change you want to share with CBC News? Pitch a First Person column here.

The Big Picture: Beavers pose methane problem in the Arctic

Climate change is helping beavers colonize the Arctic, and those beavers are in turn causing more climate change. A study by Alaskan researchers that looked at aerial and satellite photos of Alaska’s Arctic tundra between 1949 and 2019 (see below) found that dams built by beavers created 11,000 new ponds between 1980 and 2019.

A new study by the same team finds those ponds are releasing methane, a powerful greenhouse gas, accelerating climate change. The methane is produced as vegetation flooded by the dams rots in the absence of oxygen, and as the spreading water thaws the surrounding permafrost. The researchers say this means beavers in the Arctic will initially increase the release of methane, although they don’t know what the long-term impacts will be.

Interestingly, while beavers may be bad for climate change in the North, they’re being recruited to protect against the impacts of wildfires and droughts in places like California. Research shows that areas with beavers are more resilient to wildfire impacts and have more open water during droughts compared to areas without beavers.

Hot and bothered: Provocative ideas from around the web

• Filmmakers have launched a petition calling on Toronto’s International Film Festival to drop sponsorship from RBC, noting it’s one of the world’s biggest financiers of fossil fuels.

• A California high school is offering paid student internships for climate action with the aim of preparing the students for green jobs. Bonus: The students have saved their district $850,000 US on a $2.9-million energy budget.

Humidity makes a sweltering apartment that much harder to live in

On a hot summer day, the air in Sridharan Vankeepuram’s room can be nearly unbearable.

“It feels like a furnace inside,” he said.

His small bedroom — crammed with a single bed and desktop computer — doesn’t get much cooler at night, especially when it’s humid, as is often the case during a Montreal heat wave.

Vankeepuram has spent the past two years in an aging brick building on the western edge of Montreal’s downtown, while completing his MBA at Concordia University. One day in July, Vankeepuram’s room felt like it was 39 C when taking the humidity into account.

To better understand the challenges of living in extreme heat as the climate changes, this summer CBC News installed sensors in 50 homes that were either wholly or partly without air conditioning across five Canadian cities, including Montreal.

(CBC used “heat index” to measure the combination of air temperature and humidity, rather than humidex, a similar index developed in Canada.)

The sensors took temperature and humidity readings every 10 minutes. In some places — particularly in apartments in Toronto, Windsor and Montreal — the humidity made the residences feel much hotter. Winnipeg and Vancouver, which tend to have drier heat, were the other two cities featured in the project.

For half of the 56 days measured, Vankeepuram’s room didn’t drop below 26 C, the threshold considered dangerous for seniors and those with pre-existing conditions if they’re exposed to it for a prolonged period. And Vankeepuram’s room consistently felt even warmer, because of the humidity.

Knowing he would move out after graduating, Vankeepuram didn’t invest in an air conditioner. On the worst days, he took multiple showers or brought a bucket of ice water into his room.

For others, the consequences can be more dire. Humans cool down by sweating, but when the air is saturated with moisture, that doesn’t work as well.

“The more humid it is in the air, the harder it is for that process to occur,” said Prof. Daniel Gagnon, a researcher at the Montreal Heart Institute. “We might still produce sweat, but instead of it evaporating, it will drip off onto the floor and then we lose all of its cooling power.”

Gagnon, an associate professor at the school of kinesiology and exercise science at the University of Montreal, reviewed CBC’s data and found it striking that although Montreal escaped the worst of the Canadian summer’s heat, the temperatures inside often felt like more than 30 C with the humidity factored in.

“We need to factor in humidity as well, because a given temperature might be comfortable if it’s very dry, but become very uncomfortable if it’s very humid, and the body’s response to those environments will also be different,” Gagnon said.

Research isn’t conclusive on whether humidity increases the likelihood of mortality in cases of extreme heat, but it nevertheless puts strain on the body. 

During a historic 2018 heat wave, 66 people died in Montreal — and 80 per cent of those people died in their homes.

Gregory Walton, a 51-year-old who lives in an apartment in Windsor, Ont., said nights are especially difficult. In his apartment, the temperature almost never dropped below 26 C during the period CBC monitored and, with the humidity, it felt like nearly 32 C on one particularly muggy day.

Overall, in Montreal, Toronto and Windsor, high rates of relative humidity sometimes added as much as five to seven degrees to how hot a residence felt.

Here are the highest heat index measures our sensors recorded, by city:

• Windsor: 39.

• Montreal: 39.

• Toronto: 38.

• Winnipeg: 37.

• Vancouver: 34.

Climate scientists say hotter, more humid summers are likely in the coming years, as the planet warms, largely because of the burning of fossil fuels.

According to Environment and Climate Change Canada, a humidex in the mid- to high-30s is when the average healthy person should be more careful. Above 40 is considered extremely high and all unnecessary physical activity should be avoided.

Dr. David Kaiser, associate medical director at Montreal Public Health, said over the long term, better urban planning and changes to housing will help bring down the heat — and humidity — indoors.

In the more immediate term, Kaiser said the most at-risk would benefit from having an air conditioner. British Columbia recently announced a $10-million program for free air conditioners for those most vulnerable to the heat.

“I think it’s important from a health perspective that if you have an air conditioner at home and it works, you’re not going to die in a heat wave,” Kaiser said.

— Benjamin Shingler

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