How climate change affects public health

Apr 13, 2019

There are plenty of news stories about how climate change is affecting the environment, but it is only recently we are discovering the long-term outcomes of climate change on our health. Dr. Jay Lemery, associate professor of emergency medicine at the University of Colorado School of Medicine, said climate change has adverse, complex effects on our health.

Lemery discussed his findings about the public health effects of global warming in “Enviromedics: The Impact of Climate Change on Human Health,” which he co-authored with Paul Auerbach. Lemery joined us on "Take Care," and said one of the main results of climate change is prolonged heat waves.

“We think about heat waves, which, historically, were those two weeks in the summer where there would be an intense heat event, and then it would sort of fade,” Lemery said. “Now, what we’re seeing is that these heat waves are lasting longer, and those two weeks are now two months in any given area.”

Rising temperatures mean hotter summers, which lead to extreme weather conditions like tropical storms and wildfires. Wildfires in particular, Lemery said, degrade air quality and can cause people with pre-existing pulmonary diseases to have exacerbated symptoms.

In addition to weather events, Lemery said, climate change indirectly leads to an increase in chronic diseases in those particularly vulnerable.

“It rarely can be attributed as the sole cause of an exacerbation of chronic disease, but it’s definitely a force-multiplier, where it pushes these people that are existing with very tenuous physiology over the cliff,” Lemery said.

Other diseases, like those spread by mosquitos and ticks, can increase as warm temperatures create perfect breeding grounds for disease-spreading insects in the Midwest and northern states.

“The correlations are really pretty straight forward, which is the warmer the temperature throughout the year, the better the conditions generally for mosquitoes to thrive,” Lemery said. “[We see] mosquitoes and ticks that carry these diseases into places where they historically haven’t existed.”

Lemery said the people most susceptible to health effects of climate change are those in socioeconomic or medically vulnerable situations, like those who work outside often, do not have reliable air conditioning or have pre-existing conditions that can become worse with rising temperatures.

Another susceptible group is people in developing countries, where extreme weather conditions like flooding and drought can devastate food supply and poorly affect communities in many ways.

“When a food staple is disrupted by extreme flooding, that really affects downstream nutrition for communities,” Lemery said. “That brings in civil strife and poverty cycles and things like that.”

The effects on things as seemingly minor as allergies can also make life more difficult for those most vulnerable, Lemery said. When there are warmer air masses, it changes chemistry in the air and an increase in ozone, which affects air quality and respiratory problems and leads to longer allergy seasons.

“This is something we tend to downplay, ‘Oh, it’s just allergies,’ but if you suffer from seasonal allergies, you know you’re incapacitated and you are miserable while you’re having those flair-ups,” Lemery said.

Mitigating these effects is not an individual process, Lemery said. Instead, it needs to be handled at the governmental level.

“We talk about energy usage and recycling and things like that, but I actually think the smart thing to do is to make this a priority for our legislatures,” Lemery said. “If we can convince both parties that this is an issue that has to be dealt with and that we can’t keep ignoring it, then I think we can advance to a new level of talking about it.”

The most important change that needs to occur, Lemery said, is for people to realize this is man-made climate change so a real dialogue can open up toward positive legislative action.

“The smart science tells us that this is human-induced. Then, it’s incumbent upon us to say, ‘Hey, how can we have a meaningful debate about this and understand risk-assessment?’” Lemery said. “If we can understand the risks, then we can move forward with meaningful policy changes.”