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Monday Feb 18, 2019

Let's Take a Public Health Approach to Climate Change

In my pursuit of a master's degree in public health, I recently took a class that analyzed climate change policy. This fabulous class helped me sort out an unfortunately hyperpartisan issue, and it was timely, given all the climate-related shenanigans going on here and abroad. In this post, I will lay out what the public health message regarding climate change should be.

[small boat in dry lake bed]

Let's start general. The CDC has guidelines for a "public health approach"(www.cdc.gov) to issues that affect entire populations. Think car safety, violence, pollution or measles. There are four steps:

  • Define and monitor the problem.
  • Identify risk and protective factors.
  • Develop and test prevention strategies.
  • Assure widespread adoption.

For our purposes, I will combine these into the first two and last two steps. In my recent post about campaigning and organizing, I noted that when trying to enact policy change, you have to identify the decision-maker(s). As a provider of patient care, you are often the decision-maker, but when talking about city ordinances and nationwide policy, odds are you are not -- yet.

The first step of convincing decision-makers to do something is convincing them there actually is a problem. This is easy with things like Escherichia coli outbreaks in romaine lettuce, but it is harder with controversial subjects, such as climate science.

Part I: Defining and Monitoring the Problem

There are three potential types of problems with climate change: direct, indirect and social.

Direct effects are things like storms, heat waves, air quality, fires and floods. These are things that happen whether or not climate change is caused by humans, or, as in the case of air quality, that result in health impacts whether or not climate actually changes. As an example, the Asthma and Allergy Foundation of America reports(www.aafa.org) that those who have asthma are "40 percent more likely to have acute asthma episodes on high-pollution summer days than on days with average pollution levels." Notably, we are already seeing phenomena such as increased pollution, worsening heat waves, widespread flooding, shifting polar vortices and massive storms, which are having dramatic health and economic impacts and are occurring regardless of whether humans are causing climate change.

According to a recent report,(www.wired.com) 157 million more people experienced a heat wave in 2016 than in 2000, including more than 12 million Americans. Heat and injuries associated with those events cost the world 153 billion hours of labor, including more than 1 billion hours in the United States.

The United States experienced 11 "climate disasters"(www.ncdc.noaa.gov) that each cost $1 billion or more last year, and that's bundling all the California wildfires into one disaster.

Indirect effects are things such as increases in famines, worsening droughts, a rise in vector-borne diseases as habitats spread (think ticks, malaria, dengue, leishmaniasis or Chagas disease), and ever more prevalent food- and water-borne pathogens.

Again, we are already seeing some of these effects. In 2004, passengers on a cruise ship developed an infection after eating raw oysters. Vibrio parahaemolyticus was the offending agent, which is unsurprising because it is famous as a cause of cruise ship diarrhea outbreaks. The interesting bit is that this cruise ship was in Alaska, and this is a warm-water bacterium. According to the New England Journal of Medicine,(www.nejm.org) mean water temperatures in July and August at the implicated oyster farm have increased 0.5 degrees per year since 1997.

Global hunger increased for the third straight year(www.fao.org) in 2017, and at least part of the cause was climate disaster, such as the decimation of food supplies in vulnerable countries due to storms and drought. According to Physicians for Social Responsibility,(www.psr.org) "For every 1.8 degree increase in global average surface temperature, we can expect about a 10 percent decline in yields of the world's major grain crops."

It doesn't matter if rising temperatures are caused by humans or not, we get hungry without wheat either way.

Social factors are those that result from demands on individuals, communities and infrastructures. Think posttraumatic stress syndrome and depression, or the difficulty of mass relocation if seafront property is submerged, or all the problems that result from sudden population density increases in "refuge" locations, such as poor access to health care or sanitation. These will set in most poignantly if sea levels rise as predicted, especially if we have not prepared for the fallout.

Now that we have a framework in which to think about the potential problems caused by pollution and climate change, we have a few new ways of presenting them. And if your conversation partner has doubts about climate change, your tack should take into account the reason why.

There are three major reasons people will be resistant to taking action concerning climate change:

  • They don't believe it's happening. Thankfully, people in this camp are a minority. For example, President Donald Trump stated in 2016, concerning climate change, "I think there is a difference,"(www.theverge.com) walking back his 2012 claim that climate change is a hoax.(twitter.com) Heck, even lawyers representing Chevron agree that climate change is real and human-driven.(www.wired.com)
  • They think humans are not a primary cause of climate change and, thus, do not need to change anything to be part of a solution, given that the earth experiences cyclical climate changes.
  • They believe that climate change is happening and humans may even be contributing, but don't think it is as serious or as worrisome as some are making it out to be.

In any of these situations, skeptics are not likely to take action because, to them, any action would be a waste of money, as well as rife with needless and draconian regulation that would likely lead to economic depression.

However, nearly 80 percent of Americans believe climate change is occurring and is causing extreme weather patterns, up from 70 percent in 2015. Importantly, 64 percent of Republicans now believe this, up from 49 percent three years ago.(www.monmouth.edu)  

Part II: Prevention Strategies and Adoption

From a public health perspective, there are two timeframes and two types of action to choose from. In terms of timeframes, we can take steps that affect the short-term causes and symptoms we see today (asthma, COPD, heat waves, storms), and we can take steps that affect the long-term causes and symptoms we predict we will see decades from now (sea level rise, global temperature elevation).

Secondly, we can take adaptive or mitigative steps. Adaptation is preparing to absorb the impacts of climate change when they occur, reducing harm from warming temperatures, storms or increased pollutants. Mitigation is preventing the bad things from happening as best we can.

Now we have four types of interventions to talk about:

  • short-term adaptation,
  • short-term mitigation,
  • long-term adaptation and
  • long-term mitigation.

No matter what your decision-maker believes about long-term climate change risks and whether or not climate changes are caused by humans, they should respond to worsening asthma rates due to pollution,(www.theguardian.com) increased deaths and injuries due to heat waves or fires, or increased damage due to floods and storms.

These things we can mitigate by maintaining emissions laws for private vehicles, increasing regulation for industrial emissions, developing infrastructure for public transport, and improving planning for floods and fires. We can adapt by increasing green spaces, permeable cement and water features in cities, thus minimizing urban heat islands, which can increase temperatures in cities by as much as 10 degrees.(scied.ucar.edu) We can focus on the most vulnerable by adding cooling zones to schools, elderly care homes and poor neighborhoods where people are least likely to have air conditioning.

For the long term, skeptics have a point, and it's a fair one. All we have are models that try to predict what will happen in the future. Many people think that because models are not actual measures of future temperatures, they are not good enough to risk the world economy. Public health should have two responses.

First, convince them that the science is sound. Start by reminding people that a climate model is different than a weather model;(blogs.ei.columbia.edu) weather concerns whether it is going to rain tomorrow, but climate considers whether this 30-year cycle will be warmer than another 30-year cycle.

Next, you can try to prove that, given that measurements from the future are a little hard to come by, climate models are the best we have -- and they actually are pretty good. We know this by hindcasting with current models (looking back to a measured event like the eruption of Mount Pinatubo in 1991 and using the model to predict what will happen after said event, then comparing modeled and measured results), and by evaluating old climate predictions. Both are scarily accurate.(www.skepticalscience.com)

In 1972, a meteorologist named J.S. Sawyer, M.A., F.R.S., predicted a 25 percent increase in atmospheric carbon from the 1850s to 2000 and a corresponding rise in temperatures. Both were spot on.(skepticalscience.com) Similarly accurate climate predictions were made by Wallace Broecker, M.A., Ph.D., in 1975(skepticalscience.com) and James Hansen, Ph.D., in 1981.(skepticalscience.com) Hopefully the shock and awe of a confirmation of predictions will sway people, and you can progress to the mitigation and adaptation strategies so sorely needed.

If not, we move to the second tactic. Ignore their disbelief of the science, usually based on distrust of climate models, and ask them to make a value assessment. In this assessment, I am proposing we are only looking at increased mortality (not even morbidity) related to pollution, which we can all agree exists regardless of whether it is affecting the climate.

How much a life is worth? Given that the Paris Agreement(unfccc.int) will reduce pollution as a side effect of trying to curb climate change, it will cost the world 33 trillion euros between 2020 and 2050 (1.3 percent of the world's GDP) but will save 101 million people from premature death due to pollution-related lung disease.(www.thelancet.com) In the context of the devastation predicted by climate change models, this is a side benefit -- but maybe it is enough to make climate-change skeptics think about at least reducing pollutants in the long term, and that's a foot in the door.

A public health approach can help you accomplish wonderful things. You will reframe something political into something focused as purely as possible on health and wellness. Try to bring that to the forefront. Good luck!

Stewart Decker, M.D., is a family physician practicing in southern Oregon. He focuses on the intersection of public health and primary care.

Posted at 01:20PM Feb 18, 2019 by Stewart Decker, M.D.

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