Skip Navigation


September 26, 2006

Q & A: What Can We Do About Global Environmental Change?

Scientists have concluded that the global environment is changing as a result of human activity. Changes in the environment, particularly the rise in temperature that’s changing the climate, could have serious consequences on our health. Cindy Parker, MD, MPH, an environmental health expert with the Bloomberg School’s Center for Public Health Preparedness, sat down for an interview with Tim Parsons of the Office of Communications and Public Affairs, to discuss the health impact of global environmental change.

In August, Parker co-authored the article “Global Environmental Change: What Can Clinicians and the Environmental Health Community Do About It Now,” in the journal Environmental Health Perspectives with fellow Bloomberg School of Public Health researchers, Brian Schwartz and Thomas Glass, and University of Michigan School of Public Health researcher, Howard Hu. In their article, the authors outline the unique role clinicians and public health workers play in helping to limit global environmental change.

Question: What are some of the problems we face as a result of global environmental change and more specifically climate change?

Answer: Usually what people think of first is an increased risk of heat stroke and heat stress. In fact in 2003 when Western Europe had its heat wave, 35,000 people died as a direct result of the heat. With climate change we can expect to see more frequent heat waves lasting longer and with higher temperatures.

Also people tend to think of infectious diseases as being a risk with climate change. For example, in some parts of the world, malaria’s range has been limited by cooler temperatures at higher elevations. As temperatures warm, mosquitoes may be able to thrive at elevations where they weren’t able to live before—exposing virgin populations to malaria—in which the morbidity and mortality from malaria is much higher. A new spread of malaria is not necessarily a risk for the United States because malaria already occurs here and is kept in check by our public health system. The recent spread of West Nile virus, however, does have a climate component to it.

Question: What are some of the other challenges?

Answer: One thing at the top of the list is the impact on the water supply. Climate change can affect precipitation patterns. We are expecting with a changed climate more of our precipitation will come during the spring and summer months. It won’t be stored up in snow packs, which provide water gradually through the summer months when we need it the most. Instead it will come at a time when more of it will just wash off and is less likely to be captured and used later. Water is obviously absolutely necessary for our life and our health. A world with far less water will have huge health impacts.

Air quality is another issue. We know that climate change makes our air quality worse. Ozone, for instance, forms in the presence of heat and light. In a changed climate, we can expect higher concentrations of ozone, particularly in the summer months. Ozone is really bad for our health when we breathe it in at ground level. Climate change makes air pollution worse and air pollution makes climate change worse. It’s a nasty snowball effect.

Question: We often hear about the dangers of sea level rise. What is the concern?

Answer: We know that the glaciers are melting. In fact, they are melting at a rate much faster than we had originally modeled or projected and this is of real concern. As the glaciers melt, the sea levels rise. Thirteen of the worlds 20 largest cities are located at sea level.

We saw in New Orleans with Hurricane Katrina how difficult it is to evacuate people in an emergency. It’s impossible to evacuate infrastructure. In New Orleans, for example, the health care system was severely crippled by the storm and flooding and is still not anywhere close to what it was before.

When you think about where our major infrastructure is located, it tends to be in our cities. Our biggest, most advanced hospitals are in our largest cities. That’s also where things like water treatment plants are located. Most of the infrastructure that keeps our society healthy tends to be in our cities. With sea level rise, we could lose a lot of this infrastructure as well as the lives of those people in flooded areas immediately at risk.

We also expect to see more storm surge. Again as we saw with New Orleans, as the sea level rises, the big waves that come with storms get bigger and can move farther inland,causing more damage.

We can expect more people injured and killed during extreme weather events. In fact, extreme weather events themselves are much more likely to happen under a changed climate. We can expect hurricanes to be more intense. Hurricanes are driven by sea surface temperature. Certainly as global temperatures warm, sea surface temperatures warm as well. That drives the hurricane wind patterns and makes them stronger. Warm air holds more water than cold air so the hurricanes can have more water in them. As we saw in New Orleans, it’s the flooding that brings most of the damage.

All these factors working together do not bode well for health.

Question: Environmental change seems to have tremendous potential for causing a great deal of social upheaval don’t you think?

Answer: When you think about potentially relocating hundreds of millions of people under perhaps already stressed conditions that is going to cause a lot of social problems. Bangladesh could lose a third of its land mass with a moderate increase in sea level—an increase less than the extreme worst-case scenario—something that is within the realm of possibility within the next 50 to 100 years. The countries around Bangladesh are already crowded and that infrastructure is already stretched to capacity. If you have to relocate one third of the population of Bangladesh into an area where the infrastructure is already stressed, you are going to have conflict. In fact, the Pentagon commissioned a report investigating some of the worst-case scenarios for climate change and concluded that climate change is a greater threat to our security here in the United States than terrorism.

Question: What are some of the things clinicians can do to address climate change?

Answer: Clinicians have long counseled their patients on measures to keep healthy. Normally, it’s some measure that patients do to prevent a disease or bad health outcome in that particular patient. Climate change and global environmental change are true population issues. When I reduce my greenhouse gas emissions that may help to protect coastal populations some time in the future, but it may or may not have any effect on me personally.

This is a real change in a way we counsel patients about preventive measures. There have been some precedents set. With secondhand smoke for example, we counsel patients that smoke not only is affecting you but it is affecting those around you in a limited environment like your children, your family and your coworkers. With environmental change, we’re talking about helping people you don’t even know.

We need to start counseling patients about reducing their carbon foot print—how much carbon dioxide they are putting into the air. It is sort of a leap in how we think about things. These steps may not necessarily help me personally, they may indeed, but they will help the earth’s population as a whole. If nobody does anything, that will definitely impact me personally. This is not an environmental issue per se, it is actually a huge health issue.

Question: What should doctors be telling patients?

Answer: Conserving energy is a key to the whole problem. Simple things like switching from the incandescent light bulbs we all grew up with to compact fluorescent light bulbs that use a fourth to a fifth of the energy and last 7 to 10 times longer can make a huge difference. As one individual person, it won’t make any difference—except on my electricity bill—but if we work together to change billions of light bulbs to some that use a fifth of the amount of energy, that’s a huge amount of change.

Adjust the thermostat. There is no reason when it is 100 degrees (Fahrenheit) outside that you have people inside wearing sweaters because the air conditioning is too high. Timers can shift the thermostat to more conservative temperatures at night when you’re asleep or when you’re not there.

How we get from point A to point B makes a huge difference too. What we drive, and if we drive at all make a difference. Shopping close to home also makes a difference. Driving the most fuel-efficient car for your needs makes a difference.

These are just a few of the things everyone can do that take very little effort and don’t make us feel like we are denying ourselves life’s pleasures.

Question: What could be done to address the economics of climate change?

Answer: Our economic structure is set to measure development by the amount of products produced. This doesn’t take into account our health and from a health standpoint, it doesn’t make any sense at all. The typical example given is that every time someone gets cancer our Gross Domestic Product actually goes up, because all the medications, treatment and testing required to treat the patient adds revenue. Clearly that is not a good measure of development in any sort of social or health sense.

One of the things we need to do is to develop some sort of a Global Environmental Health Index as a different way to measure development that takes into account health and environmental issues. We can’t expect people to be healthy if the environment is not healthy. We need to be measuring different things, not just how much actual revenue is generated. We need to subtract from that revenue for the bad things, like how much pollution was generated by that revenue, or how much forest was removed, or how much warmer our climate was.

It would also be useful if we had a better way to tell if the products we are buying are more or less environmentally damaging. We recommend some sort of environmental labeling for consumers. Right now, when we look at our food labels for example, it tells us the content and how much fat and calories the food has. If we came up with something similar for a toaster, for instance, we could see that the manufacturing of this toaster produced X amount of pollution or greenhouse gases. We could then compare it to another product that used fewer resources or produced less pollution. It could help consumers make better decisions.

Public Affairs media contacts for the Johns Hopkins Bloomberg School of Public Health: Tim Parsons or Kenna Lowe at 410-955-6878 or