Lyceum Lecture Series: Week 5

Climate Change and Emerging Infectious Diseases

Dr. Kathryn Docherty, WMU Department of Biological Sciences

Climate change not only has an effect on the environment but it also has an effect on human health. Asthma, cancer, various neurological effects, and developmental effects can be attributed to climate change. It especially has an effect on how we interact with other organisms. So what does this have to do with infectious diseases you might ask? Well, we can start by investigating three types of diseases: water-borne, food-borne, and vector-borne, and we can see how these various diseases will adapt to climate change.

First, let’s start with water-borne diseases. As we should all know, the Earth is covered with water. 97% of it is saline while only 3% of it is freshwater. Of this small amount of freshwater, only 0.3% comprises our surface water. If you’ve been following this lecture series you know that climate change causes ice caps to melt and sea levels to rise, more intense storms, and increased extreme drought. All of these things will lead to a limited supply of fresh surface water. As water becomes limited, use of these limited areas will increase and promote the spread of disease.Let’s look at an example of a water-borne disease to put this all in perspective. Vibrio cholerae, the bacteria that causes the disease known as Cholera, caused 7781 deaths out of 589,104 cases in 2011. In Haiti alone there were 340,311 cases that led to 2869 deaths. The earthquake in Haiti in 2010 caused the disease to spread throughout the country in a short period of time. Because of the earthquake, wastewater treatment plants were flooded and the disease entered the groundwater thus causing the outbreak that eventually followed. Cholera can be prevented by filtering water and there is a vaccine available. If you do contract Cholera you can also take antibiotics to treat it. Legionella pneumophila, another water-borne bacteria that causes Legionnaire’s Disease, has tripled its cases within the last ten years. This disease can be prevented by simply cleaning your air conditioning unit. However, there is no vaccine for the disease but it is treatable with antibiotics.

Next, we can look at various food-borne diseases. 48 million Americans get sick with food-borne illnesses each year. US fisheries depend on species that are sensitive to ocean acidification caused by global warming. Molluscs and shellfish cannot form shells and are therefore more susceptible to infections. The warmer waters also create a better environment for various bacteria to reproduce. All of these factors cause an increase in food-borne illnesses. Between 1997 and 2006 there were 4754 cases. These diseases are preventable by cooking shellfish. There is no vaccine currently available but they are treatable with antibiotics.

Lastly we can look at vector-borne illnesses. Malaria is one of the best known vector-borne diseases and it is already a global threat with 660,000 deaths in 2010. Plasmodium falciparum, a protozoan parasite that infects the liver and red blood cells, is transmitted by mosquitoes. This disease depends on various factors in order to be especially infectious. The speed of development in the mosquito, the range of the vector, the elevation changes of the vector, and the length of the transmission season can all determine whether the disease is effective or not. With climate change the range and elevation of these vectors, and the length of the transmission season are likely to change and possibly increase the infection rate of these diseases.

So we can conclude that the increase of global temperatures will likely lead to a drastic increase in disease outbreaks across the entire globe. This gives us more reason to react drastically to climate change. If we want to protect human lives something needs to be done sooner rather than later.

Lyceum Lecture Series: Week 4

The Dance of the 3 “E’s”: Environment – Energy – Economy

Dr. David Barnes, WMU Department of Geosciences

Environment

It was best said by Al Gore in his book, The Inconvenient Truth, that “its hard to make someone understand when their paycheck is dependent on not understanding.” This is exactly why more effort has not gone into preventing climate change. We know that radiative forcings such as solar irradiance, the Earth’s albedo, and the change in effective re-radiation of heat energy are reasons why the Earth goes through warming events. Climate change throughout geological time has had various causes and rates. Climate sensitivity, the equilibrium climate response to doubled CO₂, decreases with increasing atmospheric CO₂ concentrations. This means that as we increase our carbon emissions, we are in turn causing the Earth’s ability to cope with climate change to decrease.

Many people argue that the Earth goes through climate cycles and that we can explain our current warming by attributing it to a Milankovitch cycle. It turns out that by following these Milankovitch cycles in geologic time we can predict what our current climate should look like. It turns out that we should actually be currently experiencing a global cooling event! We are increasing our CO₂ by almost one hundred times what in should be and our temperature is increasing by almost fives times as much as what it should be. The NCADAC even predicts a possible temperature increase of 5-10^oC and a sea level rise of 6.6 feet by 2100.

Environment & Energy

We can develop stabilization wedges that can address greenhouse gas emissions for 50 years with current technologies. These can be used to determine where changes in emissions need to be made. Coal combustion produces approximately two times the amount of carbon as other fossil fuels and yet it still dominates our energy use. A process called geosequestration has been developed where CO₂ from the atmosphere is deposited into geological media. Further development of this technology could save us from a climate crisis.

Environment, Energy, & Economy

The Hartwell Paper, published in May of 2010, reported that the Kyoto Protocol had failed at reducing CO₂ emissions.In order to effectively reduce CO₂ emissions we need to level the costs of low-carbon electricity technologies. The paradox with renewable energy, however, is that even though it has low carbon  emissions it can be extremely expensive to run. With wind and solar energy, the base load needs to be dialed down to accomodate these energies but then must be dialed up when no wind or solar energy is available. Staged hydraulic fracturing in shale gas and oil reserves on the other hand provide a cleaner energy that does not require as much money to distribute. Staged hydraulic fracturing does have its drawbacks with water acquisition, chemical mixing, and treatment and disposal of wastewater flow-back.

Overall, the US has started to reduce its overall CO₂ emissions. In early 2012, energy related CO₂ emissions were the lowest since 1992. Some progress is better than no progress!

Sustainability …

Sustainability is a new idea to many people, and many find it hard to understand. But all over the world there are people who have entered into the exercise of imagining and bringing into being a sustainable world. They see it as a world to move toward not reluctantly, but joyfully, not with a sense of sacrifice, but a sense of adventure. A sustainable world could be very much better than the one we live in today.

Donella H. Meadows, The Limits to Growth: The 30-Year Update

Is There a Green Side to the Superbowl?

The day after one of the largest consumerism holidays I find myself wondering if there were any environmental benefits to the Superbowl. I mean, did you see those lights that they were using in the stadium?! You can be sure that those lights were not saving any energy (besides when the power decided to go out). So, my curiosity got the best of me and I then stumbled on this article by the New York Times. It shows that energy consumption is down during and after the Superbowl, most likely because everyone is glued to the television, but who knows! It’s worth the read and can be found here. Enjoy!

-C