Saturday, October 17, 2009

Climate Change: It's Hot in Topeka!

In the summer of 2006, it was hot in Topeka. Very hot. Record-breakingly hot. Swimming-pool-and-bath-water-what’s-the-difference hot. Even lizards are unhappy hot. So hot, in fact, that when the character of Blue in the Cartoon Network show “Foster’s Home for Imaginary Friends” was watching an animated weatherman note that there were showers in Spokane and that it was hot in Topeka, the latter phrase quickly morphed into a frantic chant of “It’s hot! My toe is hot! I’m a hot toe picker. Pick my toe!” Needless to say, he was rapidly adopted as a community icon, and virtually everyone could be found sitting on their doorstop in the evening shade picking at their pedal piggies. (See for yourself at http://www.youtube.com/watch?v=AzdWMcLvn2g.)

Of course, Al Gore would tell us that in the future, we’ll all be hot (and presumably it’ll be HOTTER in Topeka, in which case we’ll be picking the toes of otters). But while most people in our polarized world see climate change as an either/or problem, a battle between “greens” and “greenbacks,” it’s always been interesting to me that the real battleground is this country is not in the heavily populated or industrialized states but in rural America. Certainly there are articles and stories about ethanol production, and every now and then you’ll hear about some work on using bovine methane as an energy source (and if you’ve ever hung around a feed lot, you have no doubt as to that potential). By and large, however, rural America is often thought of as immune to energy politics, except when trying to determine how many cows you can displace for a wind farm.

But in Kansas, energy politics dominated the legislative process for the past two years and virtually paralyzed the rest of state government. At issue was the decision of the Secretary of Kansas Department of Health and Environment (KDHE) to reject a permit for building a coal-fired power plant in Southwest Kansas. The reasons for and against the plant are too numerous to mention in this brief piece, but essentially it became a conflict between legislators from poorer rural areas who wanted development versus those from relatively more affluent urban areas who were more eco-friendly. But what I think is most unfortunate about the situation is that it bodes poorly for national efforts after health care reform, as energy policy and “cap and trade” are next on the President’s Wish List. For just as the West Coast tends to be a harbinger of social change, for better or for worse Kansas has always been ahead of the curve on political conflict. (While Republicans nationally are now recognizing the depth of the schism within their party, Kansas has essentially been a three party state for a decade. Of course, we put our own twist on it…our parties are Libertarian Conservatives, Traditional Republicans, and Conservative Democrats who would be considered Liberal Republicans anywhere within 60 miles of either coast.)

As some of my readers know, I was the Director of Health within KDHE during the time of this decision, though I was not directly involved in it. Shortly after leaving the state agency, however, I was asked to summarize for some legislators what we do and do not know, from the perspective of science and health, about global warming and specifically what it would mean to a state like Kansas. With the winter coming up, energy costs rising again, and the President’s focus on energy policy, it seems like the time is ripe to revisit the issue, with some specific attention (and a shout out) to that place I still call home.

The Warm Earth and Greenhouse Gases

To properly begin this review, it’s vital to note that the earth normally goes through cycles of global warming and cooling. These cycles are a result of a number of a number of factors, the most significant of which is the relative quantity of “greenhouse gases” in the atmosphere. Less important drivers include solar variation, subtle changes in the earth’s orbit, plate tectonics, volcanism, and the manner in which the oceans distribute heat. (Try getting all that into one sentence at a cocktail party.)

The role of “greenhouse gases” is critical to note. The atmosphere of the earth can be thought of as a “closed” system, within which no substance save energy (heat) can get in or out. Greenhouse gases are those molecules within the atmosphere that trap the sun’s heat energy within the atmosphere, preventing it from being radiated into space and, in turn, radiating the energy back to the surface. These gases include water vapor, carbon dioxide (CO2), methane (CH4), and other compounds. They are crucial to maintaining normal global temperatures; without them, the mean temperature of the earth’s surface would hover just below 0 F. Not all greenhouse gases are created equal; a molecule of methane has 23 times the Global Warming Potential, or GWP, than a molecule of CO2. (This gets us back to the cows, suggesting that if we all go to Chik-Fil-A more often, we can combat global warming.)

Increased amounts of greenhouse gases within the atmosphere lead to increased surface temperatures. For example, increased surface temperatures induce evaporation of ice sheets and bodies of water, increasing the content of water vapor in the atmosphere. This increases global heat retention, and the cycle is magnified and begins again. The planet Venus, often thought of as the “twin” of the earth, is an example of a runaway greenhouse gas effect. It’s atmosphere is composed mostly of carbon dioxide, and it’s barren and arid surface bakes at over 872 F, hot enough to melt lead. From the standpoint of human activity, increased temperatures increase demand for cooling of homes and business, driving up CO2 production at power stations and further increasing the temperature, which again drives increased energy demands and further CO2 production.

What is Climate Change?

It’s important at the outset to differentiate weather from climate. Weather refers to events that occur in the “present,” over days or perhaps weeks. Climate describes the overall character of events and conditions as measured over time (decades, centuries, or more). This difference is critical, for you’ll often hear that the presence of a cold snap argues against a theory of global warming. Similarly, a heat spell cannot be taken n and of itself as evidence of climate change. (While the contemporary debate rightly focuses on global warming, climate change is actually a more correct term to use because it describes epochs when the earth cools as well.)

As previously noted, the earth normally undergoes cyclical climate changes of both warming and cooling throughout history. In the context of the history of the earth, we are still technically in an ice age (defined as a time in which sheets of ice continue to cover areas of the planet). We happen to be in a warmer period of the current ice age known as an interglacial. This is important to note because glaciers have been recognized as a sensitive early indicator of climate change. But just as weather cannot be taken as an indication of climate, the fact that we still have ice on the planet does not argue against the concept of global warming. This key difference is emphasized by noting the current retraction of the glacier sheet across the globe.

While climate change is a long-term natural phenomena, there is unmistakable evidence that the normal cycle of global warming is being accelerated, and that the cause of this acceleration is human activity (“anthropogenic” factors). The majority of the impact is caused by the burning of fossil fuels such as oil and coal, followed by the production of methane though large-scale agricultural production. Both of these activities produce “greenhouse gases,“ which are significant drivers of global warming as we‘ve discussed. Interestingly, cement manufacturing also accounts for a small percentage of CO2 release. There is also a human influence on global warming based on land use patterns, deforestation, and development, but this effect is marginalized by the contributions of greenhouse gas production.

Since the 1850’s, CO2 levels have risen from 280 parts per million (ppm) to 380 today, and if they continue on the current trend they would near 600 ppm by the end of the century. CO2 levels are known to be higher now than at any time in the past 750,000 years, and it‘s speculated that they are higher now than at any point in the past 20 million years.

Predicted Effects of Climate Change on Health

The increase in CO2, and the accelerated “greenhouse effect,” lie behind the predictions of a mean global temperature change of up to 6 C during our children’s lifetime. Rises in global temperature are considered to result in rises in sea level and changes in agricultural production, biodiversity (species extinctions), the number and severity of extreme weather events, and significant effects on human health.

It’s somewhat more difficult to specify the effects of climate change on an individual state like Kansas. The climate of Kansas features a large air mass division across the middle of the state, which is one of the reasons for the stark differences in the ecology between the forested eastern half of the state and the high plains that characterize the western plateau. As a result of this air mass, different parts of Kansas could expect to see differing effects in an era of global warming. Eastern Kansas will become wetter, while western counties will become drier and more arid. Experts in climatology would be better equipped to provide more detailed estimates of the effects of climate change on both the agricultural industry and upon the parks and wetlands of Kansas. But you can guess that if’s it hard to make a specific prediction for an area as large as a state, it’s all the more difficult to determine the effects global warming on a local area, or of a greenhouse gas producer on its’ immediate proximity.

The predicted health effects of climate change fall into five major categories. The first is that of temperature-related death and disability. This category includes direct effects such as heat strokes and heat illness, as well as indirect effects such as stress on other organ systems induced by heat. The second relates to changes in rates of vector-borne (mosquitos, et al) diseases due to hotter, wetter environments. Problems linked to air pollution represent a third broad class, and increases in food and water-borne disease encompass a fourth. The fifth category includes the negative health effects of extreme weather events such as tornadoes and flooding.

In Kansas, it’s probably safe to say that all of these categories would be likely to apply. However, it should be noted that these effects are posited to occur in a regional sense at best. Models do not yet exist that can accurately predict specific local effects. This being said, thinking specifically about Kansas a final possible health effect comes to mind. Climactic changes may also result in decreased agricultural production and crop-shifting. While it’s unlikely that Kansans will suffer from nutritional disorders as may occur in the undeveloped world, these events may influence the economic well-being of the state.

Mitigating the Effects of Climate Change

While climate change is inevitable over geologic time, human activity is clearly accelerating the timeline of events, making the consequences of global warming something our children can expect to confront rather than an event in the remote future. As someone interested in public health (where I’ve always said you can be a paid professional liberal), I hope to see the human effects of climate change minimized. So let’s briefly review some strategies that can be used to prevent worsening of the problem.

There are three main strategies to mitigating these effects. The first is to simply eliminate the means of production of greenhouse gases. Industries and means of transportation that produce greenhouse gases are no longer sanctioned and alternatives, such as solar or wind power, must be identified and developed. Speaking strictly from the standpoint of efficacy, without regard for the economics of the issue, it is the most immediate way to curb greenhouse gas emissions.

A second strategy is to get rid of the greenhouse gases produced. For example, carbon dioxide can be taken up by a “sink,” a reservoir used to remove CO2 from the atmosphere. Examples of this strategy include reforestation, in which the large-scale planting of trees encourages CO2 uptake in the process of photosynthesis. Encouraging plankton growth in bodies of water and adapting agricultural processes are other examples of “natural“ ways to enhance CO2 removal from the environment. “Artificial“ methods include carbon capture during the combustion process and injecting CO2 into underground geologic formations such as oil fields, coal seams, and saline aquifers.

Each of these methods is controversial to a degree. For example, there is some debate as to the efficacy of reforestation given different climatic and geographic conditions; and in many cases, experience and technology have yet to fully support the theory. Nonetheless, they do offer real potential and, in my own view, should be aggressively explored as part of a comprehensive, cutting-edge energy plan

The third strategy is to maximize the energy output per unit of greenhouse gas created, therefore decreasing the “carbon footprint” of the total amount of energy produced. This can be done in two ways. The first is by influencing the process of production itself, using technologies to burn fuels more efficiently with less “off-gassing.“ The second is the use alternate energy sources to increase the total amount of energy produced per unit of greenhouse gas. On a small-scale, this is what hybrid automobiles do; they use the power from the combustion engine to charge a battery, which provides more power for the auto given the same amount of fuel used than a traditional gasoline engine. Supplementing fossil fuel power plants with wind or solar energy projects is a larger model for the same basic concept. Combustion of agricultural methane to produce both energy and CO2, a gas with a lower GWP than methane, is a variation of this idea.

I have deliberately left out the idea of “carbon offsets” in this discussion. The term is most often thought of as an economic tool where permits for industry resulting in greenhouse gas production are “traded” for dollars to be used elsewhere to remove or reduce other emissions or develop alternative energy sources. But scientifically, it means simply that if carbon is released into the atmosphere through one mechanism, something else removes it form the air so there is an even balance of production and disposal. In this sense, the use of “carbon offsets” is most similar to the sequestration strategies noted above.

All of these are large-scale mitigation strategies. To my understanding, accurate models do not yet exist that are able to predict how much or how little any single project contributes to global climate change, nor how much or how little any particular strategy will mitigate these effects. One is not necessarily preferable to the other, and all are reasonable and logical ways to approach the problem. This being said, if we acknowledge that global warming is a reality and that human activity is accelerating the process to our detriment, it is my personal belief that we have an obligation to begin to lay a groundwork for change using any or all of our options.

That being said, a friend has just told me that on this Friday night in mid October, it’s rainy and cold in Topeka. Cold rain on my toe. My toe has a cold. Pick that toe!

(And just for the record, the only other mention of Topeka in popular culture? The remarkable Loretta Lynn lyrics that remind us:

“But here in Topeka, the rain is a fallin'
The faucet is a drippin', and the kids are a bawlin'
One is a toddlin,' and one is a crawlin'
And one's on the way.”)

No comments:

Post a Comment