Wednesday, May 17, 2017

Listen up: Escape the effects of noise pollution

This appeared as an original post for Blue Ridge Outdoors on May 17, 2017:

I’m awake early this morning, and I walk to the end of the driveway to retrieve the papers. The sky is clear, the air fresh and cool. But the drone of the highway hangs in the air, too, the monotonous, dull sound of trucks, cars, and motorcycles passing through Asheville on I-40, just a few hundred yards to the west of me. Even through a dense forest of mature trees, the drone is continuous and palpable. My neighbor and friend has begun recording birdsong on our campus, and the resulting sonogram reveals that, even at times when we are not quite conscious of the highway sounds, the drone is present, ever titillating our senses at a deep level. And I wonder: What effect has this had on me and my family over the past thirteen years?

Environmental health researchers report that tens of millions of Americans suffer adverse effects from noise exposure, including sleep disruption, stress, hypertension, and even cardiovascular disease. Many readers of this magazine are probably especially susceptible to noise exposure, given that we live in the populated eastern United States. Our exposure to noise is unrelenting, stemming from road and rail traffic, air transportation, and industrial and occupational sources. And, of course, there’s always the ubiquitous leaf blower and the yapping dog down the street.

Mostly, we are not even aware of some or any of the effects, as we have become desensitized at a conscious level, accepting noise exposure as a tradeoff for the benefits of modernity. The good news is that many people are working at all levels of society to help reduce noise exposure for Americans, too. For example, the technology exists now for quieter leaf blowers, and police and fire sirens are being developed to focus on horizontal sound, so that people in high-rise buildings will not hear them. There are nonprofits dedicated to the cause of reducing noise exposure, such as Noise Free America. Of course, when we all drive electric cars—and some day we will—there will be almost an overnight transformation of the urban soundscape.

A recent study published in Science and summarized by the national news outlets, found that almost two-thirds of protected areas in the continental United States suffer from significant human-induced noise pollution. Still, these wilderness areas, national forests, and urban parks may be our only reprieve from the unrelenting noise we hear in our urban/suburban residential and commercial areas in which many of us spend most of our lives.

I am fortunate to live less than an hour’s drive from Great Smoky Mountains National Park. Driving to the crowded Clingman’s Dome or Cades Cove areas will not suffice, but obtaining a backcountry permit and spending a couple of nights deeper in the wilderness may. Most of us have access to a quieter area in our region, even if it takes some effort to get there. A few days of hearing cascading brooks and wood thrushes may be just the antidote to modernity all of us need. Go outside and play … and listen.

Tuesday, May 9, 2017


This appeared as an original piece for Blue Ridge Outdoors on May 9, 2017:

About three years ago I was introduced to phenology, the study of the cyclical timing of natural phenomena. One interested in phenology looks at the exact timing of the emergence of milkweed shoots from the soil, the bursting of leaf buds on a red maple, and the sudden appearance of the black-throated green warbler from its Central American winter breeding grounds. Stated simply, phenology is the study of nature’s calendar.

I was introduced to phenology during a trip with a colleague and our environmental science classes to the Appalachian Highland Science Learning Center, located on the eastern edge of Great Smoky Mountains National Park. Sitting at just over 5,000 feet in elevation on Purchase Knob, the center offers educational programs for students and houses scientists collecting data on air quality, salamander health, phenology, and other topics. In addition to its functional capacities as a research site, Purchase Knob is beautiful, affording visitors stunning views of the Southern Appalachians.

I read the supporting pre-lab materials offered by the program, but it took a while for me to grasp the essence and importance of phenology. “Why would anyone want to spend time studying phenology?” I wondered.

Here’s why: Climate change is not only about warming temperatures, rising sea levels, and stronger storms. Quite subtly, climate change affects the timing of spring and fall events, such as when oaks leaf out and flower in spring—and then drop their leaves in the fall—and when insect larvae (caterpillars) hatch. Climate change threatens to alter these timings, and scientists are already gathering evidence of phenological mismatches. For example, what happens to worm-eating warbler populations if, after their long flight across the Gulf of Mexico in spring during their annual northerly migration, they encounter forests with decreased populations of caterpillars, which have begun their reproductive cycle earlier due to climate change? It may be that the worm-eating warbler may alter its timing, too, but it may also be that the warbler cannot adjust as rapidly as events change due to climate change. Hence, the study of phenology.

After the trip with my class to Purchase Knob, I returned to Asheville School and set up our “phenology circuit,” a 20-minute walk with six forest trees tagged for us to monitor over the years. Throughout the school year, my classes and I walk the loop with clipboards and pencils, and we note the various phenophases of each of our trees—flowering dogwood, two red maples, Northern red oak, American hornbeam, American beech—looking closely at the leaves, flowers, and fruits. We enter our data on our Nature’s Notebook page, run by the USA National Phenology Network, which organizes the phenology data collected by students, researches, and volunteers, and then makes the data and developed models available for use available to the public.

Here are some reasons why I like this simple project, and why I encourage you to consider participating, too:
  • We are participating in citizen science, collecting data with thousands of others across the country for the greater good. Through studying years of collected data, scientists will be able to understand the effects of climate change on many different living organisms.
  • The project is a great excuse to get outside. Inevitably, many other observations and learning opportunities arise during a phenology walk.
  • One’s observation and estimation skills are sharpened. For example, it is not enough to note the white “flowers” of the flowering dogwood, because these are not the reproductive parts of the tree. What we generally consider to be flowers are leaf-like bracts, and the flowers are the small reproductive parts in the center of the bracts. As shown in the figure above, our flowering dogwood had 25-49% of its flowers open on April 13, and 75-94 % of its flowers open six days later.
  • These observations allow us time to appreciate the trees. One of our trees is a small Northern red oak, and I have enjoyed simply watching it grow since the fall of 2014.
Participation in this project is easy, and I encourage everyone to participate. Find a tree (or herbaceous plant or even animal) in your yard, neighborhood, or a nearby park; sign up on the Nature’s Notebook website; print out some data sheets; and get started. You’ll have one more excuse get outside, have one more reason to practice mindfulness through observation, and you’ll collect valuable research data all the while. The climate is changing, and we can all take part in helping to understand the impacts of climate change on the other living organisms in our midst.

Wednesday, May 3, 2017

Response: Climate of Complete Certainty

An April 29 op-ed piece by newly-hired New York Times writer Bret Stephens, a neoconservative formerly of The Wall Street Journal, has caught the attention of many. Mr. Stephens pretends to accept the claim of climate scientists that the planet is warming and that humans are causing it, but that he is above the fray and holds a healthy skepticism concerning the certainty of scientists as to exact direction we are heading. Here we have the simple tactic used by climate change deniers: obfuscation—let’s use some fancy language and a few strategically-placed statistics to cast some more doubt, delaying our action even further down the road. (Four more years?)

Perhaps the most troubling sentence in the article is this one: “Anyone who has read the 2014 report of the Intergovernmental Panel on Climate Change knows that, while the modest (0.85 degrees Celsius, or about 1.5 degrees Fahrenheit) warming of the earth since 1880 is indisputable, as is the human influence on that warming, much else that passes as accepted fact is really a matter of probabilities.” Modest? We continue to pump out greenhouse gases every second of every day, Mr. Stephens, and we are essentially adding to this “modest” temperature increase every day. We are already more than halfway to the globally-accepted target of no more than warming of 1.5 degrees Celsius, to stave off the worst possible effects, and we are not doing nearly enough to meet that target.

One more thing: This is not about probabilities, but about basic physics. It is about energy imbalance and energy budgets. NASA’s description of the basic physics is informative:

Carbon dioxide forces the Earth’s energy budget out of balance by absorbing thermal infrared energy (heat) radiated by the surface. The absorption of outgoing thermal infrared by carbon dioxide means that Earth still absorbs about 70 percent of the incoming solar energy, but an equivalent amount of heat is no longer leaving. The exact amount of the energy imbalance is very hard to measure, but it appears to be a little over 0.8 watts per square meter. The imbalance is inferred from a combination of measurements, including satellite and ocean-based observations of sea level rise and warming.

When a forcing like increasing greenhouse gas concentrations bumps the energy budget out of balance, it doesn’t change the global average surface temperature instantaneously. It may take years or even decades for the full impact of a forcing to be felt. This lag between when an imbalance occurs and when the impact on surface temperature becomes fully apparent is mostly because of the immense heat capacity of the global ocean. The heat capacity of the oceans gives the climate a thermal inertia that can make surface warming or cooling more gradual, but it can’t stop a change from occurring.

The changes we have seen in the climate so far are only part of the full response we can expect from the current energy imbalance, caused only by the greenhouse gases we have released so far. Global average surface temperature has risen between 0.6 and 0.9 degrees Celsius in the past century, and it will likely rise at least 0.6 degrees in response to the existing energy imbalance. As long as greenhouse gas concentrations continue to rise, the amount of absorbed solar energy will continue to exceed the amount of thermal infrared energy that can escape to space. The energy imbalance will continue to grow, and surface temperatures will continue to rise.

Have even one climate change denier explain to us how our understanding of this basic process is all wrong—and use decades of peer-reviewed science to back up his claim—and then we’ll stop marching in the streets and go back to our day jobs satisfied that everything will be just fine for future generations, after all.

The conversation has shifted, Mr. Stephens, from “Is climate change really happening?” to “Ok, what do we do about it now?”. We can certainly have intelligent discussions about what policies we should enact to ween ourselves from fossil fuels (and ween we must), but we can’t waste more time questioning the proven science. No climate scientist claims to know to the hundredth of a degree how much we will warm and when, and no climate scientist states exactly where the worst effects will occur, but no real climate scientist will tell us to sit back and wait for it to all play out so that we can obtain this precision. It’s called the Precautionary Principle (“When human activities may lead to morally unacceptable harm that is scientifically plausible but uncertain, actions shall be taken to avoid or diminish that harm.”), and the beings of this planet—and future ones—deserve precaution. We have enough data and enough science to act now, even as the science continues.