Posted on December 9, 2018
Earth’s climate is changing, and the smoking gun is ours. Sadly, in the United States policy lags insight and reason, and the world is suffering.
Climate change science is complex, with many moving parts that make it difficult to communicate to the general public. Climate change also represents a significant reset for some of the world’s most profitable corporations. Those colliding realities created a perfect storm for fostering the doubt and confusion that persists among people who don’t understand climate science and the principles that underpin it.
I’m not a scientist, but I do have enough science background (majors in astronomy and geology before finally earning my degree in economics) to respect and appreciate the scientific method, with all its checks and balances. I also spent 20 years doing technical communication in the high tech industry (tech writing, training, and support). So I know that the fundamentals of climate change don’t need to intimidate, and the more accessible they can be to the general public, the better off we’ll all be.
Recently it feels like I’ve been living on the climate change front lines. On each visit to Yosemite, more dead and dying trees stain forests that were green as recently as five years ago. And throughout the Sierra (among other places), thirsty evergreens, weakened by drought, are under siege by insects that now thrive in mountain winters that once froze them into submission. More dead trees means more fuel, making wildfires not just more frequent, but bigger and hotter.
Speaking of wildfires, for a week last month I couldn’t go outside without a mask thanks to smoke from the Camp Fire that annihilated Paradise (70 miles away). I have friends who evacuated from each of this November’s three major California wildfires (Camp, Hill, and Woolsey), and last December the Thomas Fire forced a two-week evacuation of Ojai, where my wife and I rent a small place (to be near the grandkids). Our cleanup from the Thomas fire took months, and we still find ash in the most unexpected places (and we were among the lucky who had a home to clean).
Despite its inevitable (and long overdue) death, the climate change debate continues to stagger on like a mindless zombie. We used to have to listen to the skeptics claim that our climate wasn’t changing at all, so I guess hearing them acknowledge that okay-well maybe-the-climate-is-changing-but-humans-aren’t-responsible can be considered progress.
Despite what you might read on social media or fringe websites, climate change alternative “explanations” like “natural variability” and “solar energy fluctuations” have been irrefutably debunked by rigorously gathered, thoroughly analyzed, and closely scrutinized data. (And don’t get me started on the whole “scientists motivated by grant money” conspiracy theory.)
One thing that everyone does agree on is the existence of the greenhouse effect, which has been used for centuries to grow plants in otherwise hostile environments.
As you may already know, a greenhouse’s transparent exterior allows sunlight to penetrate and warm the interior. The heated interior radiates at longer wavelengths (infrared) that don’t escape as easily through the greenhouse’s ceiling and walls. Because more heat is added to a greenhouse than exits, the interior stays warmer than the environment outside.
Perhaps the most common misperception about human induced climate change is that it’s driven by all the heat we create when we burn stuff. But that’s not what’s going on, not even close.
Our atmosphere behaves like a greenhouse, albeit with far more complexity. The sun bathes Earth with continuous electromagnetic radiation that includes infrared, visible light, and ultraviolet. Solar radiation not reflected back to space reaches Earth’s surface to heat water, land, and air. Some of this heat makes it back to space, but much is absorbed by molecules in Earth’s atmosphere, forming a virtual blanket that makes Earth warmer than it would be without an atmosphere. In a word, inhabitable.
Because a molecule’s ability to absorb heat depends on its structure, some molecules absorb heat better than others. The two most common molecules in Earth’s atmosphere, nitrogen (N2: two nitrogen atoms) and oxygen (O2: two oxygen atoms), are bound so tightly that they don’t absorb heat. Our atmospheric blanket relies on other molecules to absorb heat: the greenhouse gases.
Also not open for debate is that Earth warms when greenhouse gases in the atmosphere rise, and cools when they fall. The rise and fall of greenhouse gases has been happening for as long as Earth has had an atmosphere. So our climate problem isn’t that our atmosphere contains greenhouse gases, it’s that human activity changes our atmosphere’s natural balance of greenhouse gases. While water vapor is our atmosphere’s most prevalent greenhouse gas, water creates a feedback loop that increases the heat caused by carbon dioxide—if carbon dioxide raises the temperature of the air, the air can hold more water, which increases the temperature more. Water vapor also responds quickly to temperature changes, leaving the atmosphere relatively fast as rain or snow. The other greenhouse gases hold their heat far longer.
The two most problematic greenhouse gases where climate change is concerned are carbon dioxide (CO2: one carbon atom bonded with two oxygen atoms) and methane (CH4: one carbon atom bonded with four hydrogen atoms). The common denominator in these “problem” gases is carbon. (There are other, non-carbon-based, greenhouse gases, but for simplicity I’m focusing on the most significant ones.)
Carbon exists in many forms: as a solo act like graphite and diamond, and in collaboration with other elements to form more complex molecules, like carbon dioxide and methane. When it’s not floating around the atmosphere as a greenhouse gas, carbon in its many forms is sequestered in a variety of natural reservoirs called a “carbon sink,” where it does nothing to warm the planet.
Oceans are Earth’s largest carbon sink. And since carbon is the fundamental building block of life on Earth, all living organisms, from plants to plankton to people, are carbon sinks as well. The carbon necessary to form greenhouse gases has always fluctuated naturally between the atmosphere and natural sinks like oceans and plants.
For example, a growing tree absorbs carbon dioxide from the atmosphere, keeps the carbon and expels oxygen (another gross simplification of a very complex process); this process stops when the tree dies. As the dead tree decomposes, some of its carbon is returned to the atmosphere as methane, but much of it returns to the land where it is eventually buried beneath sediments. Over tens or hundreds of millions of years, some of that sequestered carbon is transformed by pressure and heat to become coal.
Another important example is oil. For billions of years, Earth’s oceans have been host to simple-but-nevertheless-carbon-based organisms like algae and plankton. When these organisms die they drop to the ocean floor, where they’re eventually buried beneath sediment and other dead organisms. Millions of years of pressure and heat transforms these ancient deposits into…, oil.
Coal and oil (hydrocarbons), as significant long-term carbon sinks, were quite content to lounge in comfortable anonymity as continents drifted, mountains grew, and glaciers crept. Through all this slow motion activity on its surface, Earth’s temperatures ebbed and flowed and life on the surface evolved accordingly.
Enter humans. We have evolved, migrated, and established civilizations based on a relatively stable climate. And since the discovery of fire we humans have burned plants for warmth and food preparation. Who knew that such a significant advance was the first crack in the climate-change Pandora’s Box?
Burning organic material creates carbon dioxide, releasing sequestered carbon. For thousands of years the demand for fuel was met simply by harvesting dead plants strewn about on the ground and the reintroduction of carbon to the atmosphere was minimal. But as populations expanded and technology advanced, so did human’s thirst for fuel to burn.
We nearly killed off the whales before someone figured out that those ancient, subterranean metamorphosed dead plants burn really nicely. With an ample supply of coal and oil and a seemingly boundless opportunity for profit, coal and oil soon became the driving force in the world’s economy. Suddenly, hundreds of millions of years worth of sequestered carbon was being reintroduced to our atmosphere as fast as it could be produced—with a corresponding acceleration in greenhouse gases (remember, when we burn hydrocarbons, we create carbon dioxide).
Compounding the fossil-fuel-as-energy problem is the extreme deforestation taking place throughout the world. Not only does burning millions of forest and jungle acres each year instantly reintroduce sequestered carbon to the atmosphere, it destroys a significant sink for present and future carbon.
Scientists have many ways to confirm humans’ climate change culpability. The most direct is probably the undeniable data showing that for millennia carbon dioxide in Earth’s atmosphere hovered rather steadily around 280 parts per million (ppm). Then, corresponding to the onset of the Industrial Revolution in the late 18th century, atmospheric carbon dioxide has risen steadily and today sits somewhere north of 400 ppm, with a bullet.
Humans don’t get a pass on atmospheric methane either. While not nearly as abundant in Earth’s atmosphere as carbon dioxide, methane is an even more powerful greenhouse gas, trapping about 30 times more heat than its more plentiful cousin. Methane is liberated to the atmosphere by a variety of human activities, from the decomposition of waste (sewage and landfill) to agricultural practices that include rice cultivation and bovine digestive exhaust (yes, that would be cow farts).
While the methane cycle is less completely understood than the carbon dioxide cycle, the increase of atmospheric methane also correlates to fossil fuel consumption. Of particular concern (and debate) is the cause of the steeper methane increase since the mid-2000s. Stay tuned while scientists work on that….
For humans, the most essential component of Earth’s habitability is the precarious balance between water’s three primary states: gas (water vapor), ice, and liquid. Since the dawn of time, water’s varied states have engaged in a complex, self-correcting choreography of land, sea, and air inputs—tweak one climate variable here, and another one over there compensates.
Earth’s climate remains relatively stable until the equilibrium is upset by external input like solar energy change, volcanic eruption, or (heaven forbid) a visit from a rogue asteroid. Unfortunately, humans incremented the list of climate catalysts by one with the onset of the Industrial Revolution, and our thirst for fossil fuels.
As we’re learning firsthand, even the smallest geospheric tweak can initiate a self-reinforcing chain reaction with potentially catastrophic consequences for humanity’s long-term wellbeing. For example, a warmer planet means a warmer ocean and less ice, which means more liquid water and water vapor. But that’s just the beginning. More liquid water swallows coastlines; increased water vapor means more clouds, precipitation, and warmer temperatures (remember, water vapor is a greenhouse gas). Wind patterns and ocean currents shift, changing global weather patterns. Oh yeah, and ice’s extreme albedo (reflectivity) bounces solar energy back to space, so shrinking our icecaps and glaciers means even more solar energy to warm our atmosphere, which only compounds the problems.
Comparing direct measurements of current conditions to data inferred from tree rings, ice and sediment cores, and many other proven methods, makes it clear that human activity has indeed upset the climate balance: our planet is warming. What we’re still working on is how much we’ve upset it (so far), what’s coming, and where the tipping point is (or whether the tipping point is already in our rearview mirror).
We do know that we’re already experiencing the effects of these changes, though it’s impossible to pinpoint a single hurricane, fire, or flood and say this one wouldn’t have happened without climate change. And contrary to the belief of many, everyone will not be warmer. Some places are getting warmer, others are getting cooler; some are wetter, others are drier. The frequency and intensity of storms is changing, growing seasons are changing, animal habitats are shifting or shrinking, and the list goes on….
We won’t fix the problem by simply adjusting the thermostat, building dikes and levees, and raking forests. Until we actually reduce greenhouse gases in our atmosphere, things will get worse faster than we can adjust. But the first step to fixing a problem is acknowledging we have one.
The Camp Fire had been burning for ten days, devouring Paradise and filling the air in Sacramento with brown smoke so thick that at times not only could we not see the sun, we couldn’t see the end of the block. But on this afternoon, when an orange ball of sun burned through the smoke I donned a mask, grabbed my camera bag, and headed for the hills.
I have a collection of go-to foothill oak trees for sun and moonsets, but most of these trees are too close to my shooting position for the extreme telephoto image I had in mind. Too close because at this kind of focal length, the hyperfocal distance is over a mile. So I made my way to a quiet country road near Plymouth where I thought the trees might just be distant enough to work. But I’m less familiar with this location than many of my others, so I didn’t know exactly how the trees and sun would align. Turning onto the road, I drove slowly, glancing at the sun and trees until they lined up. Because there wasn’t a lot of room to park on either side, I was pleased that the shoulder at the location that worked best was just wide enough for my car.
Envisioning a maximum telephoto shot, I added my Sony 2X teleconverter to my Sony 100-400 GM lens. While my plan was to use my 1.5-crop Sony a6300, when I arrived the sun was high enough that that combination provided too much magnification, so I started with my full frame Sony a7RIII. But soon as the sun dropped to tree level I switched to the a6300 and zoomed as tight as possible.
When I started the sun was still bright enough that capturing its color made the trees complete silhouettes, with no detail or color in the foreground. But as the setting sun sank into increasingly thick smoke, it became redder and redder and my exposure became easier. It always surprises me how fast the sun and moon move relative to the nearby horizon, so found myself running around to different positions to get the right sun and tree juxtaposition as the sun fell. The smoke near the horizon was so thick that it swallowed the sun before it actually set.
Later I plotted my location and the sun’s position on a map and realized that I was pointing right at San Francisco, about 100 miles away, with a large swath of the Bay Area in between. Then I thought about this air that was thick enough to completely obscure the sun, and the millions of people who had been breathing that air for weeks.
I’d be lying if I said I don’t like this image—it’s exactly what I was going for. But I’d be very happy if I never got another opportunity to photograph something like this.
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