Looking around the American landscape in mid-autumn 2020, it’s easy to find cause for concern. A deeply divided electorate. The Covid pandemic still raging out of control. An economy in shambles, with huge numbers of citizens facing potential disaster as winter approaches. The list goes on.
These are examples of immediate, relatively short-horizon problems — bad things happening right now. These kinds of concerns capture our attention more readily than do longer term, slower-emerging issues. That’s understandable.
When the near-term is filled with urgent problems, the longer-term tends to fade into the background. But that creates another kind of problem. Steps that could be taken now to prevent or minimize a big, longer-term problem are ignored, not prioritized. While we’re engaged in fighting fires on our doorstep, a bigger fire might be raging just over the next hill.
Climate change is a prime example of a more distant but much bigger fire. And it’s coming toward us.
You’ve undoubtedly heard of climate change, maybe even given it some thought. If you’re in the most forward-thinking 20 percent of US citizens, you’ve already made some adjustments in your life-style that reflect your concern for humankind’s role in accelerating this global threat. But even if you are such a person, it’s unlikely that you’ve undertaken the sorts of changes that truly acknowledge the threat that climate change poses to life as we know it. Hardly any of us have — notably including myself.
This is not meant as criticism; rather it is a reflection of the fact, briefly stated above, that climate change is arriving by increments not easily noticed on a day-to-day basis. As bad as it is now certain to become, and as catastrophic as its consequences are now sure to be, it is not easy for normal humans to register and appropriately respond to such a threat. Our brains are wired by evolution to respond mostly to urgent, in-your-face threats: an attacking beast, a gun to the head, an awareness of sudden financial calamity. Faced with this sort of threat, we humans can and generally do mount an energetic defense. But when the threat can barely be perceived in moment-to-moment awareness, mounting a proper response is much more difficult.
Therefore, if public policy is to address climate change with the urgency it actually demands, it is first necessary to make the case for that urgency in terms that a majority of ordinary citizens not only understand but can feel viscerally for the threat that it is. How this is to be done is not yet clear.
When a normal person is confronted with a sudden threat, alarm bells go off in the nervous system. Fear wells up immediately, accompanied by a heightened sense of alertness. The brain begins calculating defensive reactions even before the person fully understands the nature of the threat. “Fight or flight” is an instinctive defense mechanism rooted in the amygdala, a part of the brain that processes emotions. As soon as our senses (mainly eyes or ears) register threat, the amygdala fires off distress hormones to the hypothalamus, a part of the brain that acts as a command center for defensive response. The hypothalamus signals the whole body that danger is imminent, that the person must either flee or prepare to fight for survival. Muscles tense, eyes dilate, breath-rate increases, a sense of nervous alertness takes hold. This remarkable stress-response mechanism traces back to the earliest stages of human evolution, and it has undoubtedly saved countless human lives.
But if a threat is not perceived as imminent danger, this survival mechanism does not respond.
Herein lies one of the core problems in dealing with climate change. Its effects are not urgently apparent to normal humans on a day-to-day basis. Even when huge wildfires engulf California, and massive heatwaves in Australia kill dozens of people and an estimated 1 billion animals, and the melting Greenland ice sheet threatens to create catastrophic sea-level rise that will gradually inundate places like south Florida, Boston and much of California’s Bay Area — all directly linked to climate change — normal humans do not compute the urgency. The cause-and-effect equation does not scream loudly enough. We are not moved to decisive action.
Yet the evidence pointing to climate change is so conclusive that an estimated 95% or more of all scientists agree not only that it is occurring, but that human activity is the single most important cause. In simple terms, the amount of carbon dioxide (CO2) in the atmosphere is the prime determinant of prevailing atmospheric temperature: the more CO2, the higher average temperature will be. It doesn’t take much CO2 to cause this effect. In fact, CO2 amounts to just 4 one-hundredths of one percent of the atmosphere. Its exact concentration is expressed in parts-per-million; and at present (mid-2020) that number is roughly 410 parts-per-million. Even at such a low concentration, however, atmospheric CO2 results in approximately 76% of the so-called greenhouse effect — the tendency of the atmosphere to retain heat. Raising the amount of CO2 by even a tiny amount, therefore, means the atmosphere will retain more heat.
Depending on who you ask, it has been at least 800,000 years, and possibly as much as 3 million years, since the last time the earth’s atmosphere contained as much CO2 as it does today. Back then, average atmospheric temperatures were roughly 3.6 to 5.4 degrees Fahrenheit higher than they were at the start of the industrial revolution (around 1800 AD); and average sea levels were an astonishing 50 to 80 feet higher than today.
It is now known that the amount of atmospheric CO2 has increased by as much as 35% since the beginning of the industrial revolution, the time not so long ago when humans began burning fossil fuels in very large amounts. The correlation between burning fossil fuels, rise in atmospheric CO2 and attendant rise in atmospheric temperature is now established beyond any reasonable doubt. Atmospheric warming is a direct consequence of human activity; and it will continue until human activity shifts dramatically away from using fossil fuels.
Sadly, despite the near-universal scientific consensus on humankind’s role in driving climate change, here in the United States acceptance of these scientific facts varies hugely, depending on one’s political persuasion. According to a recent study by Pew Research, regardless of one’s self-assessed science knowledge, no more than 25% of Republicans believe human activity contributes substantially to climate change; and President Donald Trump has aggressively disparaged the notion. By comparison, the more science-educated a Democrat is, the more likely that he/she believes human activity is a key driver of climate change: 41% of Democrats with low science knowledge believe so, while 89% with high science knowledge do.
When we speak of climate change, we acknowledge that the “change” is characterized first of all by rising global atmospheric temperature. That rising temperature is the driver of other effects implicit in climate change: loss of polar ice, rising sea levels, dramatic changes in global weather patterns, shifting crop distributions, extinction of species, emergence of exotic diseases, and more. It all begins with higher temperature; and it leads to a completely different world than the one we’re used to. As of now, late-autumn 2020, most of the above-mentioned negative effects of climate change are certain to occur in varying degrees, even if we could stop using fossil fuels all at once, right now. Which, of course, we can’t.
In fairness, we must note that a great many citizens in the US and around the world are at least somewhat aware of the foregoing dire predictions and are taking responsible steps to respond. For example, millions of people have exchanged huge gas-guzzling cars for much more efficient, smaller vehicles with lower, more environment-friendly emissions. Many others have greatly reduced or even eliminated fuel-burning vehicles entirely, some turning to electric vehicles, others taking to small motorbikes or pedal-powered bicycles, still others relying entirely on public transit. However, at the same time, the global fleet of vehicles continues to grow. The result is that, despite better average fuel efficiency, net global emissions from vehicles is still climbing.
Since 2015, every nation on earth has joined the Paris Agreement on climate change. In doing so, each nation pledged to cut their greenhouse gas (mainly CO2) emissions by a substantial amount over the next several decades, with the intent of preventing runaway global warming. Well-intentioned as this agreement was and is, most nations are so far not on track to meet their pledged emission reductions. Worse still, under the leadership of President Donald Trump, the United States withdrew from this agreement in mid-2017. The US is the world’s second-largest emitter of greenhouse gases, after China.
President-elect Joe Biden has pledged to rejoin the Paris Agreement as soon as he takes office. Though this is heartening, it represents the bare beginning of an adequate response. In the five years since the Paris agreement was signed, our planet has seen the five hottest years on record. Barring some monumental and sustained human effort starting right now, catastrophic climate change is a near certainty.
Bottom line: Human behavior is a key driver of global climate change. Climate change is accelerating, and its predictable consequences will bring immeasurable hardship to people the world over, while hastening the destruction of the natural environment and the extinction of countless species. This unprecedented tragedy is still largely preventable, but human society shows little willingness to prevent it. In effect, we are accelerating toward a cliff.