On the morning of September 9, 2020, the colour of the sky in the San Francisco Bay Area was burnt orange. By noon, the sky grew darker instead of lighter. The morning sky resembled the red planet Mars, while the afternoon sky gave the impression that there is a solar eclipse, but a longer one.
The orange-coloured sky confused almost everyone and everything. The Bay Lights, programmed to turn off after sunrise, remained on, their digital algorithms flummoxed by the darkness, and the circadian rhythms of the locals were hopelessly out of sync with the natural world. Postings on social media reported that people, awakened by alarm clocks, rolled over and went back to sleep after looking at the sky because they thought the clock-settings were wrong.
The colours of the sky at different times of the day are a metaphor for life in the days of climate change. They were caused by smoke from countless wildfires burning across California. The smoke, mixed with clouds and fog, stained the sky and just about everything else with an apocalyptic orange hue. Vehicles, buildings, park benches, and chairs and tables of restaurants that serve outside because of the Covid-19 pandemic were covered with ashes.
Western United States, particularly California, is now the epicentre of out-of-control wildfires. Despite the fact that much of the region is yet to enter what is typically the most active phase of the fire season, the fires this year are far more intense and widespread than previous years. This is not an aberration though.
In California, the fires are raging unchecked from the Sierra Nevada to San Francisco and south to Los Angeles county. So far, at least 25 people have died, dozens remain unaccounted for, and thousands are displaced. The death toll will surely climb by the time the fires are tamed. Also, more than three million acres have already burned. This is about 25 times as much the land that burned at this point last year. Amid winds and high temperatures, Oregon and Washington are also under assault from wildfires of historic proportions.
Wildfires have created extremely hazardous atmospheric conditions throughout the Western United States as smoke from the cataclysmic blazes stretches for thousands of miles. Air quality in San Francisco, Seattle, Portland and Los Angeles, among others, is currently some of the worst in the world. Indeed, instead of the usual benign fog, San Francisco is now blanketed in a choking layer of soupy fog and smoke, leaving people with sore throat and stinging, teary eyes. Breathing the polluted air is like smoking the strong, non-filter Gauloises cigarettes.
California, Oregon and Washington are not the only places that have erupted in flames. Blazes devastated parts of every state of Australia earlier this year. Capping the second extraordinary fire season in a row, wildfires blazed along the Arctic Circle this summer, incinerating tundra and blanketing Siberian cities in smoke. And the Amazon is headed for another record burn.
While wildfires have the fingerprints of climate change, human acts, such as arson or tossing a burning cigarette in a forest or leaving a campfire unattended, can result in wildfires too. Among the natural causes, lightning is the major one. Lightning of varied electric voltages cause fire by directly igniting vegetation with high currents.
Although fire has always been a natural and beneficial part of a forest's ecosystem, climate change is fundamentally altering the frequency and intensity of wildfires. In fact, changes in weather pattern that create searing hot days with low humidity, drought and high winds are the biggest driver of out-of-control wildfires. Drier conditions and higher temperatures increase not only the likelihood of a wildfire to be ignited by lightning, but also affect its severity and duration. This means when a wildfire breaks out, it spreads faster and burns more areas as it moves in unpredictable ways.
Forest fires act in a synergistic manner in increasing the concentration of greenhouse gases in the atmosphere. In a forest, trees and plants release water through tiny pores in their leaves called stomata. The higher the ambient temperature, the more water they release. Fires will cause these water to evaporate, including water from dead plants littering the grounds. It is well-known that water vapour is one of the major greenhouse gases.
If wildfires become more frequent or intense, carbon dioxide released by the burning woods and leaves could exacerbate the progression of climate change, leading to a kind of positive feedback loop—more warming leading to more fires, which will release more carbon dioxide, thereby causing more warming, and so on. This is of particular concern for boreal forests in North America and Eurasia, which contain large deposits of carbon-rich peat.
Since the Industrial Revolution, global temperature rose roughly one degree Celsius. Yet, raging wildfires, severe droughts, once-in-a-thousand-year storms, devastating floods, melting of Arctic ice at an alarming rate, and lethal heatwaves are on the rise. On August 17, 2020, temperature in Death Valley, California reached 55 degrees Celsius, a potential record for the highest temperature ever reliably recorded on Earth. A derecho—a dangerous, ferocious wall of fast-moving wind that is like an inland hurricane—lashed through Nebraska, Iowa, Illinois, Indiana, Wisconsin and Michigan last month, flipping cars, downing trees, causing widespread property damage and knocking out power to more than a million.
If a one-degree rise in temperature is wreaking so much havoc, what will happen to our planet if we take the free pass of heating up the atmosphere by two degrees before the end of this century, as agreed upon by the stakeholders in the 2015 Paris Agreement?
Clearly, the links between anthropogenic climate change and extreme events like wildfires and derechos are real and dangerous. They are a frightening reminder of how the cascading effects of climate change are accelerating faster than predictions of many climate change models. The situation will only get worse from here on. Hence, today's wildfires will not be the last infernos of a hot, bone-dry summer. We should expect more disastrous and more frequent wildfires raging through forests of the world. It is, therefore, time for us and our leaders to wake up and face this stark reality. Hopefully, the forest fires and other catastrophic natural disasters will make the world leaders think rationally and prompt them to take climate change seriously.
Finally, there is an old saying about the weather: "Red sky at night, sailors' delight. Red sky in the morning, sailors take warning." We can now add to this saying: Orange sky in the morning, climate change smacking in the face.
Quamrul Haider is a professor of physics at Fordham University, New York.