Photo credit and copyright © Dr. Alexander More (@natureofalex)
CANADIAN WILDFIRE SMOKE TURNS NYC's SKY RED AND AIR UNBREATHABLE
Wildfires as far as 2000 miles turned NYC and the Northeastern US into a hellscape. Is climate change to blame?
As NYC was celebrating a blue week, with events leading to World Oceans Day, the air and sky turned red. Perhaps more frightening than the hellscape and inability to breathe without throat and lungs being irritated was observing most people continuing to go about their lives as if nothing were happening. The event highlights what most don't know, about the effects of climate change, but also about how sunlight affects our atmosphere and our lives.
Why did the sky turn red? Smoke particles from wildfires in Nova Scotia, Quebec, and even Alberta traveled with Westerly winds to the Northeast. The particles only allow red and orange light to go through, reflecting all other colors of the rainbow (sunlight).
Smoke from the Canadian wildfires moving across N. America with westerly winds in the first week of June 2023. Video credit: NOAA
What does the color tell us about sunlight and climate change?
The color shows us parts of sunlight usually invisible to us. Normally, we see blue in the sky, because the atmosphere reflects that color, just like the ocean reflects green and blue. We know this from high-school science: white reflects all colors and heat, black absorbs them (which is why white surfaces are cooler). If the air is clear, we don't see the other colors, except in special circumstances, like a rainbow, where water droplets in the air make all colors visible.
Water droplets in the air scatter sunlight and create a rainbow. The human eye can't see light in infrared and ultraviolet, but that doesn't mean that light in those wavelenghts doesn't also carry heat.
As we produce more greenhouse gases and pollution (like wildfire smoke) the air we breathe changes, and its color will change too. Places like Singapore and Delhi are now used to this, but other cities in the developed world are also experiencing it. New York is just the latest example, after San Francisco, Seattle and Los Angeles.
Wildfire smoke from 2020 turning the sky over San Francisco red. Creative Commons License.
What effect do greenhouse gases (carbon dioxide, methane etc.) have on heat and our air quality?
Greenhouse gases act like a blanket that stops the sun's heat, in the form of light, to reflect back to space. As the example of the wildfires shows, sunlight is more than just the invisible force that lets us see and gives things the color we are used to.
How greenhouse gases warm the planet. Creative Commons License.
Sunlight carries energy, which is heat, from the infrared to the ultraviolet, including all colors of the rainbow we see. Humans can't see infrared or ultraviolet, but that doesn't mean that infrared and ultraviolet light don't carry energy. This is why painting your roof white won't stop sunlight from heating your house, and why a better technology should be adopted to deflect sunlight and reduce the need for air conditioning, as the world warms due to man-made pollution.