In early July, after days of torrential downpours, over a half dozen rivers in Vermont flooded, causing severe flooding. In some areas of Vermont up to nine inches or 23 centimeters (or 23 cm) of rain was recorded, which is higher than even the amounts of rainfall caused by Hurricane Irene (2011). Scientists say that floods, which were once considered to be a 1-in-100 year event, will become more common as climate change warms up the region. That’s because warmer air can hold more moisture.
Burlington has been largely spared. Lake Champlain which runs along the city’s length was spared. As the water from the Winooski — a 145-kilometer river that swamped the state capital, Montpelier — flows into the lake near where I live, so too does the garbage, gasoline and other pollutants that it swallowed up.
While biking along a lake path with friends shortly after the worst floods, I saw this pollution up close. The water in the south of the lake was still surprisingly clean, free of debris and appeared light blue. As we rode north, past where the river meets the lake, the water became murky and brown.
That color shift reminded me of something I’d recently read about deep-sea divers in Estero Salado, a fishing town in the Dominican Republic. Divers described similar experiences Changes in ocean huesThey have a complex color vocabulary that is based on their fishing locations. They speak of blue, black, yellow, green, purple and chocolate to describe the seawater’s appearance at different times and under different circumstances, writes medical anthropologist Kyrstin Mallon Andrews in July in the Journal of the Royal Anthropological Institute. These colors inform divers of the condition of the water, and the possible impact on behavior and visibility of marine life.
Divers also mention drastic changes in these colors over the years. Purple water, which “surpasses clean,” has become increasingly rare. Yellow water, caused by flooding in the nearby river and toxic runoff from the region’s rice fields, wreaks havoc on once fertile fishing grounds. Longer hurricane seasons turn the waters chocolate brown — a color too dangerous for diving — for months rather than weeks.
After my own experience as well the experiences of deep-sea diving, I wondered if using colors to describe climate changes could be a useful communication tool. Tim Edensor is a cultural and social geographer at Manchester Metropolitan University, England. He agrees with my idea.
Historically, the colors of a person’s world would have stayed fairly constant, he says. The climate change has a rapid impact on our visual environment. It’s hard to ignore these changes. “This transformation of the color of the water, I think this is really quite perturbing and it’s also disorienting,” he says.
These color changes do not only affect our waterways. Scientists have been talking about changes to the world’s color palette for several years. New England is a great place to start. autumn’s vibrant leaves could become duller due, in part, to warmer nighttime temperatures that slow chlorophyll’s degradation process, researchers say. Satellite images reveal that, while the Arctic is becoming greener in general, certain areas are browning, a sign of a warming climate. Plants could be dying (SN: 4/11/19).
In 2020, researchers found that the ultraviolet pigments in many flowers had increased. These natural sunscreens protect against rising temperatures, and the thinning of ozone layers. Current Biology While these changes are invisible to the human eye — we can’t see UV radiation — the flowers Pollinators appear darker. That change in hue could reduce a pollinator’s attraction to affected flowers, the researchers wrote.
When it comes to the world’s waterways, satellite images taken over the past 20 years show that over half the world’s The oceans have turned greenResearchers reported on July in Nature.Emmanuel Boss says the most probable culprits are dissolved organic matter in the water, or changes in phytoplankton type or quantity. “The bacteria are very happy. There is a whole microbial community that I think is having a blast.”
A study of satellite imagery found that lakes near areas where summer temperatures used to be moderate and waters would freeze in winter were also likely affected. Switch from blue to green, or even brownThe climate is expected to warm in the coming years.SN: 10/3/22). This shift is most noticeable in northern Europe and the northeastern part of North America.
At such vast scales, color changes can be difficult for the human eye to comprehend. But Mallon Andrews’ research with the Dominican deep-sea divers shows how individuals experience these changes in their communities.
Mallon Andrews of Syracuse University, New York, visited the Dominican Republic in 2015 to study water issues. She spent many days on a bridge looking out over a bay, and quickly learned the ocean language of the divers. “Their mode of communicating ocean conditions was always based around color,” she says. “Some colors you can dive in. Dive in some colors and you will suffer consequences. And some colors are used for navigation purposes.”
Mallon Andrews also began to recognize the subtleties of color as divers taught her to dive over a number of years. She eventually realized that the divers’ color scheme was more than descriptive; it was also diagnostic. Once, for instance, one diver described the water as “methylene blue.” Mallon Andrews had never heard the term, so she looked it up and found that methylene blue is a medication used to treat people suffering from hypoxia. “What he is saying is that previous to these conditions, there was more oxygen in the water,” she says.
Some colors can affect the divers’ physical and mental health, Mallon Andrews says. For instance, because yellow water clouds the water’s surface, the fishermen must dive continually to see fish, an exhausting process. Yellow water also causes skin rashes and debilitating ear infections, along with “sort of generalized angst,” she says.
Some scientists believe that pairing local first-hand knowledge with remote monitoring techniques will help to better understand the way climate change alters our planet’s colors. “It is very valuable for space agencies to have local people take high quality measurements that can be used to validate what we are inferring from space,” Boss says.
The camera on the satellite Boss’ team used to look at the world’s oceans, for instance, can’t see anything smaller than a kilometer, so it lacks detail. Scientists who study those images must also sift through the atmospheric material, like water vapor, dirt and aerosols made by humans, in order to see the ocean clearly.
Blue shift
Some of the world’s blue lakes will shift to green or brown in coming years as regions that typically see average summer air temperatures below 19° Celsius cross that threshold, researchers reported in 2022. Researchers reported in 2022 that some lakes are already within one degree (yellow), two degrees (cyan), or three degrees (purple), of this temperature. The most susceptible lakes — those located in areas closest to the 19° C tipping point — are mostly located in northeastern North America and northern continental Europe.
Blue lakes which are prone to losing their color
Can learning to read water color provide a new tool for measuring climate change even for those like me, who barely know how to use a snorkel? Brenda Bergman is skeptical when I ask her this question. People’s subjective look at the water is too variable, says Bergman, who heads the science and freshwater programs for The Nature Conservancy in Vermont. Sensors and direct readings of water can be used to do the job in a more systematic way.
But she and Edensor say that helping people become attuned to the world’s changing colors could help them understand how climate change is impacting their local communities.
“A lot of the [climate change] literature is excessively abstract and it’s also unimaginable,” Edensor says. The everyday indicators are more tangible, such as changes in the color of the water.
A bike ride on Lake Champlain was definitely one of those visceral moments. The kids begged us to jump in the water at first. As the water changed color, those requests slowed — then stopped altogether after we spotted seven dead frogs on a rocky outcropping over that murky water.
“These changes can’t be denied,” Edensor says. “You see them with your own eyes.”
