The Earth’s colors are changing — and climate change could be partially to blame

Earth is made up of a kaleidoscope of colors—from the lush greens of tropical forests to the glistening turquoise of coastal shores. 

But over the past few decades, many of the hues that people have come to expect in nature have been thrown out of whack or changed altogether. In some cases, climate change could be to blame, a growing body of research shows. 

Warming global temperatures can have rippling effects on ecosystems, altering nutrient levels, chemical composition or biological processes. Sometimes these changes manifest themselves in a visual way, a cue that scientists are using to track climate trends across the globe. 

Leaf peeping

Many people across the U.S. associate the crimson reds and vibrant yellows of changing leaves with the first signs of fall each year. However, in some regions, warming temperatures are disrupting this annual transformation. 

Typically, as the days get colder and shorter during autumn, leaves are exposed to less sunlight. This slows down the production of chlorophyll, which helps plants create their own food through photosynthesis and gives them a natural green color. With less food fueling their sun-powered diet, that green is replaced with other primary colors. 

But warmer fall nights may be delaying the start of this process, according to a recent analysis by the nonprofit Climate Central. For example, in Maine’s Acadia National Park, peak foliage season now occurs almost two weeks later than it did in the 1950s. 

“What we thought we knew about fall foliage is really up in the air right now,” Aaron Bergdahl, a forest pathologist with the Maine Forest Service, told Maine Public Radio. “The seasons are a little bit different and our growing seasons are less predictable and generally have a little bit more stress than what we recognized 10, 20 years ago.”

Drought can also impact this natural autumnal display: Tree experts say a moderate late-summer dry spell in the Chicago region could be dulling the vibrancy of foliage colors this fall, WBEZ Chicago reports. However, scientists are still researching these climate links. 

Global greening

More than 70% of the Earth’s surface is covered by oceans, hence our nickname, the Blue Planet. But a study published last year in Nature revealed an unusual trend: Oceans have become greener over the past two decades. 

The ocean’s colors are literally a reflection of how sunlight bounces back off the substances and creatures living in the water’s upper layers. Greener water typically indicates the presence of life, particularly tiny creatures known as phytoplankton that produce chlorophyll (similar to the green leaves I mentioned earlier). 

By analyzing NASA satellite imagery from 2002–2022, researchers were able to look at how the color spectrum of visible light in seawater changed over time, uncovering this green shift in more than half of the world’s oceans. They aren’t certain what is driving the trend, but they suspect it could be due to changes in phytoplankton and ocean stratification. To determine if this phenomenon is linked to climate change, the researchers used a model to simulate the Earth’s ocean colors with and without human-produced greenhouse gases—and found that it overlapped almost exactly with the greening they observed in the satellites. 

“I’ve been running simulations that have been telling me for years that these changes in ocean color are going to happen,” study co-author Stephanie Dutkiewicz, a senior research scientist at the Massachusetts Institute of Technology, said in a statement. “To actually see it happening for real is not surprising, but frightening. And these changes are consistent with man-induced changes to our climate.”

Greening is also happening on land. Antarctica has started greening recently, as my colleague Bob Berwyn recently wrote about, with vegetation spreading at the rate of about 75 football fields per year across what has long been dubbed the White Continent. The region has experienced rapid warming over the past few decades, and these warmer and wetter conditions are likely contributing to the spread of vegetation as ice melts. A similar—though far more widespread—trend is being observed in the Arctic.

The idea that “that any part of Antarctica could, in any way, be green is something that still really jars a lot of people,” co-author Thomas Roland, a paleoecologist with the University of Exeter who collects and analyzes mud samples to study environmental and ecological change, told Inside Climate News. “Even the coldest regions on Earth that we expect and understand to be white and black with snow, ice and rock, are starting to become greener as the planet responds to climate change.” 

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