In the general context of many cultures, the rainbow is a sign of danger rather than hope. However, a recent study indicates that the climate changes that cause rainbows could be bad for the planet. The fact is, until recently, scientists had no idea how climate change would affect the appearance of rainbows. And now, finally, that has changed, with the publication of a study led by Kimberly Carlson, a professor of environmental sciences at New York University.
Dangerous Rainbow? Its Constant Appearance Becomes Harmful to the Planet
Although they were always considered “cute” for their aesthetics, science revealed a strange aspect. “Climate change is affecting rainbows; now we know that’s true,” says Carlson, the lead author of the paper, who used computer models to simulate future conditions. As major weather patterns shift due to climate change, many parts of the world (particularly places closer to the poles, such as Alaska or Siberia) will receive more rain, which could add dozens of rainbow-rich days to the end of the century. In fact, the Mediterranean, southern Africa, and even some tropical areas of South America are predicted to be drier in the future and could lose a good portion of their arc days between now and 2100.
How Is a Rainbow Formed?
But to understand the environmental impact in this regard, first, we need to understand why rainbows form. Some ingredients are necessary to see this phenomenon:
- First, raindrops are needed;
- We also need direct sunlight;
- And lastly, light should come from angles less than 42 degrees, which is usually early morning or late afternoon.
The team of scientists discovered that it was possible to look for these exact conditions in climate models, comparing them with real observations of the rainbow. In this way, it would be possible to confirm whether the models could accurately predict the phenomenon. The results were positive. Therefore, the study used computational mathematical models to simulate future conditions conducive to rainbow formation. When the team fast-forwarded to the year 2100, they discovered that the planet is more likely to have rainbows, and a warmer Earth generally means more rainbows.
The planet will experience a slight increase on average: between four and five more rainbow days per year, in addition to the current average of 108 to 117, depending on the models consulted. But the big gains are concentrated in a few places. For example, in Russia, Canada, and Alaska, as well as in extremely high places such as the Himalayan Plateau, there may be up to 50 more days a year with rainbow occurrences.
Climate Change Exacerbates the Problem
The changes follow broader patterns of climate change; In fact, the changes highlight some of the greatest risks and dangers. The increases in the Arctic, for example, are due to the fact that water that previously fell from the sky as snow will filter down more often as rain in a warmer future. Today’s rainbow-rich Amazon is expected to be hit more often by drought, because the rainforest, which currently creates its own rain, will lose that superpower as it shrinks, and because climate change across the planet is shifting and transforming the main weather patterns that cause tropical rains.
The same will happen in the Mediterranean and southern Africa, which will become increasingly drier in the future. Technically speaking, clouds are expected to become less common and more rarefied in these locations over the years. And since clouds help cool the planet by reflecting sunlight back into space, this result could further amplify the rise in global temperatures.
This story was written by Perla Vallejo in Ecoosfera
