1 . We know light pollution can threaten the heath and well-being of humans, animals, and the environment. Researchers have long studied the impact on birds and how brightness can affect their reproduction (繁殖), feeding, and migration behaviors. A new study, published in Nature, takes a comprehensive look at how light pollution affects birds throughout North America. It found that these factors can affect how birds succeed in reproduction and often are related to the impacts of climate change.

For the study, researchers looked at data collected by other researchers and by citizen scientists. They analyzed how light pollution affected the reproductive success of more than 5800 nests from 142 bird species across North America. They considered several factors including the time of year when reproduction happened and whether at least one chick got the feathers necessary for flight or independent activity.

Birds typically reproduce about the same time each year, using daylight cues to time their reproduction to coincide with when the most food will be available to feed their babies. “Artificially changing day length with light pollution essentially misleads them to stat reproducing earlier than they normally would,” Francis says. When that happens, sometimes chicks hatch before food is available. But with climate change, sometimes the results are a little different.

“We also found that the same species that reproduce earlier appear to benefit from light exposure in terms of nest success. This was unexpected. We do not know for sure that light pollution helps birds cope with climate change. It needs to be tested in further research. Nevertheless, it is quite possible that light allows birds to ‘catch up’ to earlier prey availability due to climate change,” Francis explains.

Researchers know through studies of climate change that plants and insects are starting to emerge earlier each spring. They respond to warmer temperatures rather than light. So possibly the birds are benefiting from that change. “A likely explanation is that light pollution causes birds to nest earlier and restore the match between the timing of their nesting and the highest availability of their food,” Francis says. “Again, this needs to be tested. Still, if true, it means that birds exposed to light pollution are ‘ keeping up ’ with climate change and those in pristine areas where there is no light pollution would not. ”

2 . Rain is vital to life on Earth. However, rain isn’t just made of water anymore—it’s partly made of plastic.

Millions of tiny pieces of plastic, called microplastics, are wandering around Earth’s atmosphere and traveling across entire continents, according to a study published in the journal Proceedings of the National Academy of Sciences on April 12. Another study, published in the journal Science in June 2020, has revealed that every year more than 1,000 tons of the particles (颗粒)—equivalent to over 120 million plastic bottles—fall in rain.

Microplastics are plastic particles less than 5 millimeters in diameter (直径) and come from a number of sources. Plastic bags and bottles released into the environment break down into smaller and smaller bits. Some microplastics are manufactured deliberately to provide abrasion (研磨) in a host of products, such as toothpaste and cleansers, according to the Daily Mail. Another major source is your washing machine. When you wash synthetic (合成的) clothing, tiny microfibers get flushed (冲掉) away with the wastewater. Even though the water is treated by a wastewater plant, the microplastics remain, and they are released into the sea, according to American magazine Wired.

Plastic rain may remind people of acid rain, but the former is far more widespread and harder to deal with. The tiny particles, too small to be seen with the naked eye, are collected by the wind from the ground. They are so light that they stay in the air to be blown around the globe. As they climb into the atmosphere, they are thought to act as nuclei (核心) around which water vapor (水蒸气) condenses (凝结) to form clouds. Some of the dust falls back to land in dry conditions, while the rest comes down as rain, according to the Daily Mail.

Microplastics have been found everywhere you can imagine. From fish and frogs to mice and mosquitoes, their bodies have been found, on average, to contain 40 pieces of microplastic, reported Daily Mail. As the top of the food chain, humans are exposed to microplastics, too. “We live on a ball inside a bubble,” microplastic researcher Steve Allen at University of Strathclyde, Scotland, told Wired. “There are no borders, there are no edges. It (plastic rain) raining on the land and then getting blown back up into the air again, to move somewhere else. There’s no stopping it once it’s out.”