3 . You can see a sea turtle named Hermanan octopus(章鱼) called Octavia, and a seal named Lidia at the Smithsonians National Zoo in Washington DC. Rather than real animals, they are actually artworks made out of plastic trash from the ocean.

These artworks are part of a traveling exhibit called “Washed Ashore: Art to Save the Sea”. The Washed Ashore project, led by the artist called Pozzi, works to raise awareness about plastic pollution in Earth’s oceans.

More than 315 billion pounds of plastic litter the world’s oceans today. Most of the plastic is garbage from towns and cities, as well as trash that people leave on beaches. Rainwater, winds, and high tides bring the trash into the ocean or into rivers that lead to the ocean. Once it is under the waves, the plastic begins to break up into smaller and smaller pieces.

Thousands of sea animals die each year from eating plastic bags and other things. Each year, millions more pounds of plastic end up in the ocean. A recent study found that if that continues, by 2050 the total weight of plastic will be more than that of all the fish in the ocean.

The Washed Ashore project is working to stop that from happening. Since 2010, Washed Ashore volunteers have collected 38000 pounds of plastic trash from more than 300 miles of beaches. They helped Pozzi create more than 60 artworks of sea creatures harmed by plastic pollution.

“These artworks are a powerful reminder of our personal role and global responsibility in preserving biodiversity(生物多样性)on land and in the sea,” says Dennis Kelly, director of the National Zoo.

5 . Shinrin-yoku means “forest bathing”. Forest bathing doesn't mean you take a bath in the forest; rather, you simply go for a walk in the woods or a city park, where youslackenby using all your senses to experience nature.

Yoshifumi Miyazaki, from Chiba University, is among a growing number of scientists who have begun studying the science behind the effects of nature on human health. In his bookShinrin-yoku: The Japanese Art of Forest Bathing.Miyazaki explains the techniques of forest bathing.

Miyazaki has an interesting theory about why shinrin-yoku is so effective. He points out that for more than 99.99% of the time, humans have lived in a natural environment. In fact, in 1800, only 3% of the world's population lived in cities, and by 2016, this figure reached 54%. This is only going to get worse; officials predict that by 2050, 66% will live in cities.

This suggests we live in our modern society with bodies that are still used to the natural environment, he writes in the book, because “genes cannot change over just a few hundred years". The science behind the research studies he presents in the book makes a convincing case that forest bathing is an effective method for reducing stress in today's world.

Now city planners are becoming increasingly aware of the importance of nature and are creating new kinds of “parks” out of empty spaces. There're also more city gardens where people can grow vegetables. For kids, kitchen gardens in schools are becoming popular. As Miyazaki stresses, you don't have to find a formal park or garden to practice shinrin-yoku. Instead, you can enjoy the effects of nature wherever there're plants.

Better yet, he says, we can bring nature closer to where we spend most of our time. Miyazaki's research has shown that just increasing the amount of plants in a room can affect the relaxation benefits of the room. What's more, even when people simply look at flowers, their bodies relax and stress levels decrease.

6 . A new study shows that the increased heat from Arctic (北极的)rivers is making sea ice in the Arctic Ocean gradually disappear. The study published this week in Science Advance was led by the Japan Agency for Marine-Earth Science and Technology, together with other scientists in the United States, United Arab Emi rates , Finland and Canada.

According to the research, the main Arctic rivers bring more heat to the Arctic Ocean than they did in 1980. River heat is one of the reasons that cause sea ice loss of the Arctic Ocean. That loss is equal to about 120,000 square miles of 1-mcter thick ice. "If Alaska were covered by 1-meter thick icc. 20% of Alaska would be gone," explained Igor Polyakov, a re- searcher at the University of Alaska Fairbanks' International Arctic Research Center.

Rivers have the greatest influence during spring. The wanning water pours into the ice covered Arctic Ocean and spreads below the ice， slowly destroying it. Once the sea ice melts(融化), the warm water makes the temperature go up. The research found that much more river heat energy entered the air. Since air is mobile, this means river heat can influence areas of the Arctic far from river deltas (三角洲).

The influence was the most prominent in the Siberian Arctic, where several large rivers go into the Arctic Ocean. Canada's Mackenzie River is the only river large enough to contribute to sea ice meh near Alaska, but the state's smaller rivers are also a source of heat.

Polyakov says that rising global air temperatures will continue to warm Arctic rivers in the future. As rivers heat up, more warm water will flow into the Arctic Ocean, melting more sea ice,