1 . When most of us think of sand, we immediately think of sunny beaches and summer holidays. But actually it’s in pretty much everything that surrounds us in our everyday lives, from the walls of our homes to the glass bottles in out kitchens and even the mobile phones in our hands. Sand is the second most used resource in the world after water: it accounts for more than two-thirds of everything that’s being dug out of the ground. But there isn’t a limitless supply. In fact, a UN report says we might be running out.

According to the report, we use an estimated 15 billion tons of sand every year in the construction industry alone. That’s enough to build a 20m×20m wall around the equator (赤道) every year. However, sand can take tens of thousands of years to form (形成): the process starts with rock being eroded (侵蚀) in the mountains and ends, eventually, with sand being in river beds, on beaches and on the seafloor.

Sand is heavy and difficult to transport, so in developing countries, sand is often mined from the nearest convenient source, and quite often that means a river bed or beach. But beaches and rivers are delicately balanced ecosystems and when a large amount of sand is removed, the balance is upset. The smallest fish, which eat organic matter on the sand in river beds, form the base of the food chain in a river. If this sand is removed, so is the source of food for the bottom feeders. All organisms in a food chain share the joys and the sorrows. Thus, when they disappear, so does the food for the larger fish which would have been caught and eaten, or sold by fishermen.

It is high time we took into consideration the big problem concerning the tiny thing. More and more conservationists are calling for new choices to replace sand, especially in the construction industry.

4 . 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.

6 . With greater climate catastrophe (气候突变) on Earth, it is natural for us to make every effort to stop the potential floods, snowstorms, and alarming reports from scientists. For many of us (myself included), part of that means running out to buy reusable straws, organic cleaners, and packaging-free products.

However, before you are delighted at “green” purchases, take a second to consider the results of a new study from Arizona University. By comparing the shopping habits, mental health and environmental impact of young people, the researchers reconfirmed a principle: Buying less beats buying “green” stuff without effort. And that is true whether you are looking at the impact that your purchases have on the Earth or on your own happiness.

It should not come as a shock that simply consuming less is better for the planet. After all, every new item a factory yields requires some resources to produce. Take plastic bag bans for instance. If your city is getting rid of single-use shopping bags, it can be attractive to pay for a fashionable organic cotton bag hanging in the check-out line of your local supermarket. However, experts insist that growing cotton is actually no better for the Earth than producing the conventional plastic bags. Then what is your best bet for carrying your groceries if you care about sustainability? Any bag you already own.

It is not just the Earth that will be happier if you buy less. You will feel more contented too, according to the new study. “People believe that they might well be self-satisfied about becoming environmentally conscious through ‘green’ buying patterns, but it doesn’t seem to be that way”, said the lead researcher Sabrina Helm. “Reduced consumption has effects on increased well-being, but we don’t see that with ‘green’ consumption.”

“Owning every new ‘green’ product on the market might make you feel contented, but if you relieve yourself of that burden of ownership, most people report feeling a lot better,” said Helm.

8 . Scientists often compare coral reefs(珊瑚礁) to underwater rainforests, yet unlike the leafy plant base of a forest, corals are animals. The soft creatures are naturally half-transparent and get their brilliant color from algae(藻类) living inside them. When corals experience stress from hot temperatures or pollution, they halt the interdependent relationship with algae, typically pushing them out and turning white. Corals are still alive when they are white, but they're at risk and many eventually die, turning dark brown.

Scientists around the world are looking for means to protect and maybe increase corals. One common option is to create more protected areas — essentially national parks in the ocean. Beyond nature preserves, some conservationists are looking to more hands-on methods. One research center in the Florida Keys is exploring a form of natural selection to keep corals remaining. The reef system in the Keys has been hit hard by climate change and pollution, which is especially tough, because corals there help support fisheries worth $ 100 million every year.

To keep the wild ecosystem alive, Erinn Muller, the center's director, and her team are harvesting samples of the corals that survived the environmental stress naturally, keeping them to make them reproduce, and then reattaching them to the reef. They have 46,000 corals on plastic frames under the sea. So far, the center has regrown over 70,000 corals from five different species on damaged reefs.

In The Bahamas, Ross Cunning, a research biologist at Chicago's Shedd Aquarium, focuses on corals with genes that could make them natural candidates for restoration projects. He published a study of two Bahamian reefs, one that survived an extreme 2015 heat wave, and one that didn't. "We think their ability to deal with these higher temperatures is built into their genes," says Cunning. There's evidence of corals evolving more quickly to resist rapidly warming climate. The big question scientists need investigate, adds Gunning, is how much more heat corals can adapt to.

10 . About 12 million tons of plastic wastes are entering the oceans every year. This garbage pollutes the water, kills wildlife and breaks down into small pieces that fish and other creatures eat.

Now a group of Spanish fishermen will receive economic support to catch plastics. It is part of a new project. Carlos Martin is one of the fishermen taking part in the project. He and his partners collect the plastic in the ocean and bring it back to land every week. Martin thinks rivers carry a lot of plastics to the sea. He says his most concern is no more than that the plastics often get caught in the nets, which makes nets not work properly. They take on mud（泥）, causing the nets to break because they weigh so much.

Under the new programs, one million pounds will support ocean cleanup efforts for fishermen like Martin. The money is coming from the European Union and the Catalan government. Sergi Tudela, the General Director of Catalonia Fisheries, is responsible for the cleanup project. He said, "We are hopeful that if we are successful in this project, we can apply it to other areas in the Mediterranean（地中海）."

Government reports show that the amount of plastic wastes washing up along the Spanish coastline has grown by 65 percent in just six years. Fishing equipment makes up a large part of the about 8 to 12 million tons of plastics left in the world's oceans every year.

Martin says the fishing community now understands how big the problem is. He says, "In the past we didn't see it that way. We took the plastic garbage and threw it back into the water. I think that after a few year here we have realized the problem. Nothing is thrown into the water; we collect everything and bring it to shore.