1 . Cities are diverse ecosystems. In addition to visitors from the wild, such as coyotes (丛林狼) in Los Angeles or boars (野猪) in Berlin, a large number of species share our urban areas. As our cities spread, we need to think about what it is like for other species to have human neighbors.

Because cities are built for humans, they do not always provide suitable habitats for wildlife. For example, most city parks are kept neat and tidy so that humans will find them beautiful. But when we cut grass or plant flowers, we destroy natural habitats.

Our actions sometimes help other species. When a bridge in Austin, Texas was repaired, engineers added small gaps running along the length of its bottom. This made a good home for bats, and soon the bridge was the home of thousands of bats. At first, people were afraid of the bats and tried to get rid of them. Now, they have come to value their winged neighbors. The bats are a tourist attraction, and they eat lots of bugs every night.

There are also structures built with the aim of bringing wildlife into the city. The Beijing Olympic Forest Park is a good example. The park used native plants and created open, natural spaces for wildlife. The result is a zone in Beijing with over 160 species of birds. In many ways, the park is the opposite of a zoo. Instead of being kept in cages, wildlife can move about freely.

Another example is a 2011 proposal for a tall “Birdscraper” building in New York. The building is intended to protect birds and fight pollution at the same time. It would be in the middle of a lake, birds would sit on it, and their droppings would fall into the water. The droppings would help water plants grow well and then create oxygen through photosynthesis (光合作用). If we learn to share our space, we can become better neighbors to the wildlife around us. If we do not, more species will become extinct and our own future will be endangered.

One day, my sister Alice and I were walking in our hometown and saw hundred of rubbish on the ground. They made the town look such ugly that we decided to do something. At first, we draw pictures with words in parks, in beaches to let people know the damage to the environment. Late, we raised money to buy dustbins for our town. Many newspapers have been written about my sister and me over the past five years. As the result, we have won many prizes for that we have done. But we are not interesting in prizes. We just want make our hometown a better and cleaner place.

6 . It’s Earth’s birthday! The Earth is about 4.5 billion years old! In honour of our planet, former U. S. Senator Gaylord Nelson decided we needed a special day to celebrate and learn how to care for our environment. He wrote letters to many schools about the day he planned because he knew kids like you would help.

On April 22, 1970, the first Earth Day was held. Many environmental laws were passed, and people all over the country made promises to protect the environment.

Since then, Earth Day has spread around the world and people are working together to create cleaner air and energy to take care of Mother Nature. Learn how you, your family and friends can start making a difference too!

Earth Day is now celebrated by millions of people in more than 180 countries. Here are some ways that you can help re-energize the Earth and celebrate too!

• Visit a nature conservancy (保护协会). Nature conservancies teach us how to preserve our natural history.

• Have an Earth Day block party! Invite neighbourhood kids to plant gardens or trees or pick up trash. Then celebrate your achievements with some Earth Day’ treats and nature music.

• Challenge your family to “go green”. Walk, bicycle, carpool or take the bus to reduce greenhouse gases and get outdoors!

• Wear green, a nature, or Earth Day T-shirt to help spread the word about caring for our environment.

• Make a “planet promise” to reduce your energy use and recycle.

We hope you’ll use some of these ideas during the week of April 22 to celebrate and give back to the Earth that gives so much to us.

7 . Pumpkins (南瓜) have all shapes and sizes and have colors of golden orange, white and green. Cooked in a pie, they are symbols of autumn that are grown in every county of Washington.

U.S. farmers grow more than a billion pounds of pumpkins every year, and many famers use sheets (膜) of plastic blocking the grass and preventing water loss to make their plants grow well. In the country, farmers use about a billion pounds of plastic every year. Unfortunately, that plastic is thrown away finally, and in some areas, burned in the fields.

For several years, Carol Miles has studied a new product—the soil-biodegradable (土壤生物降解的) plastic cover that can be left in the ground after harvest, then broken down by things in the soil. “You don't need to pull it out of the field and throw it away every autumn, saving time and money,” Miles said.

Most pumpkins grow along vines (藤蔓) that spread through the grass-blocking cover, and Miles wanted to see how pumpkin fruit performed over the plastic cover. That brought a challenge: the soil-biodegradable cover stuck to the bottom of the fruit.

“We have a lot of dew (露水) in the morning, and we found that if we let the fruit dry after harvest, the cover would stick more strongly to the pumpkins,” Miles said. “Nobody wants plastic stuck to pumpkins, even if it's biodegradable. But if you wipe the fruit before the dew dries, the plastic comes right off.”

Farmers who grow plants that don't set fruit on plastic covers won't meet this challenge. For those who do, it means an extra step that they'll have to weigh against advantages and disadvantages for the development.

“Challenges aside, working with this crop can bring on a happy picture,” the farmer Tymon said. “Pumpkins are great. They have bright colors, and are really fun to work with.”

8 . Although we're surrounded by millions of bricks every day, most of us don't think about them too often. For thousands of years, the humble clay-fired bricks haven't changed.

They're made from natural materials, but there are problems with bricks at every step of their production. Bricks are made from clay—a type of soil found all over the world. Clay mining is harmful to plant growth. In conventional brick production, the clay is shaped and baked in kilns(窑) mostly heated by fossil fuels, which contributes to climate change. Once made, bricks must be transported to construction sites, generating more carbon emissions. With so many bricks produced globally, their impact adds up.

Gabriela Medero, a professor at Scotland's Heriot-Watt University, decided to find solutions to that. With her university's support, Medero set up Kenoteq in 2009. The company's signature product is the K-Briq. Made from more than 90% construction waste, Medero says the K-Briq—which does not need to be fired in a kiln—produces less than a tenth of the carbon emissions of conventional bricks. With the company testing new machinery to start scaling up production, Medero hopes her bricks will help to build a more sustainable world.

The K-Briq will be comparably priced to conventional bricks. Additionally, as a new product, the K-Briq has been subjected to strict assessment and authoritative certification. Reusing old bricks is an expensive process and there is no standardized way to check the strength, safety or durability (耐久性) of recycled bricks. Medero says that K-Briq could solve both these problems. She claims that K-Briq is stronger and more durable than fired clay bricks.

Over the next 18 months, Medero plans to get K-Briq machines on-site at recycling plants. "This will reduce transport-related emissions because trucks can collect K-Briq when they drop off construction waste," says Medero.

10 . Food labels already indicate how good or bad a product is for you. But good or bad for the planet? That’s often much less clear. Now a growing number of brands are labeling their products to show their climate impact.

Swedish food company Felix is one of them. For two days in October, Felix opened a pop-up store in Stockholm, where all items were priced based on their carbon footprint. The bigger their emissions, the higher the price. The idea was to demonstrate how easy it is for shoppers to make climate-friendly choices when products are clearly labeled.

“We know that the numbers alone don’t make sense to consumers,”says Sjöberg, Felix’s marketing manager, “To give the figures meaning, we have created a climate scale that clearly shows the current average and which climate footprint is low.”

Evaluating a food’s true carbon footprint isn’t easy and brands are teaming up with specialist platforms that deal with data using complex calculation tools to work out emissions across the whole production chain.

Oatly calculates the footprint of its oat-based drinks, from the agricultural processes all the way to the grocery store, with the help of CarbonCloud, a startup spun out of research at Chalmers University of Technology, in Sweden. “We have developed a web platform that allows the food producers to perform detailed climate assessments without them needing to understand any of the science or the mathematics behind it,”explains CarbonCloud CEO David Bryngelsson.

Companies like Oatly input information including their ingredients, energy use, waste production and how products are shipped, and CarbonCloud's web tool does the rest.

CarbonCloud has done assessments for hundreds of products and brands including Estrella, Nude and Naturli, and says interest is increasing rapidly.

At the moment the food industry doesn’t have a standardized approach to calculating carbon figures, but Sjöberg says the most important thing is to give consumers the information that⁹s currently available.

“In the future, hopefully we will see a common ground for how we calculate and how we label products,” he says. “But as for right now, the climate can’t wait.”