【推荐2】Most of us spend our lives seeking the natural world.We go fishing，sit in the garden，have a picnic，live in the suburbs or go to the seaside.The most popular leisure activity in Britain is going for a walk.When joggers jog，they don't run on the streets.Every one of them tends to go to the park or the river.

But despite this，our children are growing up nature­deprived.I spent my boyhood climbing trees.These days，children are robbed of the ancient freedom，due to problems like crime，traffic，the loss of the open space and strange new ideas about what is best for children，that is to say，things that can be bought，rather than things that can be found.

The truth is to be found elsewhere.A study in the US：families had moved to better housing and the children were assessed for ADHD—Attention Deficit Hyperactivity Disorder(注意力缺陷多动症)．Those whose accommodation had more natural views showed an improvement of 19%；those who had the same improvement in material surroundings but no nice view improved just 4%.

ADHD is one of the great problems of modern childhood.One study after another indicates that contact with nature gives huge benefits to ADHD children.However，we spend money on drugs rather than on green places.

The life of old people is measurably better when they have access to nature.The increasing concern for the growing population of old people is in quality rather than quantity of years.And study after study finds that a garden is the single most important thing in finding that quality.Even problems with crime and aggressive behaviour are reduced when there is contact with the natural world.

【推荐1】The Giraffe Center in Nairobi is one of the oldest giraffe conservation organizations in the world. When it was founded in 1979, there were only 150 Rothschild's giraffes left in Kenya.

Stanley Kosgey, in charge of conservation education at the center, says the tallest animals in the world have never really gotten the same attention from conservationists and governments that other African mammals have. In some ways, he thinks, it's because they're hard to miss. In Kenya, it's not rare to see half a dozen of them as you drive past some fields on the highway. It can take you several safaris （旅行队）before you catch sight of a lion.

“Giraffes are in what I would call a silent extinction," Kosgey says.

In a lot of ways, he says, a perfect storm has fallen on the species. Climate change means longer droughts and new diseases; civil unrest means giraffes become easy food; and as African countries grow, humans have encroached （入侵）on wildlife areas and the removal of trees becomes a huge problem. Giraffes are huge creatures, and they require a lot of space and plants.

Kosgey says the good news is that the world has begun to pay attention. In Kenya, which has some of the best conservation policies on the continent, there is a plan underway to treat giraffes in the same way that lions, rhinos and elephants are treated. That's to put in place detailed action plans and programs to make sure those animals thrive. The first step for giraffes is to get a deeper understanding of their population by conducting a survey.

Kosgey says their conservation effort alone has saved the Rothschild's giraffe. There are now about 650 of them in Kenya. Worldwide, there are 1,671 Rothschild's, about 26 percent more than there were in the 1960s, according to the IUCN （International Union for Conservation of Nature）.

“They are tall, graceful animals and they should be heard/⁵ Kosgey says.

【推荐2】When John Todd was a child, he loved to explore the woods around his house, observing how nature solved problems. A dirty stream, for example, often became clear after flowing through plants and along rocks where tiny creatures lived. When he got older, John started to wonder if this process could be used to clean up the messes people were making.

After studying agriculture, medicine, and fisheries in college, John went back to observing nature and asking questions. Why can certain plants trap harmful bacteria (细菌)? Which kinds of fish can eat cancer-causing chemicals? With the right combination of animals and plants, he figured, maybe he could clean up waste the way nature did. He decided to build what he would later call an eco-machine.

The task John set for himself was to remove harmful substances from some sludge (污泥). First, he constructed a series of clear fiberglass tanks connected to each other. Then he went around to local ponds and streams and brought back some plants and animals. He placed them in the tanks and waited. Little by little, these different kinds of life got used to one another and formed their own ecosystem. After a few weeks, John added the sludge.

He was amazed at the results. The plants and animals in the eco-machine took the sludge as food and began to eat it! Within weeks, it had all been digested, and all that was left was pure water.

Over the years, John has taken on many big jobs. He developed a greenhouse — like facility that treated sewage (污水) from 1,600 homes in South Burlington. He also designed an eco-machine to clean canal water in Fuzhou, a city in southeast China.

“Ecological design” is the name John gives to what he does. “Life on Earth is kind of a box of spare parts for the inventor,” he says. “You put organisms in new relationships and observe what’s happening. Then you let these new systems develop their own ways to self-repair.”

【推荐3】The sixth mass extinction is not a worry for the future. It’s happening now，much faster than previously expected，and it's entirely our fault，according to a study puhlished Mooday.

Humans have already wiped out hundreds of species and pushed many more to the brink of extinction through wildlife trade，pollution，habitat loss and the use of toxic substances. The findings published in the scientific Journal Proceedings of the National Academy of Sciences( PNAS)show that the rate at which species are dying out has accelerated in recent decades.

Gerardo Ceballos González，a professor of ecology at the National Autonomous University of Mexico and one of the authors of the study，said approximately 173 species went extinct between 2001 and 2014. “173 species is 25 times more extinct species than you would expect under the normal extinction rate. ”he told CNN in an email. He and his team found that in the past 100 years，more than 400 vertebrate(脊椎动物的)species went extinct. In the normal course of evolution，such extinctions would have taken up to 10，000 years，they said.

Mass extinctions are just as severe as their name suggests. There have been five mass extinction events in the Earth’s history，each wiping out between 70％and 95％of the species of plants，animals and microorganisms. The most recent，66 million years ago，saw dinosaurs disappear. The past events were caused by catastrophic changes of the environment，including massive volcanic eruptions or collision with an asteroid.

The sixth mass extinction the one happening now—is different：scientists say it’s caused by humans. The researchers also said the current coronavirus(冠状病毒)crisis shows people’s recklessness(鲁莽)towards nature can seriously hurt themselves. Many endangered species are dying in large numbers due to the trade in wild animals and plants.