Half of the world’s coral reefs have died in the last 30 years. Now scientists are racing to ensure that the rest will survive.

“The threat to coral reefs isn’t something that’s going to happen 100 years from now. We’re losing them right now,” Julia Baum told the Associated Press. She is a marine biologist at the University of Victoria, in British Columbia, Canada. “We’re losing them really quickly, much more quickly than I think any of us ever could have imagined.”

Even if global warming were in stop right now, scientists predict that more than 90% of corals will die by 2050. If no major steps are taken to address the issue, the reefs may be headed for total extinction.

The planet’s health depends on the survival of coral reefs. They are often described as underwater rainforests, because they are ecosystems that provide habitats for one in four of all marine species. In addition, the reefs serve as barriers that protect coastlines from the full force of powerful storms. Corals are used in medical research for cures to diseases. They are key to local economies, as well, since the reefs attract tourists, the fishing industry, and other businesses, bringing in billions of dollars of revenue (收入).

“To lose coral reefs is to fundamentally damage the health of the human race,” Ruth Gates, director of the Hawaii Institute of Marine Biology, said.

Corals are animals that lack a backbone. They live mostly in tropical waters. The corals release a substance called calcium carbonate (碳酸钙), which forms protective skeletons around them. The skeletons grow and take on vivid colors. This is the result of the corals’ mutually beneficial relationship with algae (藻类) that live in their tissues (组织) and give them energy.

But corals are particularly sensitive to changes in temperature. A rise of just 1 to 2 degrees Celsius can force the corals to drive out the algae. Then the corals’ skeletons turn white in a process called “bleaching”. Corals can survive in these higher temperatures only for a few months.

Fast fashion has been on the rise since the early 2000s. 【小题1】 However, it has harmful effects on the environment. Here are some facts about fast fashion that you may not know.

●100 billion pieces of clothing are produced each year. To keep up with changing fashions, a large amount of clothing is produced every year — 100 billion pieces to be exact. 【小题2】 This results in a huge amount of textile (纺织品) waste. About 85% of all textiles are thrown away every year, from clothes that lose their quality to clothes that go out of fashion.

●【小题3】Every piece of clothing is made from some kind of fabric (织物). Some clothes are made from natural fibres (纤维) such as cotton or wool, which require a large amount of water to produce. For example, more than 20,000 litres (L) of water are needed to get just one kilogram of cotton! Water is also used in other clothing production processes, such as giving colour to fabrics. It can take around 7,000 litres of water to produce one pair of jeans and 2.700 litres to produce a cotton shirt!

●Fast, cheap clothes mean poor working conditions for workers.   Fast fashion is made by factory workers in developing countries. Often working conditions are poor: 【小题4】 Fast fashion companies often place making money above workers health and well-being.

As consumers (消费者), we can all play our part in reducing the environmental influence of the fashion industry. We should take care of our clothes to make sure that they last as long as possible. 【小题5】 When we grow out of our clothes we can donate them instead of throwing them away.

Sports can help contribute to a healthy body and get you close to nature. However, whether you are on the mountains, in the waves, or on the grassland, you should be aware that your sport of choice might have great impact on the environment.

【小题1】 Golf, as you may know, eats up not only large areas of countryside, but also tons of water. Besides, all sorts of chemicals and huge amounts of energy are used to keep its courses(球场) in good condition. 【小题2】 For example, in the dry regions of Portugal and Spain, golf is often held, responsible for serious water shortage in some local areas.

There are many environment-friendly sports. 【小题3】 You don’t need any special equipment except a good pair of shoes; and you don’t have to worry about resources and your purse. Simple and free, it can also keep you fit. 【小题4】 Experts say that 20 minutes daily can make you feel less anxious, sleep well and have better weight control.

Whatever sport you take up, you can make it greener by using environment-friendly equipment and buying products made from recycled materials. But the final goal should be “green gyms”. They are better replacements for traditional health clubs and modern sports centers. Members of green gyms play sports outdoors, in the countryside or other open spaces. 【小题5】 And best of all, it’s free.