【推荐1】A report on hundreds of research studies says plastic pollution at sea is reaching worrying levels. The report warned that pollution will continue to grow even if immediate (立即的) action is taken to stop such waste from reaching the world’s oceans.

The report, by Germany’s Alfred Wegener Institute, examined almost 2,600 research studies on plastic pollution.

Some areas, such as the Mediterranean, East China and Yellow Seas, already have dangerous levels of plastic. Other bodies of water will become more polluted in the future, the report found.

The writers reported that almost every kind of ocean animal has been affected by plastic pollution. That pollution is harming important environmental systems.

As plastic breaks down into smaller pieces, it is eaten by many different sea creatures. It is harmful to them and those who eat them.

Melanie Bergmann, one of the report’s writers, said getting that plastic out of the water again is nearly impossible. She added that policymakers (政策制定者) should make an effort to prevent any more pollution from entering the oceans.

Heike Vesper is with the World Wildlife Fund. She said people can help reduce plastic pollution by changing their behavior. But she added that governments must help in dealing with the problem.

The United Nations Environment Assembly is expected to meet and discuss the plastic pollution problem.

【推荐2】New research studying 20 years of ocean information has found that our oceans have changed the color. This also means a great change in the ecosystems (生态系统) of the oceans that is likely caused by human activities.

For tens of years, satellites (卫星) have been watching the color of Earth’s oceans and collecting information on the color of light reflecting (反射) off the water. Especially one of the satellites, the Aqua satellite has recently completed 20 years of collecting high-quality global ocean-color information. A new study has examined this information and found changes in ocean color over the past 20 years that cannot be explained by natural, year-to-year variability (可变性) alone.

“I’ve been running models to study the ocean color. The models have been telling me for years that these changes in ocean color are going to happen,” said Stephanie Dutkiewicz, one of the study’s writers. “To actually see it happening for real is not surprising. But I am scared that these changes are probably caused by human’s activities.”

The ocean’s color shows the life that lives in the water. Deep blue water usually has very little life. However, greener water means the presence of ecosystems, mainly plankton (浮游生物). Without plankton, many oceanic food webs would break down. This will greatly impact the sea life and humans who depend on fish for food.

“The color of our oceans has changed,” said Dutkiewicz. “And we can’t say how. But we can say that changes in color show changes in plankton communities. Plankton communities are the foundation (基础) of everything that feeds on plankton. So, we hope people take this seriously.”

Next up, Dutkiewicz will try to better understand the color changes in different ocean areas, as well as looking into what might be causing them.

【推荐3】Climate change is a big problem humans are facing. How can we deal with it? Reducing carbon emissions (碳排放) is important. But what if we could capture carbon dioxide (CO₂) from the air and use it to do other things?

Recently, SpaceX founder Elon Musk said that his company is working on a new program. It’s going to take CO₂ out of the air and turn it into rocket fuel.

It will not only be good for Earth, but “will also be important for Mars,” Musk tweeted. The air on Mars is made up of 95 percent CO₂. If we could turn CO₂ into fuel, we could travel the long journey from Mars back to Earth in the future.

The idea may sound strange but it’s not totally crazy. There are already some technologies that might help with this. According to Di-Jia Liu, a chemist at the Argonne National Laboratory in the US, the carbon atoms (原子) in CO₂ and the hydrogen (氢) atoms in water can be combined to make methane (甲烷) or ethanol (乙醇). They could be used as fuel. If we do this on Mars, energy from the sun might be used as a catalyst (催化剂).

The idea will also make space travel more eco-friendly. “If the CO₂-based fuel could be used in a rocket launch, we could prevent 715 tons of CO₂ from being emitted into the air,” said Stafford Sheehan from Air Company, a US company that focuses on CO₂ capture technologies.