1 . In 2012, James Cameron, creator of Avatar and Titanic, became the first person to reach the Challenger Deep. When he arrived at the deepest spot on Earth at 7 miles below sea level, he spent hours mapping the region and taking photos and samples.
“As human beings, we’re drawn to absolutes—the deepest, the highest, the coldest, the farthest,” he says. “And as a storyteller and curious monkey, I just wanted to see what was there.” The answer is obvious—plastic and more. “Our so-called civilization is using the ocean as its toilet,” Cameron says. “Unless this changes, ocean ecosystems are going to continue their rapid collapse.”
Despite decades of environmental studies, the impact of plastic and other forms of pollution on oceans are not entirely understood. Initial studies appear to indicate that ingesting(摄取) them—either directly or indirectly—could cause disease. Plastics can also release poisonous substances into the water, which could potentially impact animal populations.
But plastic is just one of the problems facing oceans that have yet to be fully understood. “Plastic waste in the ocean is horrifying but is only the most obvious of our many deadly waste streams, which include carbon that’s heating the atmosphere and making the ocean acidic, and the run-off nutrients from all the world’s agriculture, which is causing anoxic(缺氧的) dead zones the size of countries,” Cameron says.
Oceans, like the rest of the world, are impacted by the burning of fossil fuels and the release of greenhouse gases like carbon dioxide—about 30 percent of which is absorbed by the sea. This absorption causes ocean acidification, where the pH level is altered to become more acidic. As a result, it’s harder for some creatures to form shells and skeletons and countless species at the base of the food web can struggle to survive, which, scientists say, has the potential to cause huge disruptions to entire ecosystems. Indeed, ocean acidification is thought to have played an important role in Earth’s worst-ever mass extinction event 252 million years ago.
The effect of climate change on the world’s oceans will likely worsen in coming decades. Last June, scientists announced carbon dioxide levels had reached the highest levels since human records began. The last time carbon dioxide levels were this high was during the Pliocene era, between 3 and 5 million years ago, when global temperatures were about 4 degrees Celsius warmer than they are today. Current climate models suggest that if greenhouse gas emissions continue on their current trend, we may be on course to see 4 degrees of warming by 2100.
As a result, understanding the role oceans have on global systems is becoming more and more important.
1. What are the first two paragraphs mainly about?| A．The author’s feelings to the ocean. | B．Cameron’s movies and remarks. |
| C．The author’s discoveries under the sea. | D．Cameron’s observation and concern. |
| A．Several countries are suffering from anoxic dead zones. |
| B．More concern should have been given to the pollution on oceans. |
| C．Plastic is supposed to be the most serious environmental problem. |
| D．Ocean acidification removes the nutrients from agricultural products. |
| A．Decreases. | B．Destruction. |
| C．Diseases. | D．Discrimination. |
| A．To call on people to protect sea animals. |
| B．To compare current situations with the past. |
| C．To explain how serious the ocean problem is. |
| D．To prove pollution to be the cause of acidification. |
