Climate change is threatening our future as more and more greenhouse gases like CO2 are gathering in the atmosphere and heating up the planet. To fight the problem, both scientists and economists have suggested some good solutions. It turns out that whales, animals we've hunted to near extinction, are excellent at taking away CO2.
Whales remove CO2 from the air in two ways. First, they move nutrients（营养物） from their feeding areas deep in the ocean back to the surface, where they release them in their waste. Those nutrients aid the growth of phytoplankton（浮游植物），which, like other plants, takes away CO2 from the air. Second, whales themselves collect CO2 in their bodies when they eat other animals. The total amount of the gas adds up to about 33 tons over a whale's lifetime. When whales die, they take away all that CO2 with them down to the ocean floor.
Saving the whales could also be more cost effective than planting trees. Financial experts say that one whale, taking away CO2 and tour value, would be worth about US＄2 million over its lifetime. Compare this to the high costs needed to plant and keep forests for removing CO2， and you'll see why whales might be an effective solution.
At one time, millions of whales swam the world's oceans. Unluckily,commercial whaling between the 1600s and the mid-1900s brought many whale species close to extinction.
Starting in the 1970s, careful management of whaling began. Many species are recovering,but the giant animals still face major threats. One threat is continued hunting despite international regulation. For example,in Japan,"scientific" kills are carried out-often an excuse to get whale meat,which is considered delicious food. Public outcry has pressured many countries to limit or end whaling,and experts believe a new way to make money from whales-whale watching-will also be effective. However,another is more difficult to solve-pollution. Whales are affected by pollution from chemicals, noise, and the huge amounts of plastic and garbage that end up in the oceans.
These giants of the sea are important to the future health of our planet. If whale populations increased to where they were before commercial whaling, whales could remove an estimated 1.7 billion tons of CO2 per year. It might be an impossible dream, but it's one definitely worth fighting for.
Which of the following is NOT true about how whales remove carbon from the air？ ______
A. They move nutrients from deep in the ocean to the surface.
B. Many species of whales don't release CO2.
C. Whales collect CO2 in their bodies through the food they eat.
D. When whales die, the collected CO2 remains in their bodies.
What is the financial value of a whale compared to？ ______
A. The commercial hunting of ocean animals.
B. The financial value of ocean tourism.
C. The high costs of tree planting and forest protecting.
D. The ability of phytoplankton to remove CO2 from the air.
According to the passage, what threat is the harder to solve now？ ______
A. Pollution.
B. Scientific kills.
C. Whale watching.
D. Continued hutting.
What is the main purpose of the passage？ ______
A. To analyse the benefits whales bring.
B. To explain why whales are endangered.
C. To evaluate the effect of commercial whaling.
D. To call on people to save whales so as to protect the world.
