An elephant and a crocodile were once standing beside river. They were disputing which was the better animal.

“Look at my strength,” said the elephant. “I can pull up a tree, roots and all, with my trunk.”

“Ah! But your skin is not nearly so thick as mine,” replied the crocodile. “No knife or tooth can cut through it.”

Just as they were coming to blows, a lion happened to pass.

“My dear friends !” said the King of all animals, going up to them. “Let me know the cause of your disagreement.”

“Will you kindly tell us which is the better animal?” cried both at once.

“Certainly,” said the lion, pointing across the river. “Do you see the soldier’s metal hat on that wall?”

“Yes!” replied the beasts.

“Well, then,” continued the lion, “go and get it, and bring it to me, and I shall be able then to decide between you.”

Upon hearing this, off they started, The crocodile, being used to the water, reached the opposite side of the river first, and was soon standing beside the wall.

Here he waited till the elephant came up. The elephant, seeing that the crocodile had no way of reaching their goal, raised his long trunk, and took down the hat quite easily.

They then made their way together back again across the river. The elephant was trying to keep up with the fast-moving crocodile in the water and became careless. When he was forced to turn sharply to avoid a floating tree branch, the elephant dropped the hat and it fell to the river bottom. The crocodile noticed the accident, so down he dived, and brought it up in his huge mouth. They then returned, and the crocodile laid the metal hat at the lion's feet. The King took it up, and turning to the elephant, said:“You, because of your size and trunk, were able to reach the hat on the wall but, having lost it, you were unable to get it back. And you,” said the lion to the crocodile, “although unable to reach the hat, were able to dive for it and save it. You are both wise and able in your own ways. One is no better than the other.”

Jet airplanes are one of the largest causes of human pollution. About 3% of the world’s carbon emissions(碳排放）are believed to come from airline travel. Thai number is likely to go up—the number of people traveling by plane has been growing for years, and is expected to keep increasing.

To help fight climate change, Dutch airline KLM has started a program asking people to “ Fly Responsibly”.   The company is asking its customers to think about their choices before they buy a plane ticket. In a video, the airline suggests that travelers ask themselves questions, such as whether they could lake a train instead.

However, some people have suggested that instead of asking the public to think carefully about their actions, KLM, and other airlines, need to be considering solutions that lie with the industry itself . “ Voluntary (主动的）actions by customers are not enough; the cost of flying must increase." said Justin Francis, founder of Responsible Travel.

Anna Hughes, who runs Flight Free UK, Sees much of the “greening" in aviation(航空) as problematic. She said, “The simple fact is that climate change, worsened by our use of (fossil fuels(化石燃料），will make it difficult for our children to live on this planet. While we welcome action，to make aviation friendlier to the environment, airlines must be honest about their influence on climate change."

But the International Air Transport Association (IATA) is backing the KLM program. Rafael Schwartzman, IATA's vice-president for Europe, said, “We support it in the sense that you do have a choice. In certain cases you could have another choice. " But, he added, “the UK is an island. If you want to trade internationally, you will have to count on aviation.”