阅读下面的短文，然后按照要求写一篇150词左右的英语短文。
No doubt the planet is warming. Over the last century, the temperature has risen by around one degree Fahrenheit. It’s reported that the global temperatures will rise by 3-10 degrees Fahrenheit—enough to have the polar caps almost melted. If the ice caps melt, buildings, homes and even lives will be under water.
While we know about global warming, what can we do to save the planet? The answer is simpler than supposed. You don’t have to go miles away to protest, or spend much money. Here are several simple steps to begin with.
Firstly, plant a tree. Trees , when fully grown, will keep the planet cooler.
