TOEFL iBT Integrated Writing : Sahara

Reading passage
The Sahara is a massive desert, the world’s largest, in fact. It is approximately equal in size to the United States and covers more than 9 million square kilometers. It is more than 5,500 kilometers from east to west and 2,000 kilometers from north to south.

The Sahara has a very dry climate. The average annual rainfall is not even 10 centimeters, and many areas receive less than 2 centimeters per year. In the very driest places, it rains only about once a century.

There is little surface water in the Sahara. The Nile river does run through the Sahara, and there are some oases there, but otherwise the surface is dry. Of the oases in the Sahara, about 90 are large enough to support tiny villages.

Main idea: Characteristics of the Sahara today
MP 1: --- world's largest desert
            -- same size U.S.
            -- 9 mill sq km
            -- 5,500km E/W,  2,000 N/S
MP2: --- v. dry climate
           -- < 10cm rain a year (someplace <2cm)
           -- sometimes only once/100years
MP3: --- little surface water
           -- only Nile, few oases

Listening passage
Something that many people find quite surprising about the Sahara is that it actually used to be quite green. It once used to be a lush green jungle-like area.

When an ice-age, the Pleistocene Ice Age, ended about 10,000 years ago, the area that today is the massive Sahara Desert actually had a rather wet climate. The area was a lush green land of forests and grasslands with rivers and lakes throughout. There were large animals such as giraffes and elephants, and there were even hippopotamuses, which need water year round to live, in the area. The area was also populated by prehistoric peoples who lived at first by hunting and fishing and later by farming and raising animals.

Around 6,000 years ago, the climate there began to dry out, and the region began turning into a desert. Within 2,000 years, by 4,000 years ago, a dramatic shift had taken place, and the Sahara had become the huge desert that it is today.

Main idea: The Sahara in the past (very different)
MP 1: --- 10,000 years ago wet climate
            --  forests, grassland, rivers, lakes
            --  large animals, e.g. hippos
            --  prehistoric people, hunting, fishing, farming
MP2   --- 6,000 years ago climate changes
            -- dry out, desertification begins

MP3: -- by 4,000 years ago had become desert