Scientists believe that approximately 10 million years ago the closing of the Isthmus of Panama changed the climate of Earth so severely that winters in Europe became 10°C warmer than they had been. Why did this happen? A. Cold Caribbean Sea waters were forced up into the north Atlantic Ocean. B. Warm Caribbean Sea waters were forced up into the north Atlantic Ocean. C. The ice in the Caribbean Sea was broken apart by plate movements. D. A mountain range formed that blocked the movement of cold air into the area.

South America and North America were not connected until 10 million years ago, but instead they were separated by water, thus the Caribbean Sea was connected with the Pacific Ocean. Because of this, the warm waters from the Caribbean were not forced further north in the Atlantic, but instead they were moving between the two continents. Once the two continents merged though, the warm Caribbean waters were forced to move toward the north Atlantic, thus they started to move towards Europe. Because they were warm currents, they significantly warmed Europe, up to 10 C degrees more on average, significantly changing the climate in this part of the world.