1. Calcium carbonate minerals are the building blocks for the skeletons and shells of mini marine organisms. It is important to ocean creatures because they make their shells out of this material. Examples of animal products that are primarily of calcium carbonate include seashells, egg shells, pearls, and notably coral
1a: Calcium carbonate is a dietary supplement used when the amount of calcium taken in the diet is not enough. 1b: Oceans are an important source of food. They host 80 percent of the planet's biodiversity, and are the largest ecosystem on Earth.
2: Carbon dioxide (CO2) emissions from burning fossil fuels are making the world's oceans more acidic. In the water, CO2 reacts to form carbonic acid, and over the years, the ocean's acidity has increased by 30 percent because so much of the excess man-made CO2 is being drawn into the water.
3: Global warming is the long-term heating of Earth's climate system observed since the pre-industrial period (between 1850 and 1900) due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth's atmosphere.
