There is overwhelming evidence that human activities, especially burning fossil fuels, are leading to increased levels of carbon dioxide and other greenhouse gases in the atmosphere, which in turn amplify the natural greenhouse effect, causing the temperature of the Earth's atmosphere, ocean.
The main difference in the process of waste removal between unicellular and multicellular organisms is the fact that unicellular organisms rely on only their membrane and organelles, the whole process is in inside the cytoplasm of the cell and once waste is formed, it is "packed" in special sacs called vacuoles and then, through the process of exocytosis they are being left out of the cell. On the other hand, multicellular organisms most often have specific organs that are in charge of the process of digestion, absorption and excretion or removal of waste.
