Today, however, the phrase is most often used as climate change caused by humans. It's fueling hurricanes like Hurricane Sandy and Hurricane Irene.
Several factors contribute towards change in the climatic conditions. Earth's climate has been changing regularly for hundreds of millions of years, sometimes getting colder and sometimes warmer. Without it, Earth would be much too cold to support the huge diversity of life that it does. However, the more carbon dioxide in the air, the warmer the planet becomes.
But as time goes on, climate scientists have more and more data to work with, and computers become more and more powerful—so the models get better.
Also, warmer temperatures can increase water demand and evaporation, stressing water supplies. This trend will continue if gas emissions remain unchecked.
The seas also rise when glaciers and ice sheets melt, feeding more water into the oceans. Each of us should contribute his bit to control this global issue. But human activities are increasing the amount of greenhouse gases and trapping more heat.