Dear student. Global warming is a slow and steady rise in Earth's surface temperature.1)When people use fossil fuels like coal and oil, this adds carbon dioxide in the air. 2)When people cut down many treesGlobal warming is projected to have a number of effects on the oceans. Ongoing effects include rising sea levels due to thermal expansion and melting of glaciers and ice sheets.As the climate warms, it changes the nature of global rainfall, evaporation, snow, stream flow . Regard