Our planet has two glaciers of continental size, one being present in Antarctica and the other in Greenland. Observations made by scientists over the last thirty-five years all agree on the notion of shrinkage and/or retreat of the ice caps. Melting ice caps have far-reaching consequences for the millions of people who rely on melting glaciers for their drinking water and for the millions who will be displaced by rising sea levels as a direct result of the melting. Observations of melting ice also show that the rate at which ice is melting is accelerating. Mountain glaciers around the world are also in retreat. Some cases of particular mountain glaciers may show expansion, but studies by glaciologists show that the total mass of glaciers around the world is decreasing at an accelerating rate. These studies have been carried out using a number of different methods which all show a trend in the same direction. The methods by which polar scientists quantify the extent of ice sheet growth or decline took a big step forward in the early 1990s, when satellite observations began to provide spatial information. complete data sets. Three distinct methods, each with particular approaches and limitations, were used to acquire ice sheet mass data. Satellite altimetry measures changes in ice sheet volume from laser and/or radar altimeters. This can be converted into mass changes by taking into account the spatial and temporal distribution of surface density, coupled with spatial exploration of unsampled regions. The limitations of this method, similar to other scientific methods, lie in the models used. A second method used is called input-minus-output. Using this method, scientists calculate the difference between the screen...... middle of paper ...... Previous research suggested that ice sheets could expand under climate change due to increased precipitation from warmer air holding more moisture. As more recent studies suggest, the actual increase in precipitation due to global warming is countered by accelerating ice flow into the ocean. Overall, actually heavier snowfall will only increase future ice flow. Ice physics simulations have shown that future releases of ice into the ocean increase threefold due to additional precipitation. Snow that accumulates due to increased humidity in the air puts pressure on the ice and increases the rate at which it flows into the ocean. Clarify the concept; more snow in the interior does not result in no sea level rise. This has been quantified using several methods, each focused on the anchored parts of the glaciers..