The Little Ice Age was a period from about 1550 to 1850 when the world experienced relatively cooler temperatures compared to the time before and after. Subsequently, until about 1940, glaciers around the world retreated as the climate warmed substantially. Glacial retreat slowed and even reversed temporarily, in many cases, between 1950 and 1980 as global temperatures . Since 1980, a significant global warming has led to glacier retreat becoming increasingly rapid and ubiquitous, so much so that some glaciers have disappeared altogether, and the existence of many of the remaining glaciers is threatened. In locations such as the Andes of South America and Himalayas in Asia, the demise of glaciers in these regions has the potential to affect water supplies in those areas.