Nearly the entire ice cover of Greenland melted in a span of four days this month, more than at any time in more than 30 years of satellite observations, according to NASA and university scientists. Researchers have not determined whether it will affect the overall volume of ice loss this summer and contribute to sea level rise.
In addition to loss of mass from the Greenland and Antarctic ice sheets, NASA notes two other factors that contribute to global sea level rise: Thermal expansion of seawater due to global warming and widespread melting of land ice. As the old ice of Earth melts, photographers have captured its decline.
NASA notes that for the past 650,000 years, there have been seven cycles of natural glacial advance and retreat — the last ending 7,000 years ago. These happened, experts believe, because of slight variances in the Earth’s orbit determining how much sun the planet receives. What is significant about our current warming trend is that NASA believes it to “very likely [be] human-induced.” Using its vast resources of technology, NASA has deduced that temperatures are rising at a rate that is unprecedented in the last 1,300 years. The Earth has been warming since 1880, and most of this has happened since the 1970s. Ice sheets, most notably in Greenland and Antarctica, have decreased in mass. While NASA continues to study the effects of climate change on Earth, it is virtually certain that ice will continue to melt, and sea levels will continue to rise.
Here are eight stunning before-and-after images detailing ice melts across our planet.