Final answer:
Since 1992, the Greenland ice sheet has significantly decreased in size, with annual losses of 150-250 km³ between 2002 and 2006, indicating serious implications for rising sea levels and global climate change.
Step-by-step explanation:
The size of the Greenland ice sheet has experienced significant change since 1992. According to the information provided, Greenland lost 150-250 km³ of ice per year between 2002 and 2006. This loss is significant because it not only contributes to rising sea levels but also reflects the broader impact of climate change on our planet's polar regions. The McCarty Glacier in Alaska, as another example, completely disappeared between 1909 and 2004, underscoring the overall trend of glacier recession. Comparisons to the polar ice caps on Mars indicate that while the Greenland ice sheet is much larger, both are similar by the nearest power of 10, emphasizing the magnitude of ice present on Earth compared to Mars.
It is important to note that the provided data indicates a steep decline in ice volume over a relatively short period. The disappearance of glaciers in places like Glacier National Park in Montana further illustrates this phenomenon, where the number of glaciers larger than 25 acres decreased from approximately 150 in 1850 to about 24 by 2010. Such changes are a testament to the significant alterations occurring within our climate system.