创建一句关于全球气候变化的问句，并提供一个相关的数据统计。
What is the impact of global climate change on sea level rise, and how much has sea level risen since the early 20th century? 

According to NASA, global sea level has risen approximately 8 inches (20 cm) since 1880, with almost half of that rise occurring in the last 25 years.