As discussed in this article from the journal Science, the most recent computer modeling shows that the global warming patterns in place at the moment will result in an evitable rise in sea levels worldwide. This presumes that no additional greenhouse gases are added to the atmosphere (which, of course, isn't the case at the moment). As the world's greatest producer of greenhouse gases, the United States, sleeps, the need for urgency grows. The Union of Concerned Scientists offers some suggestions for changes in this piece, Global warming is real and underway.
The official position of the U.S., as expressed by James L. Connaughton, senior environmental and natural resources advisor to President Bush, is that more study is needed, as expressed in this article published by The Royal Society.