The end of 2016 is an uneasy moment for climate science in the United States. With a new Administration and a new Congress arriving in January 2017, future support for climate science and observing systems is uncertain. Against this backdrop, this special issue of Oceanography on ocean-ice interaction is timely. Although it was not our intent to highlight climate change, the fragile nature of Earth’s cryosphere and how it is responding to a warming world are essential parts of each article. Many aspects of the shrinking cryosphere are not yet understood, but the research described in these pages points to larger-than-anticipated—and alarming—changes to the planet’s large ice sheets, with associated future increases in global sea levels. Importantly, the articles in this special issue demonstrate the value to society of continuing vigorous scientific research that will enable us to better understand our planet’s rapidly changing polar environments.