Approximately one-third of the Earth's land surface is desert. USGS Deserts are always dry. USGS Sand covers only about 20 percent of the Earth's deserts. USGS
Whether hot or cold, deserts pose great challenges for the plants and animals that live there, which must adapt to extreme, prolonged water deficits. Met Office The Gobi Desert of east Asia is one example, where annual average temperatures can be below 0 degrees C. Met Office
The Sahara of Africa is the world's largest desert, in USGS wording. USGS Antarctica is a desert. British Antarctic Survey
Which desert is the largest?
USGS calls the Sahara of Africa "the world's largest desert" in its types essay (a non-polar framing in that sentence). The British Antarctic Survey says "Antarctica is a desert," with snowfall equivalent to only 150mm of annual rain. We report both wordings. We do not call Antarctica the world's largest desert, because none of the sources we checked for this site use that phrase.
Every fact on this site is written in our own words and checked against a named source. Where two good sources disagree, both wordings stay on the page.