For decades, scientists have been trying to figure out what all the carbon dioxide we have been putting into the atmosphere has been doing to plants. It turns out that the best place to find an answer is where no plants can survive: the icy wastes of Antarctica.

As ice forms in Antarctica, it traps air bubbles. For thousands of years, they have preserved samples of the atmosphere. The levels of one chemical in that mix reveal the global growth of plants at any point in that history.

“It’s the whole Earth — it’s every plant,” said J. Elliott Campbell of the University of California, Merced.

Analyzing the ice, Dr. Campbell and his colleagues have discovered that in the last century, plants have been growing at a rate far faster than at any other time in the last 54,000 years. Writing in the journal Nature, they report that plants are converting 31 percent more carbon dioxide into organic matter than they were before the Industrial Revolution.