In 2015, annual average atmospheric carbon dioxide (CO2) levels surpassed a level of 400 parts per million (ppm) for the first time in three million years. This has caused widespread concern among climate scientists, and not least among those that work on natural climate variability in prehistoric times, before humans. These people are known as "past climate" or palaeoclimate researchers, and author Eelco J. Rohling is one of them. The Climate Question offers a background to these concerns in straightforward terms, with examples, and is motivated by Rohling's personal experience in being intensely quizzed about whether modern change is not all just part of a natural cycle, whether nature will not simply resolve the issue for us, or whether it won't be just up to some novel engineering to settle things quickly.

This book discusses in straightforward terms why climate changes, how it has changed naturally before the industrial revolution made humans important, and how it has changed since then. It compares the scale and rapidity of variations in pre-industrial times with those since the industrial revolution, infers the extent of humanity's impacts, and looks at what these may lead to in the future. Rohling brings together both data and process understanding of climate change. Finally, the book evaluates what Mother Nature could do to deal with the human impact by itself, and what our options are to lend her a hand.