Who did start the fire?
Nature has set fires for a very long time. Lightning is a common cause, but volcanoes, meteorites, or other natural phenomena also can start fires.
Humans also set fires, usually to cook food, to provide heat, or do other things that we want. But, rarely, humans set fires for bad reasons such as to hurt someone or to collect insurance money. This is the crime of arson. Police departments and insurance companies often have arson investigators, who must understand natural fires to be able to tell whether humans or nature were responsible when something burned down.
How does arson relate to climate change? You may know one of the many people who argue that we shouldn’t worry about human-caused climate change because nature has changed climate in the past. Some of these people seem to think that the existence of natural climate change means that we couldn’t be causing the changes going on now or that may come in the future—equivalent to arguing that a fire couldn’t be arson because nature lit fires in the past. Other people seem to think that living things survived past climate changes, so ongoing and future climate changes won’t matter—equivalent to arguing that arson might happen, but it doesn’t matter because it doesn’t really hurt anyone. But while many people make such arguments about climate change, very few people make the same arguments about arson.
Those who study the history of climate, like those who study the history of fires, generally come away with a clear understanding that both nature and humans can cause changes, and that big changes caused by nature or by humans matter a lot to people and other living things. For climate, studying the history of the Earth provides strong evidence that humans can make changes that match or exceed almost anything nature has done, with huge impacts.