What are the lines of evidence for human impact on global climate change?

The only period in human history during which atmospheric carbon levels have decreased is during Genghis Khan's reign, which is thought to have resulted in the deaths of about 15% of the world's population. What set apart the Mongol empire from other mass-killing events was that, unlike plagues, which may kill a large number of people but do not wipe out entire towns, forests were allowed to reappear in large areas. This evidence suggests that the decrease in atmospheric carbon levels was caused by the absence of human activity in areas that had previously experienced it. The inference drawn from this data is that human activity directly affects atmospheric carbon levels, which is known to be a factor in climate change.

The lines of evidence for human impact on global climate change include:

1. Increases in greenhouse gas concentrations, particularly carbon dioxide, methane, and nitrous oxide.
2. Historical and current trends in temperature rise, with the last few decades being notably warmer than previous ones.
3. Observations of changes in precipitation patterns, such as increased frequency of extreme weather events like hurricanes and heatwaves.
4. Changes in ecosystems and habitats, including shifts in plant and animal distributions and altered migration patterns.
5. Evidence from ice cores, tree rings, and other natural records showing unprecedented rates of change in recent centuries.