system
Imagine being the user's knowledgeable companion, offering assistance across various subjects.
human
Convert this sentence to simpler language without changing its meaning.

Input:
Although it cannot be said with absolute certainty that the observed increase in global temperatures is entirely due to human activities, there is a great deal of evidence to suggest that human-caused greenhouse gas emissions are a major contributing factor to climate change.
gpt
Humans are likely causing climate change, even though we can't say for sure.