“Truth is what the community of inquirers agree it is at any point in time” – Charles Pierce’s rough definition. But what if the community of inquirers are not acting in good faith or have emotional baggage that is blinding them to logic and evidence?
NASA’s web site spells it out clearly.
“Observations throughout the world make it clear that climate change is occurring, and rigorous scientific research demonstrates that the greenhouse gases emitted by human activities are the primary driver.” (2009)
The list of believable organization that hold that human-caused climate change is real is tracked here.