I did a quick Wikipedia check on first two of the mentioned organizations, CEI and the Heartland Institute. Both seem to acknowledge that the climate changes because of human action. They are called 'climate deniers' because the other side does not agree with them on policies.
I did a quick Wikipedia check on first two of the mentioned organizations, CEI and the Heartland Institute. Both seem to acknowledge that the climate changes because of human action. They are called 'climate deniers' because the other side does not agree with them on policies.