Ad hoc measurement of Climate change denial limits interpretability and integration of research. This study aims to create a standardised measure of climate change denial using Item Response Theory (IRT). A pool of candidate items was administered to a U.S. sample recruited using Amazon MTurk (N = 206) along with measures of authoritarianism, social dominance orientation, mistrust in scientists, and conspiracist beliefs. After screening out poorly discriminating and redundant items, the scale contained eight items with high discrimination indices and item difficulties ranged from 0.437 to 1.167. Internal consistency was high, ω = .94. Moderate to strong correlations were found between the denial measure and the convergent measures. The limited range of item difficulties suggests that different forms of climate change denial may be closer together than previously thought.