Many of the global problems humanity is facing concern acting appropriately given the available evidence. However, issues including climate change denial (McGlade and Ekins, 2015; Steffen et al., 2015) and anti-vaccination movements (Hargreaves, Lewis, and Speers, 2003; Petrovic, Roberts, and Ramsay, 2001) appear to run contrary to overwhelming evidence. The investigation of these issues has pointed to two possible causes; either insufficient exposure to the evidence at hand, or ulterior / biased motives5. Here I show such explanations are unnecessary, and further, why current counterarguments focussed on scientific evidence may not only be ineffective, but may backfire. I highlight that denialist arguments focusing on credibility-based attacks can provoke rational scepticism of the issue at hand, requiring a shift in counterargument strategy – away from the evidence itself. I show the maximally effective counterargument strategy is to separately and directly address credibility-attacks, salvaging both the immediate issue, and future debate.