In the next few days, the world's leading authority on global warming plans to roll out a strategy to tackle a tough problem: restoring its own bruised reputation.

A months-long crisis at the Intergovernmental Panel on Climate Change has upended the world's perception of global warming, after hacked emails and other disclosures revealed deep divisions among scientists working with the United Nation-sponsored group. That has raised questions about the panel's objectivity in assessing one of today's most hotly debated scientific...