Divisions on Climate Policy Threaten Australia’s Turnbull

The country has changed prime ministers five times since 2007, with climate-policy disputes fueling leadership instability

SYDNEY—Australia’s prime minister, facing a rebellion within his conservative ranks, backed away from attempts to mandate emissions-reduction targets in a bid to save his leadership.

Malcolm Turnbull, 63 years old, has struggled to pass key parts of his legislative agenda and maintain his authority since elections in 2016 left his coalition with a wafer-thin majority.

Defeats...