Almost 35 years have passed since the Intergovernmental Panel on Climate Change released its first assessment report. It found human activities were substantially increasing concentrations of carbon dioxide (CO₂) and other gases ion the atmosphere, which was warming the global climate.
Since then, countries around the world have introduced a slew of policies designed to reduce greenhouse gas emissions. But what actually worked?
This question is at the heart of a landmark new paper by German researchers. They analysed 1,500 climate policies implemented around the world over the past two decades, and found only a small fraction were effective.
