Secretive court system poses threat to Paris climate deal, says whistleblower

Treaty allows energy corporations to sue governments for billions over policies that could hurt their profits

• Explainer: what is the ECT?

A secretive investor court system poses a real threat to the Paris climate agreement, activists have said, as governments taking action to phase out fossil fuels face a slew of multimillion-dollar lawsuits for lost profits.

New data seen by the Guardian shows a surge in cases under the energy charter treaty (ECT), an obscure international agreement that allows energy corporations to sue governments over policies that could hurt their profits.