CARBIS BAY, England—Group of Seven (G-7) leaders agreed on Sunday to raise their contributions to meet an overdue spending pledge of $100 billion a year to help poorer countries cut carbon emissions and cope with global warming, but campaigners said firm cash promises were missing. Alongside plans billed as helping speed infrastructure funding in developing countries and a shift to renewable and sustainable technology, the world’s seven largest advanced economies again pledged to meet the climate finance target. But climate groups said the promise made in the summit’s final communique lacked detail, most importantly a figure for the increases. A spokesman for British Prime Minister Boris Johnson said individual nations were expected to set out the size of the increases “in due course.” In the communique, the seven nations—the United States, Britain, Canada, France, Germany, Italy, and Japan—reaffirmed their commitment to “jointly mobilise $100 billion per year from public and …