More than a million people on Sunday began planting 250 million saplings in India’s most populous state, part of an annual mass tree planting campaign to reduce carbon emissions and mitigate the effects of global climate change. Lawmakers, government officials and volunteers from social organizations swarmed riverbanks, farms, forests, schools and government buildings, planting saplings at designated spots. The effort spans 68,000 villages and 83,000 forest sites in northern Uttar Pradesh state.