Agence France-Presse: The future of a US climate law is hanging in the balance in Congress as lawmakers gear up for crucial midterm elections amid a persistent economic slump, experts say. Further reducing the impetus, UN climate talks in Copenhagen ended last month with a non-binding agreement to limit warming to 3.6 degrees Fahrenheit (two Celsius) that did not set binding targets to reduce the emissions of gases scientists say are heating up the world’s atmosphere to dangerous levels. Among the …