Droves of cats and kittens are swarming into animal shelters nationwide, and global warming is to blame, according to one pet adoption group. Several shelters operated by a national adoption organization called Pets Across America reported a 30 percent increase in intakes of cats and kittens from 2005 to 2006, and other shelters across the nation have reported similar spikes of stray, owned and feral cats. The cause of this feline flood is an extended cat breeding season thanks to the world’s warming temperatures, according to the group, which is one of the country’s oldest and largest animal welfare organizations....