New York's former mayor and Vancouver's mayor Gregor Robertson are pushing for climate change policies at the city level.
Just before the start of the school year, President Obama signed a new law that denies visas to Iranian students who plan to take courses that might prepare them for careers in fields critical to Iran’s nuclear energy program.
The visa denials come as the number of Iranian students in the U.S. is growing sharply. Universities and high tech companies says the law is making it harder for them to recruit and keep talented engineers and scientists.
Intelligence officials are increasingly worried that important secrets are leaking to foreign students working on sensitive research projects in the U.S.