Agence France-Presse: California governor Arnold Schwarzenegger welcomed late Tuesday voters’ rejection of a proposal to backtrack on a law limiting greenhouse gas emissions in the most populous US state. Proposition 23, one of a series of referendums held alongside mid-term and governor polls, sought to all but repeal a 2006 Schwarzenegger-backed climate change law. The bill, known as AB 32, pledged to return California’s emissions to 1990 levels by 2020. Critics said oil companies wanted to repeal it because it…