Evaluating the State of the Environment on Earth Day

Organizers of today's Earth Day observances have called for "A Billion Acts of Green" — small, individual things they say can add up to big improvements in the health of the planet. We take a broader perspective, with recent assessments of the health of the oceans, the state of biodiversity and the impact of climate change. Also, new pessimism on the economy, and a US Ambassador resigns after the State Department tells him not to advocate "faith-based diplomacy."

Banner image: A woman wears a face mask in Beijing on December 1, 2010. China has met its 2010 target to cut emissions of key pollutants and is on track to meet its energy efficiency goal, state media said, quoting the country's top climate change official as saying after China last week acknowledged it had become the world's biggest emitter of the greenhouse gases that are blamed for climate change and global warming, surpassing the United States, though not in terms of emissions per capita. Photo: Frederic J. Brown/AFP/Getty Images