Observing & Predicting

As the assessment now known as the BAMS State of the Climate report pushes into its third decade, international participation is at an all-time high. From atmospheric chemists to tropical meteorologists, more than 420 authors from institutions in 57 countries contributed to this year’s report.

September 2009

  •  The Sun is the main source of power for the Earth's climate machine. Space-based measurements, begun in 1978, indicate Earth receives an average of 1,361 W/m<sup>2</sup> of incoming sunlight, and the amount varies by about one-tenth of a percent over the course of the 11-year solar cycle.