350.org, founded by author and activist Bill McKibben, sponsored over 5,200 events in 181 countries on Oct. 24.
Some 3,000 climate change action events will take place in more than 150 countries on Oct. 24.
When four U.S. troops were killed by a roadside bomb in Afghanistan Aug. 25, it made 2009 the deadliest year for foreign troops there since the 2001 U.S. invasion.
Somalia's civil war is intensifying as Islamist insurgents hit back at government attacks on rebel-held territory.
Afghanistan is increasingly in the spotlight, as the time approaches for the Obama administration to make public the results of its comprehensive review of strategic policy there.
Leading scientists warned a US conference on climate change at the weekend that the rate of global warming has been seriously underestimated.