become, the oil will eventually be burned and the emitted. In a 2007 testimony before the Iowa Utilities Board, he stated that the United States has a large reservoir of coal, which makes it a resource that can be controlled through action by U.S. politicians, unlike oil which is controlled by other countries. He has called for phasing out coal power completely by the year 2030. During his testimony before the Iowa Utilities Board in 2007, Hansen likened coal trains to "death trains" and asserted that these would be "no less gruesome than if they were boxcars headed to crematoria, loaded with uncountable irreplaceable species." In response, the National Mining Association stated that his comparison "trivialized the suffering of millions" and "undermined his credibility." Citing the reactions of "several people" and "three of his scientific colleagues" as his primary motivation, Hansen stated that he certainly did not mean to trivialize suffering by the families who lost relatives in the Holocaust and then apologized, saying he regretted that his words caused pain to some readers. Mountaintop removal mining On June 23, 2009, James Hansen, along with 30 other protesters including actress Daryl Hannah, was arrested on misdemeanor charges of obstructing police and impeding traffic, during a protest against mountaintop removal mining in Raleigh County, West Virginia. The protesters intended to enter the property of Massey Energy Company, but were blocked by a crowd of several hundred coal miners and supporters. Hansen said that mountaintop removal for coal mining "[provides] only a small fraction of our energy" and "should be abolished." Hansen called on President Barack Obama to abolish mountaintop coal mining. Hansen and about 100 other people were arrested in September 2010 in front of the White House in Washington, DC. The group was seeking a ban on mountaintop removal or surface mining. Cap and trade In 2009 Hansen spoke out against cap and trade, advocating instead what he believes would be a progressive carbon tax at source carbon as oil, gas or coal, with a 100% dividend returned to citizens in equal shares, as proposed by Citizens' Climate Lobby. He has made many appearances and talks supporting the work of CCL. Retirement from NASA Hansen retired from NASA in April 2013 after 46 years of government service, saying he planned to take a more active role in the political and legal efforts to limit greenhouse gases. The same month, the