Climate sceptic admits that humans cause global warming

Richard Muller, Professor of Physics at California University, has had a change of mind following the results of his own recent research, published in July. "The average temperature of the Earth’s land has risen by 1.5 degrees C over the past 250 years ... The most straightforward explanation for this warming is human greenhouse gas emissions."  http://berkeleyearth.org/pdf/berkeley-earth-press-release-july-29.pdf