The University of Virginia scientist at the center of the Virginia Supreme Court's global warming case is back on grounds. Students invited Michael Mann to headline a symposium Tuesday on environmental research.

Mann is a former UVA professor. The criticized climatologist returned to grounds for the first time in six years, since leaving for a research position at Penn State.

Rosemary Malfi, an environmental sciences student said, "We think he's a very important spokesperson for the separation of science and politics which, obviously, is a hot issue today."

Mann stated, "Part of the intent of these attacks is to tell scientists that certain areas of research that may be inconvenient to some vested interests and the politicians who represent them, that those areas of research are off limits."

Mann encouraged these aspiring scientists to continue controversial research despite threats. Mann is touring the country to promote his new tell-all book about being the target of the climate change debate.

That book is set for release in early March. Mann also continues his research at Penn State.