Nic Lewis, an independent scientist often critical of the IPCC, told BBC News: "The magnitude of the increase in vegetation appears to be considerably larger than suggested by previous studies. "This suggests that projected atmospheric CO2 levels in IPCC scenarios are significantly too high, which implies that global temperature rises projected by IPCC models are also too high, even if the climate is as sensitive to CO2 increases as the models imply." And Prof Judith Curry, the former chair of Earth and atmospheric sciences at the Georgia Institute of Technology, added: "It is inappropriate to dismiss the arguments of the so-called contrarians, since their disagreement with the consensus reflects conflicts of values and a preference for the empirical (i.e. what has been observed) versus the hypothetical (i.e. what is projected from climate models). "These disagreements are at the heart of the public debate on climate change, and these issues should be debated, not dismissed."