The author states:
Let us consider one such monopolist, the Intergovernmental Panel on Climate Change (IPCC). I argue that it has a natural monopoly and that it therefore should be regulated rather than broken up. This carries over to other, similar organisations.
The IPCC is a joint venture of the World Meteorological Organization and the UN Environment Programme (Oppenheimer et al. 2007). It is mandated to periodically assess the academic literature on climate change, its impacts, and policy interventions. The IPCC is the sole advisor to the international negotiations on climate policy under the UN Framework Convention on Climate Change, and certain technical features of climate treaties are taken directly from IPCC reports. Many smaller countries do not have the capacity to assess climate change and policy, so they exclusively rely on the IPCC as well. In all but the largest countries, the IPCC is a very important voice. The IPCC also bestows legitimacy (in climate research) on academics and their work. The IPCC has a monopoly in some markets and a dominant position in others.
The IPCC has a natural monopoly. Its main assets are its reputation, access to policymakers, and access to academics. A new entrant would have great difficulty building up the same position. Maintaining the IPCC already puts a strain on the academic and policy communities. Duplicating the effort would be costly, and as the new entrant would assess the same literature and presumably reach very similar conclusions, the benefits would be minor.
Natural monopolies should be regulated, particularly if they abuse their position...Indeed that is one of the major problems with the IPCC. Science is inherently a process of knowledge generation by conflict. One side observes the data and presents a model, a theory if you like then the other side using the same or perhaps new or different observations, reinterprets them and presents a differing theory. This is the constant tale of Science. Kuhn had come up with one model and Popper with a slightly differing one, but no matter which view one takes the essence of true and valid science is the conflict of views and their resolution. It is in many ways Hegelian.
The IPCC as the chosen monopoly come up with one view, it is then the only view, it is akin to the Vatican and the infallible Pope, an idea which was not formally accepted until the late 19th century. Perhaps infallibility works in religion but in science it never does.