Dr Joanne Simpson is a very important climatologist. See for example this summary of her career:
In 1983, the American Meteorological Society bestowed on her its highest honor "the Carl-Gustaf Rossby Research Award" and then named her president a few years later, a notable achievement given the fact that no other woman had ever won the job. NASA, too, has weighed in with many awards and commendations, including its coveted Exceptional Scientific Achievement Award.
Having recently retired, she has announced that she is rather sceptical of the case for catastrophic global warming.
[T]he main basis of the claim that man’s release of greenhouse gases is the cause of the warming is based almost entirely upon climate models. We all know the frailty of models concerning the air-surface system. We only need to watch the weather forecasts.
It is an indictment of the state of fear in climatology that she hasn't felt able to speak out before.