Crichton said that in a speech at Cal Tech in 2003. He was a climate change skeptic and was bemoaning the consensus then developing around climate change. I think this was not long after Mann's hockey stick graph became well known.
But Crichton overstated his complaint re science consensus. He gave several examples in his talk about consensus in science. But his examples each ended in the particular consensus changing. His examples dealt with change in consensus based on better information. One was my favorite about Alfred Wegener in the early 1900's. Wegener described continental drift based on geology, biology, paleontology etc. However, Wegener had no mechanism to support his theory. It wasn't until the middle of the last century when Heezen and Tharp, mapping the sea floor, were able to suggest a mechanism for plate tectonics that Wegener made more sense. There is now a consensus in science, a general agreement, that plate tectonics is actually the likely explanation for certain geological processes over time.
Crichton died almost 16 years ago so we cannot know if his position on climate change would have remained the same. I'll note too that Crichton was a fiction writer with an MD who never practiced. He was not a scientist. One of his complaints, maybe justified, about climate change was that emphasis and government and other money spent there took away from funds available to cure disease, feed people and ameliorate poverty. Since climate change has the potential to cause a great deal of damage to, and interference with, human culture I think understanding it is likely to effect our understanding of the impact of disease on certain areas, crop and food production and poverty. Crichton's criticism may have been well-meaning but perhaps misplaced.