We know a great deal about atmospheric physics, and from the onset, many of the claims were just plain fishy. The extreme haste with which seemingly the entire world immediately accepted the idea of Anthropogenic ( man-made ) Global Warming made us more than a little bit suspicious that no one had really taken a close look at the science. We also knew that the catch-all activity today known as "Climate Science" was in its infancy, and that atmospheric modeling did not and still does not exist which can predict changes in the weather or climate more than about a day or two in advance.
Last May, the White House tweeted: “Ninety-seven percent of scientists agree: #climate change is real, man-made and dangerous.” A few days later, Secretary of State John Kerry announced, “Ninety-seven percent of the world’s scientists tell us this is urgent.”
Climate Change Home - World Bank Group
Dr Jones is also a key part of the closely knit group of American and British scientists responsible for promoting that picture of world temperatures conveyed by Michael Mann's "hockey stick" graph which 10 years ago turned climate history on its head by showing that, after 1,000 years of decline, global temperatures have recently shot up to their highest level in recorded history.