Simplify the following text for a Grade 8 native English-speaking person.
Original: In a 2006 letter to Nature , Mann , Bradley and Hughes pointed out that their original article had said that `` more widespread high-resolution data are needed before more confident conclusions can be reached '' and that the uncertainties were `` the point of the article . ''
Simplified: In a 2006 letter to Nature , Bradley , Hughes and Mann claimed the original article had said that they could not be exact .