"For the first time," he noted, "the current climate observations are no longer reliably connected with the record from the past."
What this means is that the uncertainties that human-induced climate change bring for our future global climate also have impacts on our current ability to use historical climate information to understand the future. As we venture into what can only be called a "new climate" the lessons we have from the "old climate" are less reliable.
This is another reason to be "climate conservatives." We need to help preserve the climate we were born into, to pass on to our children the benefits of this climate and also the benefits of knowing how to predict weather and other climate extremes.
Karl notes that models predict for the US that a day so hot it occurs once every 20 years will, by 2100 become a one in 2 year event.
Another projection about the weather is that the really heavy rainfall days... the types of storms that flood Santa Barbara, that might occur once every 20 years will occur once every 8 years by 2100.