I am not a professional climatologist but a common-sense fellow. Therefore I think I have more credibility than the average person who makes a living from "climate change." I enjoyed Coyote's Catastrophe Denied, but I think even he gave too much credence to existing data.
It seems to me that there is no accurate way to measure "global temperatures" or "global climate" other than via the troposphere. Tree rings and sediments and weather stations are ridiculous "proxies" for "global climate." Furthermore, there is no such thing as a "global climate" anyway.
The reason is that, at sea level, the earth consists of thousands of climates and millions of micro-climates - all on land undergoing constant fluctuation and all impacted by natural ebbs and flows and much of it impacted in some way by man and his land use, urbanization, etc (The earth's population was 1.2 billion in 1850, now it is 6.8 billion.) - and the ocean remains incomprehensibly complex with all of its oscillations and strange fluctuating vertical and horizontal currents.
I am not a climatologist, but I am always a skeptic about whatever experts tell me. I am a skeptic even about the 0.6 degree F change in the past 150 years. I think all of our temperature data is meaningless beyond its immediate locale - except for the troposphere data which we have only for recent years.
Science is never about truth. It's just about the theory and hypothesis du jour. That's what it's supposed to be.