Quote from bigdavediode:
He didn't call it a trick, he called it Mike's "Nature trick." You don't like to answer questions? What does the "Nature trick" mean, do you think?
He would want to hide the decline because the decline was reflected in proxy data rather than the actual measurements.
Actual measurements are always preferable as opposed to proxy data (ie. inferred data from proxy sources such as tree rings.)
LOL. Are you serious?