THE M&M CRITIQUE OF THE MBH98 NORTHERN HEMISPHERE CLIMATE INDEX: UPDATE AND IMPLICATIONS
Stephen McIntyre, Ross McKitrick
ABSTRACT
The differences between the results of McIntyre and McKitrick [2003] and Mann et al. [1998] can be reconciled by only two series: the Gaspé cedar ring width series and the first principal component (PC1) from the North American tree ring network. We show that in each case MBH98 methodology differed from what was stated in print and the differences resulted in lower early 15th century index values. In the case of the North American PC1, MBH98 modified the PC algorithm so that the calculation was no longer centered, but claimed that the calculation was “conventional”. The modification caused the PC1 to be dominated by a subset of bristlecone pine ring width series which are widely doubted to be reliable temperature proxies. In the case of the Gaspé cedars, MBH98 did not use archived data, but made an extrapolation, unique within the corpus of over 350 series, and is represented the start date of the series. The recent Corrigendum by Mann et al. denied that these differences between the stated methods and actual methods have any effect, a claim we show is false. We also refute the various arguments by Mann et al. purporting to salvage their reconstruction, including their claims of robustness and statistical skill. Finally, we comment on several policy issues arising from this controversy: the lack of consistent requirements for disclosure of data and methods in paleoclimate journals, and the need to recognize the limitations of journal peer review as a quality control standard when scientific studies are used for public policy.
The "M&M strike again" phenomenon refers to the occurrence of M&M candies cracking or breaking open in certain conditions, such as exposure to heat or pressure. This phenomenon has been observed by many people and has sparked curiosity and speculation about the cause.
The exact reason for M&M candies cracking or breaking open is not fully understood. However, it is believed to be caused by a combination of factors, including the hard candy shell, air pockets within the candy, and external pressure or heat. When these factors align, the candy can crack or break open, revealing the chocolate inside.
Yes, it is safe to eat cracked or broken M&M candies. The hard candy shell is designed to protect the chocolate inside and prevent any contamination. As long as the candy was not exposed to any harmful substances, it is safe to consume.
Yes, this phenomenon can be replicated in a controlled environment. Many scientists have conducted experiments to try and recreate the cracking or breaking of M&M candies. However, there is still no definitive explanation for why it occurs.
There is no guaranteed way to prevent M&M candies from cracking or breaking open. However, keeping them in a cool, dry place and avoiding excessive pressure or heat can reduce the likelihood of this phenomenon occurring.