Not all data relating to climate change may be as dubious as those presented in Matt Kokkonen’s commentary (“Bad data underlie global warming claim,” Jan. 21). Consider the Keeling curve, for example. In 1958, Charles David Keeling of the Scripps Institution of Oceanography began collecting atmospheric CO2 data at the Mauna Loa Observatory on the top of a mountain in Hawaii. The reason this site was chosen was because of its isolation, in some of the purest air on the planet. Unlike the local sampling sites Kokkonen cited, Mauna Loa is far from civilization, industry, thermal masses, automobile exhaust; any human activity that could possibly skew local CO2 levels. The data collected there over the past 52 years is known as the Keeling curve, and is one of the oldest and most widely accepted figures produced on climate change. How can this be bad data?