My July 1 Opinion piece refuted efforts to distort scientific findings by a global warming denier. A July 26 letter by Howard Maccabee is another case in point.
The author's statement that " data show no significant global warming for the past 15 years" lacks essential perspective and is misleading. He spins a skewed tale from this assertion. Certainly, the apparent mismatch between rising greenhouse-gas emissions and broad scatter of annual surface temperature fluctuations over the past 15 years concerns climate scientists. On the simple face of it, it's possible to wonder if the rate of global warming might have slowed. This apparent mismatch needs a clear resolution. But, it is hardly a case of "global warming has stopped" and the world can continue its fossil fuel burning as usual as some would have us believe.
While the fluctuations of recent annual global average temperature measurements, out of context, might fit scatter-shot around a level line, two "ten-year mean" points (a way to interpret such data) are in alignment with the computer model projections. As researchers know, one must be especially careful about drawing conclusions or unusual extrapolations from the tail end of one's data set without a good substantiated reason.
Carbon dioxide (CO2), a green-house gas, is presently at its highest level in the atmosphere in at least 800,000 years. At current rates of human activity related production the level is estimated to double by mid-century and triple before the end of this century. Global average temperatures in the first decade of the 21st century remain almost 1.5°F above their level 100 years ago. While locally this may sound trivial, as a global average it is significant. If this CO2 trend is unchanged, global average temperatures are anticipated to increase substantially more as the atmosphere's carbon burden doubles then triples. Such temperature rises are expected to have world-wide consequences.
Several possible explanations of the scattered data points of the past 15 years are being actively investigated by climate scientists.
For example, an article in Geophysical Research Letters found that 30 percent of the ocean warming in the past decade has occurred below 2,300 feet in the ocean. The study indicates a substantial amount of global warming is going into the oceans, and the deep oceans are heating up unprecedentedly. As other scientific studies corroborate these results, perhaps such deep ocean warming might also help explain the recent annual surface temperature fluctuations.
The upcoming Report of the U.N. Intergovernmental Panel on Climate Change may show end-of-century temperature rise predictions not quite as high as previously. Nonetheless, assertions to the contrary notwithstanding, it is expected to support its well substantiated conclusions including that global warming since the mid-20th century is very likely due mainly to green-house gases from human activities and such warming is continuing.
Urgent researchable questions remain. However, there are no valid reasons to conclude that global warming is bogus, has stopped, or is part of some conspiratorial "campaign" against coal and oil. Promoters of an agenda of climate change disinformation will try to convince you otherwise.
Richard Scribner, PhD