It doesn't matter whether one considers it "normal planetary fluctuation" or "human-induced," the trend can't be denied:
Last month marked the planet's 400th consecutive month with above-average temperatures, federal scientists from the National Oceanic and Atmospheric Administration announced Thursday...The NOAA report.
NOAA's analysis found last month was the 3rd-warmest April on record globally. The unusual heat was most noteworthy in Europe, which had its warmest April on record, and Australia, which had its second-warmest...
Another milestone was reached in April, also related to the number "400": Carbon dioxide — the gas scientists say is most responsible for global warming — reached its highest level in recorded history at 410 parts per million.This amount is highest in at least the past 800,000 years, according to the Scripps Institute of Oceanography.
yeah. but some people, some really good people, they did the numbers math, and like, these really good people told me climate change was dumb, and vaccinations cause diseases, i mean.. like, they have like mercury in them and stuff, also these really good guys, i mean, they're good guys, smart guys... they said things that are good
ReplyDeletehttps://www.realclearmarkets.com/articles/2018/04/24/did_you_know_the_greatest_two-year_global_cooling_event_just_took_place_103243.html
ReplyDeleteFrom the third paragraph: "None of this argues against global warming."
DeleteI think this statistic is pretty misleading though. "400 consecutive months above average" could be accomplished by having 200 months increasing and 200 months decreasing temperatures (but still not quite hitting average). Any time you have a random walk it's possible to make an excursion away from a certain point, and then never return to that point.
ReplyDeleteSo the statement is both overly powerful (to the statistically uninitiated) and doesn't say much of anything. There are better ways to get the point across, like "every decade since the 1950's has been warmer than the last". Only that kind of statement makes it unequivocal that there's an upward trend.
I would disagree. The point is not that the temperature has increased every month for 400 straight months - nobody would claim (or expect) that. Nor even that every decade is warmer than the last. In point of fact the global mean temperature does decrease some months compared to a previous month or a previous similar month of a previous year.
DeleteIf the globe was in a steady state, with random fluctuations up and down, and if one establishes an average for a time period (NOAA used the average for the 100 years of the 20th century), then those random fluctuations should create points both above and below the average.
That the number has been above the 20th century average 400 times in a row is beyond coincidence. Impossibly way beyond.
OK, I think in a broad sense you have a point. My only quibble is that in the 100 years picked for the baseline (the 1900's) there were two "cold" periods due to the well-characterized and fairly substantial AMO (Atlantic Multidecadal Oscillation, period ~70 years) and only one warm period.
DeleteCurrently we're in the warming phase of the AMO, so you'd expect a deviation from normal of about 0.2 C degrees anyway. That "helps" bring us 400 warm months, BUT given that the normal yearly fluctuations are more like 0.4 degrees Celcius, you certainly wouldn't expect 400 straight months!
So I think I'm wrong actually (gasp). Still, I think you might over-estimate the statistic literacy of the American public (sadly) having been a physics tutor for many years, this kind of statement can sound more powerful and surprising than it actually is....