Major climate science reporting fail by Minnesota Public Radio
The fact-checking can start with the opening sentences:
St. Patrick's Day 2012 was the crowning moment of one of Minnesota's mildest winters: Jubilant parade spectators wore flip flops, Miss Shamrock beamed in sleeveless, emerald satin, and the beer never tasted so refreshing as temperatures hit 80 degrees.
Three months later, the dazzling sunlight was nowhere to be found when rain sheets pummeled the Duluth area. Muddy torrents of chocolate, fuming floodwaters tore through town, leaving shock and devastation.
Both extremes happened in a Minnesota our descendants never knew. It's warmer, especially in the winter, and rising global temperatures have stacked the deck in favor of heavier rains.
The hottest temperature during that March 2012 in Duluth was 75 degrees. Not even close to the record of 81 degrees set in 1946.
But, the alarmists may say, St. Patrick's Day 2012 was on March 17, and we've never seen temperatures this high on that date before. Perhaps, but one day in one month in one year doesn't make a trend. Over the past century, and also since 1970 and during the past three decades, there has not been any sign of a significant trend in maximum temperatures on March 17 for the Duluth area. Same goes with absolute maximum temperatures during March. No significant trends over any of these time frames, and during the last 30 years, the correlation is negative – toward lower extreme maximum temperatures in March.
In the Minneapolis-St. Paul region, the 80 degrees in March 2012 was tied with 1967 as only the fifth highest March extreme maximum temperature on record, behind 1986, 1968, 1910, and 2007. No significant trends in maximum temperatures for March 17, either, and the last three decades have a negative correlation toward lower – not higher – extreme maximum temperatures in this month.
Thus, the problems in this article start early. And they continue.
The growing season in the Twin Cities is several weeks longer than it was even in the 1970s.
This classifies as cherry-picking 101, and it is egregious science journalism. Has there been a statistically significant increase in the growing season for the Twin Cities since the 1970s? Yes. But here is the growing season length dating back to when records began in 1873.
Since records began in the 1870s, there is an overall negative correlation toward a shorter – not longer – growing season in the Twin Cities region. Even with the increase in growing season length since the 1970s, the area is only back up to where it historically was before the 1970s.
Between 1873 and 1969, the area averaged a growing season length of 165 days. The average since 1970 has been 164 days. Some climate change.
Then there are the extreme rains:
In Minnesota and the Midwest generally, 37 percent more rain falls in these big 2.5-inch-plus storms than did 50 years ago, said researcher Ken Kunkel of the National Climatic Data Center in North Carolina. 'We've found that the last decade actually has the largest number of these events since the network began in the late 19th Century.'
There are no significant trends in the number of days per year with 2.5+ inches of precipitation for any of the state's climate subregions in the National Weather Service database. The Twin Cities and Duluth climate areas have the longest records for this metric, and here are the non-existent trends since the early 1870s.
See a climate crisis? No, because there isn't one. Next issue.
The 2-inch rains historically have come about every five years in a given place. And then there are the really big storms that bring at least 6 or 7 inches of rain over a huge geographic area, with powerful enough spots within the storm dumping 8 inches or more. These types of storms are occurring more frequently, at least partly because warmer air can hold more water.
Two-inch rains come about every five years in the historic record? No chance. Between 1872 and 1970 for the Duluth region, they came about every 1.5 years (i.e., 0.65 per year on average). Overall from 1872 to 2014, they come about every 1.3 years. For the Twin Cities, the average is 0.93 per year since the 1870s, or one per year. All a far cry from "about every five years."
As for the 6- to 7-inch megastorms, the Duluth region has never (at least during recorded history) received 6 inches of precipitation in a day. The record is 5.20 inches, set in 1909, followed by 4.14 inches in 2012 and 4.00 inches in 1876, all of which seems to contradict this claim:
The 2012 storm in Duluth was considered a 500-year event. It overwhelmed culverts and took out streets.
In June 2012, Duluth received 4.14 inches over one day, and 7.25 inches over two consecutive days, with no rain on the third day. But back in July 1909, the city received 5.20 inches in one day, 6.68 inches over two consecutive days, and 7.83 inches over three consecutive days. Ergo, storms of this magnitude have happened before since records began in the late 1800s, leading to the question as whether the 2012 event was really a 500-year event, and if such events are really becoming more common.
The Saint Cloud area's top four record daily rainfalls all came before 1957, and none was more than 5 inches. The Twin Cities received 9.15 inches in a single day during 1987, and the next three daily rainfall maxima occurred in 1977, 1892, and 1903. The International Falls region's record daily rainfall is only 4.82 inches, set back in 1942. The next highest 24-hour totals are from 1966 and 1898.
It is certainly debatable whether extreme rain events are on the rise.
Then come the omnipresent concerns over unpredictability, as if weather or climate were ever predictable:
A third facet of the change in Minnesota's climate, in addition to more heat and bigger storms, is murkier because it involves scientists asking whether things are in fact getting more variable and unpredictable.
For example, because big rainstorms account for a bigger portion of total rainfall, the state can dry out for weeks without reducing annual precipitation.
Some meteorologists call it 'flash drought.' Suddenly, after a wet spring, the spigot turns off. The big May 2012 storm in Duluth gave the St. Louis River its highest-ever discharge crest. But six months later, the river was at drought levels.
Actually, both the Twin Cities and Duluth regions have positive correlations since records began in the 1870s – and statistically significant trends over the past century – toward more days per year with precipitation, not less.
Finally, we have the 2012 storm (which was in June, not May) in Duluth that "gave the St. Louis River its highest-ever discharge crest." Here is the USGS peak streamflow record for the St. Louis River at Scanlon, just upstream from Duluth:
Yes, 2012 set a record, but look at the peak flow trend since the 1970s: declining with no unusual variability aside from the single datapoint in 2012. One datapoint does not make climate change.
And about those "drought levels" in the river six months after the flood – which would mean December 2012 – the flow in the river during December was only the 18th lowest on record (i.e., hardly unusual) and almost threefold higher than the record low December flow set back in 1910. By the way, the trend since records began on the river in 1908 is toward more December flow – not less – so climate change isn't leading to wintertime "drought" flows on the river, either.
So ends the examination of but one climate change story in a single relatively small newspaper from the American Midwest. There is climate reality, but science journalism by the mainstream media is getting farther away from it.