A Dose of Climate Reality for Maine
A recent article in The Boston Globe describes the impacts of climate change on Maine, where apparently “heat waves, more powerful storms, and rising seas are increasingly transforming” the state.
Heat waves? That's odd, since there has been no significant trend in the state's average maximum temperature during the summer months since 1970.
Three NOAA-National Weather Service sub-regions exist in the state: the Bangor, Caribou, and Portland areas. Since records began in 1875, there hasn't been a hint of a trend in the number of days per year above 95º F in the Portland region. The non-correlation is almost perfect, and it actually trends downward toward fewer hot days, not more. Similarly, in both the Bangor and Caribou regions, no sign of increasing hot days, either. Again, the correlations are negative toward fewer hot days, not upward.
The record number of extreme heat days in each region of Maine were set during the 1930s, and recent decades haven't seen anything like this earlier period. For example, in the Portland area, 1937 had five days above 95º F. Since 1994, there has been a total of only four days above 95º F. In other words, the last 21 years in the Portland region have seen fewer extremely hot days than occurred in 1937 alone. In the Bangor area, 1937 provided 10 days above 95º F, and there were six days in 1944 above this temperature. Since 1944, there have been no years with more than just two extremely hot days, and since 1994, no year has registered more than one day above 95º F. The Caribou region has had only one day above 95º F since records began in 1939, and it occurred in 1977.
More powerful storms? There have been no significant trends in maximum one-day precipitation in the state since 1970. An infographic in the Globe's story tells us that climate models predict large increases in the number of days per year having more than an inch of precipitation by the 2041-2070 period. Predictions can't be proven wrong until the date predicted arrives, but since 1970, none of the climate sub-regions in Maine has seen a significant increasing trend in the number of days each year with >1 inch of precipitation.
Also predicted for Maine over the next few decades are substantial increases in the number of days each year getting above freezing (32º F). But there are no significant trends in this metric over the past three decades, either, perhaps signifying that we should be more cautious about the modeling projections.
The number of days with temperatures less than 10º F (i.e., “cold days”) is also projected to drop dramatically by the 2041-2070 period. Indeed, in recent decades, much – however, not all – of the state has seen a decline in the number of cold days each year, but that is because the 1960s and 1970s had a large number of them. For the Portland region, which is the only area with climate records dating back a century, here is what the trend in cold days looks like.
The data looks like an inverted parabola, or half of a complete climate cycle. What does the future portend? A continuing decline down to no cold days each year for Maine? Or perhaps a reversal in the post-1960s/'70s decline, with more cold days in the coming decades to complete the cycle? Time will tell, but this type of historical context is critical for the public to understand where the climate might be headed and why. The current low numbers of cold days each year in this part of Maine are nothing unusual – a century ago, we saw a similar climate.
As a final bone to pick with the science journalism in this Globe piece, the following graph of water temperatures in the Gulf of Maine is shown.
A “33-year trend”? Those following the climate debates will be well aware that the climate alarmists are continually trying to skewer the climate skeptics (aka, realists) about cherry-picking start dates for trend analyses. Why did the Globe choose a 33-year period from 1981 to 2013? Why not the more conventional 30-year climate period from 1984 to 2013? Perhaps because the trend would not have been so dramatic?
Over at Watt's Up With That, Bob Tisdale has written a good article on this very topic – and it was published almost three weeks before the Globe's piece. Tisdale looked back at the Gulf of Maine water temperatures going back well before 1981, and what he found is that there has been no trend in the temperatures since 1930. In fact, if you remove the single-year spike in 2012, the post-1930 trend has been toward cooling, not warming.
Looking at 10-year average and trailing trends from Tisdale's analyses, it doesn't look like water temperatures in the Gulf of Maine have changed much – if at all – since the mid-19th century.
All of these details should have been present in the Globe's article in order to add a much-needed dose of climate reality, but they were not. Instead we heard about how the changing climate in the state is “definitely scary” and an “apocalyptic vision.”