By Paul Homewood
Unless measures are taken to curb climate change, summers in the UK and the rest of the northern hemisphere could last for six months come 2100, a study warned.
Researchers from China used historical climate data and modelling to determine how the seasons have shifted in the past, and will likely alter in the future.
Changes could also see winters shrunk down to the span of just two months — with far-reaching impacts on agriculture, human health and the environment.
THE SEASONS, THEY ARE A-CHANGIN’
‘Numerous studies have already shown that the changing seasons cause significant environmental and health risks,’ said paper author Yuping Guan.
Disruptions to the established seasonal cycles causes, for example, birds to shift their migration patterns and plants to emerge and flower at different times.
This can lead to mismatches between animals and their food sources — disrupting ecosystems.
False springs and late snowstorms can also kill off budding plants — while longer summers cause us to breathe in more allergy-triggering pollen, and disease-carrying mosquitos to be able to increase their range.
Changing seasons will also lead to more severe weather events — including heatwaves and wildfires in summer and cold surges and winter storms on the other side of the year.
‘Summers are getting longer and hotter while winters shorter and warmer due to global warming,’ said paper author and physical oceanographer Yuping Guan of the Chinese Academy of Sciences.
‘More often [now], I read some unseasonable weather reports — for example, false spring, or May snow, and the like,’ he added.
In their study, Dr Guan and colleagues analysed historical climate data on the Northern Hemisphere that was collected daily from 1952–2011 in order to determine how the length and onset of each season has been changing with time.
The team defined the start of each summer as being when temperatures reached the hottest 25 per cent for that year, and winter as the onset of the coldest 25 per cent of temperatures.
Building on this historical dataset, the researchers next used climate change models to predict how the timing of the seasons will likely shift in the future.
Back in the Fifties, the four seasons arrived in the Northern Hemisphere in a predictable and fairly evenly distributed pattern.
However, the team found that, on average, summers grew in length from 78 to 95 days between 1952 and 2011, while winters shrank from 76 days to 73.
Spring and autumn were also seen to decrease in duration — falling from 124 to 115 days and 87 to 82 days, respectively.
As a result of these shifts, the team noted that spring and summer are now starting earlier than they used to, while autumn and winter are beginning later.
This is very curious. They are not talking about average temperatures being higher, it is instead specific to each year. Note:
“The team defined the start of each summer as being when temperatures reached the hottest 25 per cent for that year, and winter as the onset of the coldest 25 per cent of temperatures”
So it does not matter to the analysis if May temperatures, for instance, have been rising. It simply means that “summer-like” temperatures are occurring earlier than they used to, and also later in autumn – summer-like being a function of that year’s daily temperature data.
It is very simple to check this allegation against the actual data for CET.
For a start, monthly mean daily maximum temperatures are not any higher now than they have been in the past in either May or September. Indeed in the latter month, they have been lower in the last decade:
Averages of course don’t tell us everything, but we can also analyse the number of “summer days” in each month. This tells us quite categorically that they are not becoming more frequent:
It is worth noting that the study runs from 1952 to 2011, and the 1950s and 60s appear to have been a much cooler interlude, which has therefore distorted the results. We do know that picking this period will also exclude the 1920s to 40s in North America, when heatwaves were far more prevalent than now, at the same time drawing trends from the much colder period in the 1960s and 70s. Consequently the whole of the NH analysis is badly corrupted.
Clearly, as far as the UK is concerned at least, this study is worthless junk, and its conclusions baseless.
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March 11, 2021 at 04:36AM