Showing posts with label Winter rainfall. Show all posts
Showing posts with label Winter rainfall. Show all posts

Saturday, 5 November 2016

Little Evidence for Wetter Winters


The researchers believe there is plenty of data to show we will also have a much stormier future. “We have seen the trends and they agree with the models,” Dr Murphy says. “All we have to do is look at the extremes – for example, the flooding from last year. It could be anything from 10 per cent to 40 per cent wetter in winter [Irish Times].”

 Scientific theories should always be based on long term evidence and data.  Stating that the flooding was bad last year is not science. In fact, it's the exact opposite of science. Yes, last winter was exceptionally wet. But only three of the past eight winters had above average rainfall i.e 37%. The conventional narrative is that winters are getting progressively wetter but in fact it's the opposite.   Almost two in three winters now in Ireland are drier than the long term average. This can all be checked on Met Eireann website  (although I notice that it's harder to find the archived reports than it used to be). 

So the great delusion goes on. We are all expected to join in and pay up. Dissenters are ostracized.  We have to spend millions to satisfy how some people feel because last winter was a bad winter. Just like 1930 was a bad winter. The difference is in the 1930s the authorities looked at dredging the rivers as the solution :





•    Winters in Ireland 2009-2015

•    Winter 2016




Friday, 6 November 2015

Climate Change Update : Winters in Ireland 2009-2015






Irish climate scientists predicted the following changes to Ireland's winter climate due to carbon dioxide :

Global warming, driven primarily by emissions of carbon dioxide (CO2) to the atmosphere, willcontinue;
Temperatures on land by 2055 will show increases up to 1.5°C in winter and 2.0°C in summer
• A change in average rainfall by 2055 of +10% in winter and -10% to -40% in summer (greatestdecrease in the south-east);
• Around the coasts, wetter winters leading to periodic flash floods, increased storm intensity andwave height combined with rising sea levels will accelerate erosion of soft shores and increase theincidence of flooding in low-lying areas.

 - Marine Institute, Galway, 2005

• Using an approach based on General Linear Modelling, winter rainfall in Ireland by the 2050s is projected to increase by approximately 10% 
• The main challenges for Irish agriculture will come from wetter winter and drier summer soils. 

 - Climate Change, Refining The Impacts, NUI Mayooth, 2008

We are often reminded when new evidence fits with climate change predictions but there is always a deafening silence when new evidence does not fit with the climate models. We never hear when this happens.

So how have the winters been in Ireland over the past few years ? According to Irish climatologists we should see a trend towards warmer and wetter winters. Met Eireann kindly provides us with winter reports so we can see for ourselves :

•  2009 Winter : Coldest Winter for between 8 and 18 years; dry and sunny. Mean air temperatures for the season were a little below normal for the 1961-90 period; the winter was unusual when compared with recent years for the persistence of cold weather at times.

Seasonal rainfall totals were below normal everywhere.

•  2010 Winter : Coldest Winter for between 13 and 18 years in places. Mean air temperatures were around two degrees lower than average for the 1961-90 period and it was the coldest winter since 1962/3 everywhere.

Rainfall totals were below normal almost everywhere

2011 Winter : Mean air temperatures were well below normal everywhere, by between one and two degrees generally. December was one of the coldest months on record in Ireland, while cold spells also dominated January.

Rainfall totals were below normal everywhere and were well below normal in the south.


•  2012 Winter : Mean air temperatures were above average

Rainfall totals were below normal for Winter in the Midlands, South and East, with above average rainfalls along the Northwest and West coasts.

•  2013 Winter : The majority of mean air temperatures were below their Long-Term Average (LTA) with on or above LTA values recorded in parts of the western half of the country.

Most stations reported above LTA rainfall with the exception of a few stations mainly in the West,
Southwest, Midlands and East which reported below LTA values

2014 Winter : Nearly all mean temperatures were near or above their LTA for winter

Almost all seasonal winter rainfall totals were above average with most stations reporting above Long-Term Average (LTA) rainfall during the three months of winter

2015 Winter : Winter mean temperatures below average nearly everywhere. The lowest winter
minimum was -7.9°C at Dublin Airport on Feb 3rd, its lowest recorded during February since 1956.

Percentage of Long-Term Average (LTA) winter rainfall values were variable, with mainly below average values in the East, Southeast, South and in isolated parts of the Midlands.


So what is the trend ?


In five of the past seven winters, temperatures were below average.

In three of the past seven winters, rainfall was below average with variable rainfall patterns in two winters (2012 and 2015).  This means that only two winters - 2013 and 2014 - had above average rainfall at the majority of stations. Of the variable years, 2012 and 2015, the East, South and parts of the Midlands reported less than average rainfall.

So there certainly is not a trend towards a warmer and wetter winter. If anything, the trend is towards colder and drier / mixed rainfall winters.

This shows that the computer models used by climatologists are unable to accurately represent our climate and take account of the many variables which influence it. They certainly should not be used as a basis for climate policy.