From NOT A LOT OF PEOPLE KNOW THAT
By Paul Homewood
The Met Workplace have now descended to knowingly peddling misinformation:
Excessive rainfall occasions could possibly be 4 instances as frequent by 2080 in comparison with Nineteen Eighties.
For the primary time, a excessive decision mannequin that captures the element of convective, or excessive, rainfall occasions has supplied 100 years of knowledge, spanning the previous, current and future repeatedly, to analyse the longer term threat of rainfall with the depth that may trigger flash flooding.
A model of the Met Workplace Unified Mannequin, the identical that’s used for the operational UK climate forecast, has been run 12 instances at a decision of two.2km (often called k-scale modelling) to offer an ensemble of 100-year local weather projections.
That is like beginning 12 climate forecasts and working them for 100 years, besides the researchers aren’t within the climate on a given day however slightly how the prevalence of native climate extremes varies year-by-year. By beginning the mannequin runs prior to now additionally it is doable to confirm the output towards observations to evaluate the mannequin efficiency.
At this stage of element, it’s doable to extra precisely assess how convective downpours that may result in flash flooding will change, for instance when the depth of the rain exceeds 20mm/hour. Thresholds of rainfall depth like 20mm/hr are used for points of planning akin to floor water drainage and flood threat.
The analysis, revealed in Nature Communications, discovered that beneath a excessive emissions situation (RCP 8.5) rainfall occasions within the UK exceeding 20mm/hr could possibly be 4 instances as frequent by 2080 in comparison with the Nineteen Eighties. Earlier coarser mannequin output (12km) predicted a rise of round two and a half instances in the identical interval.
RCP 8.5 is a pathway the place greenhouse fuel emissions hold accelerating. This isn’t inevitable, however a believable situation if we don’t curb our emissions.
An instance of an intense rainfall occasion with 20mm/hr is London in July 2021, when 40mm of rain fell over three hours at Kew Gardens, flooding the underground and different infrastructure.
There is no such thing as a precise proof supplied to show that excessive rainfall is turning into extra frequent, as their laptop fashions say.
Certainly at stations like Oxford, the place the Met Workplace say excessive rainfall will turn out to be 3 times extra frequent, the other is the case.
https://www.ecad.eu/utils/showindices.php?3v2e59f6q4m5mu3n7rv7k0n0fl
The Met Workplace is particularly taking a look at hourly rainfall, which there’s little or no historic knowledge for. Nonetheless, if this was getting better the identical development can be seen in each day knowledge; however the precise knowledge reveals this isn’t the case.
Their projections are based mostly on essentially the most excessive GHG situation, RCP8.5, which they describe as “believable”. That is false and undeniably implausible. The one motive for the Met Workplace to make use of RCP8.5 is for propaganda functions.
To cap all of it, the Met Workplace provide this for example:
An instance of an intense rainfall occasion with 20mm/hr is London in July 2021, when 40mm of rain fell over three hours at Kew Gardens, flooding the underground and different infrastructure.
However 40mm of rain in three hours is much from being unprecedented. Maidenhead, as an illustration, had greater than twice as a lot rain in an hour. Certainly not one of the quick period rainfall information have been set since 1989:
https://www.metoffice.gov.uk/analysis/local weather/maps-and-data/uk-climate-extremes
All in all this can be a totally disgraceful and baseless piece of scaremongering, even by Met Workplace requirements.