Forget Flash Floods: The UK Met Office Now Identifies Flash Droughts - Caused By Your Car And Gas Boiler Of Course

This is the release by the Met Office’ Press Office:

For the first time a new study has confirmed droughts across the world are developing more rapidly as a result of climate change.

The international study identifies flash droughts – which intensify in a matter of weeks – have become more frequent since the late 1950s over 74% of the world’s 33 global regions, especially those over North and East Asia, the Sahara and Europe.

The Met Office’s Dr Peili Wu is one of the paper’s authors. He said: “The transition to more flash droughts is being driven by a combination of rainfall deficit along with amplified rates of soil moisture loss.”

The paper highlights that the transition from slower-onset droughts to flash droughts is projected to expand to most land areas. This transition will become most pronounced with higher rates of global greenhouse emissions.

Droughts are getting meaner, leaner and faster, and it’s all your fault you gas-guzzling scoundrels! How dare you use motorised personal transport, how dare you keep warm and comfy in winter!

But so called ‘flash droughts’ are a relatively new concept. The Met Office says:

Flash droughts haven’t always been widely recognised. Among the first to gain prominence were events in 2012 in the United States, and 2013 in China. Dr Wu added: “Like many flash droughts these events caused massive impacts with economic losses and extensive damage to crops.”

But supposedly, they’ve increased since the 1950s? Sounds odd, right, so I checked out the study itself to see what they were on about.

Sure enough, the authors of the study confirm that the concept of a flash drought was only proposed at the beginning of the 21st century and it wasn’t until the rapid onset California drought of 2012 that the concept actually became a reality.

The concept of flash droughts was proposed at the beginning of the 21st century but did not receive wide attention until the occurrence of the severe US drought in the summer of 2012 (5, 28, 30, 34).

So here’s where it gets interesting because the authors then go on to use reanalysis datasets of soil moisture going back to the 1950s to not only identify the existence of the ‘flash drought’ - which was previously only a concept - but to identify a trend in the occurrence of those flash droughts and then attribute that trend to anthropogenic greenhouse gas emissions. Stunning. I mean, brave. No, I mean stupid. I left a comment on another blog which explains my first impressions on reading this study:

It has been published. First impressions: they retrospectively identify sub-seasonal ‘flash droughts’, inspired apparently by the rapid onset of the California drought in 2012 (which went on to become a multi-seasonal drought), then they reanalyse soil moisture data going back to 1951 and find that there has been a modest increase in rapid onset sub-seasonal droughts – now retrospectively identified as ‘flash droughts’. In the paper they admit that the main driver of ‘conventional droughts’ is natural multidecadal variability such as ENSO/PDO/AMO/NAO, amplified by other factors such as land use, water usage etc. They then use CMIP6 model ensembles to attribute this modest increase over a relatively short time period (which shows some signs of cyclical variability) to anthropogenic forcings, defining natural forcings ONLY as volcanic and solar, and completely ignoring other factors such as changing land use etc.! It’s science Jim, but not as we know it. They found a new ‘thing’. They went looking for a signal of the ‘thing’ in the data and then they attributed that signal to man-made greenhouse gases.

I now intend to go into it in a bit more detail by examining this ‘research’ which was a collaboration between the British Met Office, the Americans and the Chinese:

The paper – A global transition to flash drought under climate change – has been produced by an international collaboration featuring scientists from China, the UK and the US. The paper will be published in the journal Science. The lead author is Professor Xing Yuan of Nanjing University of Information Science & Technology.

The research is part funded by the Climate Science for Service Partnership China (CSSP China) project, a collaborative climate science initiative between research institutes in the UK and China. CSSP China is part of our Weather and Climate Science for Service Partnership (WCSSP) programme, supported by the UK Government’s Newton Fund.

I trust the CCP controlled Chinese academia about as much as I trust the British Met Office.

The authors define what a drought is and what causes a drought.

Droughts are periods of time with a persistent water deficit (1, 2), which can cause devastating impacts on regional economies and environments (3–5), as well as on human health (6). Droughts mainly originate from large-scale internal climate variability, in which ocean-atmosphere teleconnections associated with phenomena such as the El Niño–Southern Oscillation, Pacific Decadal Variability, and Atlantic Multidecadal Variability play critical roles in drought formation and persistence over interannual to decadal time scales (7, 8). For droughts that occur over shorter seasonal time scales, the dominant drivers can also include local or remote land-atmosphere feedbacks (9, 10). The multiscale interactions among these different parts of the climate system raise challenges for drought forecasting and impact mitigation. Droughts are also influenced by anthropogenic forcings such as climate change (2, 11), land use or land cover change, and human water consumption and management (12, 13).

So, ‘conventional’ seasonal and even multi-year droughts are mainly due to natural internal variability. Shorter seasonal droughts can be affected by land-atmosphere feedbacks, either locally or geographically distant and lastly, droughts in general are also influenced by various anthropogenic forcings (including the dreaded climate change), land use changes and water consumption and management. All those influences, the dominant being natural climate cycles; it doesn’t leave much room for a significant influence for man-made climate change on ‘conventional’ droughts does it? But newly identified ‘flash droughts’; well, that’s a different story - demonic CO2 is apparently the main cause of the increase in these rapid onset sub-seasonal droughts over the last 70 years. The Met Office and the CCP say so.

Here’s how they arrived at their data for ‘flash droughts’, using soil moisture measurements going back to the 1950s:

In this study, we investigated changes in the speed of global drought onset and the partitioning between flash and slow droughts. We divided subseasonal droughts into flash droughts (21, 28) and slow droughts by onset speed measured by the declining rate of soil moisture and present their global distributions during the local growing season over the past 64 years. We then estimated the global trend of the ratio of the number of flash droughts to total subseasonal droughts and the global trend of the onset speed of subseasonal droughts and attributed these trends to anthropogenic climate change on the basis of the sixth Coupled Model Intercomparison Project (CMIP6) (39) climate model simulations (table S1). We also showed how these trends vary over different IPCC SREX (Intergovernmental Panel on Climate Change Special Report on EXtreme events) regions (40).

As you can see. they then attributed the observed trends in the retrospectively identified so called ‘flash droughts’ to anthropogenic climate change using CMIP6 climate models (which run even ‘hotter’ than the CMIP5 models). Now here’s the thing; when controlling for natural forcings, they only included solar and volcanic, completely ignoring the dominant drivers of ‘conventional’ droughts (multidecadal natural cyclical variability) and all those other influences mentioned above.

The upward global trends are well captured by the state-of-the-art CMIP6/ALL multi-model ensemble simulations (P < 0.1) (Fig. 2, A and B), in which both the anthropogenic climate forcings (anthropogenic emission of, for example, greenhouse gases and aerosols) and natural climate forcings (solar and volcanic activities) are considered. The CMIP6/ALL ensemble simulations also roughly capture the spatial patterns of long-term climatology of flash drought ratio and subseasonal drought onset speed (fig. S8). However, the global trends are not captured by the CMIP6/NAT ensemble simulations that only consider natural climate forcings (Fig. 2, A and B).

Can you believe that shit? They ruled out natural forcings of rapid onset ‘flash droughts’ by ruling out the dominant natural drivers of ‘conventional’ droughts which they previously admitted to! What’s their excuse for doing this? It can’t be because climate change operates mainly over very short periods, thus influencing rapid onset ‘flash droughts’; the very opposite is true, in fact climate change operates over a longer time scale than even multidecadal internal variability, which is the dominant driver of slow onset droughts. It’s complete rubbish. The paper should be withdrawn in my view, but we all know it won’t be.