Europe declares ‘worst drought in 500 years’ – Revisited studies, data and IPCC show ‘non-increasing drought’ & ‘cannot be attributed to climate change due to climate change’ Watts Up With That’ – Watts Up With That?

From Climate Warehouse

Severe weather expert Dr. Roger Pielke Jr.: For hydrological drought, IPCC is also quite strong in its conclusion: “Low confidence: Weak or negligible trend”

In Western and Central Europe – essentially Atlantic France as far as Moscow, the northern Mediterranean region and the southern North Sea region – the IPCC and colleagues essentially reviewed the research it evaluated. concluded that drought is not increasing and that, logically, increased drought cannot be caused by man-made climate change.

Via: Administrators – Total climate inventory

Dr. Pielke J. A recent study – Vincente-Serrano et al. Year 2020 – looked at long-term drought trends in Western Europe from 1851 to 2018, focusing on the rainfall deficit… The figure below shows aggregate trends for the entire region. They conclude: “Our study highlights that from a long-term perspective (1851–2018), there are no generally consistent drought trends across Western Europe.”

Another recent study – Oikonomou et al. Year 2020 – looked at more recent trends, from 1969 to 2018, and covered all four of the IPCC’s European subregions. Overall, they find: “It seems that one of the central findings of this study is that there was little change in drought characteristics between 1969–2018. There seems to be no particular trend towards more or less frequent droughts in the two main geographical regions of Europe. This reinforces the random nature of the drought natural hazard. “…

The IPCC AR6 – which summarizes a much broader literature than the two articles cited above – classifies droughts into three categories: meteorological, hydrological, and agricultural/ecological, with corresponding emphasis on the amount of rain, runoff and soil moisture. For hydrological droughts in Western and Central Europe, IPCC could not be stronger in its conclusion: “in the regions of Western and Central Europe and Northern Europe, there is no evidence of changes in the severity of hydrological droughts since 1950”

For hydrological drought IPCC is also quite strong in its conclusion: “Low confidence: Weak or negligible trend”

In Western and Central Europe – essentially Atlantic France all the way to Moscow, north of the Mediterranean and south of the North Sea – the IPCC and colleagues basically looked at the research it evaluated. The assessment concluded that drought is not increasing and, logically, increased drought cannot be caused by human-caused climate change.

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Roger Pielke Jr: The media won’t tell you anything about the drought in Europe
Roger Pielke Jr., August 15, 2022

[…] Europe is in the midst of its worst drought in 500 years. According to a European Commission drought expert in comment last week:

“We haven’t fully analyzed the event (this year’s drought), as it’s still happening, but based on my experience, I think this is probably even more extreme than 2018. Just for the sake of it. you know that the 2018 drought was so extreme that, at least looking back at the last 500 years, there has been no other event similar to the 2018 drought, but this year I think it’s actually worse than 2018.”

While a full analysis of the ongoing European drought of 2022 has yet to be completed, neither is the drought itself, which is clearly exceptional if not unprecedented. . In this post, I take a close look at the understanding of climate change’s possible role in this year’s drought.

Specifically, I report on the most recent assessment report (AR6) of Intergovernmental Panel on Climate Change (IPCC) and baseline data and literature on the detection of drought trends in Western and Central Europe and the distribution of those trends for greenhouse gas emissions. The figure below shows the specific region that is the focus of this post, which includes all of Germany, most of France, Hungary, Poland, Ukraine and western Russia, among others.

Collectively, for the other three regions in the map above, the IPCC projects with varying degrees of confidence that at different degrees of warming by 2100 drought will decrease in Northern Europe (NEU, including UK), increases in the Mediterranean (MED) and is highly uncertain in Eastern Europe (EEU). I will be happy to explore these other regions in depth in a future post. (See IPCC AR6 Chapter 11 if you want to find out for yourself.)

For Western and Central Europe, and especially for Germany and Northern France, which are subject to considerable news coverage today, precise descriptions of the current state of scientific understanding of drought are often absent. Instead, we see many confident statements by journalists and some scientists that this year’s drought is a signal of (or, if you prefer – is motivated by, Link to, proof of) anthropogenic climate change.

Let’s see what the peer-reviewed literature and IPCC actually say about drought trends in this region and their potential for climate change.

A recent study – Vincente-Serrano et al. Year 2020 – reviewed long-term drought trends in Western Europe from 1851 to 2018, focusing on the precipitation deficit. (Note that their geographical definition of Western Europe is slightly different from that of the IPCC.) The figure below shows the aggregated trends for the entire region. They conclude: “Our study highlights that from a long-term perspective (1851–2018), there are no generally consistent drought trends across Western Europe.”

Source: Vincente-Serrano et al. Year 2020

The paper presents several different drought metrics for different sub-regions across Europe. The authors are careful to note that there are other drought metrics that may give different results:

“We emphasize that our findings should be considered in the context of applying the drought measure. Our assessment of drought characteristics is based on SPI, a rainfall-based metric. For a long-term assessment of drought in the region, it is not possible to use metrics using other important variables (e.g. runoff, soil moisture or AED)”.

Another recent study – Oikonomou et al. Year 2020 – looked at more recent trends, from 1969 to 2018, and covered all four of the IPCC’s European subregions. They found overall:

“It seems that one of the central results of this study was that there was little change in drought characteristics between 1969–2018. There seems to be no particular trend towards more or less frequent droughts in the two main geographical regions of Europe. This reinforces the random nature of the drought natural hazard. “

Of course, as the studies above admit, trend analyzes can be sensitive to start and end dates. One reason for this sensitivity is the fact that climate varies greatly even in the absence of humans – and this change is of course one of the challenges faced in detecting long-term trends, especially for rare events.

About me, IPCC AR6 – which summarizes a much broader literature than the two articles cited above – classifies droughts into three categories: meteorological, hydrological, and agricultural/ecological, with corresponding emphasis on the amount of rain, runoff and soil moisture.

For hydrological droughts in Western and Central Europe, IPCC could not be stronger in its conclusion:

“In the regions of Western and Central Europe and Northern Europe, there is no evidence of changes in hydrological drought severity since 1950.”

For hydrological drought IPCC is also quite strong in its conclusion:

“Low confidence: Weak or negligible trend”

The IPCC combined the WCE with many other global regions, concluding that: “Past increases in agricultural and ecological drought are found in all continents and some regions” which it represents with average confidence, a qualitative assessment is usually explain like about 50-50 chance to come true.

Looking to the future, the IPCC is quite clear that we should not expect to be able to attribute drought trends to climate change today. The IPCC predicts only medium confidence for an increase in agro-ecological/agricultural drought at 2 degrees Celsius and low confidence for an increase in meteorological drought at 2 degrees Celsius. The IPCC does not expect that detection or attribution will happen in 2022, when we are still below 2C, and thinks it could be decades before attribute claims and findings can be supported. stronger support.

I put the summary from IPCC AR6 together Chapter 11 based on different drought data and reproduce that below (alternatively, turn to pages 1689-90 in Chapter 11 of IPCC AR6).

IPCC AR6 summarizes its conclusions for various drought metrics in Western and Central Europe. Source: Chapter 11, 1689-90

Key point:

In Western and Central Europe – essentially Atlantic France all the way to Moscow, north of the Mediterranean and south of the North Sea – the IPCC and colleagues basically looked at the research it evaluated. The assessment concluded that drought is not increasing and, logically, increased drought cannot be caused by human-caused climate change. The only exception here is that the IPCC has moderate confidence in the increasing trend of soil moisture deficits in some subregions, however the IPCC is less confident that this trend may be due to variations in soil moisture. anthropogenic climate change. Looking to the future, when temperatures change by 2C or more, the current IPCC does not expect the current state of scientific understanding to change. But stay tuned – that’s why we do science.

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