Archives par mot-clé : Exreme Events

Siberia on fire – every summer

by Pasi Autio, July 14, 2020 in WUWT


Northern hemisphere summer – the season when forest fires in Siberia are on the loop. And usually every single new article about the Siberian forest fires somehow links them to climate change. Therefore it is good time to see how the forest fires has changed during the years. Is there really an increasing trend of Siberia forest fires as the news suggests and what is continuously predicted based on climate models?

With an area of 13.1 million square kilometres (5,100,000 sq mi), Siberia accounts for 77% of Russia’s land area. Majority of the Siberia is sparsely inhabited wilderness with little or no roads. Therefore, what sets on fire, usually burns until rain or other natural factor ends the fire. Southern Siberia also has extensive logging.

Getting reliable fire area data based on available literature seems to be problematic. According to the literature (1) USSR-era fire area data is unreliable and was consistently and severely underreporting fires on sparsely populated areas due to incomplete reporting structure that left most of the country unmonitored (6). The situation was improved only after western satellite data was taken in use by post-USSR Russia. But considering the size of Siberia and the fact that it is very sparsely populated, it is not wonder that no reliable data can be generated without the help of satellites. But even on satellite era some smaller fires goes undetected due to cloud cover or sensor detection limits (6).

After extensive literature study, I found no actual study providing satellite-based dataset for Siberian forest fires for post-USSR era either, which is strange considering how much coverage the Siberian forest fires have got lately. There seem to be an effort going on to create such a dataset for USSR-era years, however, by digitizing old satellite images taken since 1979, but let’s discuss that later a bit more.

Annual burned area in Siberia 1997-2016

Wildfire, Siberia: 123rf.com

Figure: Natural forest fire in Russia.

New Analysis Confirms Extreme Weather Not Getting Worse

by B. Peiser, June 4, 2020 in ClimateChangeDispatch


A new review of the scientific literature on extreme weather events published today by the Global Warming Policy Foundation (GWPF) confirms what IPCC assessment reports have concluded: There is little evidence of any significant changes in most indices.

The paper, by physicist Dr. Ralph Alexander, looks at trends in hot and cold weather extremes, floods and droughts, hurricanes, and wildfires and finds only a minor increase in cold weather extremes.

LONG-TERM US DROUGHT AND PRECIPITATION TRENDS

by R. McKitrick & J. Christy, Sep. 14, 2019 in WUWT


Ross McKitrick and John Christy have published a new paper in the Journal of Hydrology.

Abstract : We estimate trends in US regional precipitation on multiple time spans and scales relevant to the detection of changes in climatic regimes. A large literature has shown that trend estimation in hydrological series may be affected by long-term persistence (LTP) and selection of sample length. We show that 2000-year proxy-based reconstructions of the Palmer Modified Drought Index for the US Southeast (SE) and Pacific Coast (PC) regions exhibit LTP and reveal post- 1900 changes to be within the range of longer-term natural fluctuations. We also use a new data base of daily precipitation records for 20 locations (10 PC and 10 SE) extending back in many cases to the 1870s. Over the 1901–2017 interval upward trends in some measures of average and extreme precipitation appear, but they are not consistently significant and in the full records back to 1872 they largely disappear. They also disappear or reverse in the post-1978 portion of the data set, which is inconsistent with them being responses to enhanced greenhouse gas forcing. We conclude that natural variability is likely the dominant driver of historical changes in precipitation and hence drought dynamics in the US SE and PC.