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Unsettling the apple cart V: Koonin on Precipitation Perils

18 Aug 2021 | Koonin, Science Notes

Continuing University of Guelph professor Ross McKitrick’s look at Steven E. Koonin’s landmark book Unsettled: What Climate Science Tells Us, What it Doesn’t, and Why it Matters.

Theoretical physicist Steven Koonin moved with his wife to Chevy Chase, Maryland in May 2009 to join the Obama Administration as Under Secretary for Science in the Department of Energy. Seven months later the snowiest winter ever recorded hit the Capital area, including a storm dubbed “Snowmageddon”. But in Chapter 7 of his book Unsettled, “Precipitation Perils – From Floods to Fires” Koonin resists the temptation to treat the event as proof (or disproof) of anything related to climate, and instead presents a graph of Washington DC snowfall totals from 1889 to 2018, within which it becomes clear that 2009 was an outlier against the context of a long, slow decline in average snowfall in the Washington area. When talking about precipitation, it takes a lot of data to establish the context, and that gives plenty of openings for the cherry-pickers to engage in trickery.

The declining trend in DC snowfall leads Koonin into the larger topic of precipitation trends, and specifically questions related to trends in snowfall, rainfall, droughts, flooding and wildfires. Here Koonin makes a radical departure from just about every other public commentator on the subject when he says (p. 130) “We’ll turn to the data to answer those questions.” And that approach makes it inevitable that this chapter would skewer yet another batch of alarmist slogans. Anyone who works with precipitation data (as I have done) knows it is extremely variable and trends in one location may run counter to those in nearby locations. And while one can easily cherry-pick data to tell a story, long term big-picture conclusions are extremely elusive.

Koonin begins his survey by explaining the physical basis of climate modelers’ view that global warming will intensify precipitation. But he then shows long term (115 year) graphs of global and US precipitation rates, which show minor net increases but with very large natural variability and extended periods with trend reversals. The view that there is no detectable trend is supported by published literature and past IPCC reports, both of which Koonin quotes.

He also shows data indicating that an increase in heavy precipitation events was observed in the US from 1910 to 2015. But he notes the changes are uneven across regions (and John Christy and I have shown that the apparent trends disappear using longer datasets where available.) Koonin further observes that the IPCC draws only a tepid conclusion regarding whether such increases are observable globally. As for average Northern Hemisphere snow cover, season-specific data show reductions in Spring and Summer since the 1960s, but increases in Winter, with no annual trend after the late 1980s despite the observed warming. Yet, as Koonin notes, the most recent US National Assessment states as one of its key findings, with no explanation or accompanying pesky data, that Northern Hemisphere snow cover snow cover metrics “have all declined.”

Turning to floods and droughts, Koonin again finds that the recurring pattern is the absence of a pattern. US data on flooding indicates a wide variety of changes over time, as does global data, which leads the IPCC to have only “low confidence” even in the sign (positive or negative) of the trend globally. Likewise with droughts: Despite the repeated use of local drought events as journalistic “proof” of climate change, both US and global data show much variability but no long-term trend. If anything, droughts in the 20th century appear to have been shorter and milder than those in past centuries. Yet – as Koonin notes and his readers by now will have anticipated – this information is “entirely absent” (p. 141) from the 2014 US National Climate Assessment. The 2017 report contained a brief mention of the evidence of the past millennium, but then devoted twice as much space to discussing the California drought then ongoing.

It is ironic that one of the false charges leveled against Koonin is that he doesn’t understand the difference between weather and climate. Of course he does, and carefully distinguishes the two throughout his analysis driven by, of all things, data. That charge should instead be leveled against the National Assessment authors, who ignored millennial-scale evidence in favor of a highlighting short-term local drought event (which reversed to wet conditions shortly after the report was published).

After also reviewing the evidence on wildfires (spoiler alert: they’re declining globally) Koonin ends his chapter by examining a 2015 speech by former Central Banker and now full-time UN climate guru Mark Carney, in which the latter grabbed hold of a 2014 forecast by the UK Met Office and used it as a basis to warn his audience that UK winter rainfall would go up by 10 percent over the next 5 years. The data show that it instead fell by almost 40 percent over the forecast interval. Carney, of course, learned nothing from this episode. But Koonin’s readers will by this point have learned that science bureaucracies, and their cheerleaders like Carney, are not to be trusted.

3 comments on “Unsettling the apple cart V: Koonin on Precipitation Perils”

  1. It's not clear in this great summary if the long term trend of declining snowfall in Washington is due to a general reduction in precipitation or a growth in the urban heat island resulting in less precipitation falling as snow.

  2. Thank you Ross McKitrick for keeping both feet on the ground in today's political alarm over 85% of the world's energy - fossil fuels. Fossil fuels have not only made us the best fed, longest-living, most prosperous human beings that have ever existed. The more CO2 they produce has reversed the dangerous and inexorable decline of the basic ingredient of life on earth CO2. The molecule that has made life on earth the carbon-based life that it is. I don't trust the IPCC. They were established by politicians aiming to set up a climate alarm, not to report on one. Their predictions of more frequent and intense droughts have been a colossal failure. And a simple failure to recognize where dryland agriculture's rain comes from (evaporation)! The warmer we get, the more there will be. Occasionally, the weather just doesn't bring that rain to us. That has been life on the great plains from the beginning of modern agriculture. Today 3% of us feed the other 97%. And in N.America, have enough left over to provide the majority of the world's exportable grains. I'm a lifelong farmer with a B.Sc.(biology). I have lived most of my life on a farm in a glacial meltwater valley. It's given me a lifelong interest in climate. In the 1930s, there were years of drought. Since the 1930s, no drought I'm aware of has lasted more than a year. The past twenty years have had a relative lack of drought. Normal soil test recommendations are based on thirty years of precipitation probability. Ironically the period defined by climate science as "climate" rather than weather. This year, on the Canadian prairies, on the edge of the Palliser Triangle in West Central Saskatchewan, we have experienced a hot dry year. The only drought we've experienced since the 2002 drought. This one is significant, but not as bad. Television 'journalists' have been the perfect dupes for a CO2 driven climate. They have no clue of CO2's indespensible and essential role in the environment; in life on earth. They have no clue that more CO2 has been the best gift to the environment in millions of years. They have no clue that as Bjorn Lomborg says, "weather related deaths have dropped from five hundred thousand a year to only fifty-six thousand today", see "False Alarm" by Lomborg. And television journalists fearmonger over every forest fire and flood because it makes good television. Not sound forest management. And those same journalists have no clue that as opposed to the only fifty-six thousand that die from the weather a year, thirteen MILLION still die every year from a lack of energy. Making the far too many alarmist grade school teachers and television indoctrinators some of the most dangerous and ill-informed people alive today.

  3. The IPCC was established "to assess the risk of human-induced climate change" (Wikipedia). Obviously, in the interests of self preservation, they have to MAKE people BELIEVE that 'climate change' is real and MAKE people BELIEVE that 'climate change' is human-induced, and MAKE people BELIEVE that 'climate change' is a risk. That's their job. Their only job. If they fail any of those tasks there is no reason for the IPCC to exist. And it's all make-believe.

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