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better to know...?, climate-debate

Climate Scientists Admit Clouds are Still a Big Unknown

by E. Worrall, Sep 12, 2020 in WUWT

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The authors assert that if we had a better understanding clouds, the spread of model predictions could be reduced. But there is some controversy about how badly cloud errors affect model predictions, and that controversy is not just limited to climate alarmists.

Pat Frank, who produced the diagram at the top of the page in his paper “Propagation of Error and the Reliability of Global Air Temperature Projections“, argues that climate models are unphysical and utterly unreliable, because they contain known model cloud physics errors so large the impact of the errors dwarfs the effect of rising CO2. My understanding is Pat believes large climate model physics errors have been hidden away via a dubious tuning process, which adds even more errors to coerce climate models into matching past temperature observations, without fixing the original errors.

Climate skeptic Dr. Roy Spencer disagrees with Pat Frank; Dr. Spencer suggests the cloud error biases hilighted by Pat Frank are cancelled out by other biases, resulting in a stable top of atmosphere radiative balance. Dr. Spencer makes it clear that he also does not trust climate model projections, though for different reasons to Pat Frank.

Other climate scientists like the authors of the study above, Paulo Ceppi and Ric Williams, pop up from time to time and suggest that clouds are a significant problem, though Paulo and Ric’s estimate of the scale of the problem appears to be well short of Pat Frank’s estimate.

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Whoever is right, I think what is abundantly clear is the science is far from settled.

climate and geology

Volcanic ash may have a bigger impact on the climate than we thought

by University of Colorado at Boulder, Sep 11, 2020 in ScienceDaily

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“They saw some large particles floating around in the atmosphere a month after the eruption,” Zhu said. “It looked like ash.”

She explained that scientists have long known that volcanic eruptions can take a toll on the planet’s climate. These events blast huge amounts of sulfur-rich particles high into Earth’s atmosphere where they can block sunlight from reaching the ground.

Researchers haven’t thought, however, that ash could play much of a role in that cooling effect. These chunks of rocky debris, scientists reasoned, are so heavy that most of them likely fall out of volcanic clouds not long after an eruption.

Zhu’s team wanted to find out why that wasn’t the case with Kelut. Drawing on aircraft and satellite observations of the unfolding disaster, the group discovered that the volcano’s plume seemed to be rife with small and lightweight particles of ash — tiny particles that were likely capable of floating in the air for long periods of time, much like dandelion fluff.

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Journal Reference:

  1. Yunqian Zhu, Owen B. Toon, Eric J. Jensen, Charles G. Bardeen, Michael J. Mills, Margaret A. Tolbert, Pengfei Yu, Sarah Woods. Persisting volcanic ash particles impact stratospheric SO2 lifetime and aerosol optical properties. Nature Communications, 2020; 11 (1) DOI: 10.1038/s41467-020-18352-5

climate-debate

The Dirty Dozen Tests Of Global Warming Science

by G.H. Sherrington, Sep 11, 2020 in WUWT

Assume for discussion that there has been a change of 1⁰C in the customary global near-surface air temperature, GAST, over the last century. There have been many assertions that this has produced changes. The strength of assertions is greater when a mathematical relation between temperature and the alleged change is established. Here are some relationships to ponder, for the last century or for a significant or available shorter time.

For a 1⁰C change in global temperature –

  1. By how many millimeters does the sea level surface height change?

  2. By how many ppm does atmospheric CO₂ change?

  3. By how many tonnes does the weight of terrestrial vegetation, like forests, change?

  4. By how much does the pH of the oceans change?

  5. By how many sq km does the average area of cloud cover change?

  6. What change is there to the accumulated cyclone index, ACE?

  7. What is the net change to the globalnumber of –

    1. Birds
    1. Land animals
    1. Marine algae

  8. By how many Watt per square metre does the Top of Atmosphere TOA radiation balance change?

  9. By how many tonnes does the weight of ice change –

    1. Over land
    1. Floating on sea
    1. Grounded over sea

  10. By how much does total precipitable rainfall TPW change?

  11. By what number does the number of large bush fires change?

 

By how many tonnes do yields of major food crops change, expressed as tonnes available per person, for example

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better to know...?, climate-debate

California Has Always Had Fires, Environmental Alarmism Makes Them Worse Than Necessary

by M. Schellenberger,  Sep 10, 2020 in Forbes

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“California was a very smoky place historically,” says Malcolm North of the US Forest Survey.“Even though we’re seeing area burned that is off-the-charts, it’s still probably less than what used to be burned before Europeans arrived.”

Many reporters note that more area has burned this year in California than at any other point in “the modern period,” but that period began in 1950. For the last half of the 20th Century, the annual area burned in California was just 250,000 acres a year, whereas the best-available science suggests 4.4 and 12 million acres burned in California annually before the arrival of Europeans.

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See also: California Has Always Had Fires, Environmentalism Makes Them Worse