From: bill.sloman@ieee.org
On 23/02/2026 2:18 pm, john larkin wrote:
> On Mon, 23 Feb 2026 02:27:49 -0000 (UTC), antispam@fricas.org (Waldek
> Hebisch) wrote:
>
>> john larkin wrote:
>>> On Sun, 22 Feb 2026 12:51:26 +0000, liz@poppyrecords.invalid.invalid
>>> (Liz Tuddenham) wrote:
>>>
>>>> Bill Sloman wrote:
>>>>
>>>>> On 21/02/2026 11:55 pm, Liz Tuddenham wrote:
>>>>>> Bill Sloman wrote:
>>>>>>
>>>>>>
>>>>>>> Anthropogenic global warming has already raised sea surface
temperatures
>>>>>>> by more than one degree Celcius over pre-industrial levels. That puts
>>>>>>> 10% more water vapour in the air above the oceans, and 10% more energy
>>>>>>> tinto extreme weather events.
>>>>>>
>>>>>> Where would that energy have gone otherwise?
>>>>>
>>>>> Obviously into warming the oceans even more. This decreases the amount
>>>>> of CO2 they can take up, but since CO2 levels in the atmosphere are
>>>>> going up a lot faster than the oceans are warming up, this is a long
>>>>> term problem. At the moment about half the extra CO2 we are emitting
>>>>> ends up in the oceans
>>>>
>>>> A wam ocean leads to more cloud cover which reflects more energy into
>>>> space which reduces the overall energy input from the Sun. Sounds as
>>>> though the system might be stable in the long term.
>>>
>>> Pretty obviously we have negative feedbacks, otherwise we'd be Venus.
>>
>> Of course thare are negaive feedbacks. First, as temperature grows
>> Earth emits more heat radiation. This grows with fourth power of
>> temperature, so it is pretty strong effect.
>>
>> But you ignore simple thing: system with negative feedback and
>> delay will oscilate.
>
> I design stable high-order negative feedback systems. Mine don't
> oscillate.
>
> > And there are a lot of delays in the
>> system. There is also a lot of nonlinearties. When you
>> gradually turn on power to an oscilator it will probably
>> not surprise you that with growth of supplay voltage
>> you get bigger amplitude of oscilations on the output.
>> Depending of details it would not surprise me seeing
>> negative peaks going lower with bigger voltage. Yet, when
>> you see oscilations in natural system you act as you
>> never saw an oscilator.
>>
>> Concerning limits, I do not think Venus-like scenario is
>> possible for Earth. But having Carbon again wound be very
>> hard for people. Tropical areas probably would be
>> inihibitable by humans in such a case. There would be
>> disastrous impact on agriculture: plants that we know
>> how to handle and which we selected over thousends of
>> years would be badly adapted. Antarctica would melt
>> signifcantly reducing habitable land. More energy in
>> atmosphere means strongee winds, torndoes, flooding etc.
>> Our current architecture is build on certain assumptions
>> about climate, with changed climate many current buildings
>> will be destroyed and we will need new ones.
>>
>
> Plants love CO2. Veggies are grown in hothouses at 1000 PPM of CO2.
In hot houses the plants are watered and fertilised. In the wild plants
respond to more CO2 by reducing the number of stomata in their leaves so
they can get the amount of CO2 they need while losing less water.
>
> In past times, when life flourished on earth, CO2 was 5000 PPM.
Very intermittently.
> Plants are near starving now.
Populations expand until the run into their natural limits. In fact
plant populations expand until the competition for the resources they
require means that they can barely find enough resources to keep
growing. Add more CO2 to the atmosphere and a shortage of some other
resource will limit their population.
> I'm thinking that something like 700 PPM
> would be good.
What you fondly imagine to be "thinking" is merely retrieving climate
change denial propaganda.
>> It is not clear to me if attemps to stabilize temperature at
>> level as it was 100 years ago is wise. Namely there are
>> natural variations and fighting natural change may take
>> too much effort. But our current impact is larger than
>> natural variations on similar time scale and without global
>> climate control policy will grow.
>
> Comparing temps to "pre-industrial times" clearly has instrumentation
> hazards. We are taking millions of times more measurements than we did
> in 1800.
A single measurement can be enough, if it measures the right thing.
A lot of our knowledge of pre-industrial temperatures comes from
measuring isotope ratios in geological samples. The antarctic ice ice
cores samples aren't usually seen as geological samples, but they
probably should be.
>> Of course, so people want to be "free riders", that is collect
>> benefits but let the other do the work. This seem to be current
>> US policy. And of course much of business works on principle
>> "get money now", leaving troubles to government and future
>> generations. Of course, there is hipocrisy too: European
>> governments are much less eager to adapt electric cars now,
>> when it turned out that Chinese ones are better than European
>> ones.
>>
>> But believing that nothing serious is happening to climate
>> is just ignores solid data (which a lot of politicians like
>> to do).
>
> We're lucky to be living in an interglacial. What will be serious is
> the next ice age.
Except that we now know how to stop the interglacial to ice age
transition - if we've got enough fossil carbon left to dig up and burn.
--
Bill Sloman, Sydney
--- SoupGate-Win32 v1.05
* Origin: you cannot sedate... all the things you hate (1:229/2)
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