Comment by gmuslera | Hacker News Reader

Comment by gmuslera | Hacker News Reader

That "temperature" is not your usual daily temperature. It is about global yearly average temperature. The way it manifest in the day after day lives is that the global weather system have more energy for i.e. powering extreme weather events. So what you will get extremer cold, heatwaves, cyclones, droughts, rains and so on.

And our civilization is built upon more or less mild and predictable weather. That kinds of events will compromise agricultural productions, make from cities to smaller settlements risky to live on, disrupt supply chains, air/sea travel, and so on. We are having right now a small hint on how destructive this kind of change, and it only will get worse from now on.

Another thing that will do that in a slower way is to raise enough average temperatures to trigger tipping points and activate or make stronger positive feedback loops that will make global average temperature to rise even more, so it won't be the end of the change. The 1.5ºC mark by the end of the century was to avoid reaching those thresholds or slow down the process as much as possible, but if we reach that mark this decade I don't think things will hold below 2ºC by 2050, much less 2100.

I think the focus on the increase in mean temperature has been detrimental.

Joe and Jill Average don't think about how 4,4,5,6,6 and 1,1,5,9,9 have the same average, and certainly have little understanding for how the changes in average temperature manifests in changes to the weather.

That said, humans in general are reactionary and adaptive, and don't plan that far ahead. We'll burn through our lottery winnings or inheritance and end up broke having to go back to work. I expect we'll do the same with our climate.

Joe and Jill average must've missed their probability courses and are still conflating mean with variance.

The climate cult seems to like that conflation because while their models might predict some very small trend in the mean temperatures, I've yet to see any model predict a change to the variance of temperatures. Which is quite expected as the variance of temperatures, even over a single day, are orders of magnitudes higher than the small trend over decades.

I don't think anyone predicts any measurable change in the variance. That would be like noticing a little pebble out of a huge mountain.

The climate cult do love to confuse people about it. After predicting the mean turned to be easily falsifiable by the average person paying attention, they turned into a narrative that tells you about greater variance without telling you that no, variance isn't actually expected to meaningfully change and using narrative instead of just saying variance (because then everyone would immediately call their bluff).

Apropos misleading narratives, greenhouses actually don't warm because of anything similar to the greenhouse effect, but just because of lack of convection. Yet another misleading narrative point.

They do love to bend and fabricate intricate stories using misguided intuition.

I don't know, what you said is pretty confusing.

Either the temperatures are increasing or they're not. Either CO2 is retaining heat and increasing temperatures or it's not.

But ocean surface temperatures are 0.9°C warmer whereas temperatures over land are 1.9°C warmer.

And the Arctic is warming at least three times faster than the globe as a whole since the mid-1990s primarily due to the "ice-albedo feedback" where the melting of sun-reflecting ice results in more heat absorption.

(per "The Climate Book" {Greta Thunberg} pp 78 and 62)

Without getting into the "average person paying attention" capabilities to observe the global climate, could you please elaborate on the greenhouse thing and the difference between the greenhouse effect and the lack of convection?

Greenhouses get warm because while the sunlight warms them, the cold air outside doesn't mix with the hot air inside. The hot air stays inside. Which is why ventilation is very important in greenhouses, you still want some cooling or it would get too hot. Ventilators in greenhouses bring some cold air from outside. Convection is just a word saying transfer of heat by the hot stuff moving around. That's how most cooling works because it's much more efficient than cooling by radiation. When you turn on fans, you cool faster because the cold air coming to you is moving faster and the hot air which was heated by you moves faster.

So greenhouse is like staying in a closed room with closed windows but when sunlight gets in. It gets warm and you want to open the window to let the warm air go out.

Minewhile, the greenhouse effect is a misnomer. The way that works is that CO2 absorbs thermal radiation. Most objects in room temperature radiate heat in the infra red. (Much hotter objects, like hot metals, radiate in the red wavelength, which is why hot metals look red). Even without any contact with the environment, like an object in vacuum, still radiate thermal radiation. Since earth is in vacuum, the only way for earth to cool is to radiate. And CO2 absorbs thermal radiation more than other components of the air. It also emits thermal radiation, just like everything else. The greenhouse effect is the prevention of cooling by radiation.

And this description is quite simplistic. Because actually, CO2 isn't reflective of CO2, and https://en.m.wikipedia.org/wiki/Kirchhoff%27s_law_of_thermal... means that at the same temperature, CO2 absorbs and emits the same amounts of radiation.

There's also the fact that CO2 cools with convection faster because it has higher heat capacity. So the whole narrative isn't as clear cut and obvious as it is presented. And remember that CO2 is just 0.025% of the atmosphere so you're measuring a very small effect to begin with.

You could try to do detailed calculations, but the climate models are incredibly complicated and still oversimplify by treating kilometers of earth as uniform material. Anyone presenting you with a picture where the results of CO2 should be "obvious" is intentionally misleading and skimming all the points that would contradict it.

> the greenhouse effect is a misnomer.

You're taking it too literally. Greenhouses get warm because there's a barrier that reduces the amount of energy escaping from the inside of the greenhouse to the outside.

The greenhouse effect is similar in this way in that the CO2 in the atmosphere acts like a barrier that reduces the infrared energy escaping from the surface into space, as you mention.

Sure it's not really the same. But people like short catchy names and phrases, even if they're somewhat inaccurate. Note how many say they Googled something when they didn't actually use Google.

> And our civilization is built upon more or less mild and predictable weather.

Don't tell the HVAC industry.

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