________________________________________________________________________________
How much of the global warming can be explained by this increased sun activity?
Almost none [1]. In theory, solar radiation has been decreasing a bit, so we should have cooled slightly over the past 50 years.
[1] -
https://climate.nasa.gov/faq/14/is-the-sun-causing-global-wa...
Is the little hump inn temperature in the 1940s interpretable? Is it possible this is from the mass industrialization during WW2?
No, the little hump during the war is caused by the fact that before and after the war there were various groups sampling sea surface temperatures with various techniques, but during the war only the Americans kept recording these temperatures.
So the sun is more active but irradiance is decreasing?
see the link IvyMike posted below from the same group
From the article, at the very end:
"Whether this effect could have provided a significant contribution to the global warming of the Earth during the last century is an open question. The researchers around Sami K. Solanki stress the fact that solar activity has remained on a roughly constant (high) level since about 1980 - apart from the variations due to the 11-year cycle - while the global temperature has experienced a strong further increase during that time. On the other hand, the rather similar trends of solar activity and terrestrial temperature during the last centuries (with the notable exception of the last 20 years) indicates that the relation between the Sun and climate remains a challenge for further research."
It would be nuts if high solar activity spurred abundant food and thrust humanity into the electrical age. There's gotta be some big trigger why we suddenly have all this tech within 200 years after 100k years of modern humans walking about as cavemen
For the trigger in the last 200 years, it is just fossile fuels. Having all this energy provides us with enough food and comfort to survive, thus lot's of spare time and spare manpower dedicated to research and improving tech. It also feeds all these machines we are making.
Going back to renewable will be tough (but is mandatory). We are a species that has been high on cocaine for a couple of centuries and we just realized that it slowly killing us, and it is running out anyway. Our only option is to sober up.
10000 years of unprecedented stable temperature. See Attenboroughs new documentary on Netflix!
keeping in mind that was in 2004 and a bunch of further research has happened.
Sadly not much. The stratosphere is getting colder, while the troposphere is getting hotter, and the overall energy the earth is getting from the sun is sensibly the same. See
https://earthobservatory.nasa.gov/world-of-change/Solar
(it was a quick search)
A very large portion, not all, not little.
https://en.wikipedia.org/wiki/Solar_cycle#/media/File:Sunspo...
Notice the Modern Maximum starting around ~1800 which is also when all the graphs of global warming show increases; whereas normally the industrial revolution is blamed.
Maunder minimum ->
https://en.wikipedia.org/wiki/Little_Ice_Age
Medieval maximum ->
https://en.wikipedia.org/wiki/Medieval_Warm_Period
though our data is far less clear about that period of time.
Fundamentally, you can look at this graph.
https://en.wikipedia.org/wiki/Geologic_temperature_record#/m...
The climate warms and cools quite regularly. The Earth warmed 6 celcius over the last 20,000 years without our help.
https://en.wikipedia.org/wiki/Eemian
about 115,000 years ago it was 1-2 celcius warmer. Which is roughly what is currently being predicted as part of climate change by 2100.
An absolutely tiny and negligible amount, almost immeasurably small.
According to some researchers, pretty much all of it. Take a look at the list of skeptical (and frequently demonized) scientists here:
https://thebestschools.org/features/top-climate-change-scien...
It's been about one and a half "11 year" cycles since this was published. Here's a recent paper from the same group, which covers those years:
https://www.mps.mpg.de/solar-cycle-25-has-begun?c=2169
My reading is the most recent cycle was relatively "tame" but I would love for an expert to weigh in.
The last solar cycle was extraordinarily inactive. I'm not sure why this bubbling to the top - the title even with the (2004) is misleading.
https://en.wikipedia.org/wiki/Solar_cycle_24
In a related news here today:
The Laptev Sea hasn't frozen
https://news.ycombinator.com/item?id=24932466
Is this actually related?
The sea is freezing due to an anthropomorphic climate emergency, the other is more of an astronomical observation with seemingly immeasurable impact on our climate.
It's to help us see through all the liars in power.