Tuesday set an unofficial record for the hottest day on Earth

Antarctic Sea Ice Extent records: https://www.climate.gov/news-features/event-tracker/antarcti...

Ocean Temperature records: https://www.theinvadingsea.com/2023/05/01/record-warm-oceans...

2-Meter Air Temperature records: https://climatereanalyzer.org/clim/t2_daily/

You have to look back 3 million years to see the same GHGe concentrations and temperatures that earth is reaching now (the two are closely correllated throughout most of earth history, and easily explained by science - the greenhouse effects, and the thin earth surface and atmosphere mostly acting as a closed system).

We see that both ice, ocean and air are heating up and accellerating as of 2023. What is observed now is in-line with projections, such as summed up in this hobbyist article (taken with some grains of salt): https://medium.com/@samyoureyes/the-busy-workers-handbook-to...

Even if some of what is summarized on the notes linked above may be exhaggerated, it seems this is now happening sooner, faster and more relentless than IPCC and scientific consensus have found so far.

Note that any averages or aggregates on measurements, such as those IPCC and climate scientists use, will lag reality by approximately half the period used. So using multi-year averages means we will already be too late when long-term averages show accelleration, even if final calculations will be more stable ("smoother") by using averages. Of course there's no way to really "cheat" this, but that means when we now see we are in uncharted territory, it should be taken seriously.

> The planet’s temperature spiked on Tuesday to its hottest day in decades and likely centuries,

It's not talking about "greenhouse Earth". Anyways, for immediate concerns we only need to look at the Meghalayan age.

A recent example: Nordstream bombing was the "worst case of environmental terrorism in modern history". US govt blames Ukrainian actors[1]. Yet Greta Thunberg hasn't made a peep about it, and recently did a photo op with the Ukrainian govt, which also hasn't spoke out about it.

It's unbelievably cynical. For some people, environmentalism is just a means to power.

[1] - https://www.reuters.com/world/europe/us-intelligence-suggest...

There are intuitive one-minute explanations for why climate change is real and important. However, I think that due to the complex nature of the topic a full answer requires deep study.

Thus, I think it is reasonable to rely on the decades of evidence and science that have led to a concensus among the people that spend their entire lifes studying the topic.

So returning to the brick wall - scientists are doing research everywhere contributing to the climate change theory, adding new facts brick by brick. They look the directly measured CO2 levels in the atmosphere and see an alarming trend. The trend has never reproduced previously according to research (both magnitude AND acceleration rate simultaneously, so "cycles" don't explain). They measure ocean temperature. They dig into Antarctic ice and check elements in older layer. And so on, all around the planet. When they encounter something that is hard to quantify, like say global atmosphere temperature over time they estimate. They also check if the existing data fits into an existing theory, and unsurprisingly it does. Unfortunately so far everything fits in the global climate change theory.

That is an excellent question to ask.

If climate change is not a thing or not man-made, the worst outcome would be missing a few percentage points of economic growth by unnecessarily restricting energy sources.

If climate change is a thing and it is man-made, the worst outcome would be everything that is described by the IPCC, which is bad for society as a whole.

So, just pondering the worst-case scenario is enough to give you an idea of a sensible course of action.

What if we are? Worst case we've significantly reduced the amount of pollution we are putting into our air, land and sea, and reap those health benefits, but not actually affected the climate one way or another.

I think the evidence for climate change is pretty strong, but it's not like it's the only reason to quit burning coal and pumping the smoke into our atmosphere or producing huge amounts of plastics.

If we act and we're right we've prevented catastrophe, if we act and we're wrong we're just healthier, and kill less of the ecosystem around us.

"But wait, maybe this is all just natural cycles" is borderline willful denial at this point, especially on a well-informed site like HN. Might as well ask if maybe the earth is flat after all.

Your comment reminded me of this comic, “what if we create a better world for nothing” is basically what you’re saying.

There were many extremely destructive events in the past that were perfect "normal", in the sense they're not man made, but we might not enjoy happening now.

So if there's a climate change happening ; and if it is negative / bad for us ; and if some actions we take can make it better and some can make it worse... It feeels like a no-brainer, that religion and capitalism and myriad other talking points of dissenting only distract from.

I.e. Even if without human kind, some curve would have a spike ; and that spike is bad for us ; and we can flatten that spike ; them umm lets do it.

It feels fairly intuitive that "pollution is bad" (we can argue how bad), and "adding c02 and making everything crazier is bad" (we can argue how much of the bad is our contribution).

For a long time scale, a rapid warming is associated with a rapid increase in greenhouse gases. This causes ocean acidification. Ocean acidification leaves a clear record in the paleontological record. The last one which was comparable to what we're doing through now was https://www.britannica.com/science/Paleocene-Eocene-Thermal-... about 55 million years ago. And current projections for the speed and severity of acidification are worse. Which indicates that the warming that we are going through is also faster than that experienced at any point in the last 55 million years.

Of course the population bomb turned out not to be real. Third-world birth rates drop as they grow economically. But on the path to preventing the perceived apocalypse we imposed massive harm on millions of people.

The real problem was that part of the scientific community were so confident in their ability to correctly model extremely complex systems that they were willing to do incredible harm "for the greater good". But it turns out that modeling complex systems, especially ones that have never been observed (such as a population "bomb") is really hard. They were not wrong about the data (population was growing at an unprecedented rate). But they were wrong about how that would impact the future.

This has a lot of parallels to climate change. Climate is an incredibly complex system that we have just recently started to study. We have never before observed runaway anthropomorphic climate change (obviously) so all these predictions are based on our ability to model this system. There really isn't any dispute that the global climate is warmer then it was a few decades ago, but what that actually means for the future has big error bars. This could be another "population bomb" type scenario.

But again, it might not be. The science strongly suggest that climate change is a very real and preventable phenomenon. Scientists have been right about the global harm of many other industrial activities (such as leaded gasoline or CFC's). But I am wary of people who say we need to ignore the harm of climate related policy actions because the IPCC future is "inevitable" if we don't. I am also skeptical of our ability to get the international community united enough to actually have a meaningful impact.

[1]https://www.asianstudies.org/publications/eaa/archives/india...

Not a climate scientist, but roughly, from memory:

- Past predictions didn't know exactly what future emissions will be like. Applying real emissions to the models gives "correct" warming quantities

- Climate is changing in a similar manner to predicted, e.g. the poles are warming more quickly than the other areas

Doing science. Thing is, unlike what everybody likes to pretend, doing science means to do a lot of tedious hard work and not a whole lot of quick explanations. So the thing is, that we understand the physics of dilute gasses at roughly room temperature phenomenally well, we did all the experiments of putting this gas into a piston, and then heating the piston slightly, and then do it with a slightly different gas mixture, and then we double checked all these experiments and finally we got a pretty good theory sometime around the turn of the 19th century. Then you start to integrate all that knowledge with a knowledge of radiation basis, and you start doing cross checks and try to understand weather, and at some point try to start forecasting wether, with all the associated trouble and that was then sometime in the let's say 1960ies or thereabouts. (During WWII the flying wing of the US Army had meteorologists at all airfields, I believe German news started to broadcast weather forecast in the late 60ies.) Then you do all that with bigger computers and quite a bit of theory of partial differential equations, and then you realize that understanding the 11 year average is a much much better defined problem than next weeks weather. And all of these steps do suggest different cross checks. (Actually in the Physical Science Basis part of the 5th IPCC report there is a chapter called Evaluation of Climate Models ([0], p. 741), which goes into quite a bit of detail on the most recent efforts along those lines.)

[0] AR5: https://www.ipcc.ch/report/ar5/wg1/

This is a problem to be addressed/solved regardless of the causes of climate change.

Generally in the US “official” numbers would come from the NOAA and the NCEI would be the one publishing them.

More sensationalist, Doomer nonsense. The world absolutely isn’t going to end in the next 10 years because we hit a local max in a data set that only goes back 40 years.