Comment by mike_hearn | Hacker News Reader

Comment by mike_hearn | Hacker News Reader

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It doesn't really make sense when talking about physical constants. But if someone told you that things always fall at that speed everywhere, including on space stations and on the moon, you might suspect something had gone wrong.

The point dingnut makes is that science has to be falsifiable. That means you have to be able to articulate what set of observations would lead you to abandoning your theory. If someone showed there was a place on Earth where things did not fall at that speed you would consider the claim falsified.

So what dingnuts is saying is that he feels that claims about climate are becoming unfalsifiable. If it's hot, that's evidence for climate change. If it's cold, that's also evidence for climate change. If there's no snow, climate change. If there's snow, also climate change. If it's just a sort of average week, then that's ignored and considered to not mean anything.

It's maybe more of an issue of journalists, but the trend towards presenting every possible weather event as leading to the same conclusion leads to the question of what kind of short term weather would be accepted as evidence against the theory. Is there any?

1) No, no local or short-term weather is ever going to falsify or prove anything about the global average.

2) Assuming you are already convinced by the science that the global average temperature is quickly rising; one might ask: What are the consequences? And one of the consequences is more extreme weather, as there is more energy in the weather systems..

3) So one may point to extreme weather events and say "in the future, we'll have more of those, and that's why we need to stop emitting CO2". That doesn't mean the weather event is proof of global warming in any way -- it is just pointing to an illustration of what will happen if global warming continues; as measured by the GLOBAL temperature.

Dingnuts' complaint is about (1). Your statement is true, but it's not treated as true by the media nor increasingly by governments, who are comfortable making claims of the form "this weather today is proving that the climate is changing (for the worse)".

It's a valid complaint. It's one about the practice of the philosophy of science though, not something that can be refuted with claims about temperature or CO2.

Nonlinear dynamics means that adding heat to a partially-closed system doesn't result in an even distribution of increased temperatures. Instead, we observe a net increase in temperature averaged over the planet's surface, and wild swings in local weather due to the basically infinite-dimensional state space of the planet's atmosphere being nudged. No single observation of local weather should ever be attributed to climate change, I'll give you that.

Basically, climate change is occurring, and is known to cause extreme weather events. So when there's an extreme weather event, it could be evidence of climate change. Each individual one is not proof of climate change, but in aggregate they are strong evidence. And of course they're not the only evidence.

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