This is a good opportunity to point out this strategy of climate denial, and why it is not a rational approach to refuting climate change.
Let's suppose that all the other commenters are wrong, that the river has not changed course in the past. The implication, from a probabilistic perspective is that P(evidence|climate change) is the same as P(evidence| natural variation), and your implied assumption is that because your prior belief that no climate change is more likely than climate change, then this works ultimately as evidence in favor that there is no climate change.
The reason this does not yield interesting results, even if all these other assumptions we're making hold, is because the hypothesis of climate change doesn't simply explain this one observation, it explain an enormous range of phenomena.
To explain away all of the observations explained by climate change you end up building a huge list of different hypotheses to explain away each fact. Even if individually these alternate hypothesis do explain each piece of evidence better (which in practice they often don't), and even if your prior for all of these other hypotheses is higher than climate change, because climate change is a single hypothesis that explains many observations, the joint probability of the individual hypothesis quickly becomes much lower than the climate change hypothesis.
In order to effectively argue against climate change you would need a competing singular hypothesis (or small set of very likely hypotheses) that ultimate do a better job explaining all of the observations we have collected.
I don't know if this fallacy has a name, but it sure should since it comes up in a lot of arguments about systemic problems.
Rivers change course all of the time for reasons unrelated to climate change. It’s entirely likely that the Amazon was some distance from this site 2,000 years ago.
You're entirely right. But the evidence is not a single drought, it's a staggering combination of many events that show things are changing in a drastic way.
Anyway it's also important to point out that the climate has changed before, but during humanity's existence it never changed this quickly: it looked more like this https://xkcd.com/1732/ which describes changes along thousands of years rather than a century. The derivative of in respect to time is just to steep.
Another thing to consider is that quickly changing environmental conditions is often associated with extinction events. We are in the middle of one such event https://en.wikipedia.org/wiki/Holocene_extinction but maybe one can say it's okay; on a geological scale, such disasters this happens all the time.
The question is, maybe, to ask what will happen to us and the things we care about.
I'm going to generously assume that you're asking a sincere question and not trying some tired political baiting, even though you mentioned climate change out of nowhere.
Yes, rivers are extremely dynamic -- they run dry, flood, and change course over time. Often, those changes are dramatic and oscillatory so the same path may repeatedly run dry or wet over periods of years, decades, centuries, millennia, and longer. This is why we can often predict where droughts and floods are likely to recur, without precise timing of when. None of that has anything to do with climate change.
"Climate change" didn't come in vain: there are many news using small events as a final proof of a new ice / greenhouse / warm / climate change era. So, can the fact of something happening in the past be a proof of something ? And yes, your reply was a good one. Assume "good faith" should be the norm to a open and sincere debate... Thanks!
