There's always a chance it has downsides, but worst case you block the canal and it turns back into a dead sea.

I would say we are excellent at modelling outcomes, just bad at listening to models that tell us what we don't want to hear. For example, we knew about global warming before computers existed. The model and the tech wasn't the problem, human avoidance of bad news was (and is).

We can't just avoid doing everything because our models might be wrong. I find that reasoning repulsive. If humanity took that approach we would have died long ago.

I figure we've had enough examples of well-meant interventions that lead to worse outcomes to be really conservative about "just change the ecosystem and heat/salinity circulation patterns of two large bodies of water, what's the worst that could happen?"

We should be able to extrapolate from the large-scale reservoirs that have already been built. The proposed reservoirs would be 10x larger, so there would undoubtedly be learnings. But we would probably build such projects in stages, so that the project could be stopped or altered if the effect is negative.

You’re assuming linearity and arguing that all things are equal. I would be surprised if either of those things are true.

We _are_ being conservative. As the article mentions, these kind of projects have been proposed and studied for half a century now, and despite all the predicted benefits we haven’t event built a single one!

The pervasive "Let's never do anything, just to be safe" mood is what I dislike the most about this era. It is suffocating so many possible paths to progress.

"You never know" is always true, Don't use it as a crutch.

Note: I'm an old man complaining about this era, not OP.

> The pervasive "Let's never do anything, just to be safe" mood is what I dislike the most about this era. It is suffocating so many possible paths to progress.

To evaluate such a claim with anything approaching objectivity we would need a lot more detail.

What era are you speaking of? Why do you call it a ‘mood’? A mood of who exactly?

The way you phrase it is not an accurate characterization of what people mean when it comes to concern about unintended consequences. Your phrasing is a narrow, uncharitable criticism.

You might be attempting to reference to a concept called the precautionary principle?

> The precautionary principle (or precautionary approach) is a broad epistemological, philosophical and legal approach to innovations with potential for causing harm when extensive scientific knowledge on the matter is lacking. It emphasizes caution, pausing and review before leaping into new innovations that may prove disastrous. - Wikipedia

Criticisms are well articulated on the Wikipedia page. They are worth reading and discussing. They are fair and don’t rely on mischaracterizing what they criticize.

To be clear, I’m not taking a position here on the precautionary principle. I am suggesting: don’t be vague and don’t mischaracterize others’ positions. Sorry if this sounds harsh; it seems to me that people on Hacker News have the intellectual horsepower and time to think and write well.