Would the world have been better off without Columbus?
Impossible to know, but I would have to say yes. All Columbus managed to do was terrorize an island tribe and improperly end up credited with discovery of a land that he wasn't looking for, didn't believe in and died with the idea that he actually made it to India.
There is a good reason that we don't call this landmass "Columbia".
Why would economies need to be "destroyed" to help this planet? The US government gives tens of billions of dollars as subsidies for fossil fuel production, so that the citizens can enjoy reduced energy prices (which only lead to overconsumption). If anything, our economy would make more sense if we stopped funding destructive practices.
That would be a fine first step. It's going beyond that, that is my concern.
I live in the area, and I can tell you that there was an abhorrent lack of snow. Ski areas were terrible, and the hardware stores were replacing ski equipment with golf clubs. Sure, change is possible, but this is hurting many businesses if anything.
The ski industry might be hurting, but the local tourism will adapt in time. Who knows how many people didn't freeze to death this past winter?
Toronto issues cold alerts that open up many shelters to homeless people, so it is rare to hear of a homeless person dieing. During the heat wave of 2011, however, the Great Lakes warmed considerably. This is hypothesized to have contributed to the deadly and destructive
tornado.
Well, that is interesting.
The Tropics, that will not benefit, include most of Africa and South America, two very large continents, and northern Australia. The Middle Latitudes, that will benefit include the largest continent in the world Eurasia, and third largest North America, as well as southern Australia. The Polar regions include Antarctica, and will not benefit significantly if at all. I would say that this is roughly equal, and any net benefits are not worth disrupting the status quo.
As already noted, the tropics will not benefit, but nore will they significantly be effected unless they live on the shore.
A frozen swamp will melt out to none more than a thawed swamp, which is still a swamp.
Even swampland has value to mankind, moreso than deserts.
Even if unrelated, if we're losing land to desert, shifting the usable land is hardly useful.
Depends on the relative rates. I'm guessing that the rate that the growing seasons of northern nations outpaces the growth of deserts, but I can't know that either.
What do you suggest we do instead? "Nothing" isn't very good for the future of mankind either.
How do you know that? "Nothing" is what we've been doing for 6000+ years, and the planet has managed to take care of itself. The question is, is there anything that we can do to help mankind in the long run that won't cause significant harm in the short run? So far, the correct answer to that question is, "Not that we know of."