So, what will be the significance of entering cycle 24?
Really the significance of entering cycle 24 is just that sunspots will become more numerous as we approach CYCLE 24 solar maximum. There are currently two forecast for cycle 24, one with a very active spot cycle, and one with a lower numbr of spots.
Some people believe a WEAK cycle and extended solar MINIMUMS cause the earth to cool. Some think that is nonsense. If cycle 24 is late arriving as it appears may be happening, the solar cycle/global warming hypothesis may be shown to be correct or incorrect. The last 70 years or so, the sun has been pretty active, now it appears to be less active. Time will tell.
Warmer weather, better harvests, butter quality of life for humans... It's a good thing.
The sun goes through 11 year cycles, but 24 hasn't been ramping up as it was predicted to. The concern is that we're due for another little ice age right about now and some people are concerned that it's going to start with this solar cycle. This means colder, wetter (in some places) weather and poor crop harvests. That is if you're in the camp that believes that it's the sun which controls the weather and temperatures.
The BIG concern (which I do not, at this time, share.) is that we're due to enter another big ice age. If this happens, life on the planet will cease to exist as we know it.
The thing to remember is that *normal* weather for this planet is much colder than what we're experiencing now. We go through 100-120,000 year cycles (roughly) with about 10,500 year warm periods called interglacial periods. We're right at the end of the present interglacial period and it wouldn't be surprising for the world temperatures to start dropping back to ice age conditions.
The question right now is, how fast does this happen? Some people think it takes thousands of years for the temps to gradually drop, others say it could be as fast as 20-50 years. Honestly, nobody really knows. If the latter theory is correct, we'd be in deep trouble. (I think we have more time and that it's a more gradual transition.)
Personally, I think that we're heading into another Dalton or Maunder-type minimum, but I don't know if it's going to happen this cycle or the next one. That would be bad enough.
So we're rooting for 24 to ramp up and do well. It's sure taking it's sweet time, though.
The problem is that solar science is relatively new and we really don't understand everything that affects our sun. We have no idea how it behaves during an ice age or how it looks during a transition. All we know is that it's behaving differently than it has for the last few cycles. It will take time to figure out what that means.
I hope I explained it well enough. I'm still trying to figure all of it out for myself right now.