IMO there is no doubt renewable energy, particularly solar, is effective and affordable. It's free, whereas fossil fuels have to be mined or extracted, then processed. Nuclear energy is effective; however, it requires enormous safeguards.
As far as being necessary, that ship has already sailed. Ask any insurance company, they are ratcheting up their premiums as fast as they dare. The first law of thermodynamics says storms are only going to get bigger, more intense, and more destructive with global warming. Think of hurricanes packing 400 km/hr winds hitting Miami.
The technologies are there, the science is there, it only requires funding to implement them.
Humanity's biggest obstacle is venal politicians and the fossil fuel industry that sustains them. Trump appointed an oil industry executive as his Secretary for the Environment. Closer to home, the former Liberal government in Australia had 90% of the staffers in the Prime Minister's Department with links to the fossil fuel industries. If anyone believes that's a path to renewables, I have a bridge in Sydney Harbor I'd like to sell them.