Some would be able to shift ranges, sure, but proper temperature isn't the only factor in their survival. There's also pesticide and plastic breakdown particle pollution, acidification and proper insolation. They also depend on proper currents to distribute nutrients and a proper food web of other species to maintain a healthy population.Wouldn't the phytoplankton just "relocate" and thrive in other areas? The ocean temps are not uniform globally, or is it?
It's all very complicated and interconnected. Cut the wrong cord in the web and you could have massive unintended consequences.
I think you're underestimating the practicability of solar and wind, nM. In many places they're nearly on a par with conventional energy costs, and the prices are falling. They also promise new industry and jobs, so should be a boon to the economy.The viability, reliability, and effectiveness of green energy vs conventional means is an issue. Not to mention It's hideously expensive to implement alternative technology for which there is a decent return for all the trouble.
So far the only green contender imo is primarily geothermal, hydrothermal with limited areas for solar and wind where it's pracitability and profitability warrants the time and effort.
Nobody is going to actually care about green energy unless there is a return for which one benefits in a direct way. Like reduced costs and increased efficiency.
Existing power companies resist a change to green energy 1: 'cause they already have conventional infrastructure in place, with profits rolling in, and, 2: It's hard to centralise wind and solar in discrete facilities so as to monopolise profits.
As for nobody caring for green energy, consider Germany (not known for abundant sunlight), which set out to eliminate the need for a new nuclear plant with an experimental subsidy programme for home solar power.
So successful was this programme that it matched the output of something like 14 nuclear plants and eventually had to be shut down because it was overloading their existing power grid.