Imagine a heating system that is the size of a melon, yet powerful enough to heat a whole house for half a year, without the need for fuel other than some tiny pulses of power. When the six months have passed, you can keep on heating by just replacing a cartridge with some more metals - roughly the same way you replace ink in an inkjet printer.
Is this the solution to the climate crisis? Yes, it's quite possible, according to several experienced physics researchers. At the same time, a majority of the world's physicists believe that it must be a matter of wishful thinking or measurement error.