650W PSU have plenty of room for RTX 3070. So, yes.
To check the wattage requirements, you can always refer to the GPU (i.e.: My Gigabyte RX Vega 64 gaming OC stated the recommended PSU is 750W). Usually, the recommended PSU wattage is pretty much overkill, but it sure give you a rough idea how much total power draw if you have the most powerful processors overclock to extreme, with lots of blings and storage devices + peripherals, and still have some room for future upgrade. Of course I don't need that high. My system has Ryzen 5 3600 with Gigabyte RX Vega 64 Gaming OC (overclocked), the GPU maxed out at 330W whereas my system + peripherals only uses close to 200W, making 550W just enough for me. However, if I were to change to a CPU with 95W TDP, I need to increase to 600W PSU, which is much lower than the recommended PSU.
You can always check the total power requirement in PC PartPicker to confirm your actual power requirement. They do give a good estimation of power that your system configuration really need.
As a general rule of thumb, for AMD processor, typically, 65W TDP processor would likely to consume around 100W (usually 90W+) of power whereas 95W TDP processor would consume around 150W, and that is when stressing out the CPU. Your motherboard and other component like sound chips and RGB lighting may consume 100W (depending on how much fan and RGB you have plug in to the motherboard), a SATA HDD typically took about 20W to spin its platter when the platter is not spinning, while SSD is negligible as they only use 5V.
So, I would say, Total power requirement = CPU power + 100W + GPU power. You can then select any PSU wattage with at least 50W higher (just in case). However, if you ask me, 750W PSU should be the norm as it fits most system (mainstream and high-end with 1 GPU) and you don't have to worry much about power requirements of your system even when you are upgrading to a more power consuming component, such as from RTX3070 to RTX3090. Just my opinion, but many people disagree with me last time stated it's overkill, but now, everyone is like freaking out that their PSU might not be able to power their new RTX3000 GPU.