Does microwave communications heat up water in the atmosphere like microwaves heat up food?

Yes, microwave communications can heat water vapor in the atmosphere, similar to how microwaves heat food. However, the effect is minimal and not significant enough to cause noticeable temperature changes. The microwaves used in communication systems are generally at lower power levels and designed primarily for signal transmission rather than heating. Thus, while water molecules can absorb microwave energy, the impact on atmospheric temperature is negligible.