What happens if the next solar cycle becomes less active? Will we enter into a new ice age?

No. Even if the amount of radiation coming from the Sun were to decrease as it has before, it would not significantly affect the global warming coming from long-lived, human-emitted greenhouse gases.

In more depth, scientists know that even a prolonged Grand Solar Minimum would only serve to offset a few years of warming caused by human activities. In other words, warming caused by the greenhouse gas emissions from the human burning of fossil fuels is 6 times greater than the possible decades-long cooling from a prolonged Grand Solar Minimum.

Even if a Grand Solar Minimum were to last for a century, global temperatures would still continue to warm. Because the Sun is not the only factor affecting global temperatures on Earth.

Further, given our greenhouse gas emissions to date and those expected to come, the evidence points to the next “ice age” being averted altogether.