The issue is the rate of change. We have seen times the climate changed this quickly before. Every time it happened we call a mass extinction event. Yes it is bad.
Climate change is most probably real. The cause is highly debatable.
The cause is the burning of fossil fuels. We can tell that the added CO2 in the atmosphere has lower C14. Because it is millions of years old and already all decayed to C12.
That is actually denier propaganda. Astronomers actually debunked that it isn't caused by solar cycles since those cycles do not at all correlate to the changes in the climate.