For convenience, scientists take as their reference point for predictions the time when the increases in all the greenhouse gases will have an effect similar to that due to a doubling of carbon dioxide. This is expected by about 2030. When temperatures are too high, we jump into the ocean or turn on fans and air conditioning. In, short, human beings adjust to the natural range of temperatures that occur from day to night and from season to season. Other animals make similar adjustments.
Furry animals grow thicker coats to keep warm in the winter.
Many animals seek the comparative coolness or warmth of caves, cracks, or crevices. Birds and fish leave home altogether in search of warmer or cooler zones. Among many causes, the well known phenomenon, El Nino is a temporary climate change which rarely lasts more than two years. Climate change from the greenhouse effect would last much longer. Such extreme changes are not likely to take place soon.