For those who think this warming of the Earth is just part of the normal cycle, a repost:
https://www.bloomberg.com/graphics/2015-whats-warming-the-world/?fbclid=IwAR3ubzlFGxX-t3gMQnwHWYxuijPtncPy5dA-gZeqqotPDtr42V6g2Y6qlHI
Why isn't it a normal cycle? Why did you limit the graph to a time period that is so limited?
1880 to the present is the period for which scientists have consistently gathered global climate data. (but ice cores and analysis of geological strata and fossil composition also helps to unearth longer trends in the past) Science uses a curve and then extrapolates from that, and compares the curve to other variables than temperature. It is possible to spot trends when you have over a century of measurements. This is how our present rise in surface temps and changes in storm systems, seawater temps and currents, glacier and ice cap shrinkage, etc. were all predicted back in the 70s and 80s.
It's the same scientific method that allows us to know that sunspots have regular cycles, even though we haven't had astronomers with telescopes keeping records for 20,000 years. Or that whales are mammals that evolved from land based herbivores, even though we don't have time machines that carry us back millions of years. Inference and extrapolation are basic tools of science, the science you trust when you step onto a jet or undergo brain surgery. I'll bet, if your daughter needed such surgery, you would choose the neurologist who attended Johns Hopkins, not the science denier who went to Oral Roberts University, College of Faith Healing.