What is global warming/climate change and why is it dangerous?

Need an answer asap 45 points and brainlest to the first person to answer why do scientific theories, such as biological and chemical evolution, represent the strongest explanation of the changes observed in the fossil record. must be in sentence form how can scientific theories on evolution and the fossil record change over time? must be in sentence form

Awave has a wavelength of 15 mm and a frequency of 6 hertz. what is its speed?

Which enzymes break down carbohydrates?