A misconception that affects the way people think of both evolution and climate change, is the idea that the study of the past is a necessary and integral part of the theory. That's not necessarily true.

Darwin generated his theory of natural selection by observing living species throughout the world, and Mendel developed this theory of genetic inheritance by working with living plants. Biologists studying evolutionary processes today continue to work with living creatures like viruses, bacteria, and insects.

Likewise, the theory of global warming was developed by observing current-day phenomena, like the Earth's surface temperature, absorbtion and re-emission of light by certain gases, the rate of CO2 absorbtion by the ocean, the quantity of manmade and natural emissions, solar energy inputs, orbital variations, etc.

In both cases, it was this study of the present that created additional questions that could be answered by looking at the past. Evolution gave scientists a new way of organizing and studying the fossil record--that was a result of the theory of evolution, not the cause. Likewise, the study of current climate change raised a whole host of questions that scientists could try to answer about the past.

Quite a lot of science works this way. Astrophysics is well known for the Big Bang theory, but the roots of the science are in observing the stars we see today, including our own sun.