Does global warming exist?

Global climate change is a fact, demonstrated by historical evidence about the composition of various gases throughout Earth's history. Global temperature changes over time ("ice ages", "warming periods") Ice core sampling in the Arctic and Antarctic circles give us a record of CO2 and CH4 (methane) levels, as well as nitrogen and oxygen levels. From this information, climatologists can calculate average temperature over time. As far as the evidence shows, the composition of the Earth's atmosphere has stayed essentially the same for the last 800,000 years, as far back as ice core records can show. This composition is the textbook common 78% nitrogen gas, 21% oxygen gas, 1% other (Argon, CO2, water vapor, Neon and Helium). CO2 is of particular importance to the discussion on global warming because experiments have shown it to absorb infrared light (what we feel as radiated heat, by the sun or a fire), and therefore increase the temperature of the atmosphere. It is also known that since the Industrial Revolution, which brought about the common use of fossil fuels, global CO2 levels have nearly doubled.

A:The simple answer is yes: Temperature records show that average global temperatures have risen by 0.75 degrees Celsius since the Industrial Revolution and are now the highest for at least two thousand years, estimated to likely be the highest for at least a million years. And most of this rise has occurred since the 1970s. For the purpose of this question, we do not need to establish why this rise has occurred, but even sceptics acknowledge that carbon dioxide levels have risen rapidly since the Industrial Revolution.