An Investigation Introduction It's impressive how fast the focus in things climate change has recently shifted from Thunberg back to Milankovic again in just a few weeks. Even more impressive is the fact that, though astronomic or cosmic cycles and positions can be predicted with utmost precision, weather and climate on Earth still and most obviously can not. It seems there are many other factors involved; like - well, perhaps, indeed, the makeup of a planet's atmosphere. So, the following is premised on the assumption that, just as does the Sun's intensity, the position of Earth in Space, and even its own geothermal heat, atmospheric carbon dioxide can and does influence this planet's surface temperature; at least it is doing so under the current circumstances. If it doesn't, then other explanations have to be found for the phenomena observed. If it does, the question is how, and how much; the increase in temperature induced by atmospheric CO2, as given by different authors, lies somewhere in the range of +0 °C to +30 °C, which almost renders any discussion useless. The following, in parts 1 & 2, is therefore hypothetical in its attempt. It presents one possible way of interpreting the depictions of the data as found in public. CO2: Photosynthesis and Climate Change The following shall be discussed here: - There has been a natural climate fluctuation for at least a million years - This could, at least in part, be biological by cause - Humans have most possibly played a role in the latest stages There has been much discussion about climate change, and most of it refers in some way or another to the Vostok ice cores and similar evaluations. Under the premise that the data gleaned from these is correct, their interpretation is correct (which is by no means certain, as the recent controversy of Mann vs. Ball shows), and their publicly available depiction in the graphs referred to below as well as other public statements are correct (which is by no mean