Our world has experienced five, so-called, great dying cycles in its long history, the most recent dated 65 millions of years ago. The best studied one, 252 millions years ago, marking the Edge of Permian-age, has shown massive extinction of living organisms on Earth: up to 96% of marine and about two thirds of terrestrial life, trees, animals and even microbes. Some say that we just begun our sixth route towards big dying, based on observations of quick extinction of living species, e.g. the overall weight of insects in our climate zone has dropped by two thirds over the past decade (!).. The present ppper provides information about methane and its becoming role in the fast approaching end of our civilisation. Knowledge about it is not secret, however it is rarely included in forecasts, models etc, for rather obscure reasons, perhaps due to incomplete understanding of supramolecular interations between methane and water in the form of clathrate compounds. From chemical standpoint clathrates display rather bizarr characteristic, they are non-stoichiometric compounds. The products are represented by the formula below being the essence of Van der Waals and Platteeuw theory and it shows the thermodynamic condition of clathrate stability stands for the chemical potential difference between the host structure in its modifications: clathrate ad non-clathrate, m represents a structure factor (the number of hosts molecules forming a cage), and stands for the minimum filling extent above which the clathrate is thermodynamically stable. Water is capable of forming more than just one clathrate structure but, from the point of view of the present paper we may limit ourselves to one of those, namely the clathrate hydrate type I.) Methane molecules can enter both types of the two types of cavities and the extent of filling is different. The ‗small‘ cavities are filled almost completely whilst the ‗big ones‘ in about ¾ fraction, please see the formula below  o w = [3ln(1  L ) + ln(1  S where  o w stands for the difference between chemical potentials of host modifications, as discussed earlier, and  is the minimum filling extent of, respectively, small (s ) and large (l) cavities. We note that the methane contained in the deposits in the amount estimated at 1019grams and in some estimations in the literaturę, it is more than the amount of oxygen in the atmosphere. Sudden evolution, e.g. s the result of cosmic catastrophe, would mean a total dying of biological life. Slow seeping must lead to enhanced greenhouse effect and this, in turn, accelerate destabilization and leading to positive feedback effect. I will be discussed in detail. kT