Researching the history of CO2 concentration in the atmosphere in the last 400.000 years circa, a pattern has been detected regarding global temperature and CO2 concentration: while there have been temperature fluctuations, consistent with ice-ages and goings-out of ice ages (and other fluctuations), there have never been instances where the CO2 concentration has risen without the global temperature rising as well! And today, we have the greatest leap in CO2 concentration ever recorded in the last few hundred thousand years. What used to take about 5000 years, took less than a century nowadays.

Asfor the small relative increase in temperature: if the global temperature increased uniformly by a small amount, nothing much would happen. But it's not that simple: an increase in temperature indicates an increase of the total energy of the system, and we can not predict how that increase in energy will manifest itself. However, some effects are already visible: hurricanes are more frequent and more intensive. Cyclical weather patterns are disturbed and so we have no-snow periods for some areas of the alps. Or we have droughts in southern europe and australia, much more destructive than in previous decades.

Some places are heating up more quickly than just 0.74 degrees; such is Siberia, for example.There, millions of tons of methane is being liberated from the once-frozen permafrost, and houses and other constructions are "sinking", as the permafrost on which they have been built, melts away. The methane that is being liberated is itself a greenhouse gas. In fact, its greenhouse effect is a few tens of times stronger than that of CO2.