We are basically still in an Ice Age - the Quaternary Period. For the last 20 some thousand years we have been in a warming lull. Note the definition of the Quaternary - “ typically defined by the cyclic growth and decay of continental ice sheets associated with Milankovitch cycles and the associated climate and environmental changes that occurred.” Key word is cyclic! As far as I know no one has presented any physical evidence we have left the Quaternary. (Physical evidence not computer simulations!) There seems to be a growing body of evidence we are going into a cooler era. Whether it will be like the 400-500 year “Little Ice Age” remains to be seen, if it is that will be bad. If its something more, then very very bad ! Cold kills, warmth does not ! Its possible we could be in a situation where we would wish Al Gore was right! (Isn’t it just like the Rats to not just get something wrong but to get it catastrophically wrong!) There are other contributions to these weather cycles, cosmic ray particle & solar particle density. Cosmic ray density rises and falls as we make our way around the galactic rim, solar particle determine by the sun (Sun is very dynamic!). Plus there’s the issue of the earth’s magnetic field (Now weakening!) & the dynamic magnetic fields of Jupiter & Saturn defecting or not these rays & particles.
Over all the earth system, its place in the solar system & the galaxy all contribute & interact to a greater and/or lessor extent (changes over time!) to give us our climate. Its not simple! None of the 17 computer models come close in capturing all of this or take account of the earth’s feedback in using heat, CO2 etc. We don’t even come close in knowing all the mechanisms and those we know of I challenge anyone to convince me we know exactly how they work! Even the earth’s volcanism & earthquakes contribute.
We have periods of high volcanic activity periods no so much. Why should they bunch up in time, why aren’t they evenly spread out? No one knows! Earthquakes can change ocean currents which can change weather. What if the Gulf Stream after a earthquake (not likely!) changed dramatically? That would do something dramatic to Europe! Again a highly complex interacting system!
defecting = deflecting