If you want the detailed science go to this link

Perhaps the only bit of science you really need to ‘get’.

This, somewhat confusing chart from the IPCC, attempts to show the relative flows of energy in to and out of the Earth’s atmosphere (and surfaces). 

A key point to note is that whilst the incoming radiation is indeed equal to the outgoing radiation – the diagram itself makes no reference to the fact that the 235 watts (per square metre of the Earths Surface facing the Sun) of energy it shows as “Outgoing Long-wave Radiation” doesn’t leave immediately! It hangs around as ‘heat’ in the lower atmosphere for quite some time (and that is where we live – and where our weather is made!). It is this lingering infra-red (Long-wave) radiation that is causing climate change (or global warming, if you prefer). 

For reasons that are now, at last, clear to me – the IPCC decided to use 342 watts, as explained by NASA as the measure of Incoming Solar Radiation. The real figure (measured at the edge of space – the so called ‘solar constant’ insolation – is 1367 Watts per square metre (measured on a square metre that is perpendicular to the Sun), to the extent that the averaged absorbed Infra-Red energy really is about 235 Watts or so. NASA decided to adjust the irradiance figure to represent the average figure experienced on the ground (which is the surface of a sphere) and obviously as you leave the equator the sun’s incident angle reduces, making the average per sq m energy incident (day and night) on the ground (of the whole Earth) to be 342 watts.

Whilst this model is very much simpler than later IPCC models, which factor in things like Ocean currents, Rivers, Mountains, Cities, Snow and Ice, etc. it nevertheless enables us to predict Global warming as the result of lingering Infra Red energy – itself an inevitable consequence of the presence of so-called greenhouse gases (of which CO2 is the most prevalent – and is the one we make by burning stuff). 

The ‘greenhouse’ effect of CO2 was first noted in the early 1800’s by Jean-Baptiste Joseph Fourier – perhaps more famous for his Mathematics (Fourier Transforms). Awareness of it, and its consequences, was extended  by Tyndall, Arrenhuis and other scientists in the latter part of the 19th Century!  

So it would be a lie to say “we’ve had insufficient notice of the impending climate crisis”.  Politicians please note!

I fully empathise with Greta Thunberg’s anger in this regard.