Hi John, welcome to the forum, and thx for the link.
I've read about half way through Miles' work and, while I am in agreement with the notion that the galactic environment likely plays a strong role in the solar system and here on Earth, Miles had made some mistakes in his argumentation.
The first is he misinterprets the term 'Solar Forcing'. The term doesn't not mean the Earth is forcing the Sun. In the Earth climate context, 'Forcing' of any type means a source of energy that drives Earth climate in one direction or the other.
Since Miles posted that paper in 2011, it has been discovered that there is a strong correlation in the combined angular positions of the major planets with respect to the Sun with the strength of the Sun Spot Cycles. If the Sun, the planets, and the whole solar system are essentially electrical dynamos, then what is cause versus what is effect?
It has recently been found that the solar system's heliosphere is under constant galactic bombardment by electrical plasma. This in addition to whatever the levels of Miles' galactic photons are. I have no idea what the relative differences in photons or plasma levels are in relation to either the Milky Way or its center versus other directions.
The significant effects of the combined Milankovitch Cycles have been found in ancient lake sedimentation layers, such as rock formations in New Jersey. One is left to argue the direct cause of those three different orbit cycles of the Earth with relation to the Sun, but the correlative effects upon climate are yet there. There is a theory that the precessional wobble of the Earth is caused by ... wind. And this could be so because the northern hemisphere has much more land mass than the southern hemisphere.
What concerns the likes of Carlson and the other cometary impact researchers is what can cause such sharp transitional spikes in temperatures and especially the rapid massive meltwater events seen from the last transition. The old theory of melt water being dammed up literally doesn't hold water. Ice is prone to leaking out such melting water, either out of fissures in the ice 'dam' or at the meltwater lake bottoms into the underlying ground. The massive drumlins left behind after the ice sheets retreated can only be formed via massive flows, not from typical glacial melt.
I've never read anything like Miles' claim of concentrated planar photons, while it has been demonstrated that the interconnected webbing seen in more recent images of the universe can be easily explained by Birkeland Currents of plasma flows, replicated in plasma physics labs.