Neil De Grace Tyson ......is very clear in its explanation....but I think two things must be explained to render this more understadable. There are at least two major process which have a strong influence on climate:
1-The mouvement of the earth around the sun are not regular and results of the composition of THREE MOVEMENTS (in simplifying): the earth moves elliptically during the year around the sun and also the rotation axis of the movement of the earth aroud which the earth revolves herself dayly is inclined on the plane of the ellipse....but there is more..... the axis around which the earth revolve herself dayly has also a motion. Thes three movements of astronomical origins compose themselves to produce climate cycles like ice ages and more warm climates between ice ages.....These are the Milankovitch cycles of astronomical origin which explains the climate sequences on the very long time. Obviously....volcanoes and meteors migth add a certain irregularity. This is also the case for the variations of solar activity
2-Now we change of perpective for the sake of simplicity. Just let's imagine a earth which is a perfect sphere moving around a perferct star with a perfectly stable activity......more the axis of rotation of the earth around herself is perfectly perpendicular to the yearly movement aroun the star..... I suppose also no volcano, no meteor. This perfect and homogeneous planet around a perfect star has no season, no periodic climate cycles. Now just imagine a galactic civilisation which wants to prepare this planet for further colonisation....with huge spaceship..... they imports trmendous quantities of gases with.the property of having a greenhouse effect. Let's suppose in this ideal world these gases stay in the atmosphere of the planet...do not react with the soil of the planet etc....This situation can be summarized...by a very simple...very robust physical model of the equilibrium temperature of the simplified planetary model.The temperature rise till an equilibrium is reached. The physical laws which allow the computation of the equilibrium are known since the nineteen century and have been used countless times by countless physicist (Fourrier, Arrhenius, Von Neumann......) to accurately calculate the equilbrium temperature of planets of the solar system....That is why elevation of the earth temperature is a consequence of very well known physical phenomenon which cannot be denied on the basis of past climate changes ( imputed mainly to Milankovitch cycles)
And...ho.... by the way....we ARE that galactic civilisation which tranforms a planet mean temperature....but this time its happens not to render the planet more convenient....but exactly as if we wanted to extinct all the living creatures ( and ourselves) and give birth to a new evolutionnary process of life....without us
A bit lengthy...but a necessory explanation....I would be glad....if Neil De grasse Tyson or some climatologist more competent than myself gives an opiniun on such demonstration!