[SamPhillips]

1. 100% of the problem that climatologists discuss is heat from the sun, trapped, by greenhouse gasses that we release. As you rightly point out, we can't control the sun, so we must control how much insulating gas we put in the atmosphere.

2. Even it China cuts is emissions, with the USA outputting more than 4 times per person, would that be enough? How exactly is it that China spends more on reducing emissions while USA spends zero? This is a collective action problem (much like CFC's were in the 1980s, or not peeing in the lake you depend on for drinking water), it requires grown-up behavior from all nations now so as to no despoil the inheritance we might leave to our children.

[patrickg_zill]

1. Very few talk about how the sun changes its levels of radiance and how this affects climate on Earth. The sun is not a "constant".

2. Maybe I phrased that part of my statement rather lumpily. I meant, if USA spends to reduce emissions and China and India do not spend.

[SamPhillips]

1. They don't talk about it because it is not the primary cause of the warming we see. [0] 2. China and India have agreed to reduce emissions, as part of the Paris agreement. 45% of all solar installed worldwide in 2016 was installed in China. Every country needs to do its part. [1]

https://www.bloomberg.com/graphics/2015-whats-warming-the-wo... https://en.wikipedia.org/wiki/Solar_power_by_country