Small variation of heat from the sun has little to do with anything ,it is increases and decreases in UV radiation ,not heat.
Solar Radiation and Climate Experiment (SORCE) Fact SheetThe Sun’s affect on global warming can mostly be attributed to variations in the near-infrared and visible wavelengths of solar radiation. As previously stated, these types of radiation are absorbed by the lower atmosphere, the oceans, and the land.
There are other research papers that should be used that explain how increases in UV radiation help melt ice and release CO2 and water vapor from the ice and oceans that creates types of clouds that results in global warming.