Virtually everything you've stated is just plain untrue. We know exactly how much of warming is caused by the sun because we've been closely tracking solar irradiance, we know it's not orbital variations because we know exactly the timescales they occur on and there has been no shift in orbital eccentricity over the period of warming. Volcanoes certainly aren't the cause as they emit an entirely different carbon ratio than fossil fuels so we can track their emissions. Oceanic streams certainly aren't to blame as they don't effect the total energy balance of the planet, only how it's distributed.
However what we do know is Greenhouse gases have risen massively over the last century, we know humans are entirely the cause by examining the ratio of carbon isotopes now in the atmosphere, we know the greenhouse effect has increased because we can measure to total outgoing long wave radiation into space. As well as measure the cooling in the stratosphere as more heat is trapped in the troposphere.
tldr; cope harder