2. Volcanic aerosols
3. A prolonged drop, for centuries, in volcanic activity, resulting in lower atmospheric carbon dioxide.
4. Earth's orbit becoming more circular as its axis becomes straighter.
The exhaust from cars(gasoline), trucks (diesel), planes (Chem trails/jet fuel), and construction equipment, and buses could be a contributing factor, also destruction land water air in the times of war (what are in those bombs and missiles?) And never mind the great concrete jungle. (Concrete actual soaks in the heat and radiation from the sun and warmth heating the ground underneath and the protecting it under the concrete like insulation) could all really be the cause..... But, just don't ask the government, you'll never get the truth.....p.s volcanoes account for the pre industrial revolution levels look at the post industrial revolution levels to see it.
there is no cooling recently. cooling happens when CO2 is reduced, orbital/tilt of the earth cycles (Milankovitch) over thousands of years, when the Sun goes into a minimum and temporarily when volcano dust block sunlight for a few years.
The sun with its predictable activity, water vapor. Maybe someone else can think of 2 others.
You fried my brain thinking.
If your school is into this, get out of there.
utilizing this energy source?
