Why can't recent (last 100 yrs) warming be explained by tectonic processes, orbital processes, changes in solar radiation or other natural cycles? why do scientists think it is caused by humans?

a. it led to stricter immigration laws.

a mid-ocean ridge or mid-oceanic ridge is an underwater mountain range, formed by plate tectonics. this uplifting of the ocean floor occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary.a geomagnetic reversal is a change in a planet's magnetic field such that the positions of magnetic north and magnetic south are interchanged.

b.

developed countries have tended to improve the environment, while developing countries have tended to damage it.