The climate has been changing ever since the planet earth had a climate that is to say ever since the planet earth had an atmosphere the earth climate is non-linear heterotic and has sensitive dependence on initial conditions this means it is not possible in principle I repeat not possible in principle to say what will happen as the outcome of any particular input this means that the hypothesis that human activity anthropogenic activity is causing climate change is certainly true however it is not possible in principle not possible in principle to determine what effect human beings are having human beings have been from the beginning of time subject to immense climate changes and climate disasters throughout the history of humanity and we are in that position still the fact that humanity has devised no contingencies for any dramatic changes that could happen any time and without any warning is deeply worrying however the idea that scientists know what effect human activity is having on the climate is absolutely insane and evil.