Selected response	Percentage of respondents (%)
Solar variability – the sun is increasing its energy output	25.2
The statement in the question is not true – no warming is occurring	10.3
Oscillations in the Earth's orbit around the sun (Milankovitch cycles)	15.9
Increasing water vapor / humidity in the Earth's atmosphere	28.4
Fewer clouds are present	10.7
Human emission of greenhouse gases	70.6
Earth's surface is becoming less reflective (Albedo effect)	19.1
Shifts in ocean currents	25.5
other	13.2