A new study suggests El Nino events have intensified over the past 40 years due to human-caused climate change. El Ninos are now more than 36% stronger than before the industrial age, with a 16% increase in the last 40 years, based on measurements from coral in the Galapagos Islands. Researchers link it to the burning of fossil fuels. Outside scientists are split on whether they agree with Thursday's study, saying there's not enough data to prove that El Ninos are strengthening. El Ninos, the natural and temporarily warming of parts of the equatorial Pacific, can cause extreme weather worldwide.