Scientists warn that the Pacific Ocean’s cooler period gave global warming an “false Pause” lasting more than 10 years. Climate warming will increase as the ocean heats up, scientists believe. Michael Mann (Distinguished Professor of Meteorology, Penn State) and his team said that global warming stopped in recent years due to natural climate fluctuations. The pendulum will soon swing the opposite way. These fluctuations are “variability in the internal climate system” and do not indicate that humans have stopped causing global warming. They stress that the recent slowdown is not cause to be alarmed. Spacial patterns for AMO. Credit: Giorgiop2, own work via Wikipedia. Image source: Penn State. Prof. Mann stated that they were able to identify between natural and human-caused climate variability to assess the effects of climate change. He used a mixture of observational data from the real world and simulations of climate models to find out what has contributed to the Northern Hemisphere’s climate variability. Their findings were published in Science. AMO and PDO The Atlantic Multidecadal Oscillation (or AMO) shows how North Atlantic sea-surface temperatures fluctuated over 50 to 70 year. Because the Pacific Decadal Oscillation (or PDO) fluctuates over a longer period of time, the researchers focused on the multidecadal part. This is the Pacific Multidecadal Oscillation. The scientists discovered that AMO (Pacific Decadal Oscillation) and PMO were not closely related after running several climate simulations. They aren’t, contrary to some claims, part of the global “stadium waves” oscillation. PDO Spcial Pattern during the “warm Phase”. Image: Wikipedia. The Pacific Ocean slows Northern Hemisphere heating. They found that the PMO’s steeply downward-trending trend has caused warming in the Northern Hemisphere to slow down. They could see that the AMO was relatively flat and they knew that climate warming had little to do with Atlantic Ocean temperatures. Global warming has experienced a false pause because the Pacific Ocean is cooler. The scientists concluded that cooling in the Pacific Ocean, as well as a slowdown of climate warming over recent years were caused by heat trapped beneath the tropical Pacific. Also, there was a tendency to long La Nina-type conditions. Scientists wrote that while there are some paleoclimate evidence suggesting that such a response might be caused by subtle climate features that climate models don’t currently understand, researchers noted that it is most likely that AMO random fluctuations were responsible. Prof. Mann stated that “our findings have significant implications for the attributions of recent climate shifts.” Researchers predict that the Pacific Ocean will see a cooling trend soon. Global warming will accelerate once it starts to warm up. Citation: Byron A. Steinman, Michael E. Mann & Sonya K. Miller. Science. 27 February, 2015. DOI: 10.1126/science. 1257856.
Cool Pacific Ocean heats up again, global warming is likely to accelerate
