Impacts from Climate Change Have Arrived

In a recently published series of three studies published in a special “Bulletin of the American Meteorological Society” scientists have definitely linked climate change to extreme weather events in 2016. This is the first time that scientists have been to make this link. Until now all the expected impacts from climate change were always in the future, but in 2016 several extreme weather events were found not to have been possible based solely on weather variability alone, the climate is changing.

For each of the past six years the American Meteorological Society has published the December issue containing studies of extreme weather events from the previous year that seek to disentangle the role of climate change from natural variability. So far the bulletin has published 137 studies, but this is the first time that any study has found that a weather event was so extreme that it was outside the bounds of natural variability. This year there were three such events: the heat wave in Asia, the record global temperature in 2016, and the growth and persistence of a large areas of high ocean temperatures.

The long awaited impacts of climate change are arriving. Unfortunately, many scientists believe that we have passed the tipping point which a few years ago was set a 400 parts per million of CO2 in the atmosphere. We have decisively passed that CO2 level and it appears certain that atmospheric CO2 levels will continue higher. Many scientists say that once past the tipping point there will be drastic changes in earth’s climate even if we stop emitting CO2.

The IPCC (Intergovernmental Panel on Climate Change created by the World Meteorological Organization) considers some additional warming of the planet to be irreversible. According to the IPPC, “Many aspects of climate change and associated impacts will continue for centuries, even if anthropogenic emissions of greenhouse gases are stopped. The risks of abrupt or irreversible changes increase as the magnitude of the warming increases.” The expected impacts are continued warming of the planet, rainfall pattern changes and significant rising of sea level.



However, in the news conference that announced the 2016 findings it was noted that 2017 had many extreme weather events that were likely influenced by climate change. Hurricane Harvey and the extreme rainfall that inundated Houston is the subject of three separate studies, and it appears that climate change increased the total amount of rainfall by at least 15%-19%. The die is cast. Though many nations had pledged to keep global warming from exceeding two degrees Celsius, according to the climate models the CO2 emissions trend will produce between 3 and 5 degree Celsius increase in global temperatures and we should be planning for the future we will have and hope for a better one.