Going to Extremes: Federal Climatologist Slams Alarmist Federal Climate Report
By Paul Homewood
The Met Office frequently try to persuade us that extreme rainfall is getting worse because of global warming. It comes as no surprise to learn that the same arguments are taking place in the US.
Unfortunately for the alarmists, a study led by NOAA’s own expert, Dr Martin Hoerling, finds little evidence that this is the case, and instead that extreme rainfall trends are largely dominated by naturally reoccurring ocean cycles.
Second only to incidences of high temperature, supporters of government action to restrict energy choice like to say “extreme” precipitation events–be they in the form of rain, sleet, snow, or hail falling from tropical cyclones, mid-latitude extratropical storms, or summer thunderstorm complexes–are evidence that greenhouse gas emissions from human activities make our climate and daily weather worse.
The federal government encourages and promotes such associations. Take, for example, the opening stanzas of its 2014 National Climate Assessment: Climate Change Impacts in the United States, a document regularly cited by President Obama in support of his climatic perseverations:
This National Climate Assessment concludes that the evidence of human-induced climate change continues to strengthen and that impacts are increasing across the country.
Americans are noticing changes all around them. Summers are longer and hotter, and extended periods of unusual heat last longer than any living American has ever experienced. Winters are generally shorter and warmer. Rain comes in heavier downpours.
President Obama often calls out the extreme rain meme when he is running through his list of climate change evils. His Executive Order “Preparing for the Impacts of Climate Change,” includes:
The impacts of climate change – including…more heavy downpours… – are already affecting communities, natural resources, ecosystems, economies, and public health across the Nation.
So, certainly the science must be settled demonstrating a strong greenhouse-gas altered climate signal in the observed patterns of extreme precipitation trends and variability across the United States in recent decades, right?
Here are the conclusions of a freshly minted study, titled “Characterizing Recent Trends in U.S. Heavy Precipitation” from a group of scientists led by Dr. Martin Hoerling from the NOAA’s System Research Laboratory in Boulder, Colorado:
Analysis of the seasonality in heavy daily precipitation trends supports physical arguments that their changes during 1979-2013 have been intimately linked to internal decadal ocean variability, and less to human-induced climate change…Analysis of model ensemble spread reveals that appreciable 35-yr trends in heavy daily precipitation can occur in the absence of forcing, thereby limiting detection of the weak anthropogenic influence at regional scales [emphasis added].
Basically, after reviewing observations of heavy rains across the country and comparing them to climate model explanations/expectations, Hoerling and colleagues determined that natural variability acting through variations in sea surface temperature patterns, not global warming, is the main driver of the observed changes in heavy precipitation.