Global Science Report is a weekly feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”
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?