Aaron Isaac – Staff Writer
Don’t get ready for the end of the semester yet, a substantial climate change report has been released by the federal government. The Fourth National Climate Assessment was released this week and it’s a very complicated document.
The U.S. Global Change Research Program must deliver a report to congress every four years. A first volume of the perceived causes of climate change came out last year. Like The Intergovernmental Panel on Climate Change, the U.S. report points the finger for warming temperatures on greenhouse gas emissions, the largest contributor to warming being carbon dioxide. While they also say natural factors such as the sun and short term climate cycles affect the climate, these factors would not be enough to cause warming. In fact, if the natural factors were the only contributors, there would have been “a slight cooling effect on global climate over the last 50 years,” the report states.
This new report is the second volume of a report on the impacts and causes of climate change on the United States. The report first spells out the already observed effects of climate change: water has been affected by the climate. First, research indicated that the warming planet has meant increasing droughts as the demand for water increases for agriculture and an increasing population. There has also been an increase of floods and hurricanes which has not only hit vulnerable water system infrastructure, but has cost billions of dollars in damage.
The report also pointed to air quality saying “More than 100 million people in the United States live in communities where air pollution exceeds health-based air quality standards.” Increasing wildfires has also meant increased costs of fighting these fires (2017 was the most expensive year starting from 1985). More rain could expand the niche of ticks and mosquitos, thereby affecting public health.
The report also made predictions on the future costs. They separated their predictions into different scenarios where the US takes action to mitigate change and a scenario where carbon continues to rise and less technological innovation is made. For example, the incidence of heavy precipitation (rain, snow and hail) is predicted to increase by “two to three times the historical average in every region” under the less optimistic assumptions. The more optimistic assumptions say that heavy precipitation will only increase anywhere from 50 to 100 percent.
When questioned about the report, President Donald Trump said he didn’t believe the report’s assessments. Though he did not look to anything specifically in the report, he pointed to the country’s water and air saying it was at a “record clean” and tweeted that the US had the cleanest air “by far.” One way to measure air cleanliness is exposure to particulate matter (particles, like dust, in the air). According to the Organization for Economic Co-operation and Development, the US ranked eighth in exposure, good, but not the best “by far.”
Still, many states and towns are taking steps towards cleaner air and water. It is possible to keep temperatures down, but action will have to be taken to ensure emissions are reduced.