WASHINGTON, May 6 (Xinhua) -- The White House unveiled a comprehensive climate change report Tuesday, saying that " disruptive" impacts related to rising temperatures are already being felt in every corner of the United State.
"Climate change is already affecting the American people in far- reaching ways,... disrupting people's lives and damaging some sectors of our economy," concluded the report entitled the National Climate Assessment, which called for "urgent action" to combat the threats climate change presents.
The report, the third of the kind and compiled by hundreds of top U.S. climate scientists and technical experts in more than four years, stated that the global warming "is primarily due to human activities, predominantly the burning of fossil fuels."
It found that the U.S. average temperature has increased by 1.3 to 1.9 degrees Fahrenheit (0.7 to 1.1 degrees Celsius) since record keeping began in 1895, and that most of this increase has occurred since the 1970s. And unless efforts are taken to cut emissions, temperatures are projected to increase by a further 2 degrees Fahrenheit (1.1 degrees Celsius) over the coming decades.
Meanwhile, extreme weather events influenced by climate change, including heat waves in the West and severe droughts in the Southwest, are projected to become more intense, the report found.
Heavy downpours are also increasing nationally, especially over the last three to five decades, with largest increases occurring in the Midwest and Northeast.
The intensity, frequency, and duration of Atlantic hurricanes, as well as the frequency of the strongest hurricanes, have all increased since the early 1980s, but the relative contributions of human and natural causes to these increases are still uncertain, it said.
Winter storms have increased in frequency and intensity since the 1950s, and their tracks have shifted northward over the United States, said the report.
Also, warming is causing sea level to rise and glaciers and Arctic sea ice to melt, and oceans are becoming more acidic as they absorb carbon dioxide. "The third National Climate Assessment represents the most authoritative and comprehensive knowledge base about how climate change is affecting America now, and what's likely to come over the next century," the White House said in a background statement.
It also identified the report as a key deliverable of the Climate Action Plan launched by President Barack Obama last June, which included a series of executive actions to reduce carbon emissions in order to address climate change without legislation from Congress.