For the United States, climate change is here, it is now and large-scale efforts must be undertaken in order to stave off the growing threat it poses to the nation's natural and human systems.

Those will be the key takeaways contained in the National Climate Assessment, an in-depth and far-reaching report to be released Tuesday by the National Climate Assessment and Development Advisory Committee (NCADAC), a panel of more than 250 scientists and experts charged by Congress to analyze and present the nation's scientific consensus on the issue.

Gary Yohe, an economist at Wesleyan University and vice-chair of the NCA advisory committee, spoke with the Guardian's Suzanne Goldenberg and described the nation's scientific assessment as "unequivocal" that climate change is occurring in real-time and can be seen or felt in every region of the country.

"One major take-home message is that just about every place in the country has observed that the climate has changed," Yohe told the Guardian. "It is here and happening, and we are not cherrypicking or fearmongering."

Excerpts from the draft report (pdf) make it clear:

"Climate change, once considered an issue for a distant future, has moved firmly into the present."

“Long-term, independent records from weather stations, satellites, ocean buoys, tide gauges, and many other data sources all confirm the fact that our nation, like the rest of the world, is warming, precipitation patterns are changing, sea level is rising, and some types of extreme weather events are increasing.”

"Americans are noticing changes all around them. Summers are longer and hotter, and periods of extreme heat last longer than any living American has ever experienced. Winters are generally shorter and warmer. Rain comes in heavier downpours, though in many regions there are longer dry spells in between."

The report will be officially released Tuesday at a White House ceremony.  Though this will be the third such assessment, it is the first in more than a decade due to the fact that no report was presented during the presidency of George W. Bush.

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