Almost all scientists agree that climate change is being caused by humanity's affect on our world — but the general public isn't quite so convinced. Skeptics often say that even before humans were the reigning species on Earth, the average temperatures on the planet tended to fluctuate between warmer and colder periods. But a pair of new studies basically takes the wind out of that argument, finding solid proof that the climate change we're experiencing now is a direct result of human activity.
The studies, published on Wednesday in Nature and Nature Geoscience, both investigated our current climate and compared it to previous warm periods in the Earth's history. The first study concluded that while certain regions of the Earth have experienced fluctuations in climate before, modern climate change is the first time that the entire planet has warmed — at least in the last 2,000 years.
The second study, meanwhile, assessed the intensity of modern climate change. It found that, even during warm periods in the last 2,000 years, never before has the temperature risen so swiftly as it is now. Since the beginning of the 20th century, global temperatures have risen about two degrees, NBC News explained — and it could rise over five more degrees by the end of this century. That might not seem like a lot, but it's much faster than any other warming event in the last 2,000 years.
The conclusion? "We cannot discern any event that is remotely equivalent" to modern climate change, said Scott St. George, a geographer at the University of Minnesota, in a letter published alongside the two studies.
If there's any hope of reversing the effects of climate change, "it's time for everybody to wake up and make changes now," said Jennifer Hertzberg, a paleoclimatologist not involved in the research. Read more at NBC News. Shivani Ishwar
Much of the U.S., from the Great Plains to the East Coast, was hit with record-breaking cold and snowfall on Tuesday. Thirty percent of the continental U.S. is blanketed in snow, according to National Oceanic and Atmospheric Administration estimates. The "arctic outbreak" was expected to reach the upper Texas coast on Wednesday. "The arctic airmass that has settled into the Plains will continue to spread record cold temperatures south and eastward into the Ohio Valley and down into the southern Plains," according to the National Weather Service. By Wednesday, temperatures in an estimated 300 locations will tie or break cold-weather records. Harold Maass
Pete Buttigieg, the mayor of South Bend, Indiana, is the new frontrunner in Monmouth University's poll of Iowa Democratic presidential caucusgoers. In the poll, released Tuesday, Buttigieg got support from 22 percent of likely caucusgoers, jumping 14 percentage points from Monmouth's last poll in August. Former Vice President Joe Biden lost 7 points, falling to second place with 19 percent support, and Sen. Elizabeth Warren (D-Mass.) lost 2 points, coming in at 18 percent. The only other candidate with double-digit support was Sen. Bernie Sanders (I-Vt.), who gained 5 points to 13 percent support. When first and second choices were combined, Buttigieg led Warren 37 percent to 35 percent.
Buttigieg's support increased across all major demographics. At the same time, only 28 percent of likely caucus goers said they are committed to their candidate, and most said they are open to the possibility of switching contenders. Monmouth conducted the poll Nov. 7-11 among 451 likely Democratic caucus goers; its margin of sampling error is ±4.6 percentage points. Peter Weber