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There is an increasing alarm about the extent of microplastics pollution,which has been found everywhere from Everest to the Arctic.However,it turns out there's an even smaller and more poisonous form of plastic pollution entering remote reaches of the globe.A new study published in Environmental Research found significant quantities of nanoplastic(纳米塑料)in ice samples from both the North and South Poles.

"Now we know that nanoplastic are transported to these corners of the Earth in these quantities.This indicates that nanoplastic are really a bigger pollution problem than we thought,"study lead author Dusan Materic said in a press release.

Nanoplastic are plastics that are smaller than a micrometer in size.Their small size means they are more difficult to study than microplastics,or plastics between five millimeters and a micrometer.But they may be even more dangerous.

"Nanoplastic are very toxicological active compared to,for instance,microplastics,and that's why this is very important,"Materic said.

Materic and his team used new methods to measure nanoplastic pollution in ice samples from Greenland and Antarctica.They sampled a 14-meter-deep ice core from the Greenland ice cap and sea ice from Antarctica's McMurdo Sound.They found that there were an average of 13.2 nanograms per-milliliter of nanoplastic in the Greenland ice and an average of 52.3 nanograms per milliliter in the Antarctic ice

But what was even more surprising than the amount of nanoplastic in the remote ice was just how long they had sat there."In the Greenland core,we see nanoplastic pollution happening all the way from the 1960s.So organisms,despite the lack of the solid evidence,likely all over the world,have been exposed to it for quite some time now,"Materic said.

The study also looked at the types of plastic present in the samples.Half of the Greenland nanoplastics were polyethylene(PE),the kind of plastic used for plastic bags and packaging.A quarter came from tires and a fifth were polyethylene terephthalate (PET),which is used for clothing and bottles.

High on the top of California's White Mountains, the hard conditions make it difficult for life to take root. But for a certain type of tree—and for those who have travelled here to study it—this place is a perfect place.

These bristlecone pines are the oldest individual trees in the world. Researchers like Andy Bunn have come to learn from the ancients. "It's remarkable to sit here and have your hand on one of these trees and know that it was growing when the Pyramids were built. " Bunn added.

"By studying samples (样本) from the trunks, it's possible to discover their hidden history. Each annual tree ring is like a time capsule of the environment for that year from which it was formed，" said Matt Salzer, a scientist at the University of Arizona's Laboratory of Tree Ring Research. "And it contains many different types of information—chemical information, the information on growth, and climate information. "

"If you're trying to look at people in the past through time, tree rings give you a way to do it in a way that makes sense in a human life，" said University of Arizona Professor Charlotte Pearson. She first became fascinated with the bristlecones after reading about an ancient volcanic eruption on the Greek island of Santorini. "It blew my mind that trees on the other side of the world could possibly be used to date this thing within a single year," she said excitedly.

The oldest known living bristlecone is estimated to be over 4，800 years old. For Bunn, the climate record written in the rings offers guidance for how we might think about what's happening in the present as we plan for the future. "What we're seeing increasingly is that a lot of the climate events that we are experiencing and living through right now have no example in the paleoclimate (古气候) record," he said. "So, we really are moving into unknown field."

Swot satellite is scheduled to be launched Thursday morning to conduct a comprehensive survey of Earth's vital resource. By using advanced microwave radar technology it will collect height-surface measurements of oceans, lakes and rivers in high-definition detail over 90% of the globe. It's rally the first time to observe nearly all water on the planet's surface.

The major mission is to explore how oceans absorb atmospheric heat and carbon dioxide in a natural process that adjusts climate change. Oceans are estimated to have absorbed more than 90%, of the extra heat trapped in the Earth's atmosphere by human-caused greenhouse gases. Swot will scan, the seas and precisely measure fine differences in surface elevations (高度) around smaller currents and eddies (漩涡), where much of the oceans' decrease of heat and carbon is believed to occur. "Studying the mechanism will help climate scientists answer a key question: What is the turning point at which oceans start releasing, rather than absorbing, huge amounts of heat back into the atmosphere and speed up global warming, rather than limiting it," said NadyaShiffer, Swot's program scientist.

By comparison, earlier studies of water bodies relied on data of rivers or oceans taken at specific, points, or from satellites that can only track measurements along a one-dimensional line, requiring scientists to fill in data gaps through extrapolation (外推法). Thanks to the radar instrument, Swot can scan through cloud cover and darkness over wide ranges of the Earth. This enables scientists to accurately map their observations in two dimensions regardless of weather or time of day and to cover large geographic areas far more quickly than was previously possible.

"Rather than giving us a line of elevations, it's giving us a map of elevations, and that's just a total game changer," said Tamlin Pavelsky, Swot freshwater science leader.