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The Trump administration put new restrictions this week on government scientists' freedom to communicate. Administration officials say those restrictions are temporary. In fact, some have already been lifted. Scientists are still on edge, though, because the federal government generates a huge amount of climate data. Here's NPR's Christopher Joyce with what's at stake.
CHRISTOPHER JOYCE, BYLINE: Data is the brick and mortar of science. With good data, you can say things like this.
DEREK ARNDT: 2016 was the warmest year on record, beating 2015 by a few hundredths of a degree. And together, those two years really blow away the rest of our record.
JOYCE: Derek Arndt is a climate scientist at the National Oceanic and Atmospheric Administration. He knows how warm it was because NOAA operates 17 satellites that, among other things, take the planet's temperature along with myriad instruments that do the same on land and in the oceans.
When you add NASA's satellites and instruments and scientists and those at other agencies, you get the country's biggest source of climate data by far. And researchers like Greg Asner say it's the main way we know what's going on with the climate. Asner studies forests at Stanford University.
GREG ASNER: Without it, we will go blind. It's like turning off the lights. We're not going to know what's happening at the Earth scale.
JOYCE: It doesn't stop with just collecting data. Government scientists analyze it and eventually release it to the public in reports like the National Climate Assessment. There have been three of those so far. A fourth is due out next year. The assessments are required by law. Scientists from several federal agencies write them. They summarize the latest consensus on climate science. Ocean scientist William Sweet at NOAA is writing a section on sea level rise.
WILLIAM SWEET: Sea level rise is already happening, and the impacts can be felt.
JOYCE: But those impacts are not the same everywhere.
SWEET: The ocean is not a bathtub. It may rise in one place. It may drop in the other.
JOYCE: Ocean currents, wind patterns, even sinking or rising land determine who's going to get wet and when. Research prepared for the latest assessment says the East Coast and parts of the Gulf Coast, for example, will experience even higher sea levels than the world average. And that world average - it could be eight feet higher than it is now by the end of the century. That's the worst-case scenario. It probably will be less. A lot depends on how much more carbon dioxide we put into the atmosphere.
Sweet says in the short term, the assessment provides news you can use. For example, there has been an uptick in abnormally high tides, tides that cause so-called sunny day flooding even when there's no storm.
SWEET: At what point do these damaging, disruptive tidal flood events become the new norm?
JOYCE: Sweet says the latest Climate Assessment will answer that question so that coastal towns and cities can prepare, deploy pumps, buy sandbags or even build seawalls. That's just a small part of the assessments. They also cover everything from drought to extreme rainfall.
So what happens if the Trump administration tries to censor this huge scientific enterprise? Peter deMenocal is dean of science at Columbia University. He says there just isn't any substitute for what federal climate scientists produce.
PETER DEMENOCAL: The United States I think has the best organized and some of the top talent in climate science and engineering in the world. You know, the concern is that that brain trust, that amazing compendium of knowledge that we have right now is going to disappear because it's really hard-earned.
JOYCE: Knowledge that informs not just research but weather forecasting, farming, public safety, the insurance industry, air travel, in fact just about everything we do. Christopher Joyce, NPR News.
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