JOHN YANG: The rise of artificial intelligence is requiring faster and bigger computations for even simple tests.

Then for say a Google search.

It's adding to the demand for more internet data centers, the places that house all those servers that keep the internet running.

But as Ali Rogin reports, there's a price to pay for that.

ALI ROGIN: Demand for data centers is growing rapidly.

But these facilities come at a big environmental cost, especially for the communities that host them.

Northern Virginia is the largest data center hub in the world.

The area is responsible for processing nearly 70 percent of global digital traffic.

It's a rate that local officials say is unsustainable.

Sachi Kitajima Mulkey is a science journalist and writer for the climate focus news outlet Grist.

Sachi, thank you so much for joining us.

First of all, tell us a little bit more about what a data center is.

And why do we need so many of them?

SACHI KITAJIMA MULKEY, Grist: Whenever we use the internet, upload photos to the cloud, send emails, watch a video, all of that data and digital information needs a home and it lives in these huge facilities called data centers, which hold tens of thousands of servers each and they process all that digital information for us.

Something like 70 percent of the world's digital information is processed by a cluster of data centers in Virginia alone.

And there are over 5,000 facilities in the US.

ALI ROGIN: What are the environmental impacts of having some of these data centers in your backyard?

SACHI KITAJIMA MULKEY: So to process all that information, they need two things.

The first is electricity, of course, to physically crunch and process all that gigabyte going on.

The other is water, which are used in cooling systems to protect these servers from physically overheating.

And researchers think they're in the top 10 water consuming industries in the U.S. they use 2 percent of the electricity in the U.S., which is a lot.

And a source told me that data center campuses can use the resources equivalent to a small city and as AI booms they'll use even more.

The average AI application uses six times the amount of electricity so they run a lot hotter and that is scales exponentially they just need more water to cool down.

ALI ROGIN: And how do these data centers in the United States and around the world affect global efforts to decarbonize?

SACHI KITAJIMA MULKEY: It's tricky, because right now we are building out green energy solutions at a great scale, it's happening really fast, but it might not be happening fast enough.

Currently, a lot of the grid is still running on fossil fuels, and even plans in Virginia to shut down, you know, coal firing plants may not go through, because these data centers need so much energy that grid operators need to fire those coal plants backup or just keep them running in order to meet all that demand.

So in one of the talking points of these data center reform coalition's I've spoken to is that that's a step backwards from clean energy goals, and kind of almost a betrayal of some of the promises certain states have made to, you know, get off of carbon.

ALI ROGIN: And many of these data centers are located in densely populated residential areas.

What's it like to live near one?

SACHI KITAJIMA MULKEY: Yeah, you know, they're being built near schools and neighborhoods protected nature parks in Virginia, in particular.

And one big impact is that they're really loud, they hum and they bring all this noise pollution to the area.

All that concrete also means a huge increase in stormwater runoff, because that rain can no longer soak into the ground at all has to go somewhere.

And so the amount of electricity also could be more than the grid may be able to handle.

So when there's an outage, there's kind of a question of who gets the power of residents or data centers.

ALI ROGIN: We're talking to you now via Skype, we're using a lot of data to do it.

As we increasingly rely on this type of cloud computing, to do so many things we use apps we use, we do virtual meetings, that kind of thing.

Is there any way that these data centers can continue to expand, continue to grow and support all this usage, but do so in a more environmentally friendly way?

SACHI KITAJIMA MULKEY: You know, it is possible to build cooling systems that use less water, but we don't really see those built out at scale yet.

And you could power them with green energy.

But again, right now we have a grid that's kind of stuck on fossil fuels, and we're slowly making the transition to green energy, but maybe not fast enough to meet all this demand.

First, before we can really know what we need to do next, we just need more transparency from the industry, which scientists and activists both told me is pretty secretive.

Google is saying it's a leader in sustainable data centers.

And they only began releasing their water usage data a couple of years ago, after a lawsuit.

ALI ROGIN: And to that transparency point, I want to play for you a soundbite from an environmental activist in Northern Virginia, as we've said, where so many of these data centers are located.

JULIE BOLTHOUSE, Piedmont Environmental Council: One of the big things that concerns me is that some of these data center companies are claiming to be holding federal or Department of Defense servers, and therefore their critical infrastructure and cannot be allowed to go down.

And so there's this this question of who gets the water in a trout situation?

And are they going to leverage that kind of argument of national security to potentially say they get the water first?

ALI ROGIN: Are there any safeguards that exist to make sure that these companies are being honest about the types of companies that they're supporting with their servers and what the effect on the environment is?

SACHI KITAJIMA MULKEY: We're kind of trusting companies to be transparent and do the right thing.

There are a lot of companies like to tout sustainability goals.

But truthfully, we're trying to get lost there in Virginia right now, a couple of bills were introduced in Virginia and in other states, but they're not getting a lot of traction until we have that research we need.

And so right now, Virginia is conducting a data center impact study.

And the results of that will come out later this year, hopefully.

I mean, we're just seeing a lot of action.

In Virginia in particular, the Piedmont Environmental Council is a group that has this coalition called the Data Center Reform Coalition.

And they just started this year really digging in organizing their community together with hundreds of individuals and nonprofits on board.

And they're working directly with lawmakers too to see what they can do, and how they can, you know, keep this industry a little bit more accountable.

They also are taking action through the Freedom of Information Act requests, to see what other kinds of information they can learn about these data centers even before the transparency is coming from the companies themselves.

ALI ROGIN: Science journalist Sachi Kitajima Mulkey, thank you so much for joining us.

SACHI KITAJIMA MULKEY: Great.

Thank you so much for having me.