I'm Carl Azuz. Happy to see you this Thursday.

New Delhi, the capital of India, is usually near or at the top of the list when it comes to the world's most polluted cities.

But from March 23rd to April 13th of this year, it saw a 60 percent reduction in a certain type of pollution that it saw in the same period last year.

In the capital of South Korea, there was a 54 percent reduction in the pollutant.

Wuhan, China, Sao Paulo, Brazil, Los Angeles, California, all of these cities saw a double-digit improvement in air quality.

And this is all according to one report whose release was timed to coincide with Earth Day yesterday.

It looked at air quality information recorded from government monitoring stations in ten cities.

The cleaner air was a silver lining to the lockdowns of the coronavirus pandemic.

To date, the disease has been contracted by more than 2.5 million people around the world and researchers say almost seven percent of that number have died from COVID-19.

Global efforts to keep people away from each other have forced workers, students, and would be travelers to stay home.

That means there are fewer planes in the air, vehicles on the road, and factories in production.

On the plus side, scientists say social distancing has been effective in slowing down the spread of coronavirus.

On the minus side, millions of people are out of work, and many nation's economies have been badly damaged.

The U.S. government spokeswoman says, "The trends in cleaner air are temporary and that things will go back to the way they were when the coronavirus crisis has passed."

And researchers in the air quality report say keeping factories closed and cars off the road will not be a realistic solution to the world's pollution problems.

But the lockdowns and shutdowns have changed the way cities look and how they pollute.

This is what Chinese cities usually look like this time of year.

Thick smog blanketing the skyline, but this year there's something different in the air: blue skies.

In several Chinese cities, the air pollution has improved, especially Wuhan, the original epicenter of the deadly coronavirus.

The facemasks many Chinese used to wear to filter out polluted air, now worn to protect against the virus.

NASA and the European Space Agency released satellite images from January showing Wuhan's nitrogen dioxide levels.

And the dramatic drop in February after 11 million people there were quarantined.

CO2 emissions for the past four weeks are down by at least 25 percent because of the measures to contain the coronavirus.

For the world's biggest polluter, that could mean a drop of 200 million tons of carbon dioxide.

This is more dramatic than anything else that I've seen in terms of the impact on emissions.

But of course, the, the impact on people's lives and, ah, the economy was equally dramatic.

The Center for Research on Energy and Clean Air says coal consumption at fired power stations saw a 36 percent drop compared to last year.

The research also shows carbon emissions from the aviation industry plunging due to falling demand and widespread travel restrictions.

But Greenpeace says improved environmental conditions may be temporary if China ramps up industrial output to boost the economy.

The political attention of the Chinese leaders will be distracted in the short term, ah, you know, to cut down the, uh, the outbreak of the coronavirus.

And that might distract them from other important social economic issues, including the need to fight climate change.

In neighboring Hong Kong, air quality has also improved as the virus triggered partial shutdown.

There's lots of people who work from home, and that's reduced the traffic volume and reduce the traffic congestion.

There's nothing business as usual about a global epidemic that's claimed thousands of lives.

But in the short term, this public health crisis for humans may actually be helping the environment.

Ivan Watson, CNN.

10 Second Trivia.

Which of these island chains is located the farthest north?

Shetland Islands, Orkney Islands, Canary Islands, or Azores.

These island chains are listed in order from northern most to southernmost with the Shetlands as the answer.

Since we kicked off our partnership with CNN Travel last month, all of the places we've been too, virtually at least, have one thing in common.

They're inhabited.

That's not the case for all of the Shetland Islands though.

There are roughly 100 of them in this cold and windswept part of the Northern United Kingdom, and only about 15 of the islands have full-time residents.

A traveler has unintentionally become one because of the coronavirus crisis.

So he's going to tell you what it's like to be alone on Hildasay.

My name is Christian Lewis.

This is my companion, my friend Jet.

Currently at the moment we are locked down on an island called Hildasay, which is an uninhabited island just off the east coast of Shetland.

Hildasay is less than half a square mile in size, and Chris and Jet got stuck here during the coronavirus lockdown.

Lost on a journey to walk around the entire coastline of the UK, including all its islands.

To get back to the mainland, it's only about half an hour by small boat, but that stretch of sea is not the nicest.

So we really have to pick and choose our days when we get back.

They got help from some locals and were given the keys to the only house on the island.

Yes, the family got wind of the fact that we're staying on the island in a tent and said we'd be more than happy to give you the keys to the house if you want to go in.

I mean, they don't have electric or gas or anything like this. It's just very basic.

A lot of people have been commenting that wish they were on this island.

And it is just secret.

I couldn't be at a better place for a lockdown, let's be honest.

It was not as easy as I really think,

However, that's kind of what I like doing.

Chris gets his water delivered from a local fisherman called Victor, but hunts and forages for food on the island.

I can walk down now in half an hour, and I'll have a whole plate full of mussels if I want.

You know, so, I've got no worries there.

Entertainment though is sparse.

You have to find things to do to keep yourself occupied.

You know, I play marbles.

I always carry a tennis ball and just play catch or anything, you know.

But I also do other things.

I break it up.

I do like a Rocky style training regime where I use rocks to throw around and just, you know, just to get other body parts keeping loose.

By the time Chris was locked down on Hildasay, he'd already been walking the UK coastline for over two and a half years.

To be perfectly honest with you, I suffered really badly with anxiety and depression.

I'm ex-forces, and I've had a lot of help from an organization called SSAFA who are a veteran's charity.

So it really was an absolute no brainer to give back some of the stuff and make it its name, we're really well so far, so yeah, this is perfect.

The more I got into the journey, the more people heard about it.

People have been helping me with food.

They've been helping Jet with food.

It's really lovely to see the kindness that, you know, we're receiving.

I never expected any of this when I started.

I thought I was going to be living off bugs for the next two years.

I got Jet in a place called Irvin as I was coming through, so she didn't start the journey with me.

I started this on my own.

She's been with me for nearly two years now, and I don't think there's a better walk dog out there.

Chris plans to continue their journey once the lockdown is lifted.

But for now, he documents daily life on the small island with Jet.

There's something very spiritual about it, you know, I've learned a lot myself from camping around the UK.

It's very epic in many proportions.

The lockdown with coronavirus, I also see on social media a real change of people making videos with them doing stuff with their families, being creative.

I'm seeing more musicians out there, and we think we can say that this is coming out as a fact that people coming together.

And that's beautiful isn't it. It's just lush.

[10 out of 10]

Among the many things you don't want to see approaching your house, a 30-foot-tall wall of ice.

Of course, it's going to be more likely in places like this lakeside community in Minnesota.

This is an ice shove: it's what happens when ice starts to melt on the lake, and the wind shoves it towards the shoreline where it piles up.

It can damage homes and officials say is all you can do is hope and/or pray that the wind starts blowing in the other direction.

Because while people generally like rock walls, ice sculptures, and water features, it's not going to melt anyone's heart to see Elsa's magic "Frozen" in his backyard.

It may look "cool as ice" but it'd turn up the "heat" on anyone who wants to move to where a lake house doesn't become an "ice house."

I'm Carl Azuz. Valley High School has been commenting on our official YouTube channel.

So shout out to you viewers in Louisville, Kentucky.

Come on back tomorrow because Fridays are awesome on CNN 10.