Standing in the smoky ruins of the town of Paradise, Calif., last weekend, President Trump suggested that the cause of the fire lay, to some degree, in the forests surrounding the town being improperly maintained.

“You look at other countries where they do it differently, and it’s a whole different story,” Trump said of the fire which, as of this writing, has claimed 81 lives. “I was with the president of Finland and he said, ‘We have a much different. We’re a forest nation.’ He called it ‘a forest nation.’ And they spend a lot of time on raking and cleaning and doing things, and they don’t have any problem. And when it is, it’s a very small problem. So, I know everybody’s looking at that to that end.”

The president of Finland later told the Associated Press that his conversation with Trump hadn’t included any description of raking out the forests, but by that point the damage was done. Trump’s comment became an international meme, with Finns posted photos of themselves holding rakes in what could only be described as patriotic poses.

At the heart of the comment, though, is a valid point: Underbrush in forests can dry out and help wildfires spread. If Finland (or America) really put our backs into it, what would it take to clear out our forests and reduce the ability of fires to spread?

To determine the answer to that question, we must first answer three others.

  • How much forested area is there in the country?
  • How long does it take to clear underbrush?
  • How many people are available to help?

Let’s go in order.

How much forested area is there in the country?

We can start with Finland.

To President Sauli Niinisto’s point, much of Finland is indeed covered with forest. The World Bank estimates that there are about 55 million acres of forest in the country.

The United States’ national forests cover much more territory. In total, there are more than 188 million acres of national forest in the country, mostly west of the Rocky Mountains.

The Forest Service estimates that, nationally, there are 746 million acres of forest in the country.

If Finland looks a lot more forest-y than the United States in our maps, there are two reasons. The first is that the map of the United States shows only national forests. The second is that the maps use different scales. Here’s Finland roughly scaled to the size of the United States.

For every acre of forest in Finland, then, there are about 13 in the United States.

How long does it take to clear underbrush?

To answer this, we turned to an expert: Erwin Milbourne, owner of the Virginia-based landscaping company the Turf Surgeon.

We first asked Milbourne how long it would take to clear out underbrush from an acre of forest. He suggested that the easiest way to do it would be to use a forestry cutter, a device that attaches to a small vehicle and can be driven through an area to remove brush and debris. The device “chews it up like a blender,” he said.

With one of those, you can clear an acre in about four hours, he said.

There’s just one drawback: The combination of the cutter and the vehicle to push it around costs about $150,000 by Milbourne’s estimate. What we’re assuming here isn’t that we have a ton of money but, instead a ton of manpower. So, we asked, how long would it take people without a forestry cutter to clear an acre?

"Are you kidding?” Milbourne replied. “I wouldn’t want to think about it.”

We made him think about it.

It would be a “nightmare,” he said, but using hand tools, a crew of four people could do it in three or four days.

If the government decided to invest in forestry cutters, the mulch that’s left behind would need to be bagged and removed. Milbourne said that clearing an acre of leaves would take two or three people about four to six hours on average.

Bringing us to our next question.

How many people are available to help?

The population of Finland is about 5.5 million. That of the United States is about 326 million.

But those aren’t really helpful numbers. My son Thomas is a U.S. resident, but, at about 2 years old, I would prefer he not drive a mobile blender through the forest. So let’s instead consider a metric that’s designed to establish how many people in a country can work: The size of the labor force.

In Finland, according to the World Bank, there are about 2.6 million people in the labor force. In the United States, it’s about 163 million.

Adding it all up

Let’s assume, for the sake of argument, that we need to clear out the underbrush only once a year. Here’s how the math breaks down.

Using a forestry cutter. If we have an army of forestry cutters, the work breaks down into two parts. The first pass is running the cutter through the acre of forest; the second is picking up the debris that remains.

If we assume that everyone is working 12-hour days until the work is complete, it would take about seven days for the working population of Finland to drive their forestry cutters through the nation’s forests. This could be staggered, meaning that the country wouldn’t need to buy the requisite 18 million cutter/Bobcat combinations, saving some portion of the $2.7 trillion that would require. (About €2.4 trillion, for our Finnish readers.)

The next part of the job is the cleanup. Depending on how long clearing an acre takes — four hours or six — it would require every Finn to spent 14 to 20 days raking and bagging the debris that’s left behind.

For the United States, the numbers would be different. We’d need 249 million forestry cutters to run a sweep of every acre of forest (price tag: $37.3 trillion), assuming each is used for one day. But we have a lot more people to get it done. That job would take the entire labor force about a day and a half, and the subsequent raking/clearing would take another three to five days.

Doing it by hand. Milbourne’s nightmare scenario is just that.

Let’s define a unit called the man-day, which is one person working for one day on clearing an acre. In the United States, clearing every acre by hand — raking it, if you will — would require about 9 billion man-days (total acreage times four people working for three days). In Finland, the number is smaller: 659 million man-days.

But, again, the United States has more men to work those days. It would take the U.S. labor force 55 12-hour days to clear our forests. The unlucky Finns would need to devote 245 days of the year, which would certainly be fun in the winter.

The logistics problem

We’re skipping over a lot of problems here. For example, most Americans live in cities, not in the forest. There would be a massive logistical operation to coordinate sending people to the proper forests on the proper days, involving massive caravans of trucks or trains shunting people around the country for their allotted days of service. Some portion of the workforce, of course, would end up working in the newly massive forestry-cutter-manufacturing-and-repair sector. The Bobcat corporation would likely soon have a market cap equivalent to the entire Nasdaq.

But the biggest question is what happens to the debris that’s collected. Milbourne told me that clearing an acre of leaves and debris could fill anywhere from 15 to 75 bags. (The time of filling them is incorporated above.) If we’re talking about lawn and garden bags like these from Rite-Aid, that’s an additional cost in Finland of between $494 million and $2.5 billion. In the United States, it’s between $6.7 billion and $33.6 billion. Bag manufacturing would be another new, massive cottage industry.

Where does it go? Uh, good question. The amount of debris collected in Finland would fill between 3.2 billion and 16 billion cubic feet. That latter figure is an amount equivalent to the entire volume of Sydney Harbor.

In the United States, those bags of debris would take up between 43.5 billion and 218 billion square feet. The latter amount is the equivalent of a cube 1.1 miles on each edge, just sitting there somewhere.

Imagine what a fire risk it would be.