Megan Hall: Welcome to Possibly, where we take on huge problems like the future of our planet and break them down into small questions with unexpected answers. I’m Megan Hall. 

This episode, we’re taking a look at raking. I have two huge trees in my yard and they dump a lot of leaves. Sometimes I wonder, what would happen if I just let those piles of leaves stay on the ground? We had Charlie Adams and Ashley Junger from our Possibly Team look into this. Welcome, Charlie and Ashley! 

Charlie Adams: Hi, Megan! 

Ashley Junger: Hey, Megan!

Megan Hall: So, in most people’s minds, Fall = leaf raking time. But is that true? Can we all spare ourselves the trouble?

Charlie Adams: Well, most people rake their leaves thinking it will help the grass grow and prevent plant diseases in leaf litter. But really, science paints a different picture.

Megan: Really? Raking is BAD for my lawn? 

Charlie Adams: Well, leaving the leaves where they are might make it better. Experts have been praising leaves for their fertilizing abilities for hundreds of years. 

Megan: What makes leaves a good fertilizer?

Ashley Junger: As leaves decompose, they release things like nitrogen, phosphorus, and other nutrients that help plants grow. 

Charlie Adams: Around 90% of the nutrients taken up by a forest each year are recycled from fallen leaves.

Megan: Are there other benefits to giving my rake a rest?

Charlie Adams: Quite a few! To learn more about them I spoke with Dr. Desiree Narango, a Biodiversity Ecologist at UMass Amherst. She says…

Desiree Narango: “Leaf litter is incredibly important for supporting habitat for insects like pollinators and for birds” 

Ashley Junger: Desiree says lots of bumble bees, butterflies, predatory beetles, and even tropical birds rely on leaves for their habitats.

Desiree Narango: “When you rake your lawn, you’re taking away all of these important habitats and nutrients and you’re completely removing it from the system….which might not be a big deal for a single yard. But we think about an entire suburban neighborhood or an entire city. That’s a lot of habitat that’s missing in an area.” nb 

Charlie Adams: In fact, lawns are basically biological deserts. Letting your leaves stay in fall and winter makes them a little more friendly to all sorts of critters.

Megan: If all of this is true, why would anyone rake their leaves? There has to be some reason all of this got started?

Ashley Junger: Well, a lot of people value having a “perfect” green lawn over a healthy green space. Raking makes our lawns look neater, but that means they miss out on all of the amazing benefits of leaf litter.

Megan: You’re convincing me to retire my rake, but my trees drop a lot of leaves. I’m worried that those thick piles will create issues for my lawn.

Charlie Adams: It is true that if you have a lot of large trees, those leaves can build up and potentially lead to mold and larger insect populations. But in most cases, those piles will decompose on their own and the insects help this process along!

Ashley Junger: The bottom line? The best way for us to maintain our lawns in the fall could be to put down our rakes, turn off our noisy leaf blowers, and leave the leaves where they are. 

Charlie Adams: As Desiree likes to say- you can do a lot of really great things for the environment by just being lazy. 

Megan: Great! Thanks, Charlie and Ashley! 

That’s it for today. For more information, or to ask a question about the way your choices affect our planet, go to the public’s radio dot org slash possibly. Or subscribe to us wherever you get your podcasts. 

You can also follow us on Facebook and Twitter- at “ask possibly” 

Possibly is a co-production of the Institute at Brown for Environment and Society, Brown’s Climate Solutions Initiative, and the Public’s Radio.

The post Do I need to rake my lawn? appeared first on TPR: The Public's Radio.

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Megan Hall: Welcome to Possibly, where we take on huge problems like the future of our planet and break them down into small questions with unexpected answers. I’m Megan Hall. 

Today we’re answering a question from listener Molly Magid:

Molly Magid: So I thought of this question because last year, there was a lot of buzz about the flights of SpaceX and Virgin Galactic, bringing people who are not astronauts into space and sort of sparking this discussion of what commercial space travel might look like. So I’m wondering, what are the environmental impacts of space travel and how does it compare to say, taking a plane flight

We had Charlie Adams and Ashley Junger from our Possibly Team look into this.

Megan Hall: Welcome Charlie and Ashley!

Charlie Adams: Hi, Megan!

Ashley Junger: Hey, Megan!

Megan Hall: The thought of traveling to space for ordinary (non-billionaire) people like me seems like something that’s pretty far into the future. Do I really need to worry about this? 

Charlie Adams: Yeah, not many of us can afford the $500,000 it costs to travel to space, but it does look like the industry is growing. Experts estimate that the commercial space travel industry could generate as much as a billion dollars in revenue by 2040.

Ashley Junger: So, it’s possible that more and more people will start going to space. 

Megan Hall: Got it. So what are the environmental impacts of space travel?

Charlie Adams: Rockets burn kerosene or natural gas, which means they emit carbon dioxide when they blast into space. 

Megan Hall: But how do rocket flights compare to plane rides when it comes to carbon emissions?

Ashley Junger: It depends on the aircraft, but a single SpaceX flight emits about as much carbon dioxide as two round trips flights between New York and South Africa.  

Megan Hall: Really? That’s actually not as bad as I thought it would be. 

Charlie Adams: Well, there’s more to this question.

Ashley Junger: It’s not just about what these space crafts are emitting, it’s about where those emissions happen.

Charlie Adams: When you fly into space, you’re going higher than most planes, into what’s known as the stratosphere. 

Ashley Junger: And the particles and gasses that come out of a rocket behave differently up there than in the lower parts of the atmosphere. 

Megan Hall: Differently good or differently bad? 

Charlie Adams: Well, it’s complicated. 

Ashley Junger: The truth is, we are only just learning about how those elements act when they’re more than six miles above the planet.

Charlie Adams: Some, like soot, or black carbon, are thousands of times more effective than CO2 at heating the upper atmosphere.

Ashely: And black carbon released in the stratosphere can linger for up to ten years, so it can have a long-lasting impact.  

Charlie Adams: But other substances come out of rocket boosters too, like aluminum which reacts with the atmosphere to form particles that reflect sunlight. This can actually cool the atmosphere.

Megan Hall: Wait, the stuff that comes out of rockets might cool the planet? 

Ashley Junger: Well, anything that blocks sunlight would likely cool things down, just like things that absorb sunlight will warm things up. But the exact effects are hard to predict.

Charlie Adams: So while we don’t know all the effects of space tourism on the atmosphere, it does seem pretty frivolous to burn all that fuel for a billionaire joy ride. On the other hand, those same people fly around in private 747s, which isn’t helping much either

Thanks, Charlie and Ashley!

That’s it for today. For more information, or to ask a question about the way your choices affect our planet, go to the public’s radio dot org slash possibly. Or subscribe to us wherever you get your podcasts. 

You can also follow us on Facebook and Twitter- at “ask possibly” 

Possibly is a co-production of the Institute at Brown for Environment and Society, Brown’s Climate Solutions Initiative, and The Public’s Radio.

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Megan Hall: Welcome to Possibly, where we take on huge problems like the future of our planet and break them down into small questions with unexpected answers. I’m Megan Hall. 

We cover a lot of heavy topics on this show, but today we’re bringing you a bright spot- a real success story. 

Bald Eagles almost disappeared about 50 years ago, but now they’re flourishing! We had Charlie Adams and Ashley Junger from our Possibly Team look into how this happened.

Megan Hall: Welcome Charlie and Ashley!

Charlie Adams: Hi, Megan!

Ashley Junger: Hey, Megan!

Megan Hall: So, what’s up with bald eagles? I see them around every once in a while, but I hear they used to be really rare. 

Charlie Adams: That’s right – bald eagles were endangered. But they’re back now! 

Megan Hall: Why were they endangered in the first place?

Ashley Junger: If you want to go WAY back, clear-cutting habitats and human activity have disturbed bald eagle populations since European settlers first arrived in North America. But the biggest blow to their numbers came in the 1940s.

Charlie Adams: That’s when the insecticide DDT was invented. It was seen as a miracle chemical that did everything from combating malaria to protecting crops from insects.

Ashley Junger: People started using it for everything. They’d even spray it in the streets of neighborhoods.

Charlie Adams: And this powerful insecticide quickly made its way into ecosystems across the US.

Megan Hall: What does DDT have to do with eagles?

Ashley Junger: The chemical gets more and more concentrated with each step up the food chain. So, Bald-eagles, along with other predators, ended up with big doses of DDT.

Charlie – and DDT causes bird eggs to get really thin, which makes them more vulnerable. This caused eggs to break before eagles had a chance to hatch. 

Ashley Junger: It got to the point where there were only a few hundred bald eagles in the entire country. 

Megan Hall: So, what brought these birds back?

Charlie Adams: Banning DDT. It became illegal in 1972, not long after Rachel Carson wrote about it in her influential book- Silent Spring.

Ashley Junger: Getting rid of DDT in the US made a huge difference. By 2007, bald eagles were taken off the national endangered species list. And last year, there were more than 300 thousand bald eagles in the lower 48 states.

Megan Hall: Wow, up from only about a hundred?

Charlie Adams: Yes. It’s a big victory.

Ashley Junger: But, in some places, this wasn’t enough. 

Charlie Adams: Vermont has struggled to rebuild its bald eagle population. Last year, It was the only state in the country to have them on its endangered species list. 

Megan Hall: What did they do to try to bring their bald eagles back?

Ashley Junger: Initially, they were hoping bald eagles would migrate to Vermont from nearby states with successful repopulation programs. But they didn’t. 

Charlie Adams: So eventually, they tried a new approach. About 15 years ago, they gathered up baby bald eagles from other states and raised them until they were ready to be released into the wild.

Megan Hall: Did that work?

Ashley Junger: Yes! Since the program started, the state has gone from zero to a record 68 bald eagles in 2019!

Charlie Adams: And earlier this year, Vermont was able to officially take bald eagles off their state endangered species list! 

Megan Hall: That’s incredible!

Ashley Junger: The recovery of the bald eagle is a massive success story.

Charlie Adams: It offers a great example of how, with the right policies and regulations, we can solve tough problems.

Megan Hall: Got it! Thanks, Charlie and Ashley! 

That’s it for today. For more information, or to ask a question about the way your choices affect our planet, go to the public’s radio dot org slash possibly. Or subscribe to us wherever you get your podcasts. 

You can also follow us on Facebook and Twitter. 

Possibly is a co-production of the Institute at Brown for Environment and Society, Brown’s Climate Solutions Initiative, and the Public’s Radio.

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