Planting trees is great for the environment — but only if you do it right. Here's how.
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00:00It'd be great if we could think beyond just planting trees and think about ecosystem restoration
00:05so it's not just trees that are doing the job.
00:13So there are certainly places where forests were once extensive and are no longer extensive
00:20and those are great candidates for reforestation.
00:26Actually that's something that we've seen happen a lot on the east coast of the United
00:28States.
00:29So when European colonists arrived in North America they basically cut a bunch of forests
00:36down and started farming and then as colonists moved west and started farming out west instead
00:43we've seen the regeneration of a lot of forests.
00:45But actually I think that there's some easier answers.
00:47I think a lot of us live in cities and in suburban areas and cities and suburban areas
00:54sort of universally would be happier places with more greenery and more parks and more
00:58trees.
00:59So if you want to plant a tree in your backyard that is a no-brainer.
01:09There's a temptation to imagine that if it rains enough to support a forest and if the
01:14environment is appropriate to support a forest that there have historically been forests
01:18there and that turns out not to be the case.
01:21So there's a lot of climate spaces where forests are possible but where historically
01:30some other ecosystem dominated.
01:31So in the United States the good example of that is the sort of northern American Midwest.
01:36So regions in Minnesota, Wisconsin, Michigan, Illinois historically had a climate that was
01:44appropriate for supporting forests but actually were dominated by much more open ecosystems
01:50and actually those are systems where we've seen big forest expansion.
01:53So what was there before were extremely biodiverse grasslands, so prairie grasslands, that are
01:59now extremely threatened.
02:00And then what's really interesting is that there's a lot of carbon below ground as well.
02:03And so the carbon sequestration potential of native prairie can actually be very high
02:09as well and it can actually start to approach the carbon sequestration potential of trees.
02:19In some places that planting trees can result in adverse consequences, sort of adverse and
02:27unforeseen consequences.
02:28Essentially what you're doing when you plant trees is create a bunch of shade that shades
02:32out the grass that is sort of the linchpin of any open grass ecosystem.
02:39A couple of years ago there were fires in Portugal and that really burned into suburban
02:49and urban areas and really were a threat to lives and livelihoods.
02:52And they were really catastrophic fires in Portugal.
02:56And most of those fires were burning through plantation forests.
02:59So those were burning through trees that had been planted in an ecosystem that historically
03:03is very fire prone.
03:04And so another thing to consider is whether you live in a place that historically has
03:07had a lot of fires and might tend to become increasingly fire prone under global change
03:12scenarios.
03:13In the United States context, I think probably just from watching the news, you'll be aware
03:18that California, Oregon, Washington tend to be fairly fire prone.
03:23There's also been some catastrophic wildfires in Texas.
03:32So what type of tree you choose is important.
03:35That tree is likely to do better and it's likely to yield more benefits if the tree
03:39species that you choose is something local.
03:42So if you select something that comes from the place where you live, that's going to
03:46have a number of benefits beyond just carbon sequestration.
03:58There's a huge amount of appeal to planting a tree, right?
04:00Because you plant a tree in your backyard and then you don't have to change a lot about
04:03your lifestyle.
04:04And I think that the harder truth here is that doing something about global change is
04:10going to require us all to make changes to lifestyle that are more profound than that.
04:14It is not a solution by itself.
04:17And it's probably not even the primary solution.
04:20If that's all we do, even if we can do it as perfectly, if we can plant a trillion trees,
04:26it's just not going to solve the problem in the way that has been promised.