Elahi0

Taken together, these challenges have damaged confidence in restoration projects worldwide.And the complexity of rebuilding ecosystems demonstrates how important it is to protect our existing forests.But hopefully, restoring some of these depleted regions will give us the data and conviction necessary to combat climate change on a larger scale.If we get it right, maybe these modern trees will have time to grow into carbon carrying titans.

Additionally, some researchers worry that restoring forests on this scale may have unintended consequences,like producing natural bio-chemicals at a pace that could actually accelerate climate change.And even if we succeed in restoring these areas,future generations would need to protect them from the natural and economic forces that previously depleted them.

And the study can also provide insight into existing restoration projects,like The Bonn Challenge,which aims to restore 350 million hectares of forest by 2030.But this is where it gets complicated.Ecosystems are incredibly complex,and it's unclear whether they're best restored by human intervention.It's possible the right thing to do for certain areas is to simply leave them alone.

Scientists now cite a more conservative but still remarkable figure.By their revised estimates,these restored ecosystems could capture anywhere from 100 to 200 billion tons of carbon,accounting for over one-sixth of humanity carbon emissions.More than half of the potential forest canopy for new restoration efforts can be found in just six countries.

By combining it with climate and soil data and excluding areas necessary for human use,they determined Earth could support nearly one billion hectares of additional forest.That's roughly 1.2 trillion trees.This staggering number surprised the scientific community,prompting additional research.

This means we can just plant trees to draw down carbon;we need to restore depleted ecosystems.There are numerous regions that have been clear cut or developed that are ripe for restoring.In 2019, a study led by Zurich Crowtherlab analyzed satellite imagery of the world existing tree cover.

But even if such a tree existed,it wouldn't be a good long-term solution.Forests are complex networks of living organisms,and there no one species that can thrive in every ecosystem.The most sustainable trees to plant are always native ones;species that already play a role in their local environment.Preliminary research shows that ecosystems with a naturally occurring diversity of trees have less competition for resources and better resist climate change.

So if trees are going to help fight a long-term problem like climate change,they need to survive to sequester their carbon for the longest period possible, while also reproducing quickly.Is there one type of tree we could plant that meets these criteria?Some fast growing, long-lived, super sequestering species we could scatter worldwide?Not that we know of.

During their lifetimes, trees act as carbon vaults,and they continue to draw down carbon for as long as they grow.However, when a tree dies and decays,some of its carbon will be released back into the air.A significant amount of CO2 is stored in the soil,where it can remain for thousands of years.But eventually, that carbon also seeps back into the atmosphere.

This process uses energy from sunlight to convert water and carbon dioxide into oxygen and energy-storing carbohydrates.Plants then consume these carbohydrates in a reverse process called respiration, converting them to energy and releasing carbon back into the atmosphere.In trees, however, a large portion of that carbon isn't released,and instead, is stored as newly formed wood tissue.

To combat climate change,we need to steeply reduce fossil fuel emissions,and draw down excess CO2 to restore our atmosphere balance of greenhouse gases.But what can trees do to help in this fight?And how do they sequester carbon in the first place?Like all plants, trees consume atmospheric carbon through a chemical reaction called photosynthesis.

Standing at almost 84 meters tall,this is the largest known living tree on the planet.Nicknamed General Sherman,this giant sequoia has sequestered roughly 1,400 tons of atmospheric carbon over its estimated 2,500 years on earth.Very few trees can compete with this carbon impact,but today, humanity produces more than 1,400 tons of carbon every minute.

Cotton on the other hand degrades substantially in a matter of months,and paper bags break down completely in just 90 days.So, which bag should you use?It turns out the most environmentally friendly bags have features of several materials we've discussed.They're durable and reusable, like cotton,but made of plastic,which has a lower carbon footprint than cotton or paper.These sturdy shopping bags consist of polyester, vinyl and other tough plastics,and are already used worldwide.Most importantly, they should last a lifetime making them the best option for the planet, and your groceries.

Many countries lack the infrastructure to efficiently recycle plastic bags.Cotton totes are perhaps even more difficult to breakdown and process,but since they're often reused for long periods,they're still least likely to end up in landfills.Whenever these bags aren't recycled,the third factor in calculating environmental impact comes into play:degradability.Since HDPE bags are heat-resistant and insoluble,they stick around long after we're done with them.Partially broken down plastic can circulate in ecosystems for centuries.

Evidence shows paper bags are quickly discarded due to their tendency to tear.This issue plagues HDPE plastic bags as well.But even when they're made to avoid tearing,their widespread availability makes it easy to treat them as single-use items.Fortunately, researchers estimate that 40% of HDPE bags are reused at least once for throwing out waste.Recycling these bags also offsets their carbon footprint,but it's not universally possible for each material.

Reusing or recycling these bags significantly offsets their environmental toll by reducing demand for new production.To quantify that offset, we can divide the bag carbon footprint by the number of times it reused.For example, if a typical paper bag is reused three times,it has a lower net impact than a single-use plastic bag.The carbon footprint of a cotton tote can similarly be lowered,if it reused 131 times.Of these three options, durable cloth totes are most likely to be reused.

Paper is made from wood pulp,and when you account for the carbon cost of removing trees from their ecosystems,a single paper bag can be responsible for about 5.5 kg of carbon dioxide.Meanwhile, growing cotton is an extremely energy and water intensive process.The production of a single cotton tote emits an estimated 272 kg of carbon dioxide.When we compare carbon footprints,plastic bags are the clear winner.But environmental impact is also determined by how the bag is used.

Here, coal powered machines melt the materials down and spin them into sheets of plastic,which are then folded into bags.By the time a bag reaches its final destination,it's contributed an estimated 1.6 kg of carbon dioxide to the atmosphere.That the same amount of carbon a car produces,driving a little over 6 kilometers.But the alternatives actually possess a much larger carbon footprint.

So, to get the full story on these grocery bags we need to look at how they're made,how they're used, and where they ultimately go.Let's start with plastic.The typical thin and flimsy plastic bag is made of high-density polyethylene,commonly known as HDPE.Producing this material requires extracting petroleum from the ground and applying extreme heat.The resulting polymer resin is then transported alongside additional ingredients like titanium oxide and chalk to a bag manufacturing plant.

You're filled up your cart and made it to the front of the grocery line when you're confronted with yet another choice:what kind of bag should you use?If you're seen the images of plastic bags strewn across the ocean,it might seem obvious that plastic is bad for the environment.Surely a paper bag or a cotton tote would be the better option.But is that really true?Each of these three materials has a unique environmental impact that determined by its carbon footprint,its potential to be reused and recycled,and its degradability.