Climate Change / Global Warming Discussion

[mspohr]

Deforestation and Its Effect on the Planet

Human-driven and natural loss of trees—deforestation—affects wildlife, ecosystems, weather patterns, and even the climate.

Since humans started cutting down forests, 46 percent of trees have been felled, according to a 2015 study in the journal Nature. About 17 percent of the Amazonian rainforest has been destroyed over the past 50 years, and losses recently have been on the rise.

We need trees for a variety of reasons, not least of which is that they absorb not only the carbon dioxide that we exhale, but also the heat-trapping greenhouse gases that human activities emit. As those gases enter the atmosphere, global warming increases, a trend scientists now prefer to call climate change. Tropical tree cover alone can provide 23 percent of the climate mitigation needed over the next decade to meet goals set in the Paris Agreement in 2015, according to one estimate.

In terms of climate change, cutting trees both adds carbon dioxide to the air and removes the ability to absorb existing carbon dioxide. If tropical deforestation were a country, according to the World Resources Institute, it would rank third in carbon dioxide-equivalent emissions, behind China and the U.S.

 

[jerry33]

Wow, the AGW believers

It's not belief, it's the acceptance of data and conclusions that have been known since the 1890s.
Agreed that good is not the enemy of perfect. So EVs are good, reforestation is good, kelp for cattle is good. Perfect would be a 50% reduction in human occupied areas and a similar decrease in population along with the reforestation of the exited areas. Only Japan is going that route, and it's a coincidence, not a plan.

 

[SageBrush]

Wow, the AGW believers

I'm thinking of making a business card for myself:

Acolyte of Science

 

[mspohr]

One climate crisis disaster happening every week, UN warns

One climate crisis disaster happening every week, UN warns

Catastrophies such as cyclones Idai and Kenneth in Mozambique and the drought afflicting India make headlines around the world. But large numbers of “lower impact events” that are causing death, displacement and suffering are occurring much faster than predicted, said Mami Mizutori, the UN secretary-general’s special representative on disaster risk reduction. “This is not about the future, this is about today.”

This means that adapting to the climate crisis could no longer be seen as a long-term problem, but one that needed investment now, she said. “People need to talk more about adaptation and resilience.”

Mizutori said the time for such arguments had ran out. “We talk about a climate emergency and a climate crisis, but if we cannot confront this [issue of adapting to the effects] we will not survive,” she told the Guardian. “We need to look at the risks of not investing in resilience.”

 

[mspohr]

Finally, a zombie climate apocalypse film

Jim Jarmusch: ‘I’m for the survival of beauty. I’m for the mystery of life’

Jim Jarmusch: ‘I’m for the survival of beauty. I’m for the mystery of life’

It’s clear we’re living in an ecological crisis and the situation is getting worse and worse. We’re threatened by the denial of science and by corporate greed. If this is the path that we keep going down, then it is only going to lead to the end of the world.”

If the apocalypse is pending, The Dead Don’t Die shows the way it might go, with polar fracking warping the planet’s axis, Trump-supporting racists spinning on their bar-stools, and an army of zombies shuffling up main street.

He sighs. “The tone is different from what I anticipated. It’s a whole lot darker than I imagined, especially the ending.

 

[EinSV]

It seems that you are worried that people might plant trees and forget about the threat of fossil fuels so you are trying to argue that planting trees is useless when we have a rigorous scientific study that says otherwise. <snip>

That's not my position at all, as my earlier posts made clear:

So let's replant and protect forests AND rapidly replace fossil fuels with cheap carbon-free renewables, "electrify everything" in transportation, etc.

Yes we should plant trees and protect forests, but that will not, by itself, come anywhere near solving the problem.

 

[mspohr]

??? Where did it claim that? It said 0.9B Hectares of additional forest could 'store' 205B tons of carbon. If we wanted to restore atmospheric CO2 to <300ppm we'd need to stop adding CO2 and remove >700B tons.

It took me a while to find that reference in the report. The authors say that the 205 B tons of CO2 which would be absorbed and stored by new trees would be two thirds of all the CO2 produced by human activities... leading to the statement that it would take us back to about the 1930s in terms of CO2 air concentration. (This would seem to imply a total man made excess CO2 load of about 300 B tons which is different than your assertion of 700 B tons... do you have a reference?)
Note that these are new forests to replace the 50% of original forest coverage before man started cutting them down, burning, etc. and would be done without impinging on agricultural land, etc.

Here's the quote:
"If we act now, this could cut carbon dioxide in the atmosphere by up to 25%, to levels last seen almost a century ago," Tom Crowther, a senior author of the study, said in a press release.

The global tree restoration potential

More here:
Planting trees could make a huge dent in our growing climate crisis. But we'd need to cover an area the size of the US, starting right now.

One thing that's important to understand is that the added trees would absorb and store the CO2 on land that previously has little or no CO2 storage. Yes, trees do die and decompose but they would be replaced by new growth so the added storage amount is permanent, reaching a steady state about 2050 if we had a concerted effort to plant all of these trees.

Interesting anecdote:
There are skeptics quoted in the Guardian who say that these calculations are not accurate, and of course we are actually losing forest to grazing and monoculture farming. But we have seen the effects of massive reforestation before; Oliver Milman writes in the Guardian that after 1492, when 90 percent of the Native American population died,
This “large-scale depopulation” resulted in vast tracts of agricultural land being left untended, researchers say, allowing the land to become overgrown with trees and other new vegetation. The regrowth soaked up enough carbon dioxide from the atmosphere to actually cool the planet, with the average temperature dropping by 0.15C in the late 1500s and early 1600.
Planting trees could be a "mind-blowing" solution to climate change

 

[nwdiver]

Yes, trees do die and decompose but they would be replaced by new growth so the added storage amount is permanent,

No; That's not how that works. If a tree dies and decomposes most of the carbon that is locked away is released. The process that formed most of the coal we have today no longer exists due to the evolution of microbes able to digest cellulose and lignin. Even faster if it burns which is NEEDED for a healthy forest. Which highlights the fact that a working forest is more effective for carbon sequestration than a natural one. Most harvested timber won't decompose or burn. It's a more effective method for sequestering carbon.

My 700B ton figure was CO2 not carbon. The IPCC estimates that since the beginning of the industrial revolution we've emitted 470 - 640B tons of carbon. Which would equal 1700 - 2300B tons of CO2.

Even the study points out that many areas they considered viable for re-forestation are unlikely to be viable by 2050 if the current trend continues. What happens to a forest in an area that the climate can no longer support a forest? I burns are releases all the CO2 it had trapped. We need to get better at managing the forests we have before we go looking to create more.

Wow, the AGW believers seem to be adopting some of the same attitudes as the deniers. By that I mean "I am locked into my opinion and I'm not changing for anyone." "Planting trees will save us." "Planting tree is meaningless." How about, we should do everything that helps.

I'm just looking at the numbers. 1 acre of trees is roughly the equivalent to 15 solar panels (~5kW). How would you describe that? After you take into account the odds that acre will burn and re-release most of the CO2 contrasted to the odds that those 15 solar panels will keep chugging along for >30 years I describe planting trees as a method to tackle climate change as 'meaningless'.

What percentage of CO2 sequestered by a tree stays locked away for >50 years. Is it even 20%? Forests burn. That's what they do. Not only can this not be prevented.... but it SHOULDN'T be prevented. Not only should it NOT be prevented... but if it doesn't occur in ~30 years it should be INITIATED to keep the forest healthy. There's a reason it's called the carbon CYCLE. Trees are part of it. Solar Panels and Wind Turbines are not.

We went outside the carbon cycle and added carbon to the biosphere. We need a solution that is also not a part of the carbon cycle to fix the damage.

 

[SageBrush]

^^ Do you see any problem with burning down the Amazon rain forest ?

 

[nwdiver]

^^ Do you see any problem with burning down the Amazon rain forest ?

The study was specific in referring to temperate forests not rainforests. Most forests need to burn as part of their natural life cycle. I agree we should maintain the forests we have especially the amazon.

 

[SageBrush]

I agree we should maintain the forests we have especially the amazon.

Why ?

I'm not trying to needle you Chris; I just don't really understand the difference between reforesting and preserving what is left. They seem like two sides of the same coin.

 

[jerry33]

I just don't really understand the difference between reforesting and preserving what is left. They seem like two sides of the same coin.

Preserving what's left helps biodiversity. Reforestation may not depending upon how much was originally destroyed.

 

[nwdiver]

Why ?

I'm not trying to needle you Chris; I just don't really understand the difference between reforesting and preserving what is left. They seem like two sides of the same coin.

Because protecting existing forest doesn't require repurposing land that doesn't already have a forest... it's a fraction of the resources required to add forest.

Have you seen 2nd growth forest? It takes several decades or perhaps centuries to re-establish a forest. You guys are acting like you can just plant a few trees and wait. It's not that simple. You have to thin it. You have to maintain it. You have to protect it. It's not that simple.

Old growth forests have the underlaying ecosystem required to help add resilience to fire and disease. If you just plant a bunch of trees and leave all you're doing is creating a fire hazard.

 

[mspohr]

No; That's not how that works. If a tree dies and decomposes most of the carbon that is locked away is released.

Yes, you are right. A dead tree releases its carbon. However, that tree is part of a forest which keeps growing and captures that carbon so there is a net carbon capture.
Simply:
- take a plot of land with no forest and no carbon storage
- plant trees
- forest will capture and store x amount of carbon
-trees die, are burned, etc. and release their carbon
-at the same time, the forest keeps growing and captures that carbon
-steady state: that plot of land which had no carbon storage now has x amount of carbon storage... forever.

Based on their calculations, for above- and below-ground biomass in metric tons of carbon stored per hectare, cool temperate moist forests store the most carbon, 625 tC/ha, with warm temperate moist storing slightly less, 500 tC/ha. Cool temperate dry forests stored 280 tC/ha. Tropical rainforests stored 250 tC/h. Boreal forests stored 100 tC/ha.
How Much Carbon Do Different Forests Store & What Size Offsets Your Driving For a Year?

 

[rays427]

Without fossil fuels how many trees do you think would be left. I live in Northern California Gold Country and from about 1860 to 1880s most of the trees were cut down to provide steam power. This forced them to switch to water power but that could only provide so much power before other sources were needed.

 

[SageBrush]

Preserving what's left helps biodiversity. Reforestation may not depending upon how much was originally destroyed.

That thought occurred to me but by all accounts humanity is causing a mass extinction with the status quo.

Chris makes good points about CO2 but forests are SO much more. Have you spent much time in a forest ? It is hard to explain just how much is lost when they are gone, over and above carbon sequestration and loss of biodiversity.

 

[nwdiver]

Yes, you are right. A dead tree releases its carbon. However, that tree is part of a forest which keeps growing and captures that carbon so there is a net carbon capture.
Simply:
- take a plot of land with no forest and no carbon storage
- plant trees
- forest will capture and store x amount of carbon
-trees die, are burned, etc. and release their carbon
-at the same time, the forest keeps growing and captures that carbon
-steady state: that plot of land which had no carbon storage now has x amount of carbon storage... forever.

Based on their calculations, for above- and below-ground biomass in metric tons of carbon stored per hectare, cool temperate moist forests store the most carbon, 625 tC/ha, with warm temperate moist storing slightly less, 500 tC/ha. Cool temperate dry forests stored 280 tC/ha. Tropical rainforests stored 250 tC/h. Boreal forests stored 100 tC/ha.
How Much Carbon Do Different Forests Store & What Size Offsets Your Driving For a Year?

There's no such thing as land with 'no carbon storage'... at least land that trees can grow on; Grasslands and fields full of weeds store carbon too.

If forests are so effective at sucking carbon from the air and tucking it away why weren't atmospheric CO2 levels falling before we started adding carbon? Hint: It's called a carbon CYCLE.

 

[mspohr]

There's no such thing as land with 'no carbon storage'... at least land that trees can grow on; Grasslands and fields full of weeds store carbon too.

Problem is that grazing grassland releases more carbon than it absorbs due to degradation.

 

[nwdiver]

Problem is that grazing grassland releases more carbon than it absorbs due to degradation.

There are several studies highlighting the 'mind-blowing' potential of range land to sequester carbon.

One of my former co-workers actually believed that grass-fed cattle would solve the climate crisis and we could keep burning fools fuel. One of my many experiences that informed my view that a small benefit can be easily exaggerated into a complete solution by people addicted to the status quo.

It's like the filter on cigarettes. We... we just need to quit smoking. Focus on that. As long as >80% of our energy comes from fools fuel everything else is just a distraction.

 

[Dr. J]

I hope this isn't a repeat, but I found this "Energy Investments Dialogue" with Bill Gates (Nov. 2018) perplexing. He's a literal hand-waver. Enjoy.