Climate Change/Mass Extinction Megathread

[Malthus]

Because it isn't the killing that does it, it is the returning land to its native state.

If the Mongols killing a few tens of millions didn't result in the depopulation of large areas that then over several decades returned to a state without human agriculture, it would not have the same effect.

Yes. Though there is some indication that did happen. But he Black Death does not seem to have a mortality rate quite as extreme as what seems to have happened in the New World. And though people talk about how the Mongols destroyed massive amounts of peasants and left lots of land to fallow it may not have been on the same scale. They did destroy lots of ancient irrigation systems that never got repaired as well.

Though I find it surprising pre-modern agriculture can have a noticeable impact on the climate like that.

It probably isn't just the "return land to native state" that did it, but the lack of slash-and-burn.

I would assume a lot of native peoples in NA used 'slash and burn' agriculture. This is a type where, to clear a plot for growing, you use a controlled burn of the forest. The burned tree trunks are left standing, the ash makes fertilizer; after a few years you have to leave it fallow and burn another plot.   

This is commonly used in central America and SE Asia to this day. It releases lots of smoke ... plus the deforestation lasts for years. This creates lots of carbon emissions, enhancing global warming.

https://www.wn.org/climate-change-indonesias-slash-burn-agroforestry-can-help/

Point is that different types of agriculture have different effects. The Mongols smashed irrigation in Persia, leading to not reforestation, but desert-creation: less carbon was soaked up by vegetation (as there was now desert where there used to be crops), so killing all those people did not tend to prevent global warming. In contrast, assuming pre-Columbian NA natives used slash and burn (which is likely - as clearing forest without metal axes or draught animals to pull stumps and haul logs is really tough), killing them was a net benefit in terms of reducing global warming. 

https://en.wikipedia.org/wiki/Native_American_use_of_fire_in_ecosystems

[Grey Fox]

Without commenting on the idea that this is an example, I've never really understood the reluctance that some people have to the idea that human activity can change the global environment/climate.

That part isn't that complicated at all. The globe is a basically closed system. It is a giant test tube. But it isn't really that big. We can measure the increase in CO2 for example, and surprise surprise, if we pump a lot of CO2 into the atmosphere, the amount of CO2 in the atmosphere goes up in a clearly measurable way.

The Earth is pretty big...but on the other hand, it really isn't that big. It is a closed system, and doing anything within the system that has a measurable impact on the composition of that system is creating change.

Obviously understanding how it changes is complex, even moreso *predicting* those changes. But there isn't anything magical about it - it is just science. We started thinking about it, what 50, 60 years ago? Hell, I think we've made amazing progress since then considering it was essentially a brand new field of study in many ways. But the basic idea is pretty straightforward. We have a closed system, and we are creating measurable changes, and we need to understand what those changes will do....

I just do not understand the idea that there is skepticism around the very idea that humans could change the earths climate.

I can, easily.

Climate is not something that is on a human scale. Humans are not good at integrating things that are not to their scale, especially time scales.

Also, vast majority of people think there's a God(s) that created the earth for us, how can we affect what God(s) has done?

[Valmy]

Point is that different types of agriculture have different effects. The Mongols smashed irrigation in Persia, leading to not reforestation, but desert-creation: less carbon was soaked up by vegetation (as there was now desert where there used to be crops), so killing all those people did not tend to prevent global warming. In contrast, assuming pre-Columbian NA natives used slash and burn (which is likely - as clearing forest without metal axes or draught animals to pull stumps and haul logs is really tough), killing them was a net benefit in terms of reducing global warming. 

Damn. Well with all this anti-Vaxing going on maybe we can depopulate North America with small pox and measles again soon.

[derspiess]

So what do you guys think of the New Green Deal?  Love it or shove it?

[Savonarola]

So what do you guys think of the New Green Deal?  Love it or shove it?

I think Nancy Pelosi told us all we need to know about it in her interview in Politico:

The California Democrat did agree to launch a select committee on climate change, similar to the one she created back in 2007, when she first became speaker. Pelosi said Wednesday, however, the panel would not be tasked with writing a specific bill, and brushed off the idea of the Green New Deal as a "suggestion."

"It will be one of several or maybe many suggestions that we receive," Pelosi said. "The green dream or whatever they call it, nobody knows what it is, but they're for it right?"

[Valmy]

So what do you guys think of the New Green Deal?  Love it or shove it?

I don't know exactly what that is. It sort of sounds like doing Tennessee Valley Authority type stuff to help the environment?

[Grey Fox]

Reminds us that old Democrats are no better than old & new Republicans.

[derspiess]

So what do you guys think of the New Green Deal?  Love it or shove it?

I don't know exactly what that is. It sort of sounds like doing Tennessee Valley Authority type stuff to help the environment?

Read up when you have a moment: https://www.npr.org/2019/02/07/691997301/rep-alexandria-ocasio-cortez-releases-green-new-deal-outline

A few of the nuttier suggestions: getting rid of air travel in favor of high speed rail, a guaranteed (hopefully green) job for everyone, "access to nature" (didn't realize we didn't already have that), upgrading or rebuilding all existing buildings to make them more green, offering "economic security" to those "unwilling to work"

[Valmy]

That bill all but admits it would be putting us on a kind of war mobilization effort. Obviously I would like some sort of process to reduce emissions and develop carbon capture technology to offset what emissions we do have but...I don't know. It seems really extreme and full of fluff. Maybe we could convince Canada to do it first and see if it works.

[Zoupa]

I read it. About half (hard to quantify) is pretty irrelevant to climate change.

I think that what AOC and co want is to get the dems running in 2020 to endorse greener ideas. Smart.

[Valmy]

I read it. About half (hard to quantify) is pretty irrelevant to climate change.

I think that what AOC and co want is to get the dems running in 2020 to endorse greener ideas. Smart.

It is a good idea but it is smart politically? We probably want 2020 to be a referendum on Trump and not a referendum on Climate Change....unless we are sure to win that referendum.

[Barrister]

I read it. About half (hard to quantify) is pretty irrelevant to climate change.

I think that what AOC and co want is to get the dems running in 2020 to endorse greener ideas. Smart.

Yeah, it includes medicare for all and jobs for all.

I think doing stuff like that trivializes environmental issues by making them just another political talking point, and makes it easier for right wingers to unfortunately ignore climate change as just another left wing idea.

[Valmy]

I read it. About half (hard to quantify) is pretty irrelevant to climate change.

I think that what AOC and co want is to get the dems running in 2020 to endorse greener ideas. Smart.

Yeah, it includes medicare for all and jobs for all.

I think doing stuff like that trivializes environmental issues by making them just another political talking point, and makes it easier for right wingers to unfortunately ignore climate change as just another left wing idea.

Excellent point. I mean I am all for a plan to get us to a carbon neutral state, and hopefully whatever is developed can have substantial bipartisan support so it has a chance in hell of being put into effect, but it should probably be an initiative separate from social welfare issues.

[Berkut]

Yeah,gotta agree. It makes an issue that should be a-political explicitly political.

[crazy canuck]

I read it. About half (hard to quantify) is pretty irrelevant to climate change.

I think that what AOC and co want is to get the dems running in 2020 to endorse greener ideas. Smart.

It is a good idea but it is smart politically? We probably want 2020 to be a referendum on Trump and not a referendum on Climate Change....unless we are sure to win that referendum.

The political judgment is the key.  Hopefully most Americans are agreed that climate change is a pressing problem and that reasonable policies will be developed in response.  I read the Green New Deal as an affirmational document which outlines what can be done which might make it easier for other policies to be viewed as moderate and therefore more politically saleable.  But if the scientists are right, we are running out of time.

And there is no reason to doubt they are incorrect.  So if the political judgment here is wrong, it could be fatal - literally.