Totally hypothetical – it can’t really happen – I hope.

Suppose worldwide greenhouse gas emissions are reduced to zero but global temperatures keep rising at the same rate.
What do you conclude?

a) We’ve passed the tipping point and humankind has totally f&** up the planet and there’s no going back.

b) There’s some other thing that humans are doing that is destroying the environment. Find it and fix it.

c) Greenhouse gas emissions were never the dominant climate forcing agent in the first place. Three other possibilities of high likelihood for causing global warming are: Anti-pollution measures reducing atmospheric soot; The random nature of cloud formation; Changes in Earth’s albedo due to vegetation.

mollwollfumble said:

Totally hypothetical – it can’t really happen – I hope.

Suppose worldwide greenhouse gas emissions are reduced to zero but global temperatures keep rising at the same rate.
What do you conclude?

a) We’ve passed the tipping point and humankind has totally f&** up the planet and there’s no going back.

b) There’s some other thing that humans are doing that is destroying the environment. Find it and fix it.

c) Greenhouse gas emissions were never the dominant climate forcing agent in the first place. Three other possibilities of high likelihood for causing global warming are: Anti-pollution measures reducing atmospheric soot; The random nature of cloud formation; Changes in Earth’s albedo due to vegetation.

Both A and B would be likely causes, along with (d) – Thermal inertia but the right wing media will go with C.

I think there is already some evidence of changes to cloud, types of clouds and cover, area whatever, which influenced albedo

is there likely to be revealed some dimension or aspects of structure in the environment and environmental systems that substantially have gone unaccounted for or underestimated, of global warming trend analysis, if you like

I think so, probably is some evidence of that already

the shortcoming is probably in the view of climate change that fails to consider the structure conversion humans perform, or from human activities, which there are a lot of and growing

my view is that a lot of structure is got from global cooling, and preserved, or more generally at different scales it’s been on the condensate side of thermal equations, whereas human activity sort of pumps everything up to a more energetic state, by burning too much fossil fuel for example, and little thought while doing that is given to the structure in large deposits of coal, oil and gas under the ground, more inert when it’s there

similarly little thought is given to the structure of large areas of ice, presently melting away

the joy of earth, life on earth, the reason it ever came to be, was because of some fortuitous circumstances, a complete accident, a lot of accidents, but when I look out at the stars, my very basic astronomy and thermodynamics or whatever tells me what came to be largely by cooling, expansion and cooling, even the milky way we reside, irion or whatever

> Changes in Earth’s albedo due to vegetation.

I hadn’t really thought about this one before. It’s very iffy. The effects of agriculture could go either way. It can be argued that agriculture (land clearance, replacement of forests by grasslands) almost always increases the Earth’s albedo, cooling the Earth below the natural rate of temperature rise after the end of the last Ice Age until recent times. But on the other hand, vegetation’s ability to absorb CO2 also decreased with land clearance and the replacement of forests by grasslands, which has the opposite effect of heating the Earth. So farming has two large opposite influences on global warming.

Numbers, where are the numbers? We need reliable scientific papers on this, and on the opposite effects of water as cloud cover (cooling) and water as vater vapour (heating). The effects of atmospheric water on global warming are well known to be at least five times as strong as from CO2, but has two opposite effects (from cloud and from water vapour) so the balance between the two effects is crucial.

The thing about warming by CO2 and other greenhouse gases is that it’s easy to calculate accurately. The other large influences are much more difficult to calculate accurately. In case you haven’t guessed yet, solar variability is not a big influence, it’s only about 15% of the magnitude of warming from CO2.

In the old days, back when I occasionally travelled by aeroplane, whenever I took off from an Australian airport and looked at the small patches of dark native forest and large patches of light grassland and cultivated land, I found myself wondering, how much warmer would the planet be if the forest was still at it’s original extent?

Surely someone must have done some numbers on this, but I have never seen them.

The Rev Dodgson said:

In the old days, back when I occasionally travelled by aeroplane, whenever I took off from an Australian airport and looked at the small patches of dark native forest and large patches of light grassland and cultivated land, I found myself wondering, how much warmer would the planet be if the forest was still at it’s original extent?

Surely someone must have done some numbers on this, but I have never seen them.

just burn them down now, they were going to be burnt anyway

and they’re probably over 60 and have preexisting conditions

The Rev Dodgson said:

In the old days, back when I occasionally travelled by aeroplane, whenever I took off from an Australian airport and looked at the small patches of dark native forest and large patches of light grassland and cultivated land, I found myself wondering, how much warmer would the planet be if the forest was still at it’s original extent?

Surely someone must have done some numbers on this, but I have never seen them.

I’m totally in agreement here. Even going back to the English hedgerows and beyond, the resulting albedo must be much lighter than the native forest. Albedo is a recognised major factor in calculating global warming, but I’ve never seen a calculation of how historic farming has changed the albedo.

Let’s see if I can find something on google scholar. There’s this paper. https://sci-hub.st/https://science.sciencemag.org/content/206/4425/1363 There is a table of albedo changes due to vegetation changes here, it’s mostly limited to “present rate of change” where the present is the year 1979. Hold on, there is a column “cumulative over the past few millenia”, but it’s not albedo. (The table is printed sideways which makes it difficult to read).

I’m not sure how to read this. Are they saying that the global albedo change “over the past few millenia” is only six times as large as over fifty year interval “± 25 years” ? It seems to be. But they do reduce the albedo change for both cloud cover and distance from the equator. The total change in Earth’s albedo is given as 0.006. On a baseline albedo of 0.3, that comes in at 2%. Typical monthly anomalies in the Earth’s albedo these days are about 0.2% (see chart) so the historical effect is ten times as large.

(Also noting that cloud cover over most of the Earth is taken to be 50%, so a few tenths of a percent change in cloud cover is going to have a whopping great effect on global warming).

Is this enough information to calculate the temperature fall due to historical agriculture changes?

European colonization of Americas killed so many it cooled Earth’s climate

Research finds killing of native people indirectly contributed to a colder period by causing deaths of around 56 million by 1600

https://www.theguardian.com/environment/2019/jan/31/european-colonization-of-americas-helped-cause-climate-change

Witty Rejoinder said:

European colonization of Americas killed so many it cooled Earth’s climate

Research finds killing of native people indirectly contributed to a colder period by causing deaths of around 56 million by 1600

https://www.theguardian.com/environment/2019/jan/31/european-colonization-of-americas-helped-cause-climate-change

I’ll probably have to read the article on that one …

party_pants said:

Witty Rejoinder said:

European colonization of Americas killed so many it cooled Earth’s climate

Research finds killing of native people indirectly contributed to a colder period by causing deaths of around 56 million by 1600

https://www.theguardian.com/environment/2019/jan/31/european-colonization-of-americas-helped-cause-climate-change

I’ll probably have to read the article on that one …

So if we found a country with about 55 million people, we could kill everyone and make sure the place returns to wild and nobody else repopulates it, and climate change will be mitigated for a couple of decades.

party_pants said:

party_pants said:

Witty Rejoinder said:

European colonization of Americas killed so many it cooled Earth’s climate

Research finds killing of native people indirectly contributed to a colder period by causing deaths of around 56 million by 1600

https://www.theguardian.com/environment/2019/jan/31/european-colonization-of-americas-helped-cause-climate-change

I’ll probably have to read the article on that one …

So if we found a country with about 55 million people, we could kill everyone and make sure the place returns to wild and nobody else repopulates it, and climate change will be mitigated for a couple of decades.

Kenya or Myanmar are the closest.

sibeen said:

party_pants said:

party_pants said:

I’ll probably have to read the article on that one …

So if we found a country with about 55 million people, we could kill everyone and make sure the place returns to wild and nobody else repopulates it, and climate change will be mitigated for a couple of decades.

Kenya or Myanmar are the closest.

Kenya play cricket. Myanmar it is, they’re bastards anyway.

party_pants said:

party_pants said:

Witty Rejoinder said:

European colonization of Americas killed so many it cooled Earth’s climate

Research finds killing of native people indirectly contributed to a colder period by causing deaths of around 56 million by 1600

https://www.theguardian.com/environment/2019/jan/31/european-colonization-of-americas-helped-cause-climate-change

I’ll probably have to read the article on that one …

So if we found a country with about 55 million people, we could kill everyone and make sure the place returns to wild and nobody else repopulates it, and climate change will be mitigated for a couple of decades.

China managed to knock of at least 30 million of its own citizens in the late 50s/early 60s, but no-one was monitoring the climate effects at the time, so it was a fizzer, as experiments like that go.

party_pants said:

sibeen said:

party_pants said:

So if we found a country with about 55 million people, we could kill everyone and make sure the place returns to wild and nobody else repopulates it, and climate change will be mitigated for a couple of decades.

Kenya or Myanmar are the closest.

Kenya play cricket. Myanmar it is, they’re bastards anyway.

Bloody Buddhists!

we could bump off all the people called Dave.

Bogsnorkler said:

we could bump off all the people called Dave.

Dave’s not here, man.

Bogsnorkler said:

we could bump off all the people called Dave.

“every Dave’s dead Dave”

ABC News:

‘Giants beat West Coast Fever 64-61 to set up Super Netball grand final against NSW Swifts’

I read as

‘Thyroid cases beat pyrexics to set up final against a bunch of birds’.

sibeen said:

Bogsnorkler said:

we could bump off all the people called Dave.

Dave’s not here, man.

exactly!

captain_spalding said:

ABC News:

‘Giants beat West Coast Fever 64-61 to set up Super Netball grand final against NSW Swifts’

I read as

‘Thyroid cases beat pyrexics to set up final against a bunch of birds’.

Sorry, should be in ‘Chat’.

Bogsnorkler said:

we could bump off all the people called Dave.

We might have bumped off one.