Merged Global Warming Discussion II: Heated Conversation

[jobberone]

The Earth has been between 150ppm and 400ppm for ~5 million years, and in that time life has evolved/adapted to those specific conditions. While some species will eventually do better at 500ppm CO2 others will do worse even if it's just from the increased competition. We have no guarantees which will thrive.

In terms of crops, even if crops grow well under those conditions there is not going to be anyplace for them to grow. It takes thousands of years for ecosystems to migrate during a de-glaciation and in this case it may take longer because ecosystems would need to move to places they haven't been in a very long time.

Just because wheat growing temperatures migrate to northern Canada doesn't mean we can up and start growing wheat there. It will take thousands of years for taiga to become useful agricultural soil and much longer for the rock in the Canadian Shield.


In the end it's not just the among of CO2 or the amount of warming that's the problem both are manageable if the change is slow enough, but current change is an order of magnitude higher than any change seen outside a period of mass extinction. It doesn't matter whether it's warming or cooling, if ecosystems can't migrate quickly enough to keep up with the change there is little productive environment anywhere.

There's also consequences of some species of plants invading areas not normally habitable for them or at least relatively so. This can change entire ecosystems up the food change. OTOH, if we can grow crops in areas not previously favorable for the same then food production would likely increase. I'm more concerned about unforeseen consequences than worrying about making non-arable land fit for crops. As a pure amateur in this field of climate all I can do is speculate from a biological standpoint. However, I believe there are so many variables that most everyone is speculating.

What I'd like to see is arid areas receive more rainfall although I suspect that is wishful thinking. Unless the greenbelt expands my guess is arid areas may in the main on balance become more arid.

 

[macdoc]

. OTOH, if we can grow crops in areas not previously favorable for the same then food production would likely increase.

That's a very risky proposition as in many areas there is either no top soil ( Taiga Tundra ) or inappropriate growing conditions ( soil etc )
Also there are limitation on how high planting can go in in some mountainous areas....in general - unless the Sahara really greens up we will lose out globally in arable regions.

For instance - it is expected to be too hot for wheat in India within a couple of decades and you have the barrier of the Himalayas beyond that.

Bangladesh notably will be impacted by rising sea levels and encroaching salt into the ground water and again the Himalaya's prevent a gradual accommodation to the north.

But in the big expanses of tundra and taiga there is simply no soil or very poor soil

 

[aleCcowaN]

However, I believe there are so many variables that most everyone is speculating.

A belief that seems to allows you to continue to speculate about what you admittedly don't know. A very wrong belief, because it allows to make listings of unproved possibilities with complete disregard of what is known and what is not speculative. As a natural consequence:

I'd like to see is arid areas receive more rainfall although I suspect that is wishful thinking.

Yes, it is. There'll be though some arid areas receiving more rainfall. There'll be also many arid areas that will become more arid or remain as they currently are. There'll be also many non arid areas that will become flooded or excessively wet.

 

[macdoc]

The problem with extreme weather is you can have a perfectly normal growing season with a bountiful crop wiped out by a single extreme event.

example.
say the frequency of hail and/or intense crop damaging rain storms goes up - then instead of maybe one season in 10 losing out, it might be one in 5 or 1 in six. That can tip an area from viable to uneconomic especially when you have combined risks going on ( drought or extended hot spells ).
A 6 day extended hot spell may be survivable for the crop where an 8 day may lose 90% of the crop.

The Holocene allowed fairly predictable growing seasons in enough areas to build civilization on a sparsely populated earth.

The Anthropocene sees us with better tech and knowledge but bumping the limit on arable land, available water, feedable population size and now we add in more erratic weather and shifting climate bands.

For instance one part of Australia is getting the same average annual rainfall in a certain region but now a portion of that is in the wrong season and not enough in the growing season alters the viability. in addition that out of season rainfall is causing salinity issues for existing croplands.

It's challenge enough to feed 9 billion ....add in erratic weather patterns and shifting climate bands and the challenge is that much greater.

 

[jobberone]

A belief that seems to allows you to continue to speculate about what you admittedly don't know. A very wrong belief, because it allows to make listings of unproved possibilities with complete disregard of what is known and what is not speculative. As a natural consequence:

Yes, it is. There'll be though some arid areas receiving more rainfall. There'll be also many arid areas that will become more arid or remain as they currently are. There'll be also many non arid areas that will become flooded or excessively wet.

What I was trying to say nicely was nobody actually knows what is going to happen. That translates to everybody which includes you and me. We appear to be having some difficulty reaching a consensus on a number of things including climate models. Again just a scientist looking at information and data outside my own field.

Is this your field of expertise? Would you like it if I were to treat you the same way about my area of expertise? Why don't we play nice and have a drink. Here's one on me!

Actually I was thinking about the Sahara or a greening effect say in Australia but it could include other areas of the globe including those inside the green belts not just outside it. Does anyone really know if there will be a significant change in the green belts including an expansion?

My point was there are probably going to be short, intermediate and long term consequences which are negative, neutral and positive in multiple areas over time. That's assuming we get more significant changes we can't deal with including say loss of potable water in areas like now.

Much of the time it is what we don't see coming that surprises us and I don't expect less from climate change.

You seem to be worried about rising sea levels.

 

[Reality Check]

What I was trying to say nicely was nobody actually knows what is going to happen.

Hi jobberone.
What do you mean by "nobody actually knows what is going to happen"?
No one is saying that climate scientists have some magic crystal ball that tells what is going to actually happen .

What climate science can do is predict what is probably going to happen based on modeling what has already happened using the known laws of physics. This can range from the simplistic predictions ("doubling CO2 will cause global surface temperatures to go up by X which will have consequences A, B and C") to the more complex predictions based on computer models.

These is a consensus: 97% of climate scientists agree that global warming exists and we are the primary driver.

As for a mixture of consequences: Positives and negatives of global warming (advanced version)

The consequences of climate change become increasingly bad after each additional degree of warming, with the consequences of 2°C being quite damaging and the consequences of 4°C being potentially catastrophic.

The intermediate version has a good list of negatives and positives.

 

[macdoc]

JobberOne you seem to be taking a very sanguine approach as if the likely outcome will be a wash....it won't and isn't.

Regional predictions are difficult at this point to model but there a numerous changes already in play that will simply continue to get worse for the major agricultural regions of the planet.

••••

Methane again....less than minor for sure

U.S. Methane Study Says Emissions 50 Percent Higher Than EPA Estimates

By SETH BORENSTEIN 11/25/13 03:21 PM ET EST Associated Press
http://www.huffingtonpost.com/2013/11/2 ... 39308.html

WASHINGTON (AP) — The United States is spewing 50 percent more methane — a potent heat-trapping gas — than the federal government estimates, a new comprehensive scientific study says. Much of it is coming from just three states: Texas, Oklahoma and Kansas.

That means methane may be a bigger global warming issue than thought, scientists say. Methane is 21 times more potent at trapping heat than carbon dioxide, the most abundant global warming gas, although it doesn't stay in the air as long.
Much of that extra methane, also called natural gas, seems to be coming from livestock, including manure, belches, and flatulence, as well as leaks from refining and drilling for oil and gas, the study says. It was published Monday in the Proceedings of the National Academy of Science.

The study estimates that in 2008, the U.S. poured 49 million tons of methane into the air. That means U.S. methane emissions trapped about as much heat as all the carbon dioxide pollution coming from cars, trucks, and planes in the country in six months.
That's more than the 32 million tons estimated by the U.S. Environmental Protection Administration or the nearly 29 million tons reckoned by the European Commission.

"Something is very much off in the inventories," said study co-author Anna Michalak, an Earth scientist at the Carnegie Institution for Science in Stanford, Calif. "The total U.S. impact on the world's energy budget is different than we thought, and it's worse."
Continues ...

 

[aleCcowaN]

Methane again....less than minor for sure

I'd rather say "USA busted again" in their cultural "we are the good ones". I think it's quite obvious the figure is even larger. We know we are throwing 250-350 GT a year above the level in pre-industrial times just because of the atmospheric concentration change. As the US throw 16% of all anthropogenic carbon dioxide, why weren't they going to throw less than 16% of all methane, provided they have the most active fracking industry in the world, are the second -soon to be first- largest natural gas producer, they are the second-largest coal producer and they love barbecues from local produce?

 

[aleCcowaN]

What I was trying to say nicely was nobody actually knows what is going to happen.

I heard you the first time. But it seems you'll have to say this many many times as it seems to be one of the cardinal basis of your previous and probably future unsubstantiated argumentation.

... Again just a scientist looking at information and data outside my own field.

Is this your field of expertise? Would you like it if I were to treat you the same way about my area of expertise? Why don't we play nice

Here -especially in global warming related fora-, we don't rub our parchments in each other's face for many good reasons. That said, you don't talk the way one expects from someone having a highly intellectually-oriented field of expertise, specially some scientific métier, and he or she is trying to get a hold into the basic notions of a new discipline. It seems you just have a plan:

Actually I was thinking about the Sahara or a greening effect say in Australia but it could include other areas of the globe including those inside the green belts not just outside it. Does anyone really know if there will be a significant change in the green belts including an expansion?

My point was there are probably going to be short, intermediate and long term consequences which are negative, neutral and positive in multiple areas over time. That's assuming we get more significant changes we can't deal with including say loss of potable water in areas like now.

Much of the time it is what we don't see coming that surprises us and I don't expect less from climate change.

Yes, it seems like you do. You declare you know nothing on the subject yet your assertions pretty much seem to go along this path:

1. Nobody knows for sure something about the subject
2. In the long run we'll be surprise of what have become real. Who knows?
3. There are negative and positive consequences. The positive ones offset partly or totally the negative ones. Who knows?
4. What if it comes out to be positive as a whole? Who knows?
5. Yet, I'm concerned about the negative impacts but, who knows?

But I'm probably not being patient and in spite you have argued and used as references notions that exist in denialist websites and denialist literature you are soon to show that you wanted to learn what is needed -as part of a good scientific method- previously to make any additional assertion of your own.

Most importantly, I'm sure you are going to show you don't want to direct this part of this thread into rhetorical excursions, like changing the subject without amending your sayings about the previous one according with what was discussed (or contra-arguing staying on the same subject):

You seem to be worried about rising sea levels.

Not particularly, and I haven't talked of that in a long time. What makes you think that?

 

[DC]

What I was trying to say nicely was nobody actually knows what is going to happen. .....

You seem to be worried about rising sea levels.

1. We do have a pretty good picture what will happen. a lot of people dedicate their entire career on figuring out what will happen.

2. I am worried about rising sea levels. for good reason. and the frightening thing is, our projections are underestimating sea level rise.

 

[CapelDodger]

Nice response. Thanks. I'm not ready to dismiss low CO2 levels as not being problematic although I agree we aren't likely to see it low enough to create a huge problem for organisms dependent on photosynthesis.

Why on Earth do you think that CO₂ levels might suddenly plunge? What physical process could possibly cause such a thing? I've an active imagination and I'm stumped. Stuff doesn't just go away.

I do see a benefit from a warmer climate IF more rainfall occurs esp in non arable areas and esp if CO2 levels reach the 500 level. Obviously I'm not addressing other consequences.

Arid areas aren't shaped to handle much rainfall, so the first effects of an increase will be floods and erosion. Not good for the ecosystem nor farming.

What's good for humanity is how things have been for the last few thousand years, which is what our civilisation is shaped for. Change those conditions and the results are conflict and migration - the social equivalent of floods and erosion. Now that's what I'd call problematic.

 

[CapelDodger]

T However, I believe there are so many variables that most everyone is speculating.

Almost everyone is speculating because they haven't got a clue about the subject; those who do have a clue are only speculating at the margins. Climate is not as complicated a subject as you believe. Look up Hadley Cells, Monsoons and the Coriolis Effect and you're halfway there.

What I'd like to see is arid areas receive more rainfall although I suspect that is wishful thinking. Unless the greenbelt expands my guess is arid areas may in the main on balance become more arid.

There are three green belts : the tropical belt between the two desert belts (one Northern, one Southern) and the temperate belts beyond the deserts. In a warmer world the desert belts move away from the Equator, expanding into currently populated regions. The temperate bands move towards the poles, which in the South means they expand over water and in the north they create new bogs.

On balance, not a good outcome for humanity. (Not that I care, you understand, but some people seem to. Especially those with children, in my experience. I'm not so keen on people as to have ever felt the desire to create more. They're nosiy, expensive, and make a terrible mess )

 

[CapelDodger]

2. I am worried about rising sea levels. for good reason. and the frightening thing is, our projections are underestimating sea level rise.

You have good reason to worry about sea-level in Switzerland? Now you've got me worried!

I live in a port city and GoogleEarth tells me I've got 5m of headroom so I'm fairly comfortable with that. Short of a massive storm-surge up the Bristol Channel on a high tide I should be OK.

What worries me more is rainfall : there are hills just north of Cardiff, and the area I live in gets its name from the Welsh "sblott", meaning a raised area in a bog.

 

[DC]

You have good reason to worry about sea-level in Switzerland? Now you've got me worried!

I live in a port city and GoogleEarth tells me I've got 5m of headroom so I'm fairly comfortable with that. Short of a massive storm-surge up the Bristol Channel on a high tide I should be OK.

What worries me more is rainfall : there are hills just north of Cardiff, and the area I live in gets its name from the Welsh "sblott", meaning a raised area in a bog.

well you mentioned why that is that i worry " conflict and migration - the social equivalent of floods and erosion."

but that will propably not be during my lifetime. so actually i have no reason to worry

dissappearing glaciers is something i should worry about more as it will affect us more directly.

 

[lenny]

What I was trying to say nicely was nobody actually knows what is going to happen. That translates to everybody which includes you and me. We appear to be having some difficulty reaching a consensus on a number of things including climate models.

For the basic stuff we do not need much from models.

For the detailed stuff, your right we do not know what will happen locally in detail; but the big picture ha been clear for decades.

 

[lenny]

JobberOne you seem to be taking a very sanguine approach as if the likely outcome will be a wash....it won't and isn't.

Regional predictions are difficult at this point to model... Snipp...

Right on both counts: a net significant change is indicated by the basic physics, as has been clear since the 1980's. but I did not hear JobberOne deny that. (Did you intend too suggest that JobberOne?)

In terms of regional predictions: how long do we think you can get regional predictions badly wrong, and still get the global picture accurately?

 

[macdoc]

Indefinitely as at some point it becomes weather. All models are wrong, some models are useful.

Hindcasting hurricanes correctly got to the point where the predictions were pretty good...until this year....then it fell off the rails for reasons unknown.

I'm not sure any "forecasts" for regions are of much use just now tho China is diligently working on a monsoon model that is useful.

Observation of changes in the climate bands ( tropics expanding, deserts moving north, warmer Arctic Ocean, stalled highs over continents making them cooler in winter, shifts in the winds around Antarctica ) are useful but as to forecasts arising from them???...

About the only two things that can be said are more intensity in rain storms ( not more frequency ) and higher risks of extreme weather and that is mostly from the plain physics of more moisture and more heat in the atmosphere and more heat in the upper ocean and even now in the deeper ocean impacting the ENSO events.

WHERE these will play out is a popcorn only event.

 

[aleCcowaN]

Speaking of ENSO ...

 

[CapelDodger]

Speaking of ENSO ...

According to the Aussies http://www.bom.gov.au/climate/enso/

"International climate models surveyed by the Bureau indicate that the current ENSO-neutral state of the tropical Pacific will persist through to the end of the southern hemisphere summer. "

Next update 3rd December.

Climate models aren't perfect, of course, but the chances of another La Nina must be minute.

 

[CapelDodger]

In terms of regional predictions: how long do we think you can get regional predictions badly wrong, and still get the global picture accurately?

There are actually two sets of predictions : one refers to the equilibrium state at some given warming, while the other refers to the transition from here to there. Climate is easier to model than climate change, I suspect (purely intuitively).