[AgentR11]

Does that double the recovery time?

Like most things in nature, its more an ex & log exercise, not a straight multiple. The tails of those look largely the same regardless of what linear factor you apply to them. So you can basically expect that as the number of species remaining drops, the ratio of possible survival nitches to number of species improves, thus lowering the pressure of the extinction event as it proceeds. Once the event is over, you have a long period where very few species are producing a huge amount of biomass, and from their differentiation proceeds over time.

We're currently on the part of the curve where the linear factors are noticeable, but don't give them more potency than they rate.

One should also remember, that the climate phase the Earth is headed towards is nothing unprecedented, its spent millions of years in just such hot-phases, with tons of life romping around enjoying the climate. (none of the rompers being primates might however, give one pause, I doubt Gaea gives a flip, but this writer might).

[Lore]

One should also remember, that the climate phase the Earth is headed towards is nothing unprecedented, its spent millions of years in just such hot-phases, with tons of life romping around enjoying the climate. (none of the rompers being primates might however, give one pause, I doubt Gaea gives a flip, but this writer might).

Those former beasties had hundreds of thousands of years to adapt to changing climate. When history showed relatively quick distortions in climate, life met sudden death.

[AgentR11]

Correct, a 95% diversity loss wouldn't be at all surprising. My point is about that remaining small percentage, once you're in that small percentage band, there are so many vacated hiding spots/niches that the chance of a match between the remaining species and the available niches rises. They only have to "weather the storm" as it were.

This means a huge loss in biodiversity, just as in past extinction events; but the few that remain end up with a whole planet to fill and exploit.

Don't forget, that in these extinction events, adaptation isn't so much species A remaining species A but better suited; but rather species #1-100,000 going extinct, specie #100,001 tolerates and survives, and then begins adaption and evolving into #100,002+ as life goes from tolerate&survive to thrive&exploit.

That's why the speed argument always seems so weak to me; if the magnitude is slow enough to permit simple changes in range for survival; its not abrupt. Once it is abrupt, there is no simple adaptation possible. The only difference this time around is the presence of conscious primates who can observe and acknowledge the extinction event that they are creating.

[dohboi]

Warmer climates have tended to spur faster speciation in the past--something about the warmth causing bodies to get smaller since smaller bodies shed heat more easily, but smaller bodies can adapt to smaller habitats...

On the other hand (and to save my reputation as an uber-doomer '-), all this assumes that we don't get into Hansen's Venus Syndrome. He seems to think this is pretty much a sure thing if we burn all the carbon there is to burn, and we seem to be heading in that direction. And he knows a bit about Venus, having done a lot of the groundbreaking work on the climate of that planet.

Keep in mind that it is not really about individual species finding the right niches, but of communities of species that can coexist and foster each others' existence finding the same niche at the same time. No individual life form can live by itself.

[AgentR11]

No individual life form can live by itself.

Algae sure can.
Cyanobacteria can.

[AgentR11]

Hansen's Venus Syndrome.

I think Hansen's going *WAY* out on a limb trying to predict that far out.

Its not unreasonable to think we could push the climate out of its current cold-phase equilibrium over into the Earth's normal hot-phase equilibrium; but its quite a reach to think we even know enough about that side's equilibrium state to predict pushing out of that, into an unknown, unbounded climate state.

He seems to think this is pretty much a sure thing if we burn all the carbon there is to burn,

There is no *if*. Only *when*.

[Serial_Worrier]

A several degree rise will open up a billion acres of farmland in Canada & Russia. Good times ahead!

[AdTheNad]

A several degree rise will open up a billion acres of farmland in Canada & Russia. Good times ahead!

The higher the sea rises the more land we have! Wait that doesn't sound right. Well at least there will be good farm land in Russia to replace the stuff that burns and gets flooded there.

[kiwichick]

if the worst case plays out we will lose most of the best land

and most of russia and canada have had the best land scrapped off by the ice sheets

[clif]

Not to mention, the need to build completely new infrastructure to support farming at latitudes which previously hasn't been able to be farmed do to the climate pre climate change.

BTW this new construction will have to be achieved in a declining energy environment.

[dohboi]

Not to mention that the growing season in northern Canada and Siberia lasts about two weeks.

[kiwichick]

dohboi

tut,tut

it could be 4 or 5 weeks by 2030

[dohboi]

Nice point. The amount of sun shine and its low angle won't change, though; GW doesn't change the tilt of the planet.

[Lore]

A several degree rise will open up a billion acres of farmland in Canada & Russia. Good times ahead!

The higher the sea rises the more land we have! Wait that doesn't sound right. Well at least there will be good farm land in Russia to replace the stuff that burns and gets flooded there.

You can't farm the tundra productively, no matter how pleasant the temperature may get there.

[rockdoc123]

You can't farm the tundra productively, no matter how pleasant the temperature may get there.

although the topsoil is thinner the main problem is the height of permafrost and the short growing season. If you take the two away then you have a difference. In the prehistoric past these areas were capable of supporting forests not just lichens etc. There are areas in the north where you have pretty much exposed Precambrian basement and little soil coverage but that isn't the whole tundra. There is a large group of people who have figured out how to grow various vegetables in Alaskan Tundra under current climate conditions. If it got warmer there is little reason to believe they wouldn't benefit further.

At one point in the not too distant past all of North America was covered in ice, it isn't anymore and generally is pretty productive.

[Lore]

You can't farm the tundra productively, no matter how pleasant the temperature may get there.

although the topsoil is thinner the main problem is the height of permafrost and the short growing season. If you take the two away then you have a difference. In the prehistoric past these areas were capable of supporting forests not just lichens etc. There are areas in the north where you have pretty much exposed Precambrian basement and little soil coverage but that isn't the whole tundra. There is a large group of people who have figured out how to grow various vegetables in Alaskan Tundra under current climate conditions. If it got warmer there is little reason to believe they wouldn't benefit further.

At one point in the not too distant past all of North America was covered in ice, it isn't anymore and generally is pretty productive.

Doubtful that the alpine tundra could ever support a very large population within the next several thousand years, let alone the next couple hundred. You not only have very poor soil conditions, but a short growing season as well. That growing season is also determined by the amount of sunlight crops get. The soil you can do little about with the exception, possibly, of small terraformed parcels.

[Tanada]

Doubtful that the alpine tundra could ever support a very large population within the next several thousand years, let alone the next couple hundred. You not only have very poor soil conditions, but a short growing season as well. That growing season is also determined by the amount of sunlight crops get. The soil you can do little about with the exception, possibly, of small terraformed parcels.

So far as I can tell nobody was talking about Alpine tundra, which is what you find above the tree line on mountains. We are talking about low altitude tundra here, decreasing in altitude down to sea level at the Arctic ocean shoreline.

Two things are key to growing things in the Arctic or Antarctic, you can ask people in Finland and Alaska if you don't want to accept that. The first is, the plant has to grow well and productively in whatever temperature range the summer season has. The second is there have to be enough hours of sunshine to provide the energy input the plants need to grow. You also need all the regular factors like water and nutrients but in general the Arctic actually has plenty of both or you wouldn't get forests like you see in the Paleoclimate record.

Alaska grows some of the worlds largest vegetables and that is without greenhouses or exotic chemicals. That isn't to say they are not carefully tended or fertilized, but you can grow quite a bit of food from fewer seeds in the Arctic if you choose seed lines carefully.

[dohboi]

"If you choose seed lines carefully" is key indeed.

But CC doesn't just mean that particular locations are getting gradually and reliably warmer.

It means wild, extreme and unpredictable swings in heat, cold, flood, drought, winds, humidity...things we have already been getting a little taste of in the last couple years.

So every year you will have to either gamble that the one kind of seed you used will produce the right crop for the wildly unpredictable season, or you will have to plant a wide variety of seeds hoping that one or two might end up being right for that growing season and accepting a partial or total loss for the rest. (The latter has been wiscur's strategy recently, iirc.)

And of course big ag (Monsanto, Conagra...) is doing everything it can to restrict the range of seeds available, in fact trying to wipe out the availability of varieties that can produce viable seeds themselves.

[Tanada]

Indeed dohboi, I didn't mean to imply it would be simple or easy, but people are a creative species and it is doable. A few years ago when I was investigating moving to Alaska I learned a bit about extreme northern farming. The advice I got from farmers up there boiled down to proceed with caution and don't overextend yourself, plus a big dose of use common sense.

[dohboi]

"it is doable"

Depends what "it" is. Supporting 10 billion people on the thin soils and sparse sunlight of the highest latitudes? Or growing a few nice vegetables for you isolated doomstead?