Climate set for 'sudden shifts'

[villager]

Source: BBC


Climate set for 'sudden shifts'

By Pallab Ghosh

Science correspondent, BBC News

Many of Earth's climate systems will undergo a series of sudden shifts this century as a result of human-induced climate change, a study suggests. A number of these shifts could occur this century, say the report's authors.

They argue that society should not be lulled into a false sense of security by the idea that climate change will be a gradual process. The work by an international team appears in the Proceedings of the National Academy of Sciences journal.

"Our findings suggest that a variety of tipping elements could reach their critical point within this century under human-induced climate change," he said. "The greatest threats are tipping of the Arctic sea-ice and the Greenland ice sheet, and at least five other elements could surprise us by exhibiting a nearby tipping point."

The bulk of climate scientists now believe that human induced global warming has begun to affect some aspects of our climate.

Risk assessment

But that change is the start of a series of more dramatic changes if global warming continues, according to a group of more than 50 scientists. In a formal survey the researchers said that a number of systems that influence the Earth's weather patterns could begin to collapse suddenly if there's even a slight increase in global temperatures.

At greatest risk is arctic sea ice, the Greenland ice sheet and the west Antarctic ice sheet. The researchers have listed and ranked nine ecological systems that they say could be lost this century as a result of global warming. The nine tipping elements and the time it will take them to undergo a major transition are:

* Melting of Arctic sea-ice (about 10 years)
* Decay of the Greenland ice sheet (about 300 years)
* Collapse of the West Antarctic ice sheet (about 300 years)
* Collapse of the Atlantic thermohaline circulation (about 100 years)
* Increase in the El Nino Southern Oscillation (about 100 years)
* Collapse of the Indian summer monsoon (about 1 year)
* Greening of the Sahara/Sahel and disruption of the West African monsoon (about 10 years)
* Dieback of the Amazon rainforest (about 50 years)
* Dieback of the Boreal Forest (about 50 years)

<snip>

Read more: http://news.bbc.co.uk/2/hi/science/nature/7227080.stm

[kestrel91316]

1. Sudden climate shifts = massive crop failures = global famine

I REALLY wish people would wake up and smell the coffee and quit living like there's no tomorrow.

[villager]

2. global famine = political collapse/unrest = increased repression

Yes. Quite a thrill ride ahead...

[OKthatsIT]

25. Well The Elite looks forward to all the human die-off

Its been designed that way.

SO..WHAT ABOUT THOSE CHEMTRAILS?

[laconicsax]

4. Don't worry, Clinton and Obama have pledged to do something about it by 2030

:mad:

[ryanmuegge]

28. LOL. I think the same thing every day when I see people getting all hyped up about one of those two.

It's not really funny at all, but the absurdity is amusing in a dark way.

No offense meant toward all of the passionate volunteers and supporters of one of the big two from our party.

[aquart]

6. Don't worry, we'll have fewer to feed.

Millions of us will die when our coasts are drowned. New Orleans will look like a pleasant dream by comparison.

[RaleighNCDUer]

21. Ah, there IS no tomorrow

and part of the reason is coffee.

[laconicsax]

3. I'm so glad that the two Dem candidates have taken a strong position on global warming!

80% reduction in CO₂ emissions from 1990 levels by 2050! That ought to fix the current problem.

[villager]

5. Wow! Things'll be great by 2150, then!

Arrgh.

[lapfog_1]

14. We don't have that much time

I think these projections are still way optimistic. Start thinking in terms of 10 years and 50 years instead of 50 and 100 and 300.

Not to mention that even an eighty percent reduction means that we are STILL adding CO2 to the atmosphere.

Have you ever run an acid / base titration in chemistry?

We got the valve fully open and acid is squirting into the flask. And even now, we see the color start to change every swish. So we say "Well, in another 20 minutes or so, I will begin to close the valve so that only about 20 percent of the acid that's going in right now will be going in then".

Yippee!

But you know what happens when the color changes? A whole lot of us... animals, plants, everything... die.

So do you think we are going to miss the titration point? (aka the tipping point)

[Delphinus]

34. I agree, lapfog_1.

I never took Chemistry, so can't reply to that, but when you say you think the projections are way optimistic, based on what I've read, what I see happening, and my own intuitions, the people making these projections are living in denial. Perhaps they don't want to scare us, they want to keep us believing that what we're doing is enough. But it's not enough.

[Gman]

7. I agree with all except the El Nino Southern Oscillation

I believe El Nino has nothing at all to do with global warming. My personal theory is it is caused by an increase in volcanic activity and hot vents on the floor of the Pacific. In El Nino years the vents are overly active and under active in La Nina years.

However, global warming can well exacerbate the effects of an El Nino/La Nina event.

[truedelphi]

12. That's pretty interesting.

Here's a question: Earthquke and volcano experts feel that when there is the added water from melting glaciers, the earthquake and volcano situation intensifies.

So wouldn't that mean there would be more El Nino?

And help please, I have no idea what Southern Oscillation means in reference to E N
If you can explain it, I 'd be grateful.

[Lisa]

31. El Nino is the "warm phase" of the Southern Oscillation

The opposite "cold phase" is called La Nina. Most climate oscillations or teleconnections have a couple of different phases, marked by different circulation patterns. After looking at several of these events, climatologists began to understand which parts of the world are affected by changes in rainfall and temperature that result. With El Nino, some areas dry out and others get a lot of rain. Here in Western Canada there isn't so much rainfall response, but we tend to get a warmer spring (that affects snowmelt). I heard a story that some commodities trader got wind of the research, and figured out that the weather shift could affect harvests in a particular part of North America ... and made money when he guessed correctly.

These sites might help clarify the Southern Oscillation a bit:
http://www.pmel.noaa.gov/tao/elnino/el-nino-story.html
http://www.atmos.washington.edu/gcg/RTN/rtnt.html

[amborin]

8. you can take steps

small ones, but they matter

please support preservation of the boreal forest and its biodiversity

it's as important as the amazon rainforest, but much less well known

<http://www.borealbirds.org/>

purchase only "shade" coffee....this means the coffee is from coffee plantations using the traditional cultivation methods....using coffee plants that require the shade of the forest canopy to survive....the forest canopy supports migratory and endemic bird species....

and, shade coffee does not require the pesticides or water use of the new "sun" coffees that are increasingly replacing traditional shade coffee....

rain forest is being decimated as we speak, so sun loving coffee can be planted....

but it's trashing the planet and its biodiversity

[yellowcanine]

9. But Michael Crichton in "State of Fear" had his fictional characters say it was all bullshit.

Who do you believe, some boring Academy of Sciences Proceedings article or a best selling author? Come on!

[krkaufman]

16. chuckle. I initially read that as "best sellout author" n/t

[Lisa]

10. that monsoon thing really stood out

All pretty bad, but did you see the projected time frame? It could happen very quickly, and there are so many subsistence farmers in that region.

[XemaSab]

11. Not to mention at least half a BILLION people

living in the area.

[Lisa]

27. many of whom need that rain to come on schedule

Exactly as you say, XemaSab. A lot of those half-billion depend on the food they're trying to produce for their families, and they could lose what land they do have, or go hungry, if they have a bad crop. A friend of mine works with some of those communities, and he told me that anyone lucky enough to have built up savings would be wiped out if the same thing happens next year, even if they make it through this growing season.

[Lorien]

13. The Amazon stood out for me

the "lungs of the planet", as so many scientists refer to it. So how do we mammals exist without "lungs"?

[lapfog_1]

17. Collapse of the Indian Monsoon.

in ONE YEAR.

like next year.

not 10 years, not 50 years, but 1 year.

And while the state of Punjab (India's farming heartland) is not as dependent on monsoon as the rest of the agriculture in the nation, it is an important source of water. Of even more importance to Punjab is the rapidly receding glaciers and snow packs in the Himalayas that provide the subsurface water that Punjab uses to water their lands... Farmers have for the last 10 years had to increase the depth of their wells and pay more to pump water, sometimes by 20 feet from year to year. It's a major, major concern because that region accounts for most of the domestic product of wheat, vegetables and non-rice farming for the nation. A nation of nearly 1.12 billion people.

The failure of the Monsoons will most affect the southern rice growing regions, where up wards of 80% of the farmers are dependent on good Monsoon seasons to irrigate their rice paddies.

[Lisa]

26. Exactly. There are so many people depending on the rains to come

Subsistence farmers could lose their lands, or starve, if they can't bring a crop in.

Re: the Punjab and other areas depending on the mountain snowpacks ... agreed, they probably won't lose those within a couple of years, but the inexorable decline during the next decade is going to become more and more evident. I'm doing a research project in Afghanistan -- same problem -- the whole region's going to be hit by this.

[krkaufman]

15. Like say snow thunderstorms ...

... and snow one day and 65 degrees the next? (just experienced in west-central Illinois)

edit: p.s. a lot of plants/trees died or nearly died last year, when w-c Illinois had a hot spell for about a week in late Winter, prompting the plants to think Spring had sprung. Then came the subsequent cold, cold, COLD spell and many trees failed to bloom and a lot of flowers/plants died.

[truthisfreedom]

18. We need a special room here at the forum for sudden climate strangeness.

It's going to get worse by the month.

[XemaSab]

22. Welcome aboard

http://www.democraticunderground.com/discuss/duboard.php?az=show_topics&forum=115

:popcorn:

[On the Road]

19. This Looks Like the Only Good News

Greening of the Sahara/Sahel

My only problem with the article is that many of the changes, such as the artic ice, are already changing at a rapid pace.

[alfredo]

20. This: Collapse of the Indian summer monsoon (about 1 year)

could cause a famine of such scale our leaders will be forced to act.

[Lisa]

30. I just looked at my climograph data -- this could affect Afghanistan and Pakistan too

Apparently there is a small summer rainfall peak that is not as prominent as you go further inland, but it's still very important to people who are practicing dryland farming and do not have access to irrigation. I'm doing background work for an agricultural study in that region now, and I figure I had better pass the OP along to my boss -- he's going to be upset, but I figure he should know.

[alfredo]

33. India has also privatized their water in some areas.

[RaleighNCDUer]

23. I think that 300 yrs for the Greenland ice sheet is wildly optimistic.

I wouldn't bet on more than 50. The loss of of arctic sea ice and subsequent warming of arctic waters could speed the melt off to geometric rates. Already they are finding it is melting at 5 times the speed predicted ten years ago. They are only now learning how to calculate the effects of melt-pools on the surface finding cracks to the base of the glaciers.

Then, what would the effect be of a 20' rise in ocean level (resulting from the Greenland melt off) on the Antarctic sheets? Water pushing inland all around the continent, lifting the ice sheets where they meet the sea, speeding their disintigration and that further rising ocean levels. Antarctica could go in a bare 150 years. Huge sheets of pack ice have already calved off - and that ice, while on the water and not affecting water levels, helped hold back the on-land glaciers. Without that resistance, the glaciers are already moving faster toward the ocean.

[apocalypsehow]

24. And to think there are imbeciles who still deny the reality of Global Warming

The debate is over, even if a few neanderthals like to pretend it's not.

[Massachusetts]

29. I agree "the debate is over"

However its Mother Nature who is setting the new rules, and she waits for NO ONE, Human or otherwise. This is my friends, irreversible, as she is going to cleanup OUR mess Her way..

Time to learn how to forage....

[fascisthunter]

32. Wanna Know Why Some Don't Want You to Talk about Global Warming?

liability

Many do not want to be held liable for damages incurred by extreme weather due to global warming. We aren't just talking about losing a house to a tornado.... We are talking about cities drowning. What do you think it costs an economy when a city gets destroyed? Major Polluters know they are responsible, but can you imagine what would happen if they could be held liable.... collectively?

Think something like that is stiff? Well consider all the damage: Think of New Orleans and the thousands effected..... start smaller if you have to. Think of asthma..... Think of the lives effected and myriads of ways...

There is enough to justify enforcing regulations on every polluter out there. There is no political will, at least where it most counts.