In a comprehensive study published by a group of climate experts identify the nine areas that are in gravest danger of passing critical thresholds or “tipping points”, beyond which they will not recover.
Their assessment warns it may already to be too late to save Arctic sea ice and Greenland ice sheet, which they regard as the most immediately in peril.
Next most vulnerable area is the Amazon rain-forest, where reduced rainfall threatens to claim large areas of trees that will not re-establish themselves. The scientists also expressed concerns over the Boreal forests in the north, and predicted that El Nino, the climate system which has a profound impact on weather from Africa to North America, will come more intense.
The team consists of Potsdam Institute for climate Impact Research in Germany, The University of East Anglia and Oxford University’s Environmental Change Institute. The report is published in the Proceeding of the National Academy of Science.
Last year, the UN’s expert panel of climate scientists warned average temperatures could increase by as mush as 6.4C by the end of the century, with a rise of 4C most likely. Such a rise would bring food and water shortage to vulnerable parts of the world, displace millions of people and wipe out hundreds of species.
In the latest study scientists calculate Arctic sea ice will go into irreversible decline once temperature rise between 0.5C to 2C above those at the beginning of the century, a threshold that may already have been crossed. There is already a 50% chance that the Greenland ice sheet will soon begin melting unstoppably, though it could take hundreds of years to melt completely.
The melt water would raise global sea levels by seven meters.
A temperature rise of 3C could see more intense El Ninos, with profound effects on the weather from Africa to North America.
The warming of 3C to 5C could reduce rainfall in Amazon by 30%, lengthening the dry season. The Boreal forests could also pass their tipping point, with large swaths dying off over the next 50 years. In Africa, more rainfall may re green the Sahel region, but the west African monsoon could collapse, leading to twice as many unusual dry years by the end of the century.
The Indian summer monsoon is predicted to become erratic and in the worst case scenario, begin to flip chaotically, unleashing flash floods one year and droughts the next.
Measurements of the western Antarctic ice sheet show the balance of snowfall and melting has shifted and it is now shrinking. According to the study, a local warming of more than 5C could trigger uncontrollable melting, adding five meters to sea levels within 300 years. Under the same warming, Atlantic currents that power the Gulf Stream could be severely disrupted.
– from Guardian
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Yes Beem. We already crossed the limit. So what next? There will be solutions/workarounds if water rises or weather changes. So whats the lesson we learned? Should these problems are inevitable? Whether there were any chance we could avoid these problems?
The sad thing is that all these problems are created by us. One classic example is automobile industry. Automobile which uses internal combustion engine has an efficiency of 15%. ie, 85% of fuel is burnt for nothing (yes for making oil companies rich). Also if you include losses by traffic jams, signals and inefficient gear transfers etc the efficiency will drop to less than 10%. Also manufacturing of gearboxes, clutch, carburetors, fuel injectors etc also have a carbon footprint. Should we need all these complexities for transportation? Should we need to drive these vehicles? Electric motor is more than 85% efficient. It does not require any complex machinery to run. why cant we use electric vehicles? As per Margaret Thacher if you dont have a car you are unprivileged. This is the mantra media and market spreading. Is one person per car is a necessity? Can state provide public transportation facility to its citizen ?
All these time Media and Market are fooling us. They must be punished (whether we solve all these issues or not is a different problem). One thing that we can do is to reduce our consumption. Try to reuse. Practice ethical living. Dont pay our money to these sinister blood suckers (Market and Media)
– jagadees
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Basic science, latent heat, answers the question in the title of the article and leaves no doubt. The “tipping points” were reached quite a while ago, at least for Greenland, and more recently for Antarctica. For a solid (eg. ice) to melt it first requires heat to reach melting point, then it absorbs more heat, as latent heat, then it melts. To refreeze it requires more “cold” once it reaches freezing point to solidify. Greenland ice has already absorbed heat to melt, and now Antarctica ice has too. They are already runaway trains, we need a hundred years of “global cooling” to stop them.