Extreme Sudden Change: Earth Warned on 'Tipping Points'

Question:

It’s good to know that others are taking an interest in climate change issues. We have started a blog at http://climate-today.blogspot.com/. You are very welcome to visit, leave your comments and/or participate in discussions. Weather man and Weather girl – Hide quoted text — Show quoted text – Have chosen to focus on the Arctic and North Atlantic current and cut parts not directly related in that respect. Earth warned on ‘tipping points’ By Alex Kirby BBC News Online environment correspondent The world has barely begun to recognise the danger of setting off rapid and irreversible changes in some crucial natural systems, a scientist says. High stakes He was speaking at the EuroScience Forum in Stockholm, at a briefing by the International Geosphere-Biosphere Programme entitled Beyond Global Warming: Where On Earth Are We Going? * * * "If we can afford to gaze up at the sky looking for asteroids, we should be able to watch our own planet with as much care:-Professor John Schellnhuber * * * Professor Schellnhuber said 12 "hotspots" had been identified so far, areas which acted like massive regulators of the Earth’s environment. If these critical regions were subjected to stress, they could trigger large-scale, rapid changes across the entire planet. But not enough was known about them to be able to predict when the limits of tolerance were reached. "We have so far completely underestimated the importance of these locations," he said. "What we do know is that going beyond critical thresholds in these regions could have dramatic consequences for humans and other life forms." One example of a hotspot was the North Atlantic current, the ocean circulation pattern responsible for bringing warmer air to northern Europe, the collapse of which could lead to a very large regional climate shift. "We should have a much better understanding of these tipping points, and we have to do everything we can to stop short of triggering these instabilities. Unforeseen speed "That means we have to know where they are, and they’ve been off the radar screen for far too long. "Scientists have begun to realise that change could be sudden, not gradual – in some cases it could happen within a few decades." Professor Schellnhuber urged a coordinated global effort to improve understanding and monitoring of Earth’s "Achilles’ heels". He said: "Such an effort is every bit as important as Nasa’s valuable asteroid-spotting programme designed to protect the planet from collisions. "If we can afford to gaze up at the sky looking for asteroids, we should be able to watch our own planet with as much care." http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/3597584.stm One factor that could make the North Atlantic current flip is freshwater, cut from http://www.whoi.edu/institutes/occi/currenttopics/abruptclimate_mcman… : "Rate of Ocean Circulation Directly Linked to Abrupt Climate Change in North Atlantic Region. A new study strengthens evidence that the oceans and climate are linked in an intricate dance, and that rapid climate change may be related to how vigorously ocean currents transport heat from low to high latitudes. A new study, reported April 22 in the journal Nature, suggests that when the rate of the Atlantic Ocean’s north-south overturning circulation slowed dramatically following an iceberg outburst during the last deglaciation, the climate in the North Atlantic region became colder. When the rate of the ocean’s overturning circulation subsequently accelerated, the climate warmed abruptly. Study author Jerry McManus and colleagues Roger Francois, Jeanne Gherardi, Lloyd Keigwin and Susan Brown-Leger at the Woods Hole Oceanographic Institution and in France report that the coldest interval of the last 20,000 years occurred when the overturning circulation collapsed following the discharge of icebergs into the North Atlantic 17,500 years ago. This regional climatic extreme began suddenly and lasted for two thousand years. Another cold snap 12,700 years ago lasting more than a thousand years and accompanied another slowdown of overturning circulation. Each of these two cold intervals was followed by a rapid acceleration of the overturning circulation and dramatically warmer climates over Northern Europe and the North Atlantic region." The biggest potential sources of freshwater to the North Atlantic are Greenland and increased precipitation, the one with the largest potential of rapid release, is the Beaufort Gyre. The Beufort Gyre is a clockwise swirl north of Canada/Alaska containing 45,000 km^3 freshwater, more than twice the amount contained in Arctic sea ice. Clockwise swirls in the Arctic collects sea ice and fresh surface water because of the coriolis effect(http://www.physics.ohio-state.edu/~dvandom/Edu/newcor.html ) More on the Beaufort Gyre: Text, http://www.whoi.edu/beaufortgyre/ Illustradet, http://seis.natsci.csulb.edu/rmorris/seaice/drift.htm What makes this gyre dangerous is that if climate change and melting sea ice flips the current wind regime in the Beaufort sea from anticyclonic(clockwise) to cyclonic(low pressure), westerly winds blowing on a relative ice free Arctic could blow a lot of the freshwater locked up in the gyre into the Transpolar drift and then the N.Atlantic.

Response:

Have chosen to focus on the Arctic and North Atlantic current and cut parts not directly related in that respect. – Hide quoted text — Show quoted text – Earth warned on ‘tipping points’ By Alex Kirby BBC News Online environment correspondent The world has barely begun to recognise the danger of setting off rapid and irreversible changes in some crucial natural systems, a scientist says. High stakes He was speaking at the EuroScience Forum in Stockholm, at a briefing by the International Geosphere-Biosphere Programme entitled Beyond Global Warming: Where On Earth Are We Going? * * * "If we can afford to gaze up at the sky looking for asteroids, we should be able to watch our own planet with as much care:-Professor John Schellnhuber * * * Professor Schellnhuber said 12 "hotspots" had been identified so far, areas which acted like massive regulators of the Earth’s environment. If these critical regions were subjected to stress, they could trigger large-scale, rapid changes across the entire planet. But not enough was known about them to be able to predict when the limits of tolerance were reached. "We have so far completely underestimated the importance of these locations," he said. "What we do know is that going beyond critical thresholds in these regions could have dramatic consequences for humans and other life forms." One example of a hotspot was the North Atlantic current, the ocean circulation pattern responsible for bringing warmer air to northern Europe, the collapse of which could lead to a very large regional climate shift. "We should have a much better understanding of these tipping points, and we have to do everything we can to stop short of triggering these instabilities. Unforeseen speed "That means we have to know where they are, and they’ve been off the radar screen for far too long. "Scientists have begun to realise that change could be sudden, not gradual – in some cases it could happen within a few decades." Professor Schellnhuber urged a coordinated global effort to improve understanding and monitoring of Earth’s "Achilles’ heels". He said: "Such an effort is every bit as important as Nasa’s valuable asteroid-spotting programme designed to protect the planet from collisions. "If we can afford to gaze up at the sky looking for asteroids, we should be able to watch our own planet with as much care." http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/3597584.stm

One factor that could make the North Atlantic current flip is freshwater, cut from http://www.whoi.edu/institutes/occi/currenttopics/abruptclimate_mcman… : "Rate of Ocean Circulation Directly Linked to Abrupt Climate Change in North Atlantic Region. A new study strengthens evidence that the oceans and climate are linked in an intricate dance, and that rapid climate change may be related to how vigorously ocean currents transport heat from low to high latitudes. A new study, reported April 22 in the journal Nature, suggests that when the rate of the Atlantic Ocean’s north-south overturning circulation slowed dramatically following an iceberg outburst during the last deglaciation, the climate in the North Atlantic region became colder. When the rate of the ocean’s overturning circulation subsequently accelerated, the climate warmed abruptly. Study author Jerry McManus and colleagues Roger Francois, Jeanne Gherardi, Lloyd Keigwin and Susan Brown-Leger at the Woods Hole Oceanographic Institution and in France report that the coldest interval of the last 20,000 years occurred when the overturning circulation collapsed following the discharge of icebergs into the North Atlantic 17,500 years ago. This regional climatic extreme began suddenly and lasted for two thousand years. Another cold snap 12,700 years ago lasting more than a thousand years and accompanied another slowdown of overturning circulation. Each of these two cold intervals was followed by a rapid acceleration of the overturning circulation and dramatically warmer climates over Northern Europe and the North Atlantic region." The biggest potential sources of freshwater to the North Atlantic are Greenland and increased precipitation, the one with the largest potential of rapid release, is the Beaufort Gyre. The Beufort Gyre is a clockwise swirl north of Canada/Alaska containing 45,000 km^3 freshwater, more than twice the amount contained in Arctic sea ice. Clockwise swirls in the Arctic collects sea ice and fresh surface water because of the coriolis effect(http://www.physics.ohio-state.edu/~dvandom/Edu/newcor.html ) More on the Beaufort Gyre: Text, http://www.whoi.edu/beaufortgyre/ Illustradet, http://seis.natsci.csulb.edu/rmorris/seaice/drift.htm What makes this gyre dangerous is that if climate change and melting sea ice flips the current wind regime in the Beaufort sea from anticyclonic(clockwise) to cyclonic(low pressure), westerly winds blowing on a relative ice free Arctic could blow a lot of the freshwater locked up in the gyre into the Transpolar drift and then the N.Atlantic.

Response:

Earth warned on ‘tipping points’ By Alex Kirby BBC News Online environment correspondent The world has barely begun to recognise the danger of setting off rapid and irreversible changes in some crucial natural systems, a scientist says. Professor John Schellnhuber says the most important environmental issues for humans are among the least understood. He told a briefing in Sweden that the Asian monsoon was one of the "tipping points" that could change very quickly. He said a better understanding of the risks was as important as the programme to prevent collisions with asteroids. Professor Schellnhuber is research director of the UK’s Tyndall Centre for Climate Change Research. High stakes He was speaking at the EuroScience Forum in Stockholm, at a briefing by the International Geosphere-Biosphere Programme entitled Beyond Global Warming: Where On Earth Are We Going? * * * "If we can afford to gaze up at the sky looking for asteroids, we should be able to watch our own planet with as much care:-Professor John Schellnhuber * * * Professor Schellnhuber said 12 "hotspots" had been identified so far, areas which acted like massive regulators of the Earth’s environment. If these critical regions were subjected to stress, they could trigger large-scale, rapid changes across the entire planet. But not enough was known about them to be able to predict when the limits of tolerance were reached. "We have so far completely underestimated the importance of these locations," he said. "What we do know is that going beyond critical thresholds in these regions could have dramatic consequences for humans and other life forms." One example of a hotspot was the North Atlantic current, the ocean circulation pattern responsible for bringing warmer air to northern Europe, the collapse of which could lead to a very large regional climate shift. Faltering monsoon Others were the West Antarctic ice sheet, the Sahara desert, and the forests of the Amazon basin. Yet another hotspot, Professor Schellnhuber said, was the Asian monsoon system. He told BBC News Online: "Modelling has shown that if air pollution and land use change, this could alter the albedo, the reflectivity, of the land. "This in turn could weaken or even suppress the monsoon, and there is evidence that several times in the last few years it has in fact been weaker. "We’re investing too much in things like improving the accuracy of our weather forecasts, while the really vital elements in the Earth’s system are the unstable phenomena like the monsoon. "We should have a much better understanding of these tipping points, and we have to do everything we can to stop short of triggering these instabilities. Unforeseen speed "That means we have to know where they are, and they’ve been off the radar screen for far too long. "Scientists have begun to realise that change could be sudden, not gradual – in some cases it could happen within a few decades." Professor Schellnhuber urged a coordinated global effort to improve understanding and monitoring of Earth’s "Achilles’ heels". He said: "Such an effort is every bit as important as Nasa’s valuable asteroid-spotting programme designed to protect the planet from collisions. "If we can afford to gaze up at the sky looking for asteroids, we should be able to watch our own planet with as much care." http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/3597584.stm = = = = STILL FEELING LIKE THE MAINSTREAM U.S. CORPORATE MEDIA IS GIVING A FULL HONEST PICTURE OF WHAT’S GOING ON? = = = = Daily online radio show, news reporting: www.DemocracyNow.org = = = = Sorry, we cannot read/reply to most usenet posts but welcome email For more information: http://EconomicDemocracy.org/wtc/ (peace) And http://EconomicDemocracy.org/ (general) ** ANTI-SPAM EMAIL NOTE: For email "info" and "map" don’t work. Email to ** m-a-i-l-m-a-i-l (without the dashes) at economicdemocracy.org instead

Response:

Filed under: Media activism

XHTML: You can use these tags: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

TrackBack URL | RSS feed for comments on this post.

Activism Change

Learn, read, react :: Activism