Wednesday, January 12, 2011
Videos: Atmospheric CO2, Silly Stuff
800,000 years of atmospheric CO2 from NOAA's Carbon Tracker Channel on YouTube.
That can be a little depressing when you think about it, so . . .
This is just classic:
The Australia reference is from the novel and later movie, On the Beach, about fallout from a nuclear war slowly destroying the world.
2010 Ties as Warmest Year, Brings Extreme Weather
NASA and NOAA both are reporting that 2010 has tied with 2005 as the warmest year on record. A plot of the NASA data:
It was also the wettest year on record.
The link between warmer and wetter is pretty straightforward: warmer air holds more water (about 7% per degree C of warming). A warmer atmosphere also circulates more vigorously. You might think of the atmosphere as a sponge which has gotten larger and gets wrung out more thoroughly.
Ironically, the same things that cause the atmosphere to become more heavily loaded with water (to oversimplify: enhanced evaporation) also can cause soils and plants to dry out much more quickly.
Climate Progress has interviewed climate scientist Kevin Trenberth, who had this to say:
I find it systematically tends to get underplayed and it often gets underplayed by my fellow scientists. Because one of the opening statements, which I’m sure you’ve probably heard is “Well you can’t attribute a single event to climate change.” But there is a systematic influence on all of these weather events now-a-days because of the fact that there is this extra water vapor lurking around in the atmosphere than there used to be say 30 years ago. It’s about a 4% extra amount, it invigorates the storms, it provides plenty of moisture for these storms and it’s unfortunate that the public is not associating these with the fact that this is one manifestation of climate change. And the prospects are that these kinds of things will only get bigger and worse in the future.Trenberth has written a paper, Changes in precipitation with climate change (PDF), which gets into the gory details.
Perhaps more worrying is this Climate Progress quote from meteorologist Dr. Jeff Masters, discussing the huge increase in extreme weather events in 2010:
In my thirty years as a meteorologist, I’ve never seen global weather patterns as strange as those we had in 2010. The stunning extremes we witnessed gives me concern that our climate is showing the early signs of instability. Natural variability probably did play a significant role in the wild weather of 2010, and 2011 will likely not be nearly as extreme. However, I suspect that crazy weather years like 2010 will become the norm a decade from now, as the climate continues to adjust to the steady build-up of heat-trapping gases we are pumping into the air. Forty years from now, the crazy weather of 2010 will seem pretty tame. We’ve bequeathed to our children a future with a radically changed climate that will regularly bring unprecedented weather events–many of them extremely destructive–to every corner of the globe. This year’s wild ride was just the beginning.Emphasis mine. (More on that later.)
The increase in rainfall presents a huge problem for infrastructure, not only because existing infrastructure is unable to handle the associated increases in runoff, but also because engineers have no good way to decide what to design for.
For example, a normal design criterion is to make the design (a road or drain system or bridge or whatever) able to withstand a "100-year" storm, i.e., a storm which has a 1 in 100 chance of happening in any one year. But now many areas are having 100-year storms about every 5 years.
What to do?
I saw one very sophisticated and elaborate study that went to great efforts to get data for the last 150 years. They did a fabulous analysis on that data and published beautiful color maps of 100-year (and 5-year, 10-year, etc.) storms for use in engineering design.
That's nice, but our climate started on its present path in the mid-1970s. Anything before that reflects a climate which no longer exists.
There is a saying in shooting: "You cannot miss hard enough."
Tuesday, January 11, 2011
Loss of Greenland Ice Sheet Possibly Unavoidable
Modeling results from the Danish Meteorological Institute suggest Greenland's ice sheet might be past the point of no return already. Politiken.dk reports:
There is the obvious surface melting, which is how people would normally think of an ice sheet being lost: warm air, rain, etc. melts the ice from the surface.
The resulting melt water causes some other interesting effects. One is a lubricating effect. When melt water finds a crack in the ice, it wedges the ice open and can create a conduit that brings the water deep into the ice sheet, all the way to bedrock. This water both lubricates the flow of ice and warms the ice, softening it.
There has been some speculation that large masses of ice might get warmed and soften sufficiently that it won't be able to support its own weight. That would create episodes of "iceslides" if you will: sudden structural failure of city-sized areas thousands of feet thick. It would be quite something to see.
Another mechanism of ice loss from Greenland is warm ocean water melting glaciers at their outlets from below. Some glaciers in Greenland are grounded below sea level for quite a distance inland.
In the future it is expected that, as the height of the ice sheet is reduced by ice loss, the warmer air at lower altitudes will cause even faster melting. So, once the ice sheet loses a certain amount of altitude it will be impossible to stop further melting without significant cooling of the climate.
The complete loss of Greenland would raise sea level by an average of around 7 m. This process had been expected to take a thousand years or so, but the discovery of previously unknown mechanisms outlined above shortens the timeline significantly.
It is hard to say how fast this could go. Present warming is proceeding about 10x faster than at any time known from the geologic record. A couple of hundred years perhaps?
You would have to assume the loss of Greenland would be accompanied by the simultaneous loss of West Antarctica (~5 m worth of rise), which is even more unstable, as well as some unknown contribution from East Antarctica.
If you figure losing half of Greenland's ice mass in 200 years with an equal contribution from West Antarctica, that is 3.5 m (Greenland) plus 2.5 m (W. Antarctica) over 200 years or 3 m per century without even considering East Antarctica.
Previous deglaciations have produced sea level rises of 2.5 m per century and perhaps as much as 5 m per century, with a much slower warming.
Regardless, it is very difficult to see much more than about 1 m by mid-century.
The result of an international scientific paper, based on data and models from the Danish Meteorological Institute, is suggesting that an eventual meltdown of Greenland’s ice-cap is almost unavoidable. . . .Greenland has some interesting mechanisms of ice loss, some of which were unknown just a few years ago.
After 2040, on a time scale of 1,000 years ahead, it will not be possible for the giant Greenland ice-cap to be re-created and return to current levels.
“Over the next 30 years the amount of snowfall will not compensate for melting,” Hesselbjerg Christensen tells pol.dk adding: “Based on our model, I would almost say that the point of no return has already been passed. Our result shows in principle that permanent meltdown is unavoidable.”. . .
There is the obvious surface melting, which is how people would normally think of an ice sheet being lost: warm air, rain, etc. melts the ice from the surface.
The resulting melt water causes some other interesting effects. One is a lubricating effect. When melt water finds a crack in the ice, it wedges the ice open and can create a conduit that brings the water deep into the ice sheet, all the way to bedrock. This water both lubricates the flow of ice and warms the ice, softening it.
There has been some speculation that large masses of ice might get warmed and soften sufficiently that it won't be able to support its own weight. That would create episodes of "iceslides" if you will: sudden structural failure of city-sized areas thousands of feet thick. It would be quite something to see.
Another mechanism of ice loss from Greenland is warm ocean water melting glaciers at their outlets from below. Some glaciers in Greenland are grounded below sea level for quite a distance inland.
In the future it is expected that, as the height of the ice sheet is reduced by ice loss, the warmer air at lower altitudes will cause even faster melting. So, once the ice sheet loses a certain amount of altitude it will be impossible to stop further melting without significant cooling of the climate.
The complete loss of Greenland would raise sea level by an average of around 7 m. This process had been expected to take a thousand years or so, but the discovery of previously unknown mechanisms outlined above shortens the timeline significantly.
It is hard to say how fast this could go. Present warming is proceeding about 10x faster than at any time known from the geologic record. A couple of hundred years perhaps?
You would have to assume the loss of Greenland would be accompanied by the simultaneous loss of West Antarctica (~5 m worth of rise), which is even more unstable, as well as some unknown contribution from East Antarctica.
If you figure losing half of Greenland's ice mass in 200 years with an equal contribution from West Antarctica, that is 3.5 m (Greenland) plus 2.5 m (W. Antarctica) over 200 years or 3 m per century without even considering East Antarctica.
Previous deglaciations have produced sea level rises of 2.5 m per century and perhaps as much as 5 m per century, with a much slower warming.
Regardless, it is very difficult to see much more than about 1 m by mid-century.
The Problem
Earth's climate has already warmed about 1 degree C due to the insulating effects of CO2. That's not much warming, but already changes are happening which are obvious if you look: accelerating ice loss from Antarctica and Greenland, increased drought and flooding, more wild weather events, etc.
At the depths of the last ice age Earth was around 5 or 6 C cooler than today. You can see that a temperature change which seems small can have huge effects on the condition of Earth's surface environment.
We are on track for about 5 or 6 C more warming this century, possibly within the next 50 or 60 years. So, children alive today probably will see incredible changes.
In very brief terms what this means is that we will see a significant fraction of Earth's land area turn from farm land and forest to desert. The oceans will warm enough to guarantee the loss of large portions of the ice sheets in Greenland and Antarctica, raising sea levels at least 30 ft or so. (Much of these ice sheets sit below sea level, allowing warm sea water to melt them from below.)
Even though so much damage now is inevitable, stopping further CO2 emissions does two things:
As a civilization, we need to stop pumping out CO2 as soon as possible. If we don't it is hard to see how civilization will remain intact.
As individuals, we need to brace ourselves against the problems that are to come. Identifying those problems and developing ways to deal with them is the primary purpose of this blog.
To borrow the format of my college homework days:
Given: A rapidly warming climate, as outlined above.
Required: Make it through intact, both as a civilization and as individuals.
Solution: To be continued . . .
At the depths of the last ice age Earth was around 5 or 6 C cooler than today. You can see that a temperature change which seems small can have huge effects on the condition of Earth's surface environment.
We are on track for about 5 or 6 C more warming this century, possibly within the next 50 or 60 years. So, children alive today probably will see incredible changes.
In very brief terms what this means is that we will see a significant fraction of Earth's land area turn from farm land and forest to desert. The oceans will warm enough to guarantee the loss of large portions of the ice sheets in Greenland and Antarctica, raising sea levels at least 30 ft or so. (Much of these ice sheets sit below sea level, allowing warm sea water to melt them from below.)
Even though so much damage now is inevitable, stopping further CO2 emissions does two things:
- It makes the end state of warming less severe.
- It slows the process.
As a civilization, we need to stop pumping out CO2 as soon as possible. If we don't it is hard to see how civilization will remain intact.
As individuals, we need to brace ourselves against the problems that are to come. Identifying those problems and developing ways to deal with them is the primary purpose of this blog.
To borrow the format of my college homework days:
Given: A rapidly warming climate, as outlined above.
Required: Make it through intact, both as a civilization and as individuals.
Solution: To be continued . . .
Introduction
Things are happening to the natural world which already are affecting human civilization. Weather disasters are becoming more frequent. Natural environments have begun to show real strain. The world we have come to know is vanishing as we watch, being replaced with a world in rapid transition.
The expectation is that these ongoing changes will accelerate. The implications for civilization are almost unfathomably bad, causing a large fraction of the population to reject them out of hand.
What I intend to do with this blog is report things about this process of change from my own point of view. In other words, I will report events as I watch them in morbid fascination. Along with reports I will inject my own interpretations.
Specifically I am speaking of global warming and related effects like the acidification of the oceans.
Very few people are familiar with what is going on with global warming. Some reject the whole thing as a socialist hoax. Others accept it, but don't have a good feel for the severity of the situation.
There is a lot to cover, and a lot to digest. It might take a year or so for this to really sink in.
Along with a healthy dose of doom I intend to sprinkle in some sustainability. Not the expensive, technological, fashionable kind of sustainability, but real, down-to-earth, rubber-meets-the-road sustainability: basic technologies and practices that might very well make the difference for many of us and our children.
The expectation is that these ongoing changes will accelerate. The implications for civilization are almost unfathomably bad, causing a large fraction of the population to reject them out of hand.
What I intend to do with this blog is report things about this process of change from my own point of view. In other words, I will report events as I watch them in morbid fascination. Along with reports I will inject my own interpretations.
Specifically I am speaking of global warming and related effects like the acidification of the oceans.
Very few people are familiar with what is going on with global warming. Some reject the whole thing as a socialist hoax. Others accept it, but don't have a good feel for the severity of the situation.
There is a lot to cover, and a lot to digest. It might take a year or so for this to really sink in.
Along with a healthy dose of doom I intend to sprinkle in some sustainability. Not the expensive, technological, fashionable kind of sustainability, but real, down-to-earth, rubber-meets-the-road sustainability: basic technologies and practices that might very well make the difference for many of us and our children.
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