Monthly Archives: November 2015

How to do voting

The Days When Democracy In America Was Bogus

First, three stories. One comes from other sources, not verified, but everyone at the time (it is said) knew it to be true. Political operatives in the Boston area used to visit the train yards during the days and hours before a local mayoral election. They would round up the numerous “bums and hobos” (now known as homeless people) living in the train yards. Those interested, which appear to have been most, would accept a bit of cash and a broken comb. The cash was their payoff. The comb was broken in such a way that if you set it next to the paper ballot at the voting location, the missing teeth would indicate where to place your mark.

Second story: something I observed as a kid. I would be taken to the election site every year, the fire house on Delaware and Marshall in Albany New York, by one of the adults voting in our house, usually my grandmother. On at least one occasion, I observed a man sitting on a tall ladder, I assume supplied by the fire department. Here is how you voted. You would go up to a desk and give your name. The person at the desk would say your name out loud, and the guy on the ladder would look you up on a list. Then, you would go into the voting booth and pull the big red lever, which would close the curtain. The mechanical voting machine had one lever for each candidate, which were organized in columns. President, governor, mayor, various other candidates, stacked up, all of the candidates in one party per column. At the top of the column was the lever to “vote the ticket.” If you wanted to vote for all Democrats, you just flip the lever at the top of that column.

These levers were all visible to the guy on the ladder. That is why he was on the ladder. If you pulled the Democratic Party lever, you got a check mark next to your name.

Then, the next summer, you take your kid down to city hall to get a summer job. Or, you get pulled over by the cops for speeding or get a parking ticket. Or the tax assessors come to set a value for your home to determine your property tax. Or you call in a big pothole in front of your house, to get if fixed. If your name has the check on it, your kid gets the job, your traffic ticket is fixed, your taxes are lower, and your pothole gets fixed. There was a staff of ticket fixers up on the top floor of City Hall, in the tax assessors domain, correlating, mostly, parking tickets to checkmarks. And so on.

Third: I helped a bit with the recount of a major election a couple of years ago. I heard something interesting while doing that. A democratic official working on the recount noted that he was, years ago, in the US Navy, and had the job of collecting write-in ballots for a large unit (a destroyer or something). What they really did, he said, was to get the write-in ballots, get a few guys together, and write in all the votes, for as it turns out, the Republican presidential candidate. That man should be in jail, but instead, he is in charge of elections. (The fact that he switched party is meaningless.)

My point is simply this: In America, we have a long tradition of fixing the vote. How much votes are or have been fixed varies, certainly, across states and cities. I lived in a totally rigged city, with a political machine running things. I’m intimately aware of how that machine worked, because I was one of the kids who got the summer job, and this eventually put me in direct contact with the operatives. I saw the traffic tickets getting fixed, and so on. The other thing that varies across states and cities is the degree to which the citizens assume voting is always clean vs. assume it is often dirty, or something in between. But the two, how often voting is fixed and how much people assume it is or is not, are probably not very well correlated. The vast majority of Americans, I suspect, don’t think this is a thing we do in this country.

I hope, and there is evidence for this, that the blatant and systematic fixing of votes we saw in Depression Era Boston or Machine Era Albany, is a thing of the past. Our democracy was far more bogus back than than it is now.

Right?

We Are Still Doing Voting Wrong

Maybe, maybe not. But one thing a lot of people fear is that with electronic voting, the old days of comb- or ladder-assisted election fraud are coming back.

We are not doing voting right in the US. First, we have vastly different ways of doing it across states. It is highly unlikely that each state has special problems that require different approaches. Rather it can be assumed that one or two states do it best (though maybe not well enough) and all the other states are inferior. That should give pause.

We’ve seen enough messing around with electronic voting, or voting where machines are too much involved, to suspect this is a game-able system. A recent case in Kentucky underscores this problem.

For the gubernatorial race between Democrat Conway, Republican Bevin, and some other guy, the polls looked like this:

Screen Shot 2015-11-09 at 11.41.06 AM

From Huffpo Pollster, looking only at likely voters in non-partisan polls, we have this:

Screen Shot 2015-11-09 at 11.43.19 AM

So the race should have been close, with Conway likely to win.

Here is what happened.

Screen Shot 2015-11-09 at 11.44.05 AM

Major reversals happen, and this could be that. Note that the other guy (Curtis) lost three points the final polling than in the predictive polls, so third party voters switching to a mainstream candidate could explain this. But, in down ticket races, the Democrats all did as expected in relation to the Republicans. Also, Kentucky tends to elect Democratic governors. So, this is not a 100% clear cut case of something gone wrong, but this is a race one would want to look at. Poll analyzer Richard Charnin has an analysis that certainly brings up questions. (See also this summary.)

We also know that the two major parties have differences in how often ballots are improperly counted, depending on the kind of ballot system used, such that more Democratic voter’s ballots are disregarded. This was obvious in the Coleman-Franken recount. In that case, Coleman won the election by a couple of hundred votes, which required a recount. After the recount, which was done very carefully and properly, Franken had won by an order of magnitude more votes. Most of that change consisted of Democratic voters messing up their ballots by accident. If you have a big tent party, there’s gonna be a few people in the tent who can’t draw a straight line (we use straight lines to pick our candidates in Minnesota).

How To Do Voting Right

I think we should reject electronic voting entirely. Casting an electronic ballot is asking for the vote to be hacked. Just don’t do that.

Machine assisted voting is a good idea. People will mess up a paper ballot quite often. If a machine was used to properly produce a paper ballot, the paper ballots could be checked for accuracy, would be devoid of confusing marks or other goofs, and be valid 99.99% of the time.

We could, of course, use basic counting machines to get a preliminary count of those ballots. This should be followed by an audit that verifies the overall processing of ballots and samples a subset of ballots in order to determine that everything went well. How large that sample is should be determined by the closeness of the vote.

Automatic recounts are normal for many districts, but the threshold to trigger a recount varies. That threshold should follow national best practices, and be larger than most thresholds currently are (a few percent at least).

In the end, the official ballots will be paper ballots with a low frequency of mistakes, which can be hand-and-eye recounted to verify the machine counts. In the event of a full recount, every ballot would be examined as per normal.

This is not hard. What I’m suggesting here is, as far as I can tell, the best way to do voting. Since write-in ballots would not be machine-made, adding a provision to send back bad ballots submitted prior to a certain date may be necessary, especially in states where a very large percentage of the votes are sent in.

I think the average citizen in the US is too trusting of how the system works. Well, really, most people either trust the system not at all, or assume there is not really any intentional election rigging. But election rigging has always been part of the voting process in the US, being a major factor at some times and places, and hopefully a minor factor most of the time in most place. But electronic machine voting provides yet another opportunity for both voter suppression and election fraud, and if more electronic voting is implemented, we should see more voter fraud. There is too much at stake, and people generally are not as trustworthy as we would like. We need a system that simply does not allow this to happen at all.

Big Climate Change Data Gets Musical

Scientists and journalists constantly look for fresh ways to communicate the impacts of climate change. Visualisation of data is now well-known and widely practised. But a new project is doing something a little out of the ordinary: it’s turning climate data into sound.

The idea behind ‘Climate symphony’ is to translate hard data on climate change into a musical composition that engages the public — encouraging people to question their feelings and the stories behind the data, and create a conversation.

In this audio interview we speak to Katharine Round and Leah Borromeo of Disobedient Film Company, the co-creators of the work, alongside composer Jamie Perera. They explain that, by listening to the climate symphony, people will be able to tangibly experience climate data and immerse themselves in it. Research shows that sound touches us in inexplicable ways. By using music, the hope is to create an emotional response to something that for many might look meaningless on a page. “In a world where we’re saturated with hearing the same messages,” they say, “any way to engage people with a subject [as] important [as] climate change is worthwhile.”

The story is here.

And, here is the interview.

Hat Tip: Digital Rabbit

Meat, Processed Meat and Cancer Risk: Interview

A few days ago the UN agency in charge of keeping track of cancer risks listed meat and processed meats as to some degree or another likely to cause an increase in cancer risks. I wrote about that here. More recently. I was interviewed by Joshua Holland on the Politics and Reality Radio show about that story. Here is the interview for your listening pleasure:

Keystone XL Will Become ExKeystone, ‘ell yeah.

According to sources, like this one, President Obama is about to nix the Keystone XL deal.

One of those “hastily called” press conference is set for just before noon Eastern.

Sorry about your stock values and stuff, TransCanada.

2016 US Presidential Election: Trump/Carson/Somebody vs. Clinton (polls)

The current polling as shown on the Huffpo Pollster, using only “likely voters” and “non partisan polls” shows that Trump and Carson are neck and neck and have been close for a week. Most of the other candidates are so low it is impossible to imagine any of them rising to a level of significance. On the other hand, there are still so many clowns in the clown car that it is hard to say. If eight or nine of the candidates dropped out over the next few weeks, it is possible that someone will rise up.

On the other hand, there is a thing about how the Republicans pick their candidate that may have a significant effect and cause neither Carson nor Trump to get the nomination. It works like this. There are many states (and/or Congressional Districts, which matters more in some states) where there aren’t that many Tea Bagger Republicans, but still a good number of delegates. States like New York could be sending a very large number of delegates who would never consider a Trump or a Carson, while states like Alabama might send a small number of delegates who are strongly in favor of the fringe candidates (like Trump and Carson, fringe in the sense of their, well, you know what I mean.) So, we’ll see. Frankly, we might not know what is going to happen in the GOP race until Super Tuesday or later.

In the Democratic Race, looking again only at likely voters and non-partisan pols, Clinton has been ahead of Sanders all along and her relative position has risen slightly. Hillary Clinton currently has a commanding and steadily growing lead over Sanders.

The Gop poll is shown above, the Democratic poll shown below.

Screen Shot 2015-11-05 at 1.32.45 PM

Evidence of high climate sensitivity

I’m not going to say anything about this research because I’ve not read the paper, but it looks important. If someone out there writes something up I’ll put a link here.

Here’s the deal. Climate sensitivity is, very oversimplified, how much the surface of the planet heats up as we add CO2 and other greenhouse gasses to the atmosphere. More specifically, equilibrium climate sensitivity is the number of degrees C the atmosphere at face height and the sea surface heat up with a doubling of CO2 from pre-industrial levels.

If our atmosphere had just nitrogen and CO2 and that’s it, the number would be fairly low, about 1.2 degrees C. But live would not exist here because there would be no water, so we would not be having this conversation. The fact that we are having this conversations suggests the existence of water vapor, which cranks up sensitivity quite a bit, because more CO2 means more heat means more water vapor. That is just one of a number of “positive” (read not good) feedbacks on climate sensitivity.

I’ve noted before that if you offer a group of informed climate scientist the chance to guess a single number for climate sensitivity, using the Free Beer method, is something like 3.0. Certainly not less than 2.0. But it could just possibly be much higher, like 6. The chances of climate sensitivity being 6 are small, and if it turned out to be, then we are truly Doomed. But here’s the thing. The upper range of possible values for this important number is what is sometimes called a “fat tail.” The chances are low, but not so low they can be ignored.

Here’s a picture of a fat tail.

uncertainty_sensitivity

Even a value of 4 or 5 would be bad, and the chances are not vanishingly small that this would be the value.

So, about the latest research.

Title: Long-term cloud change imprinted in seasonal cloud variation: More evidence of high climate sensitivity

Authors: Chengxing Zhai, Jonathan H. Jiang, Hui Su

Abstract: The large spread of model equilibrium climate sensitivity (ECS) is mainly caused by the differences in the simulated marine boundary layer cloud (MBLC) radiative feedback. We examine the variations of MBLC fraction in response to the changes of sea surface temperature (SST) at seasonal and centennial time scales for 27 climate models that participated in the Coupled Model Intercomparison Project phase 3 and phase 5. We find that the intermodel spread in the seasonal variation of MBLC fraction with SST is strongly correlated with the intermodel spread in the centennial MBLC fraction change per degree of SST warming and that both are well correlated with ECS. Seven models that are consistent with the observed seasonal variation of MBLC fraction with SST at a rate ?1.28?±?0.56%/K all have ECS higher than the multimodel mean of 3.3?K yielding an ensemble-mean ECS of 3.9?K and a standard deviation of 0.45?K.

Potential meaning: Ruh roh.

These results are not particularly unexpected. But one would hope that more research would show a lower number, because we really don’t want this to be a higher number.

See also: Future warming likely to be on high side of climate projections, analysis finds, which covers A Less Cloudy Future: The Role of Subtropical Subsidence in Climate Sensitivity, by John Fasullo and Kevin Trenberth. Science, 9 November 2012:

An observable constraint on climate sensitivity, based on variations in mid-tropospheric relative humidity (RH) and their impact on clouds, is proposed. We show that the tropics and subtropics are linked by teleconnections that induce seasonal RH variations that relate strongly to albedo (via clouds), and that this covariability is mimicked in a warming climate. A present-day analog for future trends is thus identified whereby the intensity of subtropical dry zones in models associated with the boreal monsoon is strongly linked to projected cloud trends, reflected solar radiation, and model sensitivity. Many models, particularly those with low climate sensitivity, fail to adequately resolve these teleconnections and hence are identifiably biased. Improving model fidelity in matching observed variations provides a viable path forward for better predicting future climate.

See also: A bit more sensitive, which discusses “Spread in model climate sensitivity traced to atmospheric convective mixing” by Stgeven Sherwood, Sandrine Bony, and Jean-Louis Dufrense, in Nature, January 2 2014.

Equilibrium climate sensitivity refers to the ultimate change in global mean temperature in response to a change in external forcing. Despite decades of research attempting to narrow uncertainties, equilibrium climate sensitivity estimates from climate models still span roughly 1.5 to 5 degrees Celsius for a doubling of atmospheric carbon dioxide concentration, precluding accurate projections of future climate. The spread arises largely from differences in the feedback from low clouds, for reasons not yet understood. Here we show that differences in the simulated strength of convective mixing between the lower and middle tropical troposphere explain about half of the variance in climate sensitivity estimated by 43 climate models. The apparent mechanism is that such mixing dehydrates the low-cloud layer at a rate that increases as the climate warms, and this rate of increase depends on the initial mixing strength, linking the mixing to cloud feedback. The mixing inferred from observations appears to be sufficiently strong to imply a climate sensitivity of more than 3 degrees for a doubling of carbon dioxide. This is significantly higher than the currently accepted lower bound of 1.5 degrees, thereby constraining model projections towards relatively severe future warming.

See also: Overlooked evidence – global warming may proceed faster than expected

Better Biofuels

This just in:

Biofuels produced from switchgrass and post-harvest corn waste could significantly reduce the emissions that contribute to climate change, according to an analysis by EWG and University of California biofuels experts.

EWG’s analysis found that the life cycle carbon intensity of cellulosic ethanol from switchgrass was 47 percent lower than that of gasoline. Ethanol made from corn stover – the leaves and stalks that remain in the field after the grain is harvested – has a life-cycle carbon intensity 96 percent lower than gasoline’s.[1]

By contrast, studies have found that the life cycle carbon intensity of corn ethanol is greater than that of gasoline (Mullins et al. 2010, EPA, 2010a). Yet current federal policies strongly favor the production of conventional biofuels such as corn ethanol at the expense of lower-carbon alternatives.

Congress should reform the federal Renewable Fuel Standard to eliminate the mandate to add corn ethanol to gasoline and should further reform the standard to accelerate development of biofuels from lower-carbon feedstocks. At the same time, Congress should adopt new protections to ensure that fuels from grasses and crop waste also meet soil and water quality goals.

If Congress fails to act, EPA should employ the “reset” provisions of the Renewable Fuel Standard to gradually reduce the mandate for corn ethanol and encourage development of lower-carbon second-generation fuels.

Read the rest here.

Academics to world leaders: stop global warming

The following is reposed from here.

More than 1,500 academics from around the world have signed an <a href="http://globalclimatechangeweek.com/open-letter/">open letter</a> asking world leaders and delegates to the upcoming United Nations Climate Conference in Paris to take vigorous action now in order to avoid a future of catastrophic global warming.


The letter was initiated by Lawrence Torcello, an assistant professor of philosophy at Rochester Institute of Technology, in conjunction with Australian philosopher Keith Horton, and other colleagues in Australia.


&#8220;I am passionate about the topic. This is the moral issue of our time and the greatest challenge humanity has yet faced,&#8221; Torcello said.


Signatories include climate scientist <a href="http://www.meteo.psu.edu/holocene/public_html/Mann/index.php">Michael E. Mann</a>, environmentalist <a href="http://www.billmckibben.com/">Bill McKibben,</a> and philosophers <a href="http://chomsky.info/">Noam Chomsky</a> and <a href="https://www.princeton.edu/~psinger/">Peter Singer</a>.


Support for the letter is being sought until Nov. 30, when the conference begins.


&#8220;The leaders of the industrialized world shoulder a grave responsibility for the consequences of our current and past carbon emissions,&#8221; the letter says.


&#8220;We undersigned concerned academics, researchers and scientists from around the world recognize the seriousness of our environmental situation and the special responsibility we owe to our communities, future generations and our fellow species,&#8221; the letter continues. &#8220;We will strive to meet that responsibility in our educational and communicative endeavors. We call upon our leaders to do what is necessary to prevent catastrophic climate change. With just as much urgency, we call upon our fellow citizens to hold their leaders responsible for vigorously addressing global warming.&#8221;


The letter warns of catastrophic climate change unless vigorous preventative measures are taken now, and points out that the current pledges being made by world leaders ahead of the Paris conference are not enough to prevent dangerous levels of global warning even if met.


&#8220;This letter makes a clear statement that acting aggressively now to prevent catastrophic global warming is the ethical responsibility of our global leaders, and that citizens must hold them accountable,&#8221; Torcello said. &#8220;The letter&#8217;s message has been widely embraced by professional ethicists and philosophers worldwide.&#8221;


He said scientists agree that a limit of 3.6 degrees Fahrenheit above preindustrial levels (between the years 1750 and 1849) is the maximum temperature limit we can risk to avoid catastrophic climate change. Vigorous actions are necessary immediately to avoid that threshold.


As of now, the world&#8217;s global temperature has increased 1.6 degrees since preindustrial levels. If it were possible to stop emitting all greenhouse gases today, the world would continue to warm another 1.1 degrees before stabilizing, Torcello said.


If no change is made, that 3.6-degree average increase will occur around 2036. Already, as glacial ice continues to melt, another three to six feet of sea level rise will displace millions of people by the end of this century, he said.


Climate change will contribute to more frequent heat waves, wildfires, droughts, crop failures and related loss of life, he said, while expanding the range of agricultural pests and tropical diseases.


Torcello said the <a href="http://globalclimatechangeweek.com/open-letter/">letter</a> will remain open for endorsement for academics to sign through the end of November.

NASA Study of Antarctic Ice Melt Misunderstood

A recent study that is getting a lot of press suggests that the massive ice sheets of Antarctica are on average growing rather than shrinking, and thus, not contributing to sea level rise. (The authors of the study warn that this will reverse in the near future with global warming.) However, there is reason to believe that these conclusions are incorrect.

Antarctica is the sleeping giant of climate change. Human activity, mainly the release of greenhouse gasses from burning fossil fuels, has been changing the climate rather dramatically for the last few decades, and the consequences of this change are mostly negative. Failed agricultural systems have led to failed states and regional political instability. Dramatic changes in weather patterns, including droughts in Australia and California, a series of unprecedented tropical storms over the last several years, major flooding (if anyone from Texas is reading this, nice to know you have internet access in your tree), all have a global warming contribution, because weather is climate and climate is changed and changing. But sea level rise, while mostly a thing of the future rather than the present, may have the biggest effect of all, at least on land. As we warm the planet, the polar ice sheets will contribute much of their ice to the sea, and based on what we know of the past, direct measurements over the last 20 years or so, and from models of the medium term future, this could mean an increase in sea level of several meters. The best available science currently suggests that by the end of the century average sea levels could be about a meter higher than they are now. It would not be unreasonable to regard that as a conservative estimate.

I’d like to take a moment and point out an important aspect of the sea which people, especially those that don’t live on the sea, forget. The average altitude of the sea at a particular point along the shore is not the part you have to worry about. Well, that is important, but it is not the part that bites. Consider the cobra snake. A cape cobra can strike at a distance well over half its own body length. So if you are standing ten feet away from a fifteen foot long cobra, the snake might seem a safe distance away, but you are actually within its striking range. One could say that the sea has two overlapping but distinct distances at which it strikes. One is the normal storm range. If you raise the sea along a beach in Cape Cod by six inches, nothing interesting happens most days. But the dozen or so medium size storms that will occur over a year (especially in winter when the storms come in from the Atlantic) will convert that foot of elevation into several horizontal feet of beach erosion, in a very short amount of time. The second is what happens when more serious storms, like tropical cyclones or their extratropical spawn, come along. New York City was built and reinforced from the sea, over time, mainly when the Atlantic was about a foot lower than it is now. A couple of years ago, when Super Storm Sandy came along, the storm gathered up that extra foot of sea level and turned it into an extra large storm surge sufficient to flood the subway system in lower Manhattan. Long before the sea in that area rises another three feet, there will be the occasional storm surge that will be even more severe.

Since a large percentage of the world’s population, a large percentage of the world’s agricultural activity, and an even larger percentage (probably) of the world’s real estate value will become subject to flooding, sometimes severe, and eventually be replaced by the rising sea over the next century and beyond, sea level rise is a very important phenomenon.

You have probably already heard about the study, “Mass gains of the Antarctic ice sheet exceed losses” by H. Jay Zwally and others (see citation and abstract below), that came out a couple of weeks ago telling us that the contribution to sea level rise by the Antarctic is currently zero or negative. Or at least, that is how many press outlets are reporting the story.

There are two problems with this study that you need to know about. First, the study examines a data set that ends in 2008. The second problem is that there are indicators that the study is simply wrong, even though it likely has significant merits.

The last decade of research on Antarctica have shown, in many studies using a variety of techniques, that Antarctica is contributing to sea level rise. They have also shown that the rate of melting in Antarctic is probably increasing. Even more importantly, they have indicated that certain areas of Antarctic are current in a state of instability, suggesting that the rate of contribution of the southern continent’s ice mass to sea level rise may increase abruptly in the near future.

The fact that the study being reported uses older data could explain why it conflicts with everything else the science is telling us. Michael Mann, quoted in The Guardian, notes, “…the claims are based on seven-year-old data, and so cannot address the finding that Antarctic ice loss has accelerated in more recent years.” To this I’ll add that it is somewhat annoying that those reporting the story, including, oddly, the authors of the study, are using forms of the word “current” to describe the result. These results are old, out dated, and while potentially valuable, a data set ending in 2008, when speaking of a rapidly changing system, is not current.

Sou at HotWhopper has a nice graphic showing estimates of Antarctic ice melt before and after 2008, strongly indicating the problem with using a study from older date to understand current conditions.

Average global sea level is a measurable verifiable established fact, and the contribution of major ice sheets to this has been measured and found to be important. If the study is correct, and Antarctica was not contributing to sea level rise during that period prior to 2008, then something is terribly wrong. There is simply not enough wiggle room in the other sources of sea level rise to account for the missing volume of water. One could argue that a beautiful hypothesis (positive mass balance in Antarctic ice) has been killed by an ugly fact (actual observed sea level rise). But Zwally’s study does not present a mere hypothesis, but rather, is based on detailed observations incorporated into a set of carefully done calculations.

So, perhaps the observations are wrong. There may be two reasons the observations (and the calculations derived from them) are wrong. One is simply that the satellite data they use are inherently less accurate than needed. The measurements are of a very small change over time over a very large area. If the satellite method is just a little off, this could cause a problem. (By the way, the data end in 2008 because the instrumentation on the satellite stopped working then.) This study’s main contribution may, in the end, to be to point out a problem with the instrumentation prior to that time. This doesn’t seem that likely for the simple reason that the whole point of putting fancy instruments in a bird is to get super accurate information.

The second possible reason seems more likely. Part of the process of determining that Antarctica has a positive mass balance (more ice over time rather than less) involves assumptions (and some measurements) about the response of the bedrock underneath the very thick ice sheets. If that is wrong, then that is a problem.

Since the sea level has in fact been going up, and there is no easy way to account for that than a certain contribution to Antarctica, and all the other science shows an increasingly melting Antarctic, and the study uses older data, then I’m afraid I have bad news. Sea level is still going up, Antarctica is still contributing to it, and the amount of this contribution is still, as the science has been suggesting for several years no, only going to increase.


The following resources will be of interest to anyone following this story.

  • Goldberg, Suzanne. 2014. Western Antarctic ice sheet collapse has already begun, scientists warn. (The Guardian)
  • Lewis, Renee. 2014. West Antarctic ice melt is now ‘unstoppable,” NASA report says. (Al Jazeera report)
  • Lewis, Renee. 2015 Experts dispute NASA study showing Antarctic ice gain. (Al Jazeera report)
  • Plait, Phil. 2015. Is Antarctica Gaining or Losing Ice? Hit: Losing. (Slate)
  • Sea Level Rise Research Group. 2015 global mean sea level time series. (data site)
  • Sinclair, Peter. 2015. Keeping it simple on sea level rise. (Blog post)
  • Sou. 2015. Antarctic ice – growing or shrinking? NASA vs Princeton and Leeds etc. (Hot Whopper)
  • The original paper is here.

    Citation:

    Zwally, H. Jay, 2; Li, Jun; Robbins, John W.; Saba, Jack L.; Yi, Donghui; Brenner, Anita C. 2015. Mass gains of the Antarctic ice sheet exceed losses. Journal of Glaciology, International Glaciological Society.

    Abstract:

    Mass changes of the Antarctic ice sheet impact sea-level rise as climate changes, but recent rates have been uncertain. Ice, Cloud and land Elevation Satellite (ICESat) data (2003–08) show mass gains from snow accumulation exceeded discharge losses by 82?±?25?Gt?a–1, reducing global sea-level rise by 0.23?mm?a–1. European Remote-sensing Satellite (ERS) data (1992–2001) give a similar gain of 112?±?61?Gt?a–1. Gains of 136?Gt?a–1 in East Antarctica (EA) and 72?Gt?a–1 in four drainage systems (WA2) in West Antarctic (WA) exceed losses of 97?Gt?a–1 from three coastal drainage systems (WA1) and 29?Gt?a–1 from the Antarctic Peninsula (AP). EA dynamic thickening of 147?Gt?a–1 is a continuing response to increased accumulation (>50%) since the early Holocene. Recent accumulation loss of 11?Gt?a–1 in EA indicates thickening is not from contemporaneous snowfall increases. Similarly, the WA2 gain is mainly (60?Gt?a–1) dynamic thickening. In WA1 and the AP, increased losses of 66?±?16?Gt?a–1 from increased dynamic thinning from accelerating glaciers are 50% offset by greater WA snowfall. The decadal increase in dynamic thinning in WA1 and the AP is approximately one-third of the long-term dynamic thickening in EA and WA2, which should buffer additional dynamic thinning for decades.