Tag Archives: Sea Level Rise

New Research: Antarctic Glaciers Destabilized

A large portion of the glacial mass in Antarctic, previously thought to be relatively stable, is now understood to be destablizing. This is new research just out in Science. The abstract is pretty clear:

Growing evidence has demonstrated the importance of ice shelf buttressing on the inland grounded ice, especially if it is resting on bedrock below sea level. Much of the Southern Antarctic Peninsula satisfies this condition and also possesses a bed slope that deepens inland. Such ice sheet geometry is potentially unstable. We use satellite altimetry and gravity observations to show that a major portion of the region has, since 2009, destabilized. Ice mass loss of the marine-terminating glaciers has rapidly accelerated from close to balance in the 2000s to a sustained rate of –56 ± 8 gigatons per year, constituting a major fraction of Antarctica’s contribution to rising sea level. The widespread, simultaneous nature of the acceleration, in the absence of a persistent atmospheric forcing, points to an oceanic driving mechanism.

The paper is “Dynamic thinning of glaciers on the Southern Antarctic Peninsula” by B. Wouters, A. Martin-Español, V. Helm, T. Flament, J. M. van Wessem, S. R. M. Ligtenberg, M. R. van den Broeke, J. L. Bamber.

Here is a simulation of grounding line retreat in action from NASA:

Karl Mathiesen at the Guardian has a writeup on the research here.

The sheet’s thickness has remained stable since satellite observations began in 1992. But Professor Jonathan Bamber of Bristol university, who co-authored the study, said that around 2009 it very suddenly began to thin by an average of 42cm each year. Some areas had fallen by up to 4m.

“It hasn’t been going up, it hasn’t been going down – until 2009. Then it just seemed to pass some kind of critical threshold and went over a cliff and it’s been losing mass at a pretty much constant, rather large, rate,” said Bamber.

The estimate of ice loss by this research might be overestimated, according to Andrew Shepherd, who notes that some of the thinning of the glacier could be due to changes in snowfall amounts on tip, rather than melting from the bottom. It will be interesting to see how this works out.

Caption for the figure at the top of the post:

Fig. 2 Mass variations for the sum of basins 23 and 24, as observed by GRACE and modeled by RACMO2.3.
Basins 23 and 24 are defined in (21, 22). The faint blue dots are the monthly GRACE anomalies with 1? error bars (20), and the thick blue line shows the anomalies with a 7-month running average applied so as to reduce noise. Cumulative SMB anomalies from RACMO2.3 are shown in red, with the light red area indicating the 1? spread in an ensemble obtained by varying the baseline period (20). The dashed light blue line shows the estimated dynamic mass loss (GRACE minus SMB). The vertical dashed lines indicate January 2003, December 2009, and July 2010, the start and ending of the different altimetry observations. (Inset) The GRACE time series for the individual basins 23 (blue) and 24 (red), before (full lines) and after (dashed lines) applying the SMB correction.

Global Warming: Getting worse

I recently noted that there are reasons to think that the effects of human caused climate change are coming on faster than previously expected. Since I wrote that (in late January) even more evidence has come along, so I thought it was time for an update.

First a bit of perspective. Scientists have known for a very long time that the proportion of greenhouse gasses in the Earth’s atmosphere controls (along with other factors) overall surface and upper ocean heat balance. In particular, is has been understood that the release of fossil Carbon (in coal and petroleum) as CO2 would likely warm the Earth and change climate. The basic physics to understand and predict this have been in place for much longer than the vast majority of global warming that has actually happened. Unfortunately, a number of factors have slowed down the policy response, and the acceptance of this basic science by non scientists.

A very small factor, often cited by climate contrarians, is the consideration mainly during the 1960s and 1970s, that the Earth goes through major climate swings including the onset of ice ages, so we have to worry about both cooling and warming. This possibility was obviated around the time it was being discussed, though people then may not have fully realized it at the time, because as atmospheric CO2 concentrations increased beyond about 300ppm, from the pre-industrial average of around 250–280ppm (it is now at 400ppm), the possibility of a new Ice Age diminished to about zero. Another factor mitigating against urgency is the fact that the Earth’s surface temperatures have undergone a handful of “pauses” as the surface temperature has marched generally upwards. I’m not talking about the “Faux Pause” said to have happened during the last two decades, but earlier pauses, including one around the 1940s that was probably just a natural down swing that happened when there was not enough warming to swamp it. A second pause, shorter, happened after the eruption of Mount Pinatubo, in 1991.

Prior to recent anthropogenic global warming, the Earth’s surface temperature has squiggled up and down do to natural variability. Some of these squiggles were, at least reionally large enough to get names, such as the “Medieval Warm Period” (properly called the “Medieval Climate Anomaly”) and the “Little Ice Age.” When the planet’s temperature started going distinctly up at the beginning of the 20th century, these natural ups and downs, some larger and some smaller, caused by a number of different factors, eventually became imposed on a stronger upward signal. So, when we have a “downward” swing caused by natural variation, it is manifest not so much as a true downturn in surface temperatures, but rather, less of an upward swing. Since about a year and a half ago, we have seen very steady warming suggesting that a recent attenuation in how much temperatures go up is reversing. Most informed climate scientists expect 2015 and even 2016 to be years with many very warm months globally. So, the second factor (the first being the concern over the ice age as possibly) is natural variation in the Earth’s surface temperature. To reiterate, early natural swings in the surface temperature may have legitimately caused some scientists to wonder about how much greenhouse gas pollution changes things, but later natural variations have not; Scientists know that this natural variation is superimposed on an impressive long term upward increase in temperature of the Earth’s surface and the upper ocean. Which brings us to the third major factor delaying both non-scientists’ acceptance of the realities of global warming, and dangerous policy inaction: Denialism.

The recent relative attenuation of increase in surface temperatures, likely soon to be over, was not thought of by scientists as disproving climate models or suggesting a stoppage of warming. But it was claimed by those denying the science as evidence that global warming is not real and that the climate scientists have it all wrong. That is only one form of denialism, which also includes the idea that yes, warming is happening, but does not matter, or yes, it matters, but we can’t do anything about it, or yes, we could do something about it, but the Chinese will not act (there is little evidence of that by the way, they are acting) so we’re screwed anyway. Etc.

The slowdown in global warming is not real, but a decades-long slowdown in addressing global warming at the individual, corporate or business, and governmental levels is very real, and very meaningful. There is no doubt that had we started to act aggressively, say, back in the 1980s when any major hurdles for overall understanding of the reality of global warming were overcome, that we would be way ahead of where we are now in the effort to keep the Carbon in the ground by using clean energy. The precipitous drop we’ve seen in photovoltaic costs, increases in battery efficiency and drop in cost, the deployment of wind turbines, and so on, would have had a different history than they have in fact had, and almost certainly all of this would have occurred faster. Over the last 30 or 40 years we have spent considerable effort building new sources of energy, most of which have used fossil Carbon. If even half of that effort was spent on increasing efficiency and developing non fossil Carbon sources, we would not have reached an atmospheric concentration of CO2 of 400ppm in 2015. The effects of greenhouse gas pollution would be less today and we would not be heading so quickly towards certain disaster. Shame on the denialists for causing this to happen.

I should mention a fourth cause of inappropriate rejection of the science of climate change. This is actually an indirect effect of climate change itself. You all know about the Inhofe Snowball. A US Senator actually carried a snowball into the senate chamber, a snowball he said he made outside where there has been an atypical snowfall in Washington DC, and held it aloft as evidence that the scientists had it all wrong, and that global warming is a hoax. Over the last few years, we have seen a climatological pattern in the US which has kept winter snows away from the mountains of California, contributing significantly to a major drought there. The same climatological phenomenon has brought unusual winter storms to states along the Eastern Seaboard that usually get less snow (such as major snow storms in Atlanta two winters ago) and persistent unseasonal cold to the northeastern part of the US. This change in pattern is due to a shift in the behavior of the Polar jet stream, which in turn is almost certainly caused by anomalous very warm water in parts of the Pacific and the extreme amplification of anomalous warm conditions in the Arctic, relative to the rest of the planet. (The jury is still out as to the exact process, but no serious climate scientists working on this scientific problem, as far as I know, doubts it is an effect of greenhouse gas pollution). This blob of cold air resting over the seat of power of one of the more influential governments in the world fuels the absurd but apparently effective anti-science pro-fossil fuel activism among so many of our current elected officials.

Climate Sensitivity Is Not Low

The concept of “Climate Sensitivity” is embodied in two formulations that each address the same basic question: given an increase in CO2 in the atmosphere, how much will the Earth’s surface and upper ocean temperatures increase? The issue is more complex than I’ll address here, but here is the simple version. Often, “Climate sensitivity” is the amount of warming that will result from a doubling of atmospheric CO2 from pre-industrial levels. That increase in temperature would take a while to happen because of the way climate works. On a different planet, equilibrium would be reached faster or slower. Historically, the range of climate sensitivity values has run from as low as about 1.5 degrees C up to 6 degrees C.

The difficulty in estimating climate sensitivity is in the feedbacks, such as ice melt, changes in water vapor, etc. For the most part, feedbacks will increase temperature. Without feedbacks, climate sensitivity would be about 1.2 degrees C, but the feedbacks are strong, the climate system is complex, and the math is a bit higher level.

As time goes by, our understanding of climate sensitivity has become more refined, and it is probably true that most climate scientists who study this would settle on 3 degrees C as the best estimate, but with wide range around that. The lower end of the range, however, is not as great as the larger end of the range, and the upper end of the range probably has what is called a “fat tail.” This would mean that while 3 degrees C is the best guess, the probability of it being way higher, like 4 or 5, is perhaps one in ten. (This all depends on which model or scientist you query.) The point here is that while it might be 3, there is a non-trivial chance (one in ten is not small for an extreme event) that it would be a value that would be really bad for us.

Anyway, Dana Nuccitelli has a recent post in The Guardian that looks at climate sensitivity in relation to “The Single Study Syndrome.”

There have been a few recent studies using what’s called an “energy balance model” approach, combining simple climate models with recent observational data, concluding that climate sensitivity is on the low end of IPCC estimates. However, subsequent research has identified some potentially serious flaws in this approach.

These types of studies have nevertheless been the focus of disproportionate attention. For example, in recent testimony before the US House of Representatives Committee on Science, Space and Technology, contrarian climate scientist Judith Curry said,

Recent data and research supports the importance of natural climate variability and calls into question the conclusion that humans are the dominant cause of recent climate change: … Reduced estimates of the sensitivity of climate to carbon dioxide

Curry referenced just one paper (using the energy balance model approach) to support that argument – the very definition of single study syndrome …

…As Andrew Dessler told me,

There certainly is some evidence that climate sensitivity may be below 2°C. But if you look at all of the evidence, it’s hard to reconcile with such a low climate sensitivity. I think our best estimate is still around 3°C for doubled CO2.

So there is not new information suggesting a higher climate sensitivity, or a quicker realization of it, but there is a continuation of the consensus that the value is not low, despite efforts by so called luke-warmists or denialists to throw cold water on this hot topic.

Important Carbon Sink May Be Limited.

A study just out in Nature Geoscience suggests that one of the possible factors that may mitigate against global warming, the terrestrial sink, is limited in its ability to do so. The idea here is that as CO2 increases some biological activities at the Earth’s Surface increase and store some of the carbon in solid form as biomass. Essentially, the CO2 acts as plant fertilizer, and some of that Carbon is trapped in the detritus of that system, or in living tissue. This recent study suggests that this sink is smaller than previously suspected.

Terrestrial carbon storage is dependent on the availability of nitrogen for plant growth… Widespread phosphorus limitation in terrestrial ecosystems may also strongly regulate the global carbon cycle… Here we use global state-of-the-art coupled carbon–climate model projections of terrestrial net primary productivity and carbon storage from 1860–2100; estimates of annual new nutrient inputs from deposition, nitrogen fixation, and weathering; and estimates of carbon allocation and stoichiometry to evaluate how simulated CO2 fertilization effects could be constrained by nutrient availability. We find that the nutrients required for the projected increases in net primary productivity greatly exceed estimated nutrient supply rates, suggesting that projected productivity increases may be unrealistically high. … We conclude that potential effects of nutrient limitation must be considered in estimates of the terrestrial carbon sink strength through the twenty-first century.

Related, the Amazon carbon sink is also showing long term decline in its effectiveness.

Permafrost Feedback

From Andy Skuce writing at Skeptical Science:

We have good reason to be concerned about the potential for nasty climate feedbacks from thawing permafrost in the Arctic….research bring good news or bad? [From recent work on this topic we may conclude that] although the permafrost feedback is unlikely to cause abrupt climate change in the near future, the feedback is going to make climate change worse over the second half of this century and beyond. The emissions quantities are still uncertain, but the central estimate would be like adding an additional country with the unmitigated emissions the current size of the United States’ for at least the rest of the century. This will not cause a climate catastrophe by itself, but it will make preventing dangerous climate change that much more difficult. As if it wasn’t hard enough already.

Expect More Extreme Weather

Michael D. Lemonick at Climate Central writes:

disasters were happening long before humans started pumping heat-trapping greenhouse gases into the atmosphere, but global warming has tipped the odds in their favor. A devastating heat wave like the one that killed 35,000 people in Europe in 2003, for example, is now more than 10 times more likely than it used to be…. But that’s just a single event in a single place, which doesn’t say much about the world as a whole. A new analysis in Nature Climate Change, however, takes a much broader view. About 18 percent of heavy precipitation events worldwide and 75 percent of hot temperature extremes — defined as events that come only once in every thousand days, on average — can already be attributed to human activity, says the study. And as the world continues to warm, the frequency of those events is expected to double by 2100.

Melting Glaciers Are Melting

This topic would require an entire blog post in itself. I’ll give just an overview here. Over the last year or so, scientists have realized that more of the Antarctic glaciers are melting more than previously thought, and a few big chunks of ice have actually floated away or become less stable. There is more fresh water flowing from glacial melt into the Gulf of Alaska than previously thought. Related to this, as well as changes in currents and increasing sea temperatures, sea level rise is sparking sharply.

The Shifting Climate

I mentioned earlier that the general upward trend of surface temperature has a certain amount of natural variation superimposed over it. Recent work strongly suggests that a multi-decade long variation, an up and down squiggle, which has been mostly in the down phase over recent years, is about to turn into an upward squiggle. This is a pretty convincing study that underscored the currently observed month by month warming, which has been going on for over a year now. It is not clear that the current acceleration in warming is the beginning of this long term change … that will be known only after a few years has gone by. But it is important to remember that nothing new has to happen, no new scientific finding has to occur, for us to understand right now that the upward march of global surface temperatures is going to be greater on average than the last decade or so has suggested. We have been warming all along, but lately much of that warming has been in the oceans. Expect surface temperatures to catch up soon.

Antarctic Ice Shelves Melting at Accelerating Rate

Antarctica is pretty much covered with glaciers. Glaciers are dynamic entities that, unless they are in full melt, tend to grow near their thickest parts (that’s why those are the thickest parts) and mush outwards towards the edges, where the liminal areas either melt (usually seasonally) in situ or drop off into the sea.

Antarctic’s glaciers are surrounded by a number of floating ice shelves. The ice shelves are really the distal reaches of the moving glaciers floating over the ocean. This is one of the places, probably the place at present, where melting accelerated by human caused greenhouse gas pollution occurs. The ice shelves are fixed in place along their margins (they typically cover linear fjord like valleys) and at a grounding point underneath the shelf some distance form the ice margin but under sea level.

The collapse or disintegration of an ice shelf is thought to lead to the more rapid movement of the corresponding glacial mass towards the sea, and increased melting. This is the big problem right now with estimating the rate of glacial melting in the Antarctic. This is not a steady and regular process, as rapid disintegration of an ice shelf is possible. Most likely, Antarctic glacial melting over the coming decades will involve occasional catastrophic of an ice shelf followed by more rapid glacial melting at that point.

Unfortunately, the ice shelves are generally becoming more vulnerable to this sort of process, a new study just out in Science shows. From the abstract:

The floating ice shelves surrounding the Antarctic Ice Sheet restrain the grounded ice-sheet flow. Thinning of an ice shelf reduces this effect, leading to an increase in ice discharge to the ocean. Using eighteen years of continuous satellite radar altimeter observations we have computed decadal-scale changes in ice-shelf thickness around the Antarctic continent. Overall, average ice-shelf volume change accelerated from negligible loss at 25 ± 64 km3 per year for 1994-2003 to rapid loss of 310 ± 74 km3 per year for 2003-2012. West Antarctic losses increased by 70% in the last decade, and earlier volume gain by East Antarctic ice shelves ceased. In the Amundsen and Bellingshausen regions, some ice shelves have lost up to 18% of their thickness in less than two decades.

This is one of many reasons that even the most extreme of the IPCC estimates of ice loss (generally) and its contribution to sea level rise have to be seen as a lower limit. This is a substantial change, and it is very recent. It isn’t just that the ice sheets have gotten thinner, but also, that the rate of melting at these margins is increasing.

Caption to figure: Fig. 1 Eighteen years of change in thickness and volume of Antarctic ice shelves.
Rates of thickness change (m/decade) are color-coded from -25 (thinning) to +10 (thickening). Circles represent percentage of thickness lost (red) or gained (blue) in 18 years. Only significant values at the 95% confidence level are plotted (see Table S1). Lower left corner shows time series and polynomial fit of average volume change (km3) from 1994 to 2012 for the West (in red) and East (in blue) Antarctic ice shelves. Black curve is polynomial fit for All Antarctic ice shelves. We divided Antarctica into eight regions (Fig. 3), which are labeled and delimited by line segments in black. Ice-shelf perimeters are shown as a thin black line. The central circle demarcates the area not surveyed by the satellites (south of 81.5°S). Original data were interpolated for mapping purposes (see Table S1 for percentage area surveyed of each ice shelf). Background is the Landsat Image Mosaic of Antarctica (LIMA).

Bjorn Lomborg Is Wrong About Bangladesh And Sea Level Rise

Human caused greenhouse gas pollution is heating the Earth and causing the planet’s polar ice caps and other glacial ice to melt. This, along with simply heating the ocean, has caused measurable sea level rise. Even more worrisome is this: the current elevated level of CO2 in the atmosphere was associated in the past with sea levels several meters higher than they are today. Even if we slow down Carbon pollution very quickly, we can expect sea levels to be at least 8 meters higher, eventually. How soon? Nobody knows, nobody can give you a time frame on this because the rate of melting of the major glaciers in Greenland and the Antarctic is hard to measure. All we know for sure is that the rate of melting is speeding up, and that in the past, the current level of atmospheric CO2 has typically caused a very large amount of melting.

Bangladesh is low country. A very large percentage of the country is on the Bangladesh Plain, which is almost entirely below 10 meters in elevation. This is where a large portion of the population in that country lives, and where a large portion of the food is grown. The greenhouse gas pollution we have caused so far is sufficient to virtually guarantee that Bangladesh will become a very small country over the next generation or two. Much sooner than that, though, sea level rise in the region will affect, and is already affecting, freshwater reserves. We expect the largest tropical storms to become larger and more intense as an effect of human caused global warming. Sea level rise makes the storm surges from those events worse. So of immediate concern and becoming more of a problem every year is the threat of deadly and damaging tropical storms exacerbated by warming of the seas and increased sea levels.

The deadliest tropical cyclone on record occurred in Bangladesh; that was the Great Bhola Cyclone of 1970, which killed up to one half of a million people. The second deadliest cyclone known hit Bangladesh and India in great antiquity. Eight of the ten deadliest known tropical cyclones hit the region. So, tropical cyclones are already a problem in Bangladesh, and sea level rise and increased cyclone strength are going to make that much much worse.

Bjørn Lomborg, in a recent interview, told Bangladesh, the country, not to worry too much about global warming, and instead, to focus on other problems. He equated concern over sea level rise in a country where sea level rise is a very significant problem with immorality. While Lomborg may be correct to point out the obvious – that Bangladesh has a lot of problems in public health and other areas to worry about – he is wrong to suggest that sea level rise in that low lying country can be addressed just as the Dutch have managed the sea in The Netherlands.

Lomborg seems to not know much about sea level rise. He once noted that sea level rise had stopped, or even decreased, by referring to a single year’s worth of data (see graphic above). That statement and his suggestion that sea level rise should be a low priority in a country that may be the most threatened by sea level rise in the world (aside from island nations) is reminiscent of a statement by J.R. Spradley, a delegate at an international conference on climate change in 1990, speaking about sea level rise in Bangladesh. He was quoted in the Washington Post as saying “The situation is not a disaster; it is merely a change. The area won’t have disappeared; it will just be underwater. Where you now have cows, you will have fish.” (Washington Post, December 30th, 1990.)

Part of Lomborg’s argument is typical for him. He generates a straw man by equating concern over climate change with concern over a meteor about to smash into the earth. In the interview he said,

Projecting scary scenarios are probably unhealthy to deal with real issues. Now, if there was a meteor hurtling towards earth, we should tell people. If there was really something destroying the earth we should definitely be telling people and doing something about it. My point is if you, for instance, look at climate change, it is often portrayed as the end of the world. But if you look at for instance the UN climate panel, they tell us by about 2070 the total cost of global warming is going to be somewhere between 0.2 and 2% of the GDP. And that emphasises what I am trying to say – global warming is real, it is a problem, it is something we should fix, but it’s not the end of the world.

The problem with this is that sea level rise is, essentially, the end of the world, if you are Bangladesh.

The most troubling part of Lomborg’s statements is that he equates the Netherlands with Bangladesh. The Netherlands is about 25% below sea level, but the sea is kept back by dikes. Other than their cheese, chocolate, love of splitting the restaurant tab, this is probably what the Dutch are most known for. Indeed Dutch engineers were drafted into managing water related problems around the world for centuries. So maybe the Dutch can help Bangladesh keep the Indian Ocean off it’s turf when that ocean is 8 meters above the present level. Lomborg looks to the Dutch to do just this:

… how much of a problem is [sea level rise in Bangladesh]? The Dutch has shown us 200 years ago, you can handle sea level rise fairly, easily and cheaply, you can do the same thing here and you will do the same thing here. Remember when people say, global warming is a big problem and we need to put a wind turbine here – any amount of wind turbine or solar panels that we are going to put in the next 50 years, are going to have absolutely no impact on the sea level rise that towards the end of the century. They may make a tiny difference towards the 22nd century, but if want to do anything about sea level rise, it’s all about adaptation. Globally there seems to be actually less ferocious hurricanes, one measure is accumulated cyclone energy, which is sort of a good global estimate and it’s actually been at some of the lowest levels since we started monitoring in the 1970s. There is a theoretical argument that you will see slightly fewer but slightly stronger hurricanes towards the end of the century. Again, this is not by any means the end of Bangladesh.”

The Netherlands is about 41,543 square kilometers in size with about 17% of that reclaimed from the sea, this and other land kept dry by dikes. Bangladesh is about 147,570 square kilometers. The Netherlands does not get tropical cyclones very often. Bangladesh gets the worst of them. There are geological differences between the regions that matter as well. Bangladesh is, essentially, a giant delta (I oversimplify slightly) which means that part of is is sinking all the time even while the sea level goes up. Flooding along rivers becomes a big problem with sea level rise. Both regions have rivers. Bangladesh, however, is a country made out of rivers, and among them is the Ganges, which is the world’s third largest river by discharge. Bangladesh probably has more problems with flooding than any other nation. In 1988, 75% of the entire country of Bangladesh was covered by a flood.

It is estimated that a 1 meter rise in sea level would take about 17.5%, or 25,000 square kilometers, of Bangladesh. I’m a little unsure of that estimate (and others I’ve seen) because different researchers count or don’t count large regions of the country that are already flooded by the sea. Another estimate gives 16% of the land to the sea with a 1.5 meter sea level rise. (You can explore various scenarios here if you like.) In any event, an 8 meter rise in sea level, which is expected long term, would take a very large part of the country, displace most of the population, and destroy most of the agricultural land. In case it is not obvious, let me note that as sea level rise threatens Bangladesh, it also threatens The Netherlands, which might keep the Dutch rather busy in their own homelands.

It is also important to note that sea level does not treat all coastlines equally. Some areas are being affected more than others. A report in CBS news recently noted, “Seas are rising more than twice as fast as the global average here in the Sundarbans, a low-lying delta region of about 200 islands in the Bay of Bengal where some 13 million impoverished Indians and Bangladeshis live. Tens of thousands … have already been left homeless, and scientists predict much of the Sundarbans could be underwater in 15 to 25 years.”

The Dutch reclaimed so much of the sea, and developed defenses against storm surges and flooding, over a period of centuries. During much of this time, The Netherlands was a major player in the European economic theater, acting as a center during the development of the world economic and colonial systems of the 17th and 18th centuries. To suggest that somehow Bangladesh can do what the Dutch did while the entire world is also busy adapting to sea level rise is absurd.

Peter Gleick of the Pacific Institute has done quite a bit of research on the potential effects of sea level rise, focusing on California (see, for example, Heberger M, Cooley H, Herrera P, Gleick P, Moore E (2009) The impacts of sea level rise on the California coast. California Climate Change Center, Sacramento, California. Paper CEC–500–2009–024-F). I asked him what he felt about the Lomborg interview. He said, “So a rich Dane tells poor Bangladeshis to stop whining and just ‘handle’ sea level rise, because that’s what the rich countries do? The reality, of course, is that even in rich countries, the poor will suffer most from sea-level rise. In our analysis of the risks to California from even modest SLR over the coming decades, nearly 500,000 people – disproportionately communities of color and low-income people – will be affected. And the cost of protecting them far exceeds the money available for coastal protection.”

There is also an absurdity to Lomborg’s assertion that we (our species) and Bangladesh (the country) should put off the global project of keeping the Carbon in the ground. We don’t know how long it takes for a warming planet to melt polar glaciers, but we do know that there is a pretty well established relationship between CO2 levels and global temperature, and between global temperature and sea levels. We know this from looking at numerous case studies from the past. It turns out that the relationship, ultimately, between CO2 levels and sea level rise is sigmoidal. Below about 400ppm, as CO2 levels rise, sea levels rise rapidly. Then, between about 400ppm and 650ppm, they rise more slowly, then above that level, the rate increases again.

Now, I want to pause for a second and clarify a very important point. We are now at 400ppm. This does not mean that sea levels will start to rise slowly. The expected sea level stand for 400ppm is probably close to 8 meters above the current level. In other words, the adjustment of sea level to CO2 that we expect should be very rapid, as fast as it generally goes (or nearly so) over coming decades. Once that level is reached, and CO2 continues to increase (and it will), then there may be a slowing down as we approach but have not yet reached about 650ppm.

So, what is absurd about Lomborg’s assertion? If we forestall efforts to keep the carbon in the ground for now, we will power through that range of decreased (but continuing) ultimate increase in sea level rise between the 400 and 650 levels of CO2, and nearly guarantee returning to the higher rate, and ultimately, seeing sea level rises in the tens of meters in coming centuries.

In his interview, as well as in a brief Twitter exchange we had, Lomborg made another error, one we often seen made by lesser informed people engaged in the climate or energy conversations. Lomborg seems to think that there is a fixed amount and class of resources and that one problem must be addressed at a time. But that is not how it works. First, there are resources primarily available for one thing such as public health, while other resources may be more generally applied. Also, we can in fact address more than one problem at once. I asked Professor Michael Mann, climate scientist, what he thought about Lomborg’s interview, and he told me, “Bjorn Lomborg is a master of the false choice, often claiming that dealing with climate change will somehow detract from our ability to deal with other societal problems. In reality, we can walk and chew gum at the same time. We can and must work on solving numerous societal problems. In reality, climate change exacerbates most of those problems. It is a threat multiplier. Lomborg conveniently ignores that!”

Speaking of the same problem, Peter Gleick told me, “Lomborg’s classic argument that other problems like disease are far more important than climate change and sea-level rise is a common Lomborgian false dilemma. Society can, regularly does, and must tackle multiple problems at once. This is like saying that because a patient has a broken arm the doctors shouldn’t treat her life-threatening pneumonia. Patently nonsense.”

I would add that increased flooding, decreased food supply, the mass exodus of people from inundated regions, etc. will create far more disease and starvation related public health problems than Bangladesh has at the moment. Forestalling or reducing the extent of this sort of disaster has to be a high priority.

Which brings us to the question of development. Bangladesh, like so many other countries, is likely to become more and more electric over time as it develops. Lomborg seems to want that to happen with the use of fossil fuels rather than clean energy sources. But, one of the obstacles to switching from fossil Carbon based energy to clean energy in the developed world is that our infrastructure is already set up to exploit mainly fossil Carbon based sources. In nations or regions where the use of energy is being developed every effort should be made to ensure this is done with clean energy. That is independent of any local or regional issues with sea level rise. This is what makes sense and this is what we have to do.

Lomborg is often wrong. I’ve noted this before (see: Are electric cars any good? Lomborg says no, but he’s wrong. and Bjørn Lomborg WSJ Op Ed Is Stunningly Wrong). Climate Hawks critiques Lomborg’s Bangladesh strategy here noting issues I did not cover above. Scientific American published a stunning takedown of Lomborg’s book here. Recently, Steven Newton of the National Center for Science Education expanded on that critique in a note about the support of Lomborg’s approach by the anti-science Discovery Intitute.

And in his statements on Bangladesh, he is wrong again.

ADDED: I’m adding a note to address, collectively and once, a number of comments that have been posted (some moderated) about scales of time.

This post is not about reconciling geological time with day to day time. I make as an assumption, in dealing with sea level rise, the idea that all recent estimates of polar glacial melt are at best minima, and fail to get at the real problem. I feel this is true because of my bias towards paleoclimate. I see in the ancient record changes in sea level stand that seem to occur over time periods that don’t look like a few mm a year of melting. I may be wrong, but the paleo record is pretty hard data while the melt estimates are a very preliminary stab at a very large problem that we are only starting to get a handle on.

This is not the point of the present post, but several commenters, who generally deny the importance of climate change and would prefer that we do nothing about it, seem to feel a) it does matters if large proportions of Bangladesh or other low lying countries are obliterated in 30 years or 300 years. The people who will be affected ten instead of 2 generations from now don’t matter; b) the ultimate multi meter rise in sea level, which will happen, is beyond their level of credulity, so they argue from that position that therefore a one meter rise in a region that is mostly about one meter above sea level does not matter; and c) feel that our ignorance of how to reconcile geological time scales of climate change in paleoclimate (mostly) is somehow evidence that there is not change; d) as usual, failure to accept the muddled yammering that arises from these starting points constitutes a lack of true scientific rational thinking, or a liberal bias, or some other such hogwash.

There is a handful of other annoyances that come with this group of deniers, but that’s mainly it. So, now, the questions you have had, are having now, or may have in the future, have been address in this area.


If you want a higher resolution copy of the graphic at the top of this post, click through to HERE then click on the graphic.

Other posts of interest:

SUNGUDOGO_cover_art_colorFACE-223x300Also of interest: In Search of Sungudogo: A novel of adventure and mystery, set in the Congo.

On Sea Level Rise

Sea levels are rising with increasing global temperatures. It seems that whenever there is a new estimate of the rate of melting of one or more major parts of the polar ice caps, that estimate is higher than previously thought. By the end of the century, the most aggressive estimates suggest that we will have close to 2 meters (6 feet) of sea level rise along the coasts.

So,here are three sea level rise items for you.

First, the Obama Administration will begin to plan for sea level rise in all major federal projects to which this variable pertains. See this item in the Washington Post.

The order represents a major shift for the federal government: while the Federal Emergency Management Administration published a memo three years ago saying it would take global warming into account when preparing for more severe storms, most agencies continue to rely on historic data rather than future projections for building projects.

The new standard gives agencies three options for establishing the flood elevation and hazard area they use in siting, design and construction of federal projects. They can use data and methods “informed by best-available, actionable climate science”; build two feet above the 100-year flood elevation for standard projects and three feet above for critical buildings such as hospitals and evacuation centers; or build to the 500-year flood elevation.

Second, not breaking news but something you may want to know about, is the US Army Corps of Engineers report on risk management for coastal communities, here.

Third: you may remember a while back I made a map that showed North American coast lines under the extreme scenario where all of the polar ice on Earth melts. That would represent about 80 meters of sea level rise. Well, the data I used to do that, from the USGS, had a problem, and with new data I’ve redone the map (and focused on the eastern part of the continent because it is more interesting). See: How high can the sea level rise if all the glacial ice melted?

That is all, thank you very much.

How much sea level rise will occur with glacial melting?

PotentialSeaLevelRise2Sea level rise is a serious issue, and the sea is rising because of global warming. How bad can it get?

The USGS has estimated the potential contribution of melting ALL of the glacial ice around the world to sea level rise. This is very rough, because many different factors affect sea level, including ocean temperature, gravity, and current. But this gives a rough idea. If the release of CO2 and other greenhouse gasses continues apace, we could actually see the eventual melt of all of this ice. If we stop releasing these greenhouse gasses in a reasonable time, it is unlikely that these very large numbers will be achieved. But it is important to realize the potential, to understand that the amount of available ice to melt into the sea is so large that that factor in and of itself will not come to our rescue.

I made a map, which is also very approximate, indicating about where the sea will reach in much of North America, and posted it here.

So, the following data are from the USGS. The total is Continue reading How much sea level rise will occur with glacial melting?

The Hottest Year: 2014

NOAA will announce today that 2014 was the warmest year during the instrumental record, which begins in 1880. The announcement, which addresses findings of both NOAA and NASA, will be made today at 11:00 Eastern. Below is the press release from NOAA.

I talked about this and other climate matters in a radio interview at Green Divas:

Michael Mann has made the following statements regarding this news:

2014 Was Earth’s Warmest Year On Record
Three major climate organizations (JMA, NASA, and NOAA) have now released their official estimates for the 2014 Global Mean Surface Temperature. Both JMA and NOAA conclude that 2014 was substantially higher, i.e. outside the margin of error, of previous contenders (1998, 2005, and 2010) while NASA finds 2014 to be warmest, but within the margin of error of 2005 and 2010 (i.e. a “statistical tie”).

Based on the collective reports, it is therefore fair to declare 2014 the warmest year on record. This is significant for a number of reasons. Unlike past record years, 2014 broke the record without the “assist” of a large El Niño event. There was only the weakest semblance of an El Niño and tropical Pacific warmth contributed only moderately to the record 2014 global temperatures. Viewed in context, the record temperatures underscore the undeniable fact that we are witnessing, before our eyes, the effects of human-caused climate change. It is exceptionally unlikely that we would be seeing a record year, during a record warm decade, during a multidecadal period of warmth that appears to be unrivaled over at least the past millennium, were it not for the rising levels of planet-warming gases produced by fossil fuel burning.

The record temperatures *should* put to rest the absurd notion of a “pause” (what I refer to as the “Faux Pause” in Scientific American in global warming. There is a solid body of research now showing that any apparent slow-down of warming during the past decade was likely due to natural short-term factors (like small changes in solar output and volcanic activity) and internal fluctuations related to e.g. the El Nino phenomenon. The record 2014 temperatures underscore the fact that global warming and associated climate changes continue unabated as we continue to raise the concentrations of greenhouse gases in the atmosphere.

See also:

  • this post by Laurence Lewis
  • <li><a href="http://www.carbonbrief.org/blog/2015/01/explainer-how-do-scientists-measure-global-temperature/">Explainer: How do scientists measure global temperature?</a></li>
    
    <li><a href="http://www.theguardian.com/environment/climate-consensus-97-per-cent/2015/jan/16/global-warming-made-2014-record-hot-year">Global warming made 2014 a record hot year – in animated graphics</a></li>
    
    <li><a href="http://www.washingtonpost.com/blogs/capital-weather-gang/wp/2015/01/16/scientists-react-to-warmest-year-2014-underscores-undeniable-fact-of-human-caused-climate-change/">Scientists react to warmest year: 2014 underscores ‘undeniable fact’ of human-caused climate change</a></li>
    
    <li><a href="http://mashable.com/2015/01/16/2014-earth-warmest-year-not-random/">There is less than a 1-in-27 million chance that Earth's record hot streak is natural</a></li>
    
    <li><a href="http://thinkprogress.org/climate/2015/01/16/3612351/noaa-nasa-2014-hottest-year-on-record/">NOAA, NASA: 2014 Is Officially Hottest Year On Record, Driven By Global Warming</a>
    
    <li><a href="http://www.huffingtonpost.com/2015/01/16/2014-hottest-year-on-record_n_6479896.html">2014 Was The Hottest Year Since At Least 1880, Government Finds</a></li>
    
    <li><a href="http://www.bloomberg.com/graphics/2014-hottest-year-on-record/">Interesting graphic at Bloomberg</a></li>
    
    <li><a href="http://blog.ucsusa.org/born-after-1976-you-have-lived-your-entire-life-on-a-hotter-planet-784">Born after 1976? You’ve Lived Your Entire Life on a Hotter Planet</a></li>
    
    <li><a href="http://www.ucsusa.org/news/press_release/2014-hottest-on-record-0459#.VLlDH4rF-6Z">2014 a Record Hot Year</a></li>
    
    <li><a href="http://www.onearth.org/earthwire/2014-hottest-year">2014: ONE FOR THE RECORD BOOKS</a></li>
    
    <li><a href="http://climatecrocks.com/2015/01/16/its-official-2014-hottest-year/">It’s Official, 2014 Hottest Year</a></li>
    

    The Press Release

    NOAA: 2014 was Earth’s warmest year on record
    December 2014 record warm; Global oceans also record warm for 2014

    The globally averaged temperature over land and ocean surfaces for 2014 was the highest among all years since record keeping began in 1880, according to NOAA scientists. The December combined global land and ocean average surface temperature was also the highest on record.

    This summary from NOAA’s National Climatic Data Center is part of the suite of climate services NOAA provides to government, business, academia and the public to support informed decision-making.

    In an independent analysis of the data also released today, NASA scientists also found 2014 to be the warmest on record.

    2014

        <li>During 2014, the average temperature across global land and ocean surfaces was 1.24°F (0.69°C) above the 20th century average. This was the highest among all years in the 1880-2014 record, surpassing the previous records of 2005 and 2010 by 0.07°F (0.04°C).</li>
    
        <li>Record warmth was spread around the world, including Far East Russia into western Alaska, the western United States, parts of interior South America most of Europe stretching into northern Africa, parts of eastern and western coastal Australia, much of the northeastern Pacific around the Gulf of Alaska, the central to western equatorial Pacific, large swaths of northwestern and southeastern Atlantic, most of the Norwegian Sea, and parts of the central to southern Indian Ocean.</li>
    
        <li>During 2014, the globally-averaged land surface temperature was 1.80°F (1.00°C) above the 20th century average. This was the fourth highest among all years in the 1880-2014 record.</li>
    
        <li>During 2014, the globally-averaged sea surface temperature was 1.03°F (0.57°C) above the 20th century average. This was the highest among all years in the 1880-2014 record, surpassing the previous records of 1998 and 2003 by 0.09°F (0.05°C).</li>
    
        <li>Looking above Earth’s surface at certain layers of the atmosphere, two different analyses examined NOAA satellite-based data records for the lower and middle troposphere and the lower stratosphere.</li>
    
        <ul>
    <li>The 2014 temperature for the lower troposphere (roughly the lowest five miles of the atmosphere) was third highest in the 1979-2014 record, at 0.50°F (0.28°C) above the 1981–2010 average, as analyzed by the University of Alabama Huntsville (UAH), and sixth highest on record, at 0.29°F (0.16°C) above the 1981–2010 average, as analyzed by Remote Sensing Systems (RSS).</li>
    
    
                <li><li>The 2014 temperature for the mid-troposphere (roughly two miles to six miles above the surface) was third highest in the 1979-2014 record, at 0.32°F (0.18°C) above the 1981–2010 average, as analyzed by UAH, and sixth highest on record, at 0.25°F (0.14°C) above the 1981–2010 average, as analyzed by RSS.</li>
    
    
                <li><li>The temperature for the lower stratosphere (roughly 10 miles to 13 miles above the surface) was 13th lowest in the 1979-2014 record, at 0.56°F (0.31°C) below the 1981–2010 average, as analyzed by UAH, and also 13th lowest on record, at 0.41°F (0.23°C) below the 1981–2010 average, as analyzed by RSS.  The stratospheric temperature is decreasing on average while the lower and middle troposphere temperatures are increasing on average, consistent with expectations in a greenhouse-warmed world.</li></ul>
    

    According to data from NOAA analyzed by the Rutgers Global Snow Lab, the average annual Northern Hemisphere snow cover extent during 2014 was 24.95 million square miles, and near the middle of the historical record. The first half of 2014 saw generally below-normal snow cover extent, with above-average coverage later in the year.

    Recent polar sea ice extent trends continued in 2014. The average annual sea ice extent in the Arctic was 10.99 million square miles, the sixth smallest annual value of the 36-year period of record. The annual Antarctic sea ice extent was record large for the second consecutive year, at 13.08 million square miles.

    December 2014

        <li>During December, the average temperature across global land and ocean surfaces was 1.39°F (0.77°C) above the 20th century average. This was the highest for December in the 1880-2014 record, surpassing the previous record of 2006 by 0.04°F (0.02°C).</li>
    
        <li>During December, the globally-averaged land surface temperature was 2.45°F (1.36°C) above the 20th century average. This was the third highest for December in the 1880-2014 record.  </li>
    
        <li>During December, the globally-averaged sea surface temperature was 0.99°F (0.55°C) above the 20th century average. This was also the third highest for December in the 1880-2014 record.</li>
    
        <li>The average Arctic sea ice extent for December was 210,000 square miles (4.1 percent) below the 1981-2010 average. This was the ninth smallest December extent since records began in 1979, according to analysis by the National Snow and Ice Data Center based on data from NOAA and NASA.</li>
    
        <li>Antarctic sea ice during December was 430,000 square miles (9.9 percent) above the 1981-2010 average. This was the fourth largest December Antarctic sea ice extent on record.</li>
    
        <li>According to data from NOAA analyzed by the Rutgers Global Snow Lab, the Northern Hemisphere snow cover extent during December was 130,000 square miles below the 1981-2010. This was the 20th smallest December Northern Hemisphere snow cover extent in the 49-year period of record.</li>
    

    A more complete summary of climate conditions and events can be found at: http://www.ncdc.noaa.gov/sotc/global/2014/13

    Lots of new climate change science stuff

    I just did an interview on Green Diva Radio, and talked about a lot of climate change science news. For those who want to see the sources, here is a quick summary:

    On Friday, NASA and NOAA are expected to announce that 2014 was the hottest year on record. I had been planning to write an extensive blog post going into all sorts of details about how that works, how they calculate it, etc. But then the people at Climate Nexus wrote a post that would have blown mine out of the water with the detail and informtation provided in it. Go here to read this excellent post: 2014: Putting The Hottest Year Ever in Perspective.

    More than one new paper has come out describing new work on melting glaciers, especially in the Antarctic. One of the papers is described by an author, John Abraham, in this blog post: The Antarctic ice sheet is a sleeping giant, beginning to stir. You can get to the original paper via a link in that blog post. Bottom line is that the polar ice sheets are melting faster and faster every time someone looks. There is also some interesting stuff about melting glaciers, gravity, and sea level rise. Very much worth a look.

    There is also a new sea level rise curve. I’ve not looked at this so I have no comments on it, but you can see a write up here: A new sea level curve.

    The first in a series of predictions for the 2015 Atlantic Hurricane seasons has come out: 2015 Hurricane Zone Predictions: Stronger Season with Three U.S. Hot Spots. Bottom line is that it will be a pretty average hurricane season, which, in turn, means more hurricanes and more severe hurricanes than during the last few years, which have been rather anemic. Which, by the way, is probably a side effect of climate change.

    There has been some recent work confirming some earlier work, suggesting that a lot of “small” volcanoes have created a lot of dust contributing to cooling of the Earth’s atmosphere, slowing greenhouse gas caused warming. Despite what at lease one of these items says, we are now pretty sure that most of the surface temperature slowdown is because most of that heat is going into the ocean (see this), but volcanic dust has also made a contribution (as has the sun, being in a somewhat weak phase). So there are two things you should have a look at: Volcanoes may be responsible for most of the global surface warming slowdown and Small volcanic eruptions explain warming hiatus. Imma go out on a limb and guess that a little over 50% of the lack of warming (though it is warming, just slower) is from the ocean taking in more heat, the next biggest contribution is the volcanic dust, and a smaller but still two digit percentage (maybe) is from the sun. Feel free to challenge me on those numbers but do so with evidence please. I’ll be happy to see that estimate refined.