Don't breathe too deeply, and other stories
Climate change is here: Climate change is already contributing to the deaths of nearly 400,000 people a year and costing the world more than $1.2 trillion, wiping 1.6% annually from global GDP, according to a new study. The impacts are being felt most keenly in developing countries, according to the research, where damage to agricultural production from extreme weather linked to climate change is contributing to deaths from malnutrition, poverty and their associated diseases. Air pollution caused by the use of fossil fuels is also separately contributing to the deaths of at least 4.5m people a year, the report found. That means failing to tackle a fossil fuel based economy will contribute to something like 100 million deaths by the end of next decade.
Warming oceans: warming and acidification will cut the productivity of fisheries in many countries. "About 1 billion people depend on seafood as their main source of protein. But some of those countries most dependent on fishing are expected to lose up to 40% of their fish catch by the middle of the century." Hardest hit will be the Persian Gulf, Libya, and Pakistan. Of course, this is just from carbon-related changes and does not take into account patterns of overfishing, invasive species, pollution, eutrophification, stratification, shifting currents or habitat loss from coral reef degradation. And even the size of fish will shrink in warmer oceans.
Dying trees: Who will speak for the trees? Trees are dying by the millions all around the world due to a wide range of factors. Not just deforestation - which, though it has slowed down a little in Brazil, still continues with increasing rapidity elsewhere - but also due to ground level ozone pollution, infectious diseases (a third of all UK trees face wipeout from a new fungal threat that is expected to wipe out over 90% of Danish Ash trees) and a variety of threats associated with climate change, such as heat stress, invasive species (pine bark beetle) and droughts. For instance, last year's drought in Texas killed over three hundred million trees (or about 6% of all its trees). Heat stress has been linked to widespread tree mortality in scores of studies over the last few years.
Ocean acidification: A basic primer with FAQs, including excellent brief answer to common misconceptions.
Killer cats: How much do cats actually kill? The Oatmeal summarises some recent research. There are hundreds of millions of domestic cats around the world, and tens or hundreds of millions of feral cats. They are taking a big toll on small wildlife.
Australian coal: Australia's carbon price, far from signalling the "death of the coal industry" as claimed repeatedly by the Opposition, has apparently done little to dent the explosive growth of coal exploration in the country. Australia is the world's largest exporter of coal, fifth largest extractor of fossil hydrocarbons globally and has the highest per capita domestic carbon emissions in the OECD. Despite setting very modest carbon reduction targets in recent legislation, both government and industry are planning on a doubling of coal exports in the coming decade, representing emissions many times greater than Australia's tiny domestic reductions, which will largely come from international offsets in any case.
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45 comments:
Monbiot: Ash tree threat reminds us that when we lose wildlife, we lose stories.
The Conversation: What about your carbon pawprint?
The Conversation: Australia's international offsets plan.
Guardian: Ash tree imports into the UK banned, but possibly too late. The UK government were warned about this roughy three years ago, according to one article.
Guardian: Ash dieback fungus now suspected at 20 UK sites outside of nurseries.
Guardian: 100,000 ash trees already destroyed in an attempt to limit/slow the spread of the fungus.
Boyd, chief scientific adviser at the Department for Environment, Food and Rural Affairs: "In general we have to accept that this is a bit of a disaster for our ash trees."
Yes, just as the arrival of Europeans in the Americas was "a bit of a disaster" for the locals, with mortality rates over 90-95%. Classic British understatement.
From that previous link: "Clark pointed out that ash trees make up around 5% of woodland in Britain, not a third of British trees as some newspapers have reported."
Hmmm, I'd like clarification on this claim. 5% of woodland ≠ 5% of British trees (or at least these are not necessarily equal). Does this claim mean that 5% of woodland is dominated by ash or that 5% of trees are ash? Very different claims. And what is the source of the one third of all British trees claim that has been frequently quoted?
Guardian: Government ignored ash warnings three years ago.
Monbiot: Open letter about ash trees.
Guardian: Best ash tree summary so far, with quotes from various experts, investigating the question of whether more could and should have been done. In short, yes.
Though it does repeat the "one-third" claim, while also mentioning "80 million ash trees", which seems dodgy in light of these 2009 figures from the Forestry Commission. I suspect it all comes down to the definition of a tree.
Guardian: UK ash dieback found in yet more locations.
Guardian: Ash dieback can be overcome if we act now.
Hey Byron,
I mentioned earlier that I think sequestering carbon into the ground by making new topsoil is THE solution to global warming (and a fast solution, too, once folks start implementing it more widely). I recently stumbled across a video you might like which summarizes this possibility: http://www.youtube.com/watch?feature=player_embedded&v=wgmssrVInP0 (Note: The first 2:30 minutes summarize "Why our brains can't handle this problem", which you might want to skip to save time.)
Like I said earlier, I worked for a guy in Vermont who easily sequestered 100 tonnes of CO2 per acre annually for three consecutive years. This is very doable.
The Conversation: Why Australia must stop exporting coal. And Australian energy white paper plans to burn, burn, burn it all.
Brad, thanks for sharing the video. I enthusiastically agree that better management of degraded lands can have all kinds of positive benefits, including some significant carbon sequestration. However, I have two reasons to think that this is only ever likely to be one small part of a much bigger puzzle, rather than a silver bullet.
First (and less importantly), I'm a little uncertain about some of his numbers.
a. His comparison of the volumes required to store atmospheric CO2 vs solid carbon implied that biomass is pure carbon (like graphite), which is simply not the case. The density of carbon in biomass is less than half that of graphite. 1 kg of dry wood contains between 0.42 and 0.55 kg of carbon. Living wood can be quite a bit lower.
b. His equation of 1 ppmv = 7.8 Gt CO2 ignores the CO2 in the ocean, which reaches equilibrium with the atmospheric CO2 and so ends up increasing that number. That is, to raise CO2 concentrations by 1 ppm you need 7.8 Gt extra CO2 in the atmosphere, but since the ocean will absorb quite a chunk of that (with terrestrial biomass absorbing another chunk), then we actually need to add roughly double his number to see concentrations rise by 1 ppmv. Yet while this helps slow the rise of atmospheric concentrations (at the dire cost of ocean acidification), if we're talking about carbon sequestration and drawing down atmospheric concentrations, it actually makes the task 1.5-2 times as large, since as atmospheric concentrations drop, oceanic concentrations will reach new equilibria by degassing (and biomass will grow more slowly), meaning that we need to suck much more tan 7.8 Gt of CO2 out of the atmosphere for every ppmv we want to decrease.
But second, and more importantly, the numbers he races through extremely quickly at the end are far less optimistic than your claims. The total estimated sequestration potential (according to the slide at 18:15) is 1-4GtCO2/yr at a carbon price of US$20-$100/tCO2. The next slide (18:18) suggests that the technical (not economic) capacity might be 5.5-6Gt CO2/yr by 2030). That's certainly not to be sneezed at, but when global emissions are already over 30 Gt/yr and continue to rise, it is not going to singlehandedly solve the problem. Since terrestrial carbon from biomass has contributed something like 500 Gt CO2 over the course of human history (through land use change), then getting that much CO2 back out of the atmosphere and oceans is of course theoretically possible. It may, of course, also be theoretically possible to increase this. But the fact remains that we are overloading the active carbon cycle (biomass-atmosphere-oceans) by dumping enormous amounts of fossil carbon into it. Until we stop doing that, then shifting the carbon from one part of the active cycle to another is only going to be a partial and short term solution.
Remember, one of the major effects likely from our current trajectory is that the majority of the earth's terrestrial surface will shift biomes. This is very unlikely to be a net carbon sink for a very long time, since newly established ecosystems will be less complex and productive. Furthermore, by far the largest store of carbon in the biosphere is found in the frozen (yet thawing) soils of Siberia and northern Canada. These represent a store of carbon large enough to overwhelm (or at least seriously undermine) sequestration efforts if they start to thaw in earnest.
Guardian: Ash dieback - ministers accused of hiding inconvenient truths. Could the spores have come on the wind from the continent? In which case, the spread was inevitable and the government's failure to ban imports earlier less culpable. Or has the government leaned on scientists to acknowledge that this is theoretically possible (while unlikely) in order to improve their image?
ABC: What's the point of exporting our emissions elsewhere?
Sorry for my delay here---I only just realized you responded.
Regarding the numbers:
a. Gas vs. solid. I think you misunderstood the point about solid carbon vs. CO2. As I understood it, his point was simply that carbon in a solid state (as in humus) takes up a lot less room than carbon in a gaseous state (as in CO2). Therefore, it would take a LOT of space and energy to store CO2... an infeasible amount of space and energy. That's the point. By comparison, sequestering solid carbon into soil it's actually quite feasible: the space required is insignificant (since it's located in the formerly lifeless subsoil) and the energy required is insignificant (because it's performed by plants using solar energy).
b. The amount of sequestration required. Good point about oceans and equilibrium. I hadn't taken that into consideration. In that case, you're right; I suppose one would have to sequester 15.62 Gt of CO2 to lower atmospheric concentrations by 1 ppm. I don't know who this presenter Tony Lovell is, but I do know unrelated scientists/farmers who make similar arguments. The people I know have slightly different numbers, and it might be that they're already taking ocean acidification into consideration; I can't be sure. I'll email my friends and make sure that they're aware of this. Thanks for the tip. In any case, you're right about the ocean and equilibrium, so let's revise these numbers:
Current atmospheric concentration of CO2 is 395 ppm. Hansen et al have argued that 350ppm would be safe, so let's run with that number for a moment. Personally, I think it's likely we'll go even lower eventually, but let's be conservative here. Going from 395ppm down to 350ppm means we would have to sequester ~700 Gt of CO2. That's definitely attainable, as I'll outline below.
Ah, but you say, this ignores future carbon emissions. Okay, let's take those into consideration as well. Current global emissions are ~30 Gt annually, which is roughly equivalent too an increase of 2 ppm each year. Any reductions we can make in our emissions would make the job easier, but let's be pessimistic here and assume that they increase instead (I think this would be unlikely under this particular scenario, particularly since the agricultural reforms we're talking about would also have the double effect of eliminating certain agricultural emissions, which would itself take a significant chunk out of global emissions even without any other lifestyle changes... but we'll set that issue aside for the moment; let's be pessimistic and assume that emissions go up as usual anyway). Let's say we have a 20 year goal: we want to reverse global warming and get down to 350ppm in just two decades. If global emissions rise as predicted, then by that time we'll be emitting ~40 Gt annually. Over a 20 year period, that's adds up to roughly another ~700 Gt of emissions that we would need to sequester (equivalent to another 45 ppm). So with these assumptions, we would need to sequester a total ~1,400 Gt of CO2 during 20 years: 700 Gt current + 700 Gt future. After that, we would be down to 350ppm, and it would simply be a matter of maintaining that status quo, or reducing it even further if we wished. Ideally fossil fuels would be replaced by sustainable energy (for many reasons!), but even if they're not it would be very easy to maintain the status quo of 350ppm at that point, especially if we've already successfully removed 1400 Gt!
Regarding your second and more important point:
My understanding was that the numbers he raced through at the end were not his numbers, but were the IPCC's numbers. The rhetorical intent seemed to be something along the lines of, “Hey, even the IPCC recognizes some significant potential here, and they don't even know the half of it!” The IPCC isn't yet aware that topsoil can be built/improved this quickly and easily. I expect they'll be aware of it within a few years, but in the meantime I can't blame them for overlooking this process. Personally, I wouldn't believe claims about 8 inches of new topsoil in a year unless I had seen it with my own eyes. It seems too good to be true. Thankfully, it is true. It's just a matter of combining some simple, obscure farming techniques. Different regions have different potentials of course, and making 8 inches of topsoil in Vermont is much easier than making it in Arizona. Nevertheless, the global potential is incredibly high. We don't need 8 inches of new topsoil to reverse global warming; we can make do with much less.
Here is my thesis:
To sequester ~1400 Gt of CO2, we need to increase the SOM in the first 12 inches of our agricultural land by 3.6%
How I arrived at these figures:
1 hectare of soil 12 inches deep is approximately 3,658 metric tons (100 m x 100 m x 30.48 cm x soil density of 1.2 compared to water = 3,658 tons)
Soil Organic Matter (SOM) is approximately 58% carbon, and CO2 is 12/44th carbon.
3.6% of 3,658 tons = 132 tons of SOM = 76 tons of solid carbon = 280 tons CO2
280 tons of CO2 per hectare x 5 billion hectares of agricultural land worldwide = 1400 Gt of CO2.
Why I believe this is attainable:
I have personally seen gains of ~240 tons of CO2 per hectare in a single year. This was on a dairy farm, and the two methods used were non-inverse tilling and rotational tall grazing. Non-inverse tilling is basically the exact opposite of plowing. Whereas plowing turns the soil upside down and ruins the soil's mini-ecosystem, non-inverse tilling enhances the ecosystem by dragging 18-inch tines cleanly through the soil. See a couple pictures I took here and here. The plants above remain relatively undisturbed, but beneath the surface miracles are happening. Non-inverse tilling delivers vital nutrients (air, water, food) directly to the lifeless subsoil, which quickly converts into topsoil. Roots are able to penetrate more deeply and the plants grow far more vigorously. Combined with rotational tall-grazing, it was a double-whammy that sequestered 240 tons per year (I only witnessed one growing season personally, but I'm told that similar gains occurred during the previous year and the subsequent year... 700 tons of CO2 per hectare in only 3 years! Woohoo!).
Thanks for spelling out your assumptions and calculations in more detail.
Perhaps I've misunderstood, but here is the problem. You've assumed that the mass of the soil = the mass of SOM, which is simply not the case. For most soils, SOM is only a few percent, which shifts your calculations by more than an order of magnitude.
I understand that SOM is only a few percent. And the aim articulated above is to increase the total SOM in a hectare by 3.6% (so if a given soil has 1.4% SOM, then the aim is to increase it to 5%). Does that make sense?
You know, on second thought I'm going to tentatively retract my claim about seeing ~240 tons of CO2 sequestered in a hectare in a single year. The more I think about it, the more I think I might be overestimating it or remembering incorrectly. After all, it was 6 years ago, and at the time I was a climate skeptic and didn't particularly care about the CO2 (I went to the farm learn more about building topsoil for agricultural reasons, not for climactic reasons). I definitely did see 8 inches gain in a single year, but I'm not sure if that involved 240 tons of CO2. My assumption/remembrance was that we with an additional 1.5% of SOM in the top 24 inches of soil. If true, that would certainly work out to 240 tons of CO2, but maybe I'm wrong about those two numbers. Maybe we only added 0.5% in the top 18 inches. If so, then that would work out to be a mere 75 tons of CO2. That sounds more plausible. The Amazon rainforest sequesters about 30 tons/ha, and I know that prairie has higher potential than rainforest, so 75 tons seems more realistic. In any case, I'm going to call them in Vermont and ask again for the exact numbers so I can get this right. But for now, please take that claim I made with a grain of salt, and realize that it might be significantly lower. But either way, my point stands: topsoil is the solution, and it's very doable.
And of course, my numbers regarding ocean degassing are very conservative/pessimistic. I based my numbers above on a 1:1 ratio of ocean to atmosphere, when in reality it's probably more like a 2:3 ratio. But I couldn't find any really reliable numbers to back that up, so I just went with the more pessimistic 1:1 ratio (and hey, it has the added bonus of making math simpler!).
Just making a comment here so I can receive email updates for any further comments (I never ticked that box previously).
Guardian: Climate change linked to declining Caribbean fish stocks.
Brad - Sorry for not replying sooner, and for not replying via email as you suggested. I'd be happy to chat further, though as you're already aware, I'm consciously spending less time on blogging and emailing in order to focus on trying to finish my PhD.
I have two main thoughts in response to what has been said so far.
1. What kind of limits are there on the accumulation of soil organic matter (SOM)? I presume that a given field can't continue to add SOM year after year indefinitely, but reaches a point of equilibrium. If the Serengeti is an example of the kind of soil management through rotation of grazers with long return periods that you have in mind, then I presume its SOM reached some kind of limit. I also assume that the maximum would be affected by myriad variations in soil composition. The point is that while impressive initial sequestration may well be possible, assuming that this is some kind of silver bullet rendering climate change benign requires that this kind of sequestration can be repeated year after year for some time.
2. How confident are you that the increased SOM is retained long term in the soil? I guess this relates to the previous question, as my somewhat naïve assumption is that the soil would reach a saturation point at which decomposition of SOM would be balanced the addition of new SOM. And what factors affect this rate? I have read that warmer climates is likely to increase the rate of decomposition, perhaps even turning many soils from carbon sinks into sources at some point.
3. I hope that your former boss who taught you about this approach has submitted his work to this competition, because if the numbers truly stack up (even if they don't reach the level of being called a "solution", merely a "material contribution") then he could win $25m.
"I have two main thoughts"
Oops - three, obviously.
No worries for the delay. Blog comments shouldn't be a high priority in everyday life anyway. :-)
Before I say anything else, I want to clarify my intention in bringing up this strategy and its accompanying numbers. My intention is NOT to defend “business as usual” and argue that burning fossil fuels is perfectly fine because we'll just sequester everything. On the contrary, I believe burning fossil fuels is unwise and should be strongly discouraged, and I'm in favour of a carbon-tax. It would be wiser to embrace other forms of energy instead---in particular, I'm a fan of super-efficient solar panels and forms of nuclear energy that produce little/no waste. Unfortunately, such solar-panels are only in the prototype stage right now, and such forms of nuclear energy are either controversial (like France's model, which produces almost no waste) or theoretical (like Bill Gates' model, which would leave no waste). We are a probably a few decades away from realistic alternatives to fossil fuels. Therefore, it seems highly unlikely to me that worldwide carbon emissions will decrease. Sure, Europeans might slow down their usage a little bit, but do you honestly think that Americans and the emerging middle class worldwide will decrease their carbon emission? I'm pessimistic. Maybe carbon emissions would decrease a little bit on accident as people use more natural gas (a “cleaner” fossil fuel), but overall I don't have much hope for worldwide reduction in carbon emissions, and I have absolutely no hope that the USA (for example) would ever pass a carbon-tax. So please understand, my intention is not to defend the usage of fossil fuels; I'm just assuming people will foolishly continue business as usual, and I'm trying to tailor the solution to that.
1. I don't know what the exact theoretical limits of SOM would be, but I do know they are high enough that we wouldn't need to worry about them. 5% SOM in the top 12 inches is definitely attainable on most agricultural land. Personally, I would be disappointed if my farm didn't have 9% SOM in the top 36 inches. And remember, to reverse global warming all we need is another 3-4% in the top 12 inches (using my pessimistic “business as usual” numbers above), which is nowhere near potential saturation levels.
Concerning initial gains: In most cases it actually becomes easier to sequester more carbon the higher SOM content is, because the higher soil fertility results in greater biomass production, greater drought resistance, etc. Initial gains are often slow, and they gradually increase. Obviously the law of diminishing returns would kick in at some point as the soil reached a level of saturation, but that would take an awful lot of carbon.... especially since topsoil can be deepened considerably with subsoil work.
Side note: You mentioned the Serengeti. I'm confident that the SOM of the Serengeti could be increased by using subsoiling techniques like I mentioned above (non-inverse tilling), which would help break up difficult subsoil structures and open it up to further exploitation from the roots of grasses and forbes. Nature is brilliant, and sometimes we can help her be even more brilliant with a little mechanical help (e.g., breaking up B-grade and C-grade soil strata into more permeable chunks). I don't know of any drawbacks to deeper topsoil. I'm not saying we should actually do this with the Serengeti; my point is only to illustrate the potential of these methods. Even the Serengeti could hold more SOM.
So in short, yes, there are limits to SOM concentration, but they aren't the sort of limits that would get in our way.
Another side note: You used the phrase “silver bullet.” Although I do believe the topsoil strategy is the only way we can safely and realistically fix global warming (for reasons I can elaborate later), I don't believe it's simple enough to qualify as a 'silver bullet.' The biggest challenge with this method is, funnily enough, actually getting it to happen. Educating the majority of farmers in the world is quite a challenge. I believe it can be done, and it MUST be done, but it's still going to take massive effort to initiate. Thankfully, the effort involved is mostly up-front and doesn't require very much capital; after a farmer is educated he can continue sequestering carbon more and more easily for decades (and he can hopefully teach his friends, neighbours, etc.).
2. When we talk about SOM, we're not talking about leaf-litter or normal vegetative biomass. That sort of organic material decomposes (the speed of decomposition depending on moisture, temperature, and acidity), and you can expect it to slowly return to the atmosphere as CO2. In other words, chopping down a tree and burying it accomplishes almost nothing, because the vast majority of it will just rot and emit CO2. You could make biochar out of the tree first, which would remain stable in the soil, but that's a very labour-intensive process. So to clarify, when we talk about SOM we're talking mostly about humus and other insoluble carbon complexes. Humus/SOM is remarkably stable in the soil. You can expect it to stay there for centuries, perhaps millennia.
Side note: You mentioned the possibility of soils becoming carbon sources instead of carbon sinks. This is a very real possibility. It happens all the time, and I hate it. Two farming methods tend to transform soils into carbon sources: tilling, and nitrogen fertilizer. Tilling soil exposes the SOM to high levels of oxygen and results in small emissions of CO2 (small, but significant for soil fertility over time). Nitrogen fertilizer helps to slowly 'burn up' SOM, perhaps by encouraging unhelpful microbial populations (again, the loss is small annually, but significant over time... gosh, I hate nitrogen fertilizer! It's so bad on so many levels!). In other words, conventional farming turns soil into a carbon source. I'm suggesting that we reverse that, and reverse it in a big way. Turn soil back into a sink!
3. Wow, I didn't even know about that competition. It appears the concept has already been submitted by his mentor. Virgin has currently identified a short-list of the top 11 organizations, and the The Savory Institute made the list. Alan Savory was the mentor of my boss, and taught him everything he knows (well, almost everything :-). Hopefully he'll win. He can definitely beat the biochar and olivine organizations on the short-list. So I guess it just depends on how optimistic the judges at Virgin are about those various atmospheric carbon technologies and how optimistic they are about farmers learning to manage land properly.
Thanks - that's all very helpful. Thanks in particular for reminding/clarifying for me of your position with regards to mitigation, sequestration, possible timeframes, etc.
I hadn't realised they'd already made a shortlist of 11. I should have looked a little more closely at that site I sent you to, since it's been up since March.
As for soil being a carbon source, then yes, I'm aware that poor management can have this result, though I was referring specifically to the effects of temperature on soil carbon. However, a little extra looking around seems to indicate that this concern (which is a very real one) is focussed particularly on high latitude carbon-dense soils (peatlands and permafrost) rather than agricultural soils. I had gained the (apparently false) impression that higher temperatures alone could turn agricultural soils that are currently carbon sinks into a carbon source.
Guardian: Ash dieback spreads to 291 sites.
Guardian: Air pollution is now the 2nd leading cause of death globally, killing millions every year.
Guardian: Air pollution in Beijing breaks records.
John Vidal: Beijing pollution is the tip of the urban Asian iceberg.
"But go to the hospitals and doctors will tell you that up to 80% of people admitted come with respiratory or other chronic diseases linked to air pollution." [...]
"The biggest study done so far, published one month ago in the Lancet suggested that, worldwide, a record 3.2 million people died from air pollution in 2010, compared with 800,000 in 2000."
The Conversation: Air pollution in China.
Guardian: Cats in NZ - call for neutering.
The Conversation: Limiting Australia's ballooning coal exports is good for the economy.
Some very interesting number crunching about the effects of the mining boom.
Hey Byron,
Allan Savory himself just gave a great TED talk. You should check it out. It's a good basic summary of the principles involved, and there are some great before/after photos towards the end: here
NYT: Air pollution in China kills 1.2 million each year.
Guardian: China's environmental problems grim, according to a new report from China's Ministry of Environmental Protection.
Guardian: Europe must tackle air pollution, warn UN scientists.
"Air pollution causes 29,000 early deaths a year in the UK – more than obesity and alcohol combined."
"Massachusetts Institute of Technology research earlier this year found car exhaust fumes in Britain now caused more premature deaths than road accidents."
Guardian: Chinese air pollution reduces life expectancy in the north by around five years.
The Conversation: Warming oceans are affecting the breeding patterns and habitat of marine life.
"In total, 81% of all changes were consistent with the expected impacts of climate change."
Guardian: More than 90% of people in European cities breathe dangerous air, study finds.
Countries have downplayed hazards of air pollution despite evidence that it leads to 430,000 shortened lives a year.
Guardian: Chinese media find silver linings in smog clouds. Hard to know whether to take this as inept propaganda or a Chinese journalist with a very dark sense of humour.
Guardian: China to spend $176b clean up bill for air pollution. That is just between 2013 and 2017 and to reduce particulate pollution by 10%.
SMH: Air pollution takes its toll on Australian lives, economy: OECD report.
"The report shows that between 2005 and 2010, the number of deaths from air pollution in Australia jumped from 882 to 1483, representing a 68 per cent rise. [...] the economic cost of deaths from air pollution for OECD countries hit $US1.7 trillion in 2010. [...] the economic cost for Australia was about $5.8 billion in 2010, up from $2.9 billion just five years earlier."
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