Twenty Nile rivers, and other stories

Water stress: By 2025, to feed growing populations, the world will need to find extra fresh water equivalent to the flow of twenty Nile rivers.

Extreme weather: Bill McKibben ponders just how strange this year has been.

Junk food: George Monbiot concludes that a possible link between Alzheimer's and poor diet might be more than sensationalist media spin.

Heat: 2013 tipped to break more records. With a good chance of an El Niño forming in the coming months, combined with the ongoing warming trend from greenhouse gases, next year could be one for the record books. At least until the next El Niño...

Mangroves: Per hectare lost, mangrove destruction is three times worse for greenhouse gas emissions than deforestation.

NB The following articles are eighteen months out of date, but I neglected to post them earlier and they are interesting.
Malthusians beware: Blame the World Bank and IMF (amongst others) for famine in the Horn of Africa, but don't blame overpopulation.

Deep sea fishing: Is any deep-sea fishing sustainable? The short answer is "almost none". Deep-sea fisheries tend to regenerate very slowly, given the small amounts of energy entering the system. Many of the creatures down there are older than your grandmother.

Organic farming: It can be more profitable than conventional farming over the long term, even if organic premiums drop by 50%.

Climate panic: What we can all be doing about climate change. The Onion nearly always hits the key issue on the nose.

The Arctic is melting: 18 reasons to care

Arctic sea ice has once again smashed all kinds of records - for extent, area and volume. Every year a huge amount of ice melts in summer and refreezes in winter, but the trend over the last few decades has been strongly downwards, especially during the summer months. In fact, this year, the extent of ocean with at least 15% sea ice cover declined to a level less than half of what it used to average just twenty years or so ago. Through it is harder to measure, the volume of summer sea ice is down by about three quarters from what it used to be. I posted an introduction to sea ice area, extent and volume back here.

When compared to our best reconstructions of the history of Arctic sea ice over the last 1450 years, the last few decades are, well, unusual. The graph above, which shows the ups and downs of summer sea ice extent over the years gives a sense of just how staggeringly quickly this part of the world is changing. Indeed, the collapse in sea ice is so rapid that it continues to stun even the scientists who have been watching it closely for decades. Back in 2007, the IPCC Fourth Assessment Report said that it was unlikely the Arctic would be seasonally free until after 2100.* Now, the UK Met Office says it is likely sometime between 2040 and 2060, most other Arctic organisations speak about sometime around 2030, while a handful of individual experts warn that, depending on weather conditions, it could be as early as the next Olympics in Rio. There is almost no evidence that this has occurred for at least the last few hundred thousand years (estimates range from 700,000 to 4 million years). *There are different definitions for what "ice-free" means. The most common is when extent drops below one million square kilometres, meaning that there might still be some ice clinging on around the north Greenland coast or in bays and inlets in the high Canadian Arctic, but effectively, the main ocean is free of ice.

Whatever the precise timing, why do we care? So what if some polar bears drown? Why does it matter to me what is happening thousands of miles away in the middle of an ocean amidst a deserted wilderness? Because the Arctic is closer than you think. The effects of declining summer sea ice are many. Here are eighteen reasons to care about the likelihood of a seasonally ice-free Arctic Ocean in the coming years. Only one is polar bears:

1. Polar bears: And walruses, seals and all the other unique Arctic wildlife that depend on sea ice. Seasonal sea ice loss threatens the unique and endemic Arctic biota. The polar bear is an photogenic icon, and as the largest terrestrial predator it instantly commands widespread respect and attention, but there is so much more at stake than simply polar bears.

2. Cultural loss. The loss of sea ice undermines the way of life of various indigenous groups in the Arctic, who rely on hunting and the ice for their livelihood and culture.

3. Infrastructure damage: As the Arctic region is warming, the permafrost that covers the land is both melting and being rapidly eroded. There are many structures and roads built on the permafrost that are already suffering severe damage.

4. Albedo change: Less floating white ice means more exposed dark water, which absorbs more solar radiation, increasing the total incoming heat flux of the planet, and specifically of the Arctic Ocean. The reflectivity of the planet's surface is called its albedo, and the decrease in albedo caused by loss of Arctic ice during the period when it is receiving 24 hours of sunlight is considered by many scientists to be the greatest single threat on this list.

5. Permafrost methane: A warming Arctic Ocean and atmosphere speeds the melt of permafrost in Canada, Siberia and Alaska, not only threatening infrastructure (see #3), but also releasing stored methane (CH₄), a highly potent greenhouse gas that degrades into carbon dioxide, making it both a short term climate nasty and a long term headache. The total amount of frozen methane is vast and although it unlikely to all melt quickly, it is soon likely to become a significant and sustained drag on efforts to cut emissions. More emissions from thawing permafrost means less room and time for us to make our own transition away from carbon-intensive energy systems.

6. Submarine methane: Warmer waters increase the rate at which vast submarine deposits of methane clathrates found along the Siberian continental shelf destabilise and are released to the atmosphere, giving a further kick to warming. Some observers are petrified this "clathrate gun" could end basically all life on earth in matter of years through a catastrophic self-perpetuating release. As I've noted previously, scientists are yet to see a convincing geophysical mechanism for this being a sudden and catastrophic release (with consequent spike in global CH₄) rather than a progressive leak resulting in an elevation of CH₄ with rising CO₂. This represents further drain on our carbon budgets, though the precise scale and timing of these emissions are less understood than those from terrestrial thawing.

7. More available heat: To convert ice at 0ºC to water at 0ºC takes energy, even though the temperature has not changed. The considerable energy involved in this phase change is called latent heat. Without ice in the ocean sucking up extra energy during summer, the solar energy that previous went into melting ice can go into the oceans (and later be released to the atmosphere). This is like removing a handbrake, though my back of the envelope attempts to quantify it suggest it will be significantly smaller effect than albedo change (#4). I'd like to see these calculations made by someone who knows what they are doing.

8. Wacky weather: This is something of a wild card and could prove to be the biggest danger to human society. Losing the ice is already changing wind patterns around the Arctic, which in turn affect the weather throughout the northern hemisphere. There is some evidence that more exposed water in the Arctic and a decreased temperature difference between the equator and pole (since the Arctic region is warming much faster than further south) is increasing the amplitude of the meanders in the jet stream. In turn, this slows down progression of the meanders, leading to "blocking patterns", where one region gets "stuck" in a certain weather pattern, whether heatwave, drought or flood. The 2010 Moscow heatwave that killed 11,000 people and sent the price of wheat skyrocketing (in turn helping to spark the Arab Spring), the 2010 Pakistan floods that displaced 20 million people, the 2010/11 record cold winters in Europe and parts of the US and the 2012 US heatwave and drought have all been linked to unusually persistent blocking patterns. Losing the ice may mean we see more of these kinds of things. The jury is still out on this theory, but if not precisely like this, the loss of Arctic sea ice will almost certainly affect wind circulation patterns and so weather both regionally and hemispherically.

9. Greenland melt: Over the long term, this may be the biggest change. The warmer the Arctic Ocean gets, the warmer Greenland is likely to get, and the faster its glaciers slide and melt into the sea. While floating sea ice doesn't affect sea levels (and there's relatively little of it anyway), there's enough ice on top of Greenland to raise sea levels by 7.2 metres (on average). As I read it, glacial draining and calving of the ice sheet is a larger sea level rise contributor than straight melting (thus the recent fracas over dramatic surface melt may not be the key issue for Greenland - remember, this recent melt event cut centimetres off a sheet that averages over two kilometres thick). The real danger is the acceleration of ice flow dynamics (i.e. the ice cube is more likely to slide off the table before it has finished melting). And the largest boost to glacier acceleration is from warming oceans meeting marine terminating glaciers. No one is entirely sure how long this will take, but it is a process that once it is underway in earnest, is likely to have a momentum of its own, meaning that our descendants will be committed to ever rising sea levels for centuries to come. The somewhat good news is that it is also a process that (on present understandings) is assumed to have some physical constraints due to friction (i.e. there are speed limits for glaciers, even in very warm conditions). The West Antarctic ice sheet, being largely grounded on bedrock well below sea level is actually more plausibly in danger of catastrophically sudden break-up, though warming in the Antarctic is currently only a fraction of what is being observed in the Arctic.

10. Resource conflict: An increasingly ice-free Arctic opens up a geopolitical minefield as nations scramble to take advantage of the resources previously locked away under the ice. The starter's gun for this race has well and truly fired, with various oil companies sending rigs to begin drilling for oil and gas this season. As one signal of the seriousness with which this is now taken, meetings of the Arctic council (comprised of nations bordering the Arctic) now attract Hillary Clinton rather than a minor government official.

11. More oil: The presence of significant amounts of oil and gas under the Arctic Ocean has been suspected and known for some time. Less ice means that fossil hydrocarbons that were previously off limits now become economically viable to extract, thus increasing the pool of available carbon reserves and so worsening the challenge of keeping most of them underground.

12. Fishing: Another resource now increasingly able to be exploited due to the loss of seasonal sea ice. Pristine (or somewhat pristine) marine ecosystems are thus exposed to greater exploitation (and noise pollution).

13. Shipping lanes: The fabled North West passage through the remote islands of Canada has been open to commercial shipping without icebreakers only four times in recorded history: 2011, 2010, 2008, 2007. The North East passage has also been open in recent years. These previously inaccessible Arctic shipping routes reduce fuel needs of global shipping by cutting distances (a negative feedback) but also brings more diesel fuel into the Arctic region, leaving black soot on glaciers (a positive feedback). I'm not sure which is the larger effect overall.

14. Toxin release: For various reasons, certain toxins and heavy metals from human pollution seem to accumulate in Arctic sea ice. As it melts, they are being released once more into the environment.

15. Invasive species: Melting ice reconnects marine ecosystems that were previously separated by ice, enabling migration of species into new regions, with unpredictable ecosystem changes as a result. This is already occurring.

16. Ocean circulation? These last three points are more speculative and I'm yet to see studies on them. But loss of sea ice could well change the patterns of ocean currents in the great global conveyor belt known as thermohaline circulation. This drives weather patterns throughout the entire globe.

17. Acidification acceleration? By increasing the open ocean surface area for atmosphere-ocean gas exchange, the rate of ocean acidification could slightly increase. Would this make any difference to ocean capacity to act as CO₂ sink or rate of acidification? This could well be irrelevant, but it is a question I have.

18 Political tipping point? The loss of virtually all perennial Arctic sea ice would be a highly visual and difficult to dispute sign of rapid and alarming climate change, representing a potential tipping point in public awareness and concern. If we are waiting for that, however, before we make any serious efforts to slash emissions (especially if it doesn't occur until 2030 or later), we'll already have so much warming committed that we'll pretty much be toast. At best, therefore, this point might consolidate public support for massive rapid emissions reductions already underway. These eighteen reasons can be summarised in five broad headings:

1. Direct effects upon local wildlife, human communities and infrastructure (1, 2, 3, 12, 14, 15);
2. Positive feedback affects that accelerate the warming process (4, 5, 6, 7, 11);
3. Changes to human economic and political systems through the opening up of previous inaccessible resources and routes (10, 13, 18);
4. Disruptions to the great atmospheric and oceanic circulation patterns that shape the experience of billions of people directly (8, 16);
5. Acceleration of long term threats (9, 17).

The loss of Arctic sea ice will not suddenly be the end of the world, but it represents a major milestone on the path to self-destruction along which we are currently hurtling with accelerating speed.

UPDATE: My opening graph needs some important further clarification. The unamended graph is a 40 year smoothed average, while the additional material displays year-on-year changes and so is not comparing apples to apples. However, using only 40 year averages to capture the dramatic changes of the last few years is also likely misleading. There is further discussion of this image here, here and here.

And now for the weather report

Perhaps a few more weather reporters giving this kind of context could help public understanding, since studies indicate that weather reporters remain one of the primary sources of information about climate (despite many reporters having little or background in climate themselves).

Very helpfully, the American Meteorological Society has updated its statement on climate change to reflect scientific research completed since the last one in 2007. The new statement is considerably stronger in its language than its previous one. Here are a few tastes of the new statement:

"Warming of the climate system now is unequivocal [...] many of the observed changes noted above are beyond what can be explained by the natural variability of the climate. It is clear from extensive scientific evidence that the dominant cause of the rapid change in climate of the past half century is human-induced increases in the amount of atmospheric greenhouse gases [...] Since long-term measurements began in the 1950s, the atmospheric CO2 concentration has been increasing at a rate much faster than at any time in the last 800,000 years. [...] Climate is potentially predictable for much longer time scales than weather for several reasons. [...] A helpful analogy in this regard is that population averages of human mortality are predictable while life spans of individuals are not. [...] Future warming of the climate is inevitable for many years due to the greenhouse gases already added to the atmosphere and the heat that has been taken up by the oceans. [...] Global efforts to slow greenhouse gas emissions have been unsuccessful so far. However, were future technologies and policies able to achieve a rapid reduction of greenhouse gas emissions — an approach termed “mitigation” — this would greatly lessen future global warming and its impacts. [...] In the 21st century, global sea level also will continue to rise although the rise will not be uniform at all locations. [...] Atmospheric water content will increase globally, consistent with warmer temperatures, and consequently the global hydrological cycle will continue to accelerate. [...] changes in precipitation patterns are expected to differ considerably by region and by season [...] more severe droughts and floods [...] significant regional shifts in precipitation patterns [...] heavy precipitation events will continue to become more intense and frequent [...] longer dry spells between precipitation events in the subtropics and lower-middle latitudes [...] Widespread retreat of mountain glaciers is expected to eventually lead to reduced dry season flows for glacier-fed rivers. Drought is projected to increase over Africa, Europe, and much of the North American continental interior, and particularly the southwest United States. [...] more extreme warm periods and fewer cold periods are expected [...] more severe episodes of extreme heat. Critical thresholds of daily maximum temperature, above which ecosystems and crop systems (e.g., food crops such as rice, corn, and wheat) suffer increasingly severe damage, are likely to be exceeded more frequently. [...] It is unclear if the land biosphere and oceans will be able to continue taking up carbon at their current rate into the future. [...] Another unknown is the amount of methane that will be released due to high-latitude warming. There are indications that large regions of the permafrost in parts of Alaska and other northern polar areas are already thawing, with the potential to release massive amounts of carbon into the atmosphere beyond those being directly added by human activity. The portion of the increased CO2 release that is absorbed by the world ocean is making the ocean more acidic, with negative implications for shell- and skeleton-forming organisms and more generally for ocean ecosystems."

If you're pressed for time, or already familiar with recent climate research, then you can just skip to the conclusion. Here it is in full:

"There is unequivocal evidence that Earth’s lower atmosphere, ocean, and land surface are warming; sea level is rising; and snow cover, mountain glaciers, and Arctic sea ice are shrinking. The dominant cause of the warming since the 1950s is human activities. This scientific finding is based on a large and persuasive body of research. The observed warming will be irreversible for many years into the future, and even larger temperature increases will occur as greenhouse gases continue to accumulate in the atmosphere. Avoiding this future warming will require a large and rapid reduction in global greenhouse gas emissions. The ongoing warming will increase risks and stresses to human societies, economies, ecosystems, and wildlife through the 21st century and beyond, making it imperative that society respond to a changing climate. To inform decisions on adaptation and mitigation, it is critical that we improve our understanding of the global climate system and our ability to project future climate through continued and improved monitoring and research. This is especially true for smaller (seasonal and regional) scales and weather and climate extremes, and for important hydroclimatic variables such as precipitation and water availability.

Technological, economic, and policy choices in the near future will determine the extent of future impacts of climate change. Science-based decisions are seldom made in a context of absolute certainty. National and international policy discussions should include consideration of the best ways to both adapt to and mitigate climate change. Mitigation will reduce the amount of future climate change and the risk of impacts that are potentially large and dangerous. At the same time, some continued climate change is inevitable, and policy responses should include adaptation to climate change. Prudence dictates extreme care in accounting for our relationship with the only planet known to be capable of sustaining human life."

There is much to commend in this new statement. It clearly and unambiguously affirms the three basic pillars of climate science: (a) the planet is warming rapidly; (b) humans are the dominant cause; (c) the consequences are a serious threat. There is not a relevant scientific institution of national or international standing that questions any of those three claims.

At the same time, the new AMS statement acknowledges many areas of lower confidence, where research is ongoing, including: the precise sensitivity of the climate to greenhouse gases; the precise role of clouds and aerosol particles; the precise distribution of disruptions to the hydrological cycle; the ongoing effects of natural variation within the larger trends; the rate of ice sheet disintegration and sea level melt; the potential negative side effects of geo-engineering proposals; and perhaps most importantly the uncertainties in the human systems that cause and are impacted by climate change: how fast will we continue to modify the chemical composition of atmosphere and oceans? And how well will we respond to the risks and threats these changes will bring?

Given the uncertainties, both in the geophysical systems and especially in the human systems that drive and respond to them, the AMS statement remains agnostic about the most important debate regarding the threat of climate change: does climate change represent a level of risk that is merely disastrous or truly catastrophic?

The closest it comes to addressing this question is in the very interesting final sentence: "Prudence dictates extreme care in accounting for our relationship with the only planet known to be capable of sustaining human life." We're not talking merely about losing the polar bears, or an acceleration of species extinctions more generally, or even severe economic disruption or a rising threat of climate-related conflict. Implicitly at least, this statement acknowledges that what is at stake is the ongoing capacity of the planet to sustain human life.

UPDATE: The scriptwriter for the video above shares his thinking behind the clip.

Our climate challenge in three numbers

"When we think about global warming at all, the arguments tend to be ideological, theological and economic. But to grasp the seriousness of our predicament, you just need to do a little math. For the past year, an easy and powerful bit of arithmetical analysis first published by financial analysts in the U.K. has been making the rounds of environmental conferences and journals, but it hasn't yet broken through to the larger public. This analysis upends most of the conventional political thinking about climate change. And it allows us to understand our precarious – our almost-but-not-quite-finally hopeless – position with three simple numbers."

- Bill McKibben, Global Warming's Terrifying New Math.

Apart from missing "s" in the title and a dodgy stat in the opening paragraph, McKibben's compelling 5-page piece is a good summary of some important elements of the challenge we face. The bottom line of his three numbers is that, according to our best understanding, if we want at least an 80% chance of staying under the internationally agreed (but still very dangerous) 2ºC limit we can only burn about 20% of our current fossil fuel reserves (not resources, but reserves, i.e. what is known and could be profitably brought to market under present conditions). This is the kind of statistic that can really serve to focus the attention. We need to leave four out of every five known and already profitable barrels of oil, tonnes of coal, cubic metres of natural gas underground.

Of course, the great difficulty is that no one country wants to do anything other than burn every last molecule of fossil hydrocarbon that can be brought to the surface unless all other countries agree to limit themselves also. And when some countries have far larger reserves (and so far more at stake economically in leaving 80% of them in the ground), then reaching such an agreement is basically impossible under present political assumptions. If you look at where the blockages in international negotiations are coming from, then it's no great surprise that these are also the countries with the largest reserves of fossil hydrocarbons: China, USA, Russia, Australia, Canada, various middle eastern states. Countries with tiny (or largely depleted) reserves are the ones at the forefront: small island nations, non-oil-based African nations and the EU (esp UK and Germany, which have historically had huge fossil carbon deposits, but have already burned most of their easily accessible stuff).

And so we are left with an international multi-player game of chicken, with no country wanting to blink first and lose market advantage, ensuring that all countries suffer horrendously as a result. The fact that those with least to contribute to the problem generally have greater vulnerability only serves to entrench both the injustice and the intractability of the issue.

The slim silver lining in recent extreme weather in the US is that it might bring home to US voters and policymakers that there are no winners in a game of chicken. Even if others are going to suffer more and sooner, the US is far from immune, especially to precisely these kinds of threats (droughts, wildfires, heatwaves, water stress). Russia is facing its own wildfires and floods. China has had large areas in drought almost constantly for the last five years and a flood this week has a death toll that could pass 100. Canada has simultaneously faced deadly floods and serious drought in the last couple of months. Middle Eastern petro-states are all too aware of their dire water situation as they rapidly go from grain exporters to zero wheat production within a decade (Saudi Arabia) after basically exhausting their fossil water. And Australia has all too quickly forgotten its own droughts, bushfires and floods just a couple of years ago.

Further complicating the picture is that it is not simply countries that are making these decisions. Apart from some nationalised oil companies, most of these reserves are held by for profit corporations with very, very deep pockets and who are generally not shy at throwing their weight around, spending up big on lobbying, misinformation and propaganda at every level in order to convince us all that without them we'd be living in caves and that they are struggling to get by in tough conditions.

Yet according to the most recent data, fifteen out of the thirty most profitable companies in the world are directly fossil fuel related (many of the remaining fifteen also have significant, if slightly less direct, links).

1. Gazprom: US$44.5b
2. Exxon Mobil: $41.1b
4. Royal Dutch Shell $30.9b
5. Chevron: $26.9b
8. BP: $25.7b
11. Vale: $22.9b
12. Petronas: $21.9b
13. VW: $21.4b
14. Ford: $20.2b
15. Petrobras: $20.1b
22. China National Petroleum: $16.3b
26. GE: $14.2b
27. Statoil: $14.1
29. Rosneft Oil: $12.5b
30. ConocoPhillips: $12.4b

The bottom line is that until a very wide audience grasps just how dire our situation is and starts to demand something different from our corporate and political leaders, then none of key climate numbers are likely to improve.

For me, the most telling number in McKibben's piece is the one that he doesn't mention. McKibben is an author with a string of respected publications about environmental and economic issues. He was the first popular writer to publish a book on climate change back in the 80s. Yet in the last three or four years he has re-invented himself as an activist after becoming convinced that writing alone is too slow to effect the changes that need to happen. He has built and become the public face of the world's largest climate movement, a movement named after and dedicated to a number: 350. His organisation, 350.org, refers to the highest concentration of CO₂ in parts per million considered "safe" by some of the world's leading climate scientists. We are currently over 390 ppm and rising rapidly. For most commentators, 350 ppm is seen as a pipe dream, an impossibility, well outside the realm of the thinkable, let alone the achievable. International negotiations talk about 550 and occasionally 450, but many commentators think we'll be lucky to stay below 650 and our current path is heading for 750 or significantly higher. In this context, McKibben and 350.org have served as a witness to how far from a just and sustainable world we are currently travelling. And yet here, in one of his highest profile pieces to date, he doesn't mention the number to which he has dedicated the last few years of his life and of which he is a relentless promoter. Is this because he has been so successful in publicising 350 ppm that he felt he could move on? Or because he decided that this idea is now so detached from reality that he needed to lower his sights?
Image by ALS.

Shiver or swelter? Why Edinburgh beats Sydney

When we first announced we were moving to Edinburgh back in 2008, by far the most common reaction was some variant of "you'll be cold!". As someone who detests Sydney summers, I found this a slightly odd thing to say. I much prefer 5ºC than 35ºC. Having now lived here for almost four years, through four winters, I can confidently say that Edinburgh's climate is superior to Sydney's. While both have (more or less) nine months of reasonably pleasant weather, Edinburgh has three months of cold and dark (and actually, the dark is worse than the cold - perhaps a topic for another post) while Sydney has three months of hot and humid. It is much, much easier (and generally more pleasant) to keep oneself warm than to cool down. Mulled wine, extra layers or some physical activity are more attractive than heat lethargy, shade-hopping and the impossible task of finding an appropriate clothing compromise between sweat and sunburn.

And now, a Washington Post article has found a medical expert who agrees: freezing to death is considerably less painful than heat sickness.

“You start having severe muscle cramps,” explained Michael Kerr, an emergency doctor at MedStar Montgomery Medical Center in Olney. “Then, severe abdominal cramps. Nausea and vomiting start. Your muscles break down. Mental confusion. Maybe renal failure. Heat coma. Then, death.”

Freezing to death, this is preferable.

“Dying in the cold is very painless,” said Kerr, an experienced outdoorsman who likes camping in Montana and northern Idaho. “When you are out in the cold, you start getting confused, disoriented. You literally go to sleep.”

I rest my case.

Connect the dots

I offered a few thoughts back here on the connexions between extreme weather and climate change. This topic continues to be the subject of much investigation and the links are many and complex. Nonetheless, a few metaphors are becoming commonly accepted by scientists attempting to communicate their findings.

The first is the image of a baseball player on steroids. Adapting it for use in Commonwealth nations, let's talk about a cricketing batsman on steroids. Taking the drugs improves his muscle condition and makes it possible for him to hit balls harder. While it is not possible to say whether this or that six is the result of drug-enhancement, it is nonetheless possible to see that the player is now hitting more sixes than he was before he started taking drugs. The odds have shifted in favour of bigger shots. In the same way, we're getting weather on steroids, with greater odds of dangerous extremes.

The second commonly-used analogy, mentioned in this video, is the idea of "loading the dice". Weather is always variable, just as rolling a pair of (six-sided) dice will give you results ranging from 2 to 12, with 7 being most common. But if you take one of those dice and add a dot to each side, so that it now ranges from 2 to 7, then you'll still see a lot of variation, including the occasional low number. But 8 will now be most common, and it will be possible to roll a 13. Some of the events we've seen in the last handful of years around the globe have been the equivalent of 13s, standing as much as six standard deviations above the average (using the period 1950-80 as a baseline). Indeed, if we just look at events that are three standard deviations or more above the average, then statistically on an unchanging planet, we'd expect (on average) just 0.3% of the globe's surface to be experiencing such conditions at any one time. Yet over the last decade, the average has been about 10% of the planet's surface facing such extreme conditions. In fact, if we want to be a little more accurate, then rather than painting an extra dot on all the sides of one die, it is as though we have taken one of our pair of six-sided dice and replaced it with an eight-sided die. The point is not only has the average increased and upper extreme become more extreme, but the range of possible weather experiences has widened, leading to greater variations in temperature and precipitation. Not only are the extremes hazardous to human health and ecosystems (both natural and managed), but greater variability is now also becoming more widely accepted as harmful.

All our weather now occurs in an atmosphere increasingly shaped by human activities. There is no "natural" weather any more. We are moving into a new regime that includes higher numbers, and 13s will not be the end of it. We've only warmed about 1/5th the projected warmth of our current trajectory within my daughter's lifetime and perhaps 1/10th of the likely long-term warming.

The chances of the ball being hit out of the park keep increasing.

UPDATE: After posting this, I came across this post that examines this topic in more detail and includes the following very helpful video.

The Other Arab Spring, and other stories

Tom Friedman (NYT): The Other Arab Spring: "All these tensions over land, water and food are telling us something: The Arab awakening was driven not only by political and economic stresses, but, less visibly, by environmental, population and climate stresses as well."

SMH: Coal seam gas is no climate saviour. On the contrary, exploiting alternative fossil fuels only increases the total available pool of carbon that can be transferred from safely underground into the atmosphere and oceans. Indeed, the benefits of gas over coal are frequently overstated. Natural gas is a bridge to nowhere, in the absence of major improvements to leaking. Leaks throughout the supply chain mean that, from a climate perspective, natural gas is at best only slight better than coal (and may actually be worse) over a twenty year timeframe, since methane, while relatively short-lived, is far more potent at warming the planet than carbon dioxide. According to another new study, the benefits of even a massive switch from coal to gas would be relatively minor and would not be seen until late this century.

The Conversation: Medium density is the future.

Yahoo: Beyond 2ºC. Former UNFCCC chief admits we're not going to hold warming to two degrees, long agreed as an international target. Anyone reading the literature would have known this for some time (we're on track for four degrees. Or more), but that someone with so much invested in the international negotiations to admit this publicly is a big step, largely ignored in the media. H/T Lou.

TAE: The nature of tipping points. Some clarity on a commonly misunderstood and misused phrase. Some of the final comments about CO₂ are a little overstated, but it's a useful summary.

The Atlantic: Physiological limits of adapting to warming. A summary of this 2010 PNAS paper by Sherwood and Huber, in which they point out that there are certain climatic conditions above which humans simply cannot survive.

CC: Fascinating new study on the effect of a melting Arctic on northern hemisphere weather. The basic idea is that as the Arctic warms faster than the rest of the globe, the temperature difference between the Arctic and the equator drops, which results in a slowing down of the jet stream, which in turn results in slower-moving weather patterns, which exacerbates extreme weather by making dry or wet, hot or cold spells all longer and so more intense. This is yet another study contributing to the growing body of evidence that the extreme cold UK winters of 2009/10 and 2010/11 may well have been linked to changes in the Arctic. More of these studies are linked in the comments back here.

Bill McKibben: How we subsidise our own destruction. McKibben offers five pieces of simple and straightforward advice on distinguishing good from bad subsidies.

Guardian: Lloyd's of London warns against Arctic drilling. No one really knows how we would clean up an oil spill in the Arctic, which in icy waters would not break down at anything like the pace of the BP Gulf of Mexico disaster. But even if all the oil is safely delivered from under the Arctic to the atmosphere, via a brief sojourn in our cars, it will still spell the end for Arctic ecosystems. And much else besides.

Warragamba is spilling: first time in 14 years

Warragamba Dam, Sydney's main water catchment and storage facility, is now at 100% capacity and started spilling about an hour or two ago. This is likely to contribute to rising floodwaters downstream along the Hawkesbury-Nepean Rivers, which are rising rapidly due to heavy rain. Something like 900 houses are on evacuation alert.

However, in the headlines about localised flooding, let us not lose the wood for the trees. While a full dam is undoubtedly excellent news for the immediate prospects of Sydney's water supply, it is worth remembering that just five years ago, the dam was below 35% and it has not been full since 1998. The situation was threatening enough in 2007 to lead the NSW State government to build a major desalination plant as a precautionary back-up.

Australia has long been known as a land "of droughts and flooding rains". The intensity of our hydrological cycle, regularly bringing both extremes, is one of the challenges faced by our ecosystems (including the human social system). Our familiarity with the dangers of this intensity can numb us to the warnings of climate scientists, that our continued pollution of the atmosphere is likely to bring even more intensity to the hydrological cycle. Simply saying that we've had floods and droughts before does not excuse us from paying attention to the increasing threat these now represent. When combined with rising human population (and rising consumption levels) in a land of fragile soils and ecosystems already significantly modified and degraded by human impact, the implications of these climate projections should not be ignored.

The last 24 months have been the wettest in Australia's recorded history, and they have followed one of our most severe droughts. As always, these have been associated with the El Niño-Southern Oscillation (ENSO) cycle, however, this natural cycle now has a strong warming trend superimposed on it, bringing more moisture into the atmosphere and redistributing it differently in space and time to familiar patterns from the past. We Australians are not immune from the changes our actions are helping to cause.

And if we are tempted to minimise our contribution to this global problem, keep in mind three factors:

(a) Australian per capita emissions are higher than all other countries except some micro-nations and petro-states with heavily subsidised oil prices. Our historical emissions put us in the top ten emitters worldwide (not per capita). These figures exclude both coal exports and our propensity to take frequent overseas flights.

(b) We are the world's largest exporter of coal and have plans to continue greatly expanding our coal production on a scale that will, by 2050, use up more than 10% of the global carbon budget required to have a decent change of keeping us below 2ºC warming. Indeed, expansion of coal exports will lead to carbon dioxide emissions 11 times greater than the projected savings of the recently passed carbon pricing legislation.

(c) As a nation with one of the highest standards of living in the world (being regularly placed in the top ten for quality of life in various surveys), we can afford serious action more easily than almost any other nation, having almost greater freedom from other pressing concerns than anywhere else.

So let us thank God for a full dam, pray for those affected by flooding and love our neighbours in how we use our precious fresh water - and in how we minimise our climate impact.

"When the Pentagon and Greenpeace are on the same page, you know things are getting serious."

"Picture a map of the world. Picture the areas we’re most concerned about; where poverty, instability, and conflict meet. Parts of the Middle East and North Africa. Pockets of sub-Saharan Africa. Delicate borders on the Asian subcontinent. Now picture the areas where climate change will strike hardest. The overlap is uncanny – and unnerving."

Chris Huhne, UK Secretary of State for Energy and Climate Change, gave an speech today in which he pointed out the systemic nature of the threats posed by climate change. Rather than directly causing problems, climate change exacerbates existing threats, making food more difficult to grow, water more difficult to distribute, public health more difficult to manage, infrastructure and lives more vulnerable to extreme weather events and, crucially, where tensions already exist in the geopolitical system, generally taking us closer to violence. It was not a ground-breaking address, but summarises why climate change is not "just" an environmental problem.

Huhne concludes with these words:

"Desperate people take desperate measures. Instability is now a national problem; soon it will be a regional one. Migrants surge outwards, searching for survival.

"This is the nightmare scenario. Yet it is already tragically familiar. We have already seen civil wars compounded by water stress, in Darfur. Regional conflicts fuelled by resources in the Democratic Republic of Congo. Food prices prompting riots in Bangladesh.

"Climate change is the force that threatens to unify and magnify these pressures. It will focus and concentrate existing tensions, fracturing states and destroying societies. So far, we have not done enough to stop it. We still have time to mobilise: but that time is rapidly running out. Doing nothing is not an option."

Full speech available here.

If Brazil has to guard its rainforest, why does Canada/U.S. get to burn its tar sands?

Bill McKibben: If Brazil has to guard its rainforest, why does Canada/U.S. get to burn its tar sands? McKibben has joined with ten other prominent US and Canadian activists and scientists in calling for large-scale civil disobedience over a proposed new pipeline to deliver Canadian tar sands oil to the US.

SMH: The deadliest form of food fight, perhaps the best short piece in a mainstream media outlet on this topic. The Carbon Brief has a useful list of links on climate change and food security (more links are here).

Guardian: At the same time as they put forward a "what peak oil?" report, the UK Government had a second, far less rosy, peak oil report compiled a few years ago. It was not published, until now.

Scientific American: a three part series on the links between climate change and extreme weather. Part One. Part Two. Part Three. Politicians and pundits may pontificate and procrastinate, but the insurance industry takes this very seriously, with more places becoming uninsurable.

Oxford University: Elephant numbers have halved in the last forty years across protected areas in West and Central Africa.

Climate Central: Extreme events related to climate change threaten three US nuclear facilities. Of course, the usual caveats apply to attribution, but the point remains: nuclear has been widely touted as a low-carbon baseload energy solution, yet we are entering an increasing unstable world (climatically, ecologically, and most likely economically and politically). Is it really so wise to build nuclear plants that require rich, stable governments and predictable weather?

CP: Senator Inhofe, perhaps the most outspoken critic of climate science in US politics (a stiff contest), was forced to cancel his appearance at the flagship denier conference due to being "under the weather" after swimming in a blue-green algae bloom exacerbated by drought and a heatwave in Oklahoma. I hope he gets better soon.

Telegraph: warming oceans cause largest marine migration in two million years.

BBC: World's oceans in "shocking" decline. I recently attended a popular open-air lecture by a marine biologist who was presenting unusual creatures from the Norwegian Sea. It was a lighthearted lecture illustrated with a variety of critters and curios in small tanks. During question time afterwards, I asked what changes were evident in the ecosystems she studied. Within seconds of beginning to answer, she was fighting back tears and had to cut short her response.

Floods: again

Cyclone Anthony, which hit Queensland on the 30th, has now largely dissipated. Yet Queensland is now preparing for the much bigger cyclone Yasi, which may turn out to be the largest storm ever to hit Queensland.

And speaking of repeat flooding, my recent post Is God to blame for floods? has been cross-posted at Ethos.

On the attribution of extreme weather events

"Finally, a comment on frequently asked questions of the sort: Was global warming the cause of the 2010 heat wave in Moscow, the 2003 heat wave in Europe, the all-time record high temperatures reached in many Asian nations in 2010, the incredible Pakistan flood in 2010? The standard scientist answer is 'you cannot blame a specific weather/climate event on global warming'. That answer, to the public, translates as 'no'.

"However, if the question were posed as 'would these events have occurred if atmospheric carbon dioxide had remained at its pre-industrial level of 280 ppm?', an appropriate answer in that case is 'almost certainly not'. That answer, to the public, translates as 'yes', i.e., humans probably bear a responsibility for the extreme event."

- James Hansen, "How Warm Was This Summer?" from NASA Goddard Institute for Space Studies.

The whole piece is worth reading, not least for the prediction that 2012 is "likely" to reach "record high global temperatures", after 2010 has already repeatedly broken the twelve month running average (temperatures in 2011 are likely to be slightly suppressed from record levels by the La Niña that has developed in recent months). I also talked about the difference between weather and climate back here.

Dr James Hansen is the head of NASA GISS and was the first academic to bring climate change into mainstream awareness at his US congressional testimony on 23rd June 1988, which became front page news when he claimed there was sufficient evidence to give 99% certainty that "It is already happening now".

As you may have noticed, Hansen takes his duties as a citizen (and grandfather), as well as a scientist, seriously. Last week Dr Hansen was arrested (once again) for civil disobedience while protesting coal mining through mountaintop removal, which manages to combine a whole raft of destructive effects on the way to disrupting the climate.

Here is another quote on attribution worth pondering:

"The point is that while it is a perfectly reasonable question to ask: “Was this event due to climate change?” it would more useful to ask a related question: “are we putting ourselves at greater risk of experiencing this kind of event?” And to that scientists can answer with high confidence: yes!

"Now, you might think this question is less interesting or useful, and perhaps not as worth asking than the first one. But we would argue that, in fact, it is very important to pose this question, and to carefully consider its answers.

"Think of smoking, sun bathing without sunscreen, eating lots of junk food and so on. You may not be able – ever – to unequivocally attribute one person’s problem to the effects of these activities: people develop lung cancer without smoking, for example, but as a population we know we are better off wearing sunscreen, watching our cholesterol, and not smoking, since all of these actions have been shown to make the chances of harm to our health lower."

- Nicole Heller, Claudia Tebaldi, and Phil Duffy, "Why Can’t Scientists Say the Recent Extreme Weather Events Are ‘Proof’ of Climate Change?" at Climate Central.

Weather vs climate

There is an important and often misunderstood distinction between weather and climate.

Weather is what is happening when you go outside. It is what meteorologists study and consists of dynamical systems that are highly sensitive to initial conditions driven by the movements of blocks of hot and cold air. It is measured hour by hour (or even minute by minute) and predicted a few days in advance, beyond which the complexities and sensitivities of the system make computational estimation almost impossible.

Climate refers to long term patterns of weather. It is what climatologists study and consists of dynamical systems driven by long term fluctuations in solar activity, oceanic currents, surface albedo and atmospheric chemistry (and, over the very long term, by geological forces and plate tectonics). It is measured in decades, centuries and millennia and predicted in decades.

Predicting the climate
Yet this raises a common question: if we can't predict next weekend's weather, how can we predict the climate in 2050? Remember that climate prediction doesn't mean a prediction of weather, on which day it might rain or be a certain temperature at a given location. It means predicting the overall pattern, which, while chaotic from week to week, fluctuates within a certain range over the long term. Climate prediction means predicting changes in that range within which weather might fluctuate.

Imagine a pot of water being brought to the boil. Although predicting exactly where and when a bubble will appear is almost impossible, it is still quite possible (given knowledge of the original temperature and volume of the water and the amount of heat energy being applied) to predict when it boil with some degree of accuracy. Or consider tossing a coin one thousand times. It is almost impossible to know whether any given toss will be heads or tails, but we can all predict that there will be about five hundred of each. Or think of sitting on a packed train. You mightn't be able to guess how the person next to you is likely to vote in an election, but with knowledge of quality polling data (if that is not an oxymoron), you can make a pretty good estimate of the likely distribution of votes on the train as a whole.

So climate and weather are closely related, but it is important to keep their distinction in mind. One way of putting it I heard recently is that climate trains the boxer, the weather throws the punches.

This distinction means that it is not possible to directly attribute any particular example of weather either to anthropogenic climate change or to natural variation. A cold day doesn't disprove the theory any more than a hot day proves it. Each are a tiny piece of evidence in a much, much larger pattern. And when an extreme weather event comes along (such as the current Russian heat wave and Asian floods), this too doesn't by itself prove anything. What does count, however, is the well-recorded pattern of increasing frequency and intensity of such events. Put simply, climate change doesn't cause extreme weather, but it increases the chances of it happening, and increases the extremity of what is possible. This is because warmer air can hold more water, bringing more intense precipitation. By the way, this includes more intense snowfall if the temperature happens to be below freezing, as was seen in the northeastern US earlier in the year. Or as NASA says, this is what global warming looks like.

Read more

More doom and gloom

Asian floods affecting more people than the 2004 Indian Ocean tsunami, plus the 2005 Kashmir and 2010 Haiti earthquakes combined says UN.

Russian heat wave unparalleled in 1,000 years and could kill tens of thousands of people. What is the global cost of Russia's heat wave? When you take into account the highest cost of wheat caused by Russia's cancellation of all wheat exports for the rest of the year, it runs into billions.

But before we begin pitying Russians too much, this piece of lunacy is one of the most depressing things I've heard this week.

The largest iceberg seen in almost fifty years recently calved off Greenland. Arctic melt this year is likely to be second or third worst on record, though will very much depend on prevailing weather conditions over the next few weeks. You can follow it here. But a soot cloud from burning Russian peatland could prove to be a wild card.

Fire and rain: how can we tell when extreme weather is linked to climate change?

Commodity speculation: the price of bread depends on the whims of Wall St, not just the productivity of farms. But remember that "for each 1 degree Celsius rise in temperature we can expect a reduction in grain yields of 10 percent".

Big coal will continue to ensure US climate inertia, and without US momentum, the rest of the world will only reach small-scale and thoroughly inadequate agreements.

But at least we are cutting our throat more slowly in the Amazon.

Finally, perhaps the worst news of all comes from the Onion: Ecological disaster as millions of barrels of oil safely reach port.

Jesus and climate change I

Why Jesus cares more about climate change than you do and what he's doing about it, or "What on earth is God doing on earth?"
Last week I mentioned that I was giving a seminar at St John's Ashfield on this wordy topic (another suggested title was Why Jesus cared about climate change before it was trendy). I thought I'd post at least some of my notes here.

Scepticism: an introductory caveat
I don’t really want to talk about scepticism here tonight. I believe the debate has moved on so I’m assuming you’re basically on board. Although various details continue to be adjusted in the light of new research,* the broad claim of alarming anthropogenic climate change is almost universally agreed upon by experts in the relevant fields. That is, the global climate pattern, which includes precipitation and extreme weather events, not just temperature, has begun to change rapidly in recent decades and will continue to do so. And these changes are anthropogenic, which means human activity has been a crucial part of the cause. And they are alarming in scope and implications. We face a world that is not simply getting a little warmer on average, but which, taken as a whole, is significantly less hospitable to human society and life in general as we know it. We’re not just talking about hotter days, or more heat waves, but also rising sea levels, increased erosion and flooding (particularly of densely populated areas such as the 60 million people in the low-lying country of Bangladesh), changing patterns of precipitation, with a significant net decline in global agricultural output, stronger and perhaps more frequent extreme weather events, broader distribution of deadly tropical disease, more environmental refugees, loss of unique ecosystems and significantly increased threat of species extinction. Climate change is much more than simply global warming.

So I’m assuming we’re all familiar with and broadly in agreement with the concept of alarming anthropogenic climate change. In fact, until recently, there was only one significant scientific body in the world that was officially sceptical about it, namely, the American Association of Petroleum Geologists. But even they have now changed their position.
*Given the enormous volume of ongoing research and the complexity of technical detail, I make no promises about being entirely up to date and accurate on every point. I'm interested in these debates, but am not aiming to generate more of them here.
Five points for the city. Five more for each link to other images of the same city posted on this blog (I think there are thirteen apart from this one). No more than five points per person.
Series: I; II; III; IV; V; VI; VII; VIII; IX; IX(b); X; XI; XII; XIII; XIV; XV.

Would Jesus vote green? VI

Sorrow
Once we move beyond systematic denial of environmental destruction, we reach the second common response: sorrow.

Upon coming to accept (at least some of) these claims as true, we are filled with sadness. It is sad that human action (and inaction) continue to cause so much destruction and senseless waste. This is a natural and right response, since we’re really losing things of that are of great value. In particular, I find the rate of extinction very sad, because while most other forms of environmental damage are reversible, (sometimes only in the very long term), with the extinction of a species, once it’s gone, it’s gone for good.

It is not only the animals and plants that suffer from our environmental irresponsibility. Humans suffer too, especially those too poor to move and too marginalised to have a significant political voice. Poisoned rivers, degraded soil, more frequent and more severe extreme weather patterns – these and more cause incalculable human suffering too. This is far more serious than not being able to water your garden or having to pay a little more for electricity.

Sorrow at what is lost and sorrow at what it costs those least able to afford it – this response resonates with a deeply Christian way of viewing the world. We only grieve the loss of what is valuable. Fundamental to Christianity’s take on the environment is that the world God made was good, very good. Grief is the natural correlate of love, when the object of love is harmed or threatened.

And our sadness also accords with a second basic Christian belief: there is something deeply wrong with God’s world. The beauty is marred. There are cracks in the abundant diversity. The health of the planet is threatened by a global disease.

The Apostle Paul teaches that to follow Christ, to be filled with his Spirit, is to grieve over the plight of creation, to groan in shared pain, to be discontent with the fractures in the world. Following Christ is not a recipe for a mindlessly happy escapism; we follow the one called the man of sorrows.

Yet grief alone is insufficient, not least because despite our best – or perhaps our worst, or simply our mediocre – efforts, despite pollution, soil degradation, climate change, the squandering of finite resources, mass extinction, despite all this, the world remains a good gift from God, filled with delight and things worth celebrating. Unless we take the time to stop, notice, enjoy and give thanks for all that surrounds us, we lose the very reason to grieve because we lose sight of the goodness of this gift.
Series: I; II; III; IV; V; VI; VII; VIII; IX; X; XI; XII; XIII.