Tag Archives: carbon dioxide

Ozone Depletion and Climate Change

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“Global warming…doesn’t that have something to do with the ozone?” Well, no. Environmental issues are not all the same. It’s common for people to confuse climate change and ozone depletion, but they are separate issues – although they are indirectly connected in some interesting ways.

Ozone, which is made of three oxygen atoms stuck together (instead of two, which is what normal oxygen gas is made of), is vital to life on Earth. It forms a layer in the stratosphere, the second layer up in the atmosphere, that is very good at absorbing ultraviolet (UV) radiation from the Sun. UV radiation severely damages organisms if enough of it reaches the surface. The 3% or less that gets through the ozone already gives us sunburns and skin cancer, so you can imagine what the situation would be like if the ozone layer wasn’t there at all.

In the middle of the 20th century, synthetic gases known as chlorofluorocarbons (CFCs) became popular for use in refrigerators and aerosol products, among other applications. They were non-toxic, and did not react easily with other substances, so they were used widely. However, their chemical stability allowed them to last long enough to drift into the stratosphere after they were emitted.

Once in the stratosphere, the CFCs were exposed to UV radiation, which was able to break them down. Free chlorine atoms (Cl) were liberated, a substance that is very reactive indeed. In fact, Cl acts as a catalyst in the decomposition of ozone, allowing two ozone molecules to become three oxygen molecules, losing their UV absorbing power in the process. Since catalysts are not used up in a reaction, the same Cl radical can continue to destroy ozone until it reacts with something else in the atmosphere and is removed.

Over the poles, the stratosphere is cold enough for polar stratospheric clouds (PSCs) to form. These PSCs provided optimum conditions for the most reactive chlorine gas of all to form: ClO (chlorine monoxide). Now there wasn’t just a catalytic cycle of free Cl radicals depleting the ozone, there was also a cycle of ClO. It turns out that Antarctica was more favourable for ozone depletion than the Arctic, both because its temperatures were lower and because its system of wind currents prevented the ozone-depleting substances from drifting out of the area.

Before long, there was a hole in the ozone layer over Antarctica (due to the PSCs), and concentrations were declining in other locations too (due to the basic Cl reactions). The issue became a frontier for scientific research, and scientists Crutzen, Rowland, and Molina won the 1995 Nobel Prize in Chemistry for their work with atmospheric ozone.

In 1987, politicians worldwide decided to ban CFCs under the Montreal Protocol. This movement was largely successful, and the use of CFCs has become nearly negligible, especially in developed nations. They have been replaced with gases that safely decompose before they reach the stratosphere, so they don’t interfere with ozone. The regulations are working: the ozone hole in Antarctica has stabilized, and global stratospheric ozone concentrations have been on the rise since 1993.

In contrast, climate change is a product of greenhouse gases such as carbon dioxide. Unlike CFCs, most of them are not synthetic, and they are released from the burning of fossil fuels (coal, oil, and natural gas), not specific products such as refrigerators. Rather than destroying a natural process, like CFCs do, they strengthen one to the point of harm: the greenhouse effect. This phenomenon, which traps heat in the atmosphere, is absolutely vital, as the Earth would be too cold to support life without it. Increasing the concentrations of greenhouse gases with fossil fuels becomes too much of a good thing, though, as the greenhouse effect traps more heat, warming the planet up.

Just a few degrees Celsius of warming can cause major problems, as agricultural zones, wind and ocean currents, and precipitation patterns shift. The sea level rises, submerging coastal cities. Many species go extinct, as the climate changes faster than they can adapt. Basically, the definition of “normal” in which our civilization has developed and thrived is changing, and we can’t count on that stability any more.

Unlike the Montreal Protocol, efforts to reduce greenhouse gas emissions have more or less failed. Fossil fuels permeate every part of our lives, and until we shift the economy to run on clean energy instead, convincing governments to commit to reductions will be difficult at best. It remains to be seen whether or not we can successfully address this problem, like we did with ozone depletion.

Although these two issues are separate, they have some interesting connections. For example, PSCs form in cold areas of the stratosphere. That’s why the ozone hole is over Antarctica, and not somewhere else. Unfortunately, global warming is, paradoxically, cooling the stratosphere, as a stronger greenhouse effect means that less heat reaches the stratosphere. Therefore, as climate change progresses, it will make it easier for the ozone depletion reactions to occur, even though there are fewer CFCs.

Additionally, CFCs are very strong greenhouse gases, but their use has drastically reduced so their radiative effects are of lesser concern to us. However, some of their replacements, HFCs, are greenhouse gases of similar strength. They don’t deplete the ozone, but, per molecule, they can be thousands of times stronger than carbon dioxide at trapping heat. Currently, their atmospheric concentrations are low enough that they contribute far less forcing than carbon dioxide, but it wouldn’t take a large increase in HFCs to put us in a bad situation, simply because they are so potent.

Finally, these two issues are similar in that ozone depletion provides a smaller-scale analogue for the kinds of political and economic changes we will have to make to address climate change:

  1. Unintended chemical side effects of our economy posed a serious threat to all species, including our own.
  2. Industry representatives and free-market fundamentalists fought tooth and nail against conclusive scientific findings, and the public became bewildered in a sea of misinformation.
  3. Governments worked together to find sensible alternatives and more or less solved the problem.

We’ve already seen the first two events happen with climate change. Will we see the third as well?

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Technology as Communication

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The relationship between technology and climate change is complex and multi-faceted. It was technology, in the form of fossil fuel combustion, that got us into this problem. Many uninformed politicians hold out hope that technology will miraculously save us in the future, so we can continue burning fossil fuels at our current rate. However, if we keep going along with such an attitude, risky geoengineering technologies may be required to keep the warming at a tolerable level.

However, we should never throw our hands in the air and give up, because we can always prevent the warming from getting worse. 2 C warming would be bad, but 3 or 4 C would be much worse, and 5 or 6 C would be devastating. We already possess many low-carbon, or even zero-carbon, forms of energy that could begin to replace the fossil fuel economy. The only thing missing is political will, and the only reason it’s missing, in my opinion, is that not enough people understand the magnitude and urgency of the problem.

Here is where technology comes in again – for purposes of communication. We live in an age of information and global interconnection, so ideas can travel at an unprecedented rate. It’s one thing for scientists to write an article about climate change and distribute it online, but there are many other, more engaging, forms of communication that harness today’s software and graphic technologies. Let’s look at a few recent examples.

Data clearly shows that the world is warming, but spreadsheets of temperature measurements are a little dry for public consumption. Graphs are better, but still cater to people with very specific kinds of intelligence. Since not everyone likes math, the climate team at NASA compressed all of their data into a 26-second video that shows changes in surface temperature anomalies (deviations from the average) from 1880 to 2010. The sudden warming over the past few decades even catches me by surprise.

Take a look – red is warm and blue is cool:

A more interactive visual expression of data comes from Penn State University. In this Flash application, you can play around with the amount of warming, latitude range, and type of crop, and see how yields change both with and without adaptation (changing farming practices to suit the warmer climate). Try it out here. A similar approach, where the user has control over the data selection, has been adopted by NOAA’s Climate Services website. Scroll down to “Climate Dashboard”, and you can compare temperature, carbon dioxide levels, energy from the sun, sea level, and Arctic sea ice on any timescale from 1880 to the present.

Even static images can be effective expressions of data. Take a look at this infographic, which examines the social dimensions of climate change. It does a great job of showing the problem we face: public understanding depends on media coverage, which doesn’t accurately reflect the scientific consensus. Click for a larger version:

Global Warming - the debate

Finally, a new computer game called Fate of the World allows you to try your hand at solving climate change. It adopts the same data and projections used by scientists to demonstrate to users what we can expect in the coming century, and how that changes based on our actions. Changing our lightbulbs and riding our bikes isn’t going to be enough, and, as PC Gamer discovered, even pulling out all the stops – nuclear power, a smart grid, cap-and-trade – doesn’t get us home free. You can buy the game for about $10 here (PC only, a Mac version is coming in April). I haven’t tried this game, but it looks pretty interesting – sort of like Civilization. Here is the trailer:

Take a look at these non-traditional forms of communication. Pass them along, and make your own if you’re so inclined. We need all the help we can get.

Climate Scientists Out in the Cold

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Cross-posted from NextGen Journal

In the current economy, it’s not surprising that many countries are reducing funds for scientific research. It’s necessary to cut spending across the board these days. However, North American governments are singling out climate science as a victim – and not just reducing its funding, but, in many cases, eliminating it altogether.

Climate change research is largely supported by government money, as there aren’t many industries that recognize a vested interest in the science. Pharmaceutical companies often fund biomedical researchers, and mining companies fund geologists, but there’s no real analogue for climate scientists. Additionally, many global warming studies are particularly expensive. For example, transporting researchers and equipment to the North Pole via helicopter, and building climate models on supercomputers that stretch the limits of our data storage capacities, cost quite a bit more than injecting rats with chemicals in a lab.

In Canada, where I live, the federal government recognized these unique characteristics of climate science, and, in 2000, set up a special foundation to fund research in the field: the Canadian Foundation for Climate and Atmospheric Sciences (CFCAS). Over the past decade, it has spent $118 million supporting most of Canada’s university-based climate research, and it was assumed that it would be continually renewed as the country established itself as a leader in the field.

However, since the Conservative Party formed a minority government almost five years ago, it has only extended the foundation’s lifespan by a year, and refuses to consider long-term funding commitments. The CFCAS only has a few months left before it will run out of money and close its doors. Many of Canada’s premier climate research projects and laboratories will have to shut down as a result, as they have always relied on CFCAS, and general federal funds such as the National Science and Engineering Research Council (NSERC) simply won’t be able to fill the gap. Some researchers are leaving the country to pursue more fertile academic ground, and as an aspiring climate scientist, I am wondering whether I will have to eventually do so as well.

If it seems cruel to abandon funding for researching the greatest threat to our future, rather than simply reducing its budget until the economy recovers, take a stroll south to what my sociology professor likes to refer to as “that wild society”. The U.S. House of Representatives is becoming dominated by politicians who hate the idea of government, and wish to tear most of it down in anger. Add to that mindset a staunch denial of climate science, and you can see where this is going.

The House of Representatives just passed a bill that not only prevents the Environmental Protection Agency from regulating greenhouse gases that cause climate change, but also repeals a great deal of clean air and water protection. Other cornerstones of the bill include repealing the new American health care system and cutting off funding of Planned Parenthood.

Since not a single Democrat Member of Congress voted for this bill, it is unlikely to pass the Senate, where Democrats hold a majority. However, Republicans have threatened to take away all federal funding, effectively shutting down the entire U.S. government, if the bill is not passed into law.

An amendment to this bill, which also passed the House of Representatives, completely cuts off federal funding to the Intergovernmental Panel on Climate Change (IPCC). The IPCC, a scientific organization of the United Nations, doesn’t do any original research, but writes extensive summary reports of the academic literature on climate change. It’s hard to overestimate how important these reports, published every few years, are to governments, scientists, and citizens alike. Instead of having to dig through thousands of scientific journals and articles, with no idea where to start, people can simply read these reports to find out what science knows about climate change. They are painstakingly reviewed, are offered in several levels of technicality, and include carefully organized references to the multitude of studies whose conclusions contributed to the text. For a field of research that is quickly expanding, these reports are absolutely vital, and it’s hard to imagine how they could carry on without support from the American government.

Blaine Luetkemeyer, the Republican Member of Congress that proposed the amendment, justified cutting off the IPCC by asserting the oft-debunked, but disturbingly popular, meme that climate science is some kind of worldwide conspiracy. If the IPCC really is “corrupt” and “nefarious”, as Luetkemeyer claims, then why can’t they afford to pay any of the scientists that write the reports – not even the IPCC president? Why do they allow anyone to help review the draft reports? Why do they permit their Summary for Policymakers to be watered down by policymakers? And, most importantly, why is climate change progressing faster than the IPCC expected?

We shouldn’t have to spend time addressing paranoid conspiracy theories like Luetkemeyer’s . Sadly, the government of the most powerful country on Earth is being taken over by people who buy into these conspiracy theories, and who want to punish climate scientists as much as possible for crimes they haven’t committed. Countries like Canada, even if they refrain from public accusations, are following suit in their actions.

“It’s quite clear by their actions [with CFCAS] and its lack of funding that [the Canadian government is] basically saying ‘We don’t want your science any more’,” Andrew Weaver, Canada’s top climatologist, told the Globe and Mail.

“[Cutting off the IPCC] is like putting our heads in the sand, denying the science, and then stopping the scientists from working – because they might come to a different conclusion from the Republican Party’s ideology,” Democrat Member of Congress Henry Waxman argued.

Is this really a wise move?

Extinction and Climate

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Life on Earth does not enjoy change, and climate change is something it likes least of all. Every aspect of an organism’s life depends on climate, so if that variable changes, everything else changes too – the availability of food and water, the timing of migration or hibernation, even the ability of bodily systems to keep running.

Species can adapt to gradual changes in their environment through evolution, but climate change often moves too quickly for them to do so. It’s not the absolute temperature, then, but the rate of change that matters. Woolly mammoths and saber-toothed tigers thrived during the Ice Ages, but if the world were to shift back to that climate overnight, we would be in trouble.

Put simply, if climate change is large enough, quick enough, and on a global scale, it can be the perfect ingredient for a mass extinction. This is worrying, as we are currently at the crux of a potentially devastating period of global warming, one that we are causing. Will our actions cause a mass extinction a few centuries down the line? We can’t tell the future of evolution, but we can look at the past for reference points.

There have been five major extinction events in the Earth’s history, which biologists refer to as “The Big Five”. The Ordovician-Silurian, Late Devonian, Permian-Triassic, Late Triassic, Cretaceous-Tertiary…they’re a bit of a mouthful, but all five happened before humans were around, and all five are associated with climate change. Let’s look at a few examples.

The most recent extinction event, the Cretaceous-Tertiary (K-T) extinction, is also the most well-known and extensively studied: it’s the event that killed the dinosaurs. Scientists are quite sure that the trigger for this extinction was an asteroid that crashed into the planet, leaving a crater near the present-day Yucatan Peninsula of Mexico. Devastation at the site would have been massive, but it was the indirect, climatic effects of the impact that killed species across the globe. Most prominently, dust and aerosols kicked up by the asteroid became trapped in the atmosphere, blocking and reflecting sunlight. As well as causing a dramatic, short-term cooling, the lack of sunlight reaching the Earth inhibited photosynthesis, so many plant species became extinct. This effect was carried up the food chain, as first herbivorous, then carnivorous, species became extinct. Dinosaurs, the dominant life form during the Cretaceous Period, completely died out, while insects, early mammals, and bird-like reptiles survived, as their small size and scavenging habits made it easier to find food.

However, life on Earth has been through worse than this apocalyptic scenario. The
 largest extinction in the Earth’s history, the Permian-Triassic extinction, occurred about 250 million years ago, right before the time of the dinosaurs. Up to 95% of all species on Earth were killed in this event, and life in the oceans was particularly hard-hit. It took 100 million years for the remaining species to recover from this extinction, nicknamed “The Great Dying”, and we are very lucky that life recovered at all.

So what caused the Permian-Triassic extinction? After the discovery of the K-T crater, many scientists assumed that impact events were a prerequisite for extinctions, but that probably isn’t the case. We can’t rule out the possibility that an asteroid aggravated existing conditions at the end of the Permian period. However, over the past few years, scientists have pieced together a plausible explanation for the Great Dying. It points to a trigger that is quite disturbing, given our current situation – global warming from greenhouse gases.

In the late Permian, a huge expanse of active volcanoes existed in what is now Siberia. They covered 4 million square kilometres, which is fifteen times the area of modern-day Britain (White, 2002). Over the years, these volcanoes pumped out massive quantities of carbon dioxide, increasing the average temperature of the planet. However, as the warming continued, a positive feedback kicked in: ice and permafrost melted, releasing methane that was previously safely frozen in. Methane is a far stronger greenhouse gas than carbon dioxide – over 100 years, it traps approximately 21 times more heat per molecule (IPCC AR4). Consequently, the warming became much more severe.

When the planet warms a lot in a relatively short period of time, a particularly nasty condition can develop in the oceans, known as anoxia. Since the polar regions warm more than the equator, the temperature difference between latitudes decreases. As global ocean circulation is driven by this temperature difference, ocean currents weaken significantly and the water becomes relatively stagnant. Without ocean turnover, oxygen doesn’t get mixed in – and it doesn’t help that warmer water can hold less oxygen to begin with. As a result of this oxygen depletion, bacteria in the ocean begins to produce hydrogen sulfide (H2S). That’s what makes rotten eggs smell bad, and it’s actually poisonous in large enough quantities. So if an organism wasn’t killed off by abrupt global warming, and was able to survive without much oxygen in the ocean (or didn’t live in the ocean at all), it would probably soon be poisoned by the hydrogen sulfide being formed in the oceans and eventually released into the atmosphere.

The Permian-Triassic extinction wasn’t the only time anoxia developed. It may have been a factor in the Late Triassic extinction, as well as smaller extinctions between the Big Five. Overall, it’s one reason why a warm planet tends to be less favourable to life than a cold one, as a 2008 study in the UK showed. The researchers examined 520 million years of data on fossils and temperature reconstructions, which encompasses almost the entire history of multicellular life on Earth. They found that high global temperatures were correlated with low levels of biodiversity (the number of species on Earth) and high levels of extinction, while cooler periods enjoyed high biodiversity and low extinction.

Our current situation is looking worse by the minute. Not only is the climate changing, but it’s changing in the direction which could be the least favourable to life. We don’t have volcanic activity anywhere near the scale of the Siberian Traps, but we have a source of carbon dioxide that could be just as bad: ourselves. And worst of all, we could prevent much of the coming damage if we wanted to, but political will is disturbingly low.

How bad will it get? Only time, and our decisions, will tell. A significant number of the world’s species will probably become extinct. It’s conceivable that we could cause anoxia in the oceans, if we are both irresponsible and unlucky. It wouldn’t be too hard to melt most of the world’s ice, committing ourselves to an eventual sea level rise in the tens of metres. These long-range consequences would take centuries to develop, so none of us has to worry about experiencing them. Instead, they would fall to those who come after us, who would have had no part in causing – and failing to solve – the problem.

References:

Mayhew et al (2008). A long-term association between global temperature and biodiversity, origination and extinction in the fossil record. Proceedings of the Royal Society: Biological Sciences, 275: 47-53. Read online

Twitchett (2006). The paleoclimatology, paleoecology, and paleoenvironmental analysis of mass extinction events. Paleogeography, Paleoclimatology, Paleoecology, 234(2-4): 190-213. Read online

White (2002). Earth’s biggest “whodunnit”: unravelling the clues in the case of the end-Permian mass extinction. Philosophical Transactions of the Royal Society: Mathematical, Physical, & Engineering Sciences, 360: 2963-2985. Read online

Benton and Twitchett (2003). How to kill (almost) all life: the end-Permian extinction event. Trends in Ecology & Evolution, 18(7): 358-365. Read online

The Pendulum

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Cross-posted from NextGen Journal

A few years ago, climate change mitigation became a major political issue. Before 2005, governments certainly knew that human-caused climate change was a serious problem – but the public knew next to nothing about it, so there was no incentive to act. However, between 2005 and 2007, a perfect storm of events splashed the reality of climate change onto the world stage.

The Kyoto Protocol, an international agreement to reduce greenhouse gas emissions, finally came into force in early 2005, after years of negotiation. The United States refused to sign, and Australia signed on a little late, but every other developed nation in the world agreed to emission targets. Here in Canada, the Liberal government enthusiastically pledged its support for Kyoto. My local newspaper ran editorials exploring the different ways we could meet our targets, through combinations of clean energy, green infrastructure, and efficiency standards.

The summer of 2005 was a wake-up call for the United States, as Hurricane Katrina mercilessly demonstrated the amount of damage that extreme weather can bring. It’s impossible to say, at least with our current technology, whether or not Katrina was caused or even worsened by a warming planet. However, such devastating storms will become the norm as climate change progresses. Scientists aren’t sure whether or not hurricanes will become more frequent in a warming world, but the average hurricane is expected to become stronger and more damaging, and we are already beginning to see this rise in storm intensity. Katrina gave us an example of what we can expect from climate change – even if it wasn’t a direct effect in itself – and the world was shocked by the suffering that ensued.

2006 marked the release of An Inconvenient Truth, Al Gore’s Academy Award-winning documentary about climate change. For scientists studying climate, the film was an admirable, up-to-date example of science communication, albeit with a few minor errors and oversimplifications. However, for citizens new to the issue (I particularly remember my classmates in grade 9 social studies discussing the film), An Inconvenient Truth was a disturbing reality check – scarier than any horror movie, because it was real.

The major scientific event of 2007 was a drastic, unexpected drop in Arctic summer sea ice. That season’s melt was exacerbated by coincidental weather conditions, so the next years weren’t quite as bad, but the trend was still worrying, to say the least. The research community had assumed that summer ice would stick around for at least a century, but this timescale was soon halved and quartered as ice melt exceeded even the worst projections.

By 2007, lead-up to the 2008 US presidential election was underway, and political awareness of climate change was obvious. It was no surprise that Democrat Barack Obama had ambitious plans to cut greenhouse gas emissions, but even the Republicans seemed to be on board. During his time in office, George W. Bush had insisted that, since climate change could be natural, any mitigating action was not worth the economic risk. Republican presidential candidates seemed to realize that continuing to adopt this attitude would be political suicide. The most extreme example, John McCain, who would eventually win the Republican presidential nomination, had emissions targets only slightly less extensive than Obama’s. As he said in 2007,

The world is already feeling the powerful effects of global warming, and far more dire consequences are predicted if we let the growing deluge of greenhouse gas emissions continue, and wreak havoc with God’s creation…The problem isn’t a Hollywood invention nor is doing something about it a vanity of Cassandra like hysterics. It is a serious and urgent economic, environmental and national security challenge.

However, McCain, once an author of a bill designed to cut greenhouse gas emissions, would soon completely change his stance. By 2010, he was asserting that cap-and-trade legislation was unnecessary and carbon dioxide posed no harm to the American people. He even went so far as to question the political motivations of science he once wholly accepted:

I think [global warming is] an inexact science, and there has been more and more questioning about some of the conclusions that were reached concerning climate change. And I believe that everybody in the world deserves correct answers whether the scientific conclusions were flawed by outside influences. There’s great questions about it that need to be resolved.

The story of John McCain isn’t too surprising. Politicians frequently base their statements on public sentiment rather than personal opinion. They say what people want to hear, rather than what they truly believe is important. This aspect of our political system is depressing, but persistent. The real question, though, regards what changed public sentiment so quickly. Why did politicians like McCain feel compelled to denounce the importance of action on this problem, or even the existence of the problem itself? What happened since 2007 that made the pendulum swing so far in the other direction?

Strike one was the economy. The global recession that began in 2008 was the largest since the Great Depression, and concern for all other problems promptly went down the drain. It’s understandable for citizens to not worry about the environment when they don’t even have the means to feed and clothe their children properly. However, for governments to not realize the long-term economic implications of allowing climate change to continue, along with the potential job-creating benefits of a new energy economy, was disappointing, even though it wasn’t surprising.

Strike two was the all-out war on climate science, spearheaded by the fossil fuel industry and the far right. This PR campaign has been underway since the early 1990s, but was kicked up a notch just over a year ago. Since public understanding of the causes and effects of global warming was growing, and the science was becoming more solid by the month, the PR tactics changed. Instead of attacking the science, they attacked the integrity of the scientists. The most extreme example occurred in November 2009, when private correspondence between top climate researchers was stolen, spread on the Internet, and spun in an attempt to cast doubt on the scientists’ motives. This event, known as “Climategate”, spurred a great deal of anger among the political right, and everything from bitter editorials to death threats against scientists ensued. Perhaps most distressingly, by the time investigations found that the scientists involved were innocent, and the reality of climate change untouched, Climategate was old news and media outlets failed to adequately follow up on the story. Citizens heard the accusations, but not the exonerations, so political will to cut greenhouse gas emissions slipped even further.

Strike three – well, there has been no strike three, and a good thing too. Strikes one and two were so bad that some are hoping the pendulum has swung as far as it can go. It’s certainly difficult to imagine how the situation could get worse. The Kyoto Protocol is set to expire next year, and the Copenhagen meetings failed to create a replacement. As it was, many developed nations failed to meet their targets, and the Canadian government backed out completely.

The possibility of federal climate legislation for the United States is laughable now that not a single Republican Senator thinks action is necessary, and most doubt the reality of the problem, choosing to believe that the entire scientific community is out to lunch and/or an agent of conspiracy. President Obama’s director of climate policy, Carol Browner, recently left her position, although none of her major goals had been met. Obama’s recent State of the Union address included lots of hopeful statements about clean energy, but absolutely no mention of climate change, as if merely acknowledging the most pressing reason for a new energy economy would be political suicide. The time-honoured tradition of saying what the public wants to hear has even reached Obama, the man who promised change.

In Canada, legislation to simply set targets for emission reduction passed the House of Commons (made of elected representatives), but the Senate (composed of appointed politicians) chose to use their newfound Conservative majority to strike down the bill with no debate whatsoever, in a blatantly undemocratic move that has not happened since the 1930s. The Canadian government is all for a new energy economy, but not one based on environmental and social responsibility. The Alberta tar sands, which are substantially more polluting and carbon-intensive than traditional oil, continue to expand, and both federal and provincial governments are worryingly enthusiastic.

From 2005 to 2007, politics was high on promises of mitigation, but low on delivery. Since then, it has been devoid of both. It’s starting to seem as if it will take a major global disaster that can be unquestionably tied to climate change for governments to get their act together.

This would all be very well if there was no lag time between cause and effect in the climate system, but it doesn’t work that way. It takes several decades for all the warming in the pipeline to show up. If we waited until climate change became unbearable, and then cut off our emissions completely, the situation would still get worse for decades before it stabilized.

The worldwide failure of governments to take action on climate change is baffling. It seems that the best they can do is occasionally promise to fix the problem, but never actually get started. If this continues for much longer, we’re all going to pay the price for their mistakes – and so will people for generations to come.

The Unofficial Climate Change Book Awards

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Cross-posted from NextGen Journal

As an aspiring climate scientist, I have read dozens of books about climate change over the past few years. Here are my all-time favourites, which I present with Unofficial Climate Change Book Awards. (Unfortunately, the prizes consist entirely of bragging rights.)


Best Analysis of Future Scenarios
Climate Wars, by Gwynne Dyer
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Most of us are aware of how climate change will impact the world: more extreme weather, prolonged floods and droughts, dwindling glaciers and sea ice. In this book, renowned Canadian journalist and military historian Gwynne Dyer goes one step further, and explores how these physical impacts might affect geopolitical relations. Will India and Pakistan engage in nuclear warfare over clean water? Will the United States and Russia begin a “Colder War” over Arctic sovereignty? Many of the scenarios he writes about are, frankly, terrifying, and all have a frightening grain of plausibility to them. Read the full review


Best Introduction to Climate Science
The Discovery of Global Warming, by Spencer Weart
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Scientists overwhelmingly agree that human-caused climate change is underway, but instead of simply stating this conclusion, Weart tells the story of how it was reached: tracing the theory from the 1800s to today. This innovative approach to science education, combined with Weart’s elegant prose, makes the book a joy to read. It doesn’t feel like a textbook, although it contains as much information as one. Read the full review


Best Exposé
Climate Cover-Up, by James Hoggan and Richard Littlemore
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If scientists are so sure about the reality of anthropogenic climate change, why does so much of the public think that it’s natural/nonexistent/a global conspiracy? Why does the media present the issue as an equal-sided scientific debate? This confusion didn’t just happen by accident – it was deliberately constructed. Over the past two decades, lobby groups representing industries or ideologies that seek to delay action on climate change have engaged in a campaign to spread doubt about the reality of the problem. This book, rather than throwing around baseless accusations, methodically examines the paper trail of this widespread campaign. Reading Climate Cover-Up is an infuriating but absolutely necessary journey to take. Read the full review


Best Policy Discussion
Storms of my Grandchildren, by Dr. James Hansen
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James Hansen is possibly the most prominent climate scientist alive today, and that title is well-deserved. Throughout his career at NASA, he has frequently made discoveries that were ahead of his time. Dr. Hansen is a very intrinsic scientist who doesn’t enjoy being in the spotlight or talking about policy, but he wrote this book for fear of his grandchildren looking back at his work and saying, “Opa understood what was happening, but he did not make it clear.” Although he couldn’t resist slipping in a few chapters about the current frontiers of climate science, the bulk of the book is about policy, featuring compelling arguments for expanded nuclear power, a moratorium on coal, and a rising price on carbon. Read the full review


Best Canadian Focus
Keeping Our Cool, by Dr. Andrew Weaver
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Andrew Weaver is Canada’s top climate modeller, and a fantastic role model for science communication. This book gives a high-level, yet accessible, explanation of the mathematics of climate change – if you have some basic knowledge of calculus and statistics, you should be fine. However, what really makes this book stand out is its focus on Canadian climate journalism and politics, a rare quality in a field dominated by American research. We all know about George W. Bush’s track record of inaction, but what has Prime Minister Stephen Harper done (or not done)? High-profile studies exist on American media coverage of global warming, but how does the Canadian press compare? Read the full review


Best Insider’s Account
Science as a Contact Sport, by Dr. Stephen Schneider
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The late Stephen Schneider, who unexpectedly died last summer of a heart attack, is a true pioneer of climate modelling. He has been active in the field since the 1970s, when computers became fast enough to handle mathematical models. This memoir explains what it’s like to be a climate scientist, and how that has changed over the years. In the 70s, Schneider and his colleagues filled their mind with purely analytical questions, but today, they have to deal with the media, politicians, and hate mail as well. Science used to just be about science, but now it’s about communication as well. Read the full review


Most Gripping
Snowball Earth, by Gabrielle Walker
View on Amazon.com

Gabrielle Walker is a brilliant woman, as she possesses the ability to make a book about geology every bit as gripping as a murder mystery. Granted, Snowball Earth, a recent theory of climatic conditions during the Precambrian Era, is fascinating. In short, the continents were arranged in such a manner that the Earth would swing back and forth between “Snowball Earth” (frozen oceans and frozen land all over, even at the Equator) and “Hothouse Earth” (massive global warming from volcanic emissions of carbon dioxide). Until this period of massive climatic swings, the only thing that lived on Earth was unicellular goop…but immediately following the Snowball Earth cycles, complex life appeared. Many scientists don’t think this evolutionary timing was a coincidence. It’s possible that multicellular organisms, including us, only exist because of an accident of plate tectonics. Read the full review


If you would like to contest any of my decisions for these awards, please feel free to do so in the comments!

“It’s Just a Natural Cycle”

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My second rebuttal for Skeptical Science. Thanks to all the folks who helped to review it! Further suggestions are welcome, as always. -Kate

“What if global warming is just a natural cycle?” This argument is, perhaps, one of the most common raised by the average person, rather than someone who makes a career out of denying climate change. Cyclical variations in climate are well-known to the public; we all studied the ice ages in school. However, climate isn’t inherently cyclical.

A common misunderstanding of the climate system characterizes it like a pendulum. The planet will warm up to “cancel out” a previous period of cooling, spurred by some internal equilibrium. This view of the climate is incorrect. Internal variability will move energy between the ocean and the atmosphere, causing short-term warming and cooling of the surface in events such as El Nino and La Nina, and longer-term changes when similar cycles operate on decadal scales. However, internal forces do not cause climate change. Appreciable changes in climate are the result of changes in the energy balance of the Earth, which requires “external” forcings, such as changes in solar output, albedo, and atmospheric greenhouse gases. These forcings can be cyclical, as they are in the ice ages, but they can come in different shapes entirely.

For this reason, “it’s just a natural cycle” is a bit of a cop-out argument. The Earth doesn’t warm up because it feels like it. It warms up because something forces it to. Scientists keep track of natural forcings, but the observed warming of the planet over the second half of the 20th century can only be explained by adding in anthropogenic radiative forcings, namely increases in greenhouse gases such as carbon dioxide.

Of course, it’s always possible that some natural cycle exists, unknown to scientists and their instruments, that is currently causing the planet to warm. There’s always a chance that we could be totally wrong. This omnipresent fact of science is called irreducible uncertainty, because it can never be entirely eliminated. However, it’s very unlikely that such a cycle exists.

Firstly, the hypothetical natural cycle would have to explain the observed “fingerprints” of greenhouse gas-induced warming. Even if, for the sake of argument, we were to discount the direct measurements showing an increased greenhouse effect, other lines of evidence point to anthropogenic causes. For example, the troposphere (the lowest part of the atmosphere) is warming, but the levels above, from the stratosphere up, are cooling, as less radiation is escaping out to space. This rules out cycles related to the Sun, as solar influences would warm the entire atmosphere in a uniform fashion. The only explanation that makes sense is greenhouse gases.

What about an internal cycle, perhaps from volcanoes or the ocean, that releases massive amounts of greenhouse gases? This wouldn’t make sense either, not only because scientists keep track of volcanic and oceanic emissions of CO2 and know that they are small compared to anthropogenic emissions, but also because CO2 from fossil fuels has its own fingerprints. Its isotopic signature is depleted in the carbon-13 isotope, which explains why the atmospheric ratio of carbon-12 to carbon-13 has been going down as anthropogenic carbon dioxide goes up. Additionally, atmospheric oxygen (O2) is decreasing at the same rate that CO2 is increasing, because oxygen is consumed when fossil fuels combust.

A natural cycle that fits all these fingerprints is nearly unfathomable. However, that’s not all the cycle would have to explain. It would also have to tell us why anthropogenic greenhouse gases are not having an effect. Either a century of basic physics and chemistry studying the radiative properties of greenhouse gases would have to be proven wrong, or the natural cycle would have to be unbelievably complex to prevent such dramatic anthropogenic emissions from warming the planet.

It is indeed possible that multidecadal climate variability, especially cycles originating in the Atlantic, could be contributing to recent warming, particularly in the Arctic. However, the amplitude of the cycles simply can’t explain the observed temperature change. Internal variability has always been superimposed on top of global surface temperature trends, but the magnitude – as well as the fingerprints – of current warming clearly indicates that anthropogenic greenhouse gases are the dominant factor.

Despite all these lines of evidence, many known climatic cycles are often trumpeted to be the real cause, on the Internet and in the media. Many of these cycles have been debunked on Skeptical Science, and all of them either aren’t in the warming phases, don’t fit the fingerprints, or both.

For example, we are warming far too fast to be coming out of the last ice age, and the Milankovitch cycles that drive glaciation show that we should be, in fact, very slowly going into a new ice age (but anthropogenic warming is virtually certain to offset that influence).

The “1500-year cycle” that S. Fred Singer attributes warming to is, in fact, a change in distribution of thermal energy between the poles, not a net increase in global temperature, which is what we observe now.

The Little Ice Age following the Medieval Warm Period ended due to a slight increase in solar output (changes in both thermohaline circulation and volcanic activity also contributed), but that increase has since reversed, and global temperature and solar activity are now going in opposite directions. This also explains why the 11-year solar cycle could not be causing global warming.

ENSO (El Nino Southern Oscillation) and PDO (Pacific Decadal Oscillation) help to explain short-term variations, but have no long-term trend, warming or otherwise. Additionally, these cycles simply move thermal energy between the ocean and the atmosphere, and do not change the energy balance of the Earth.

As we can see, “it’s just a natural cycle” isn’t just a cop-out argument – it’s something that scientists have considered, studied, and ruled out long before you and I even knew what global warming was.

Storms of my Grandchildren

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I hope everyone had a fun and relaxing Christmas. Here’s a book I’ve been meaning to review for a while.

The worst part of the recent book by NASA climatologist James Hansen is, undoubtedly, the subtitle. The truth about the coming climate catastrophe and our last chance to save humanity – really? That doesn’t sound like the intrinsic, subdued style of Dr. Hansen. In my opinion, it simply alienates the very audience we’re trying to reach: moderate, concerned non-scientists.

The inside of the book is much better. While he couldn’t resist slipping in a good deal of hard science (and, in my opinion, these were the best parts), the real focus was on climate policy, and the relationship between science and policy. Hansen struggled with the prospect of becoming involved in policy discussions, but soon realized that he didn’t want his grandchildren, years from now, to look back at his work and say, “Opa understood what was happening, but he did not make it clear.”

Hansen is very good at distinguishing between his scientific work and his opinions on policy, and makes no secret of which he would rather spend time on. “I prefer to just do science,” he writes in the introduction. “It’s more pleasant, especially when you are having some success in your investigations. If I must serve as a witness, I intend to testify and then get back to the laboratory, where I am comfortable. That is what I intend to do when this book is finished.”

Hansen’s policy opinions centre on a cap-and-dividend system: a variant of a carbon tax, where revenue is divided evenly among citizens and returned to them. His argument for a carbon tax, rather than cap-and-trade, is compelling, and certainly convinced me. He also advocates the expansion of nuclear power (particularly “fourth-generation” fast nuclear reactors), a moratorium on new coal-generated power plants, and drastically improved efficiency measures.

These recommendations are robust, backed up with lots of empirical data to argue why they would be our best bet to minimize climate change and secure a stable future for generations to come. Hansen is always careful to say when he is speaking as a scientist and when he is speaking as a citizen, and provides a fascinating discussion of the connection between these two roles. As Bill Blakemore from ABC television wrote in correspondence with Hansen, “All communication is biased. What makes the difference between a propagandist on one side and a professional journalist or scientist on the other is not that the journalist or scientist ‘set their biases aside’ but that they are open about them and constantly putting them to the test, ready to change them.”

Despite all this, I love when Hansen puts on his scientist hat. The discussions of climate science in this book, particularly paleoclimate, were gripping. He explains our current knowledge of the climatic circumstances surrounding the Permian-Triassic extinction and the Paleocene-Eocene Thermal Maximum (usually referred to as the PETM). He explains why neither of these events is a suitable analogue for current climate change, as the current rate of introduction of the radiative forcing is faster than anything we can see in the paleoclimatic record.

Be prepared for some pretty terrifying facts about our planet’s “methane hydrate gun”, and how it wasn’t even fully loaded when it went off in the PETM. Also discussed is the dependence of climate sensitivity on forcing: the graph of these two variables is more or less a parabola, as climate sensitivity increases both in Snowball Earth conditions and in Runaway Greenhouse conditions. An extensive discussion of runaway greenhouse is provided, where the forcing occurs so quickly that negative feedbacks don’t have a chance to act before the positive water vapour feedback gets out of control, the oceans boil, and the planet becomes too hot for liquid water to exist. For those who are interested in this scenario, Hansen argues that, if we’re irresponsible about fossil fuels, it is quite possible for current climate change to reach this stage. For those who have less practice separating the scientific part of their brain from the emotional part, I suggest you skip this chapter.

I would recommend this book to everyone interested in climate change. James Hansen is such an important player in climate science, and has arguably contributed more to our knowledge of climate change than just about anyone. Whether it’s for the science, for the policy discussions, or for his try at science fiction in the last chapter, it’s well worth the cover price.

Thoughts from others who have read this book are welcome in the comments, as always.

An Unlikely Priority

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A small news splash surfaced this week over a recent paper in Nature, regarding the prospects for Arctic sea ice and, consequently, polar bear populations. Until this paper was published, studies had only examined business-as-usual scenarios. We didn’t really know whether or not, if we pursued aggressive mitigation, it would be too late to save the polar bears from extinction.

The GCM output this paper analysed suggested that there is hope. They found the relationship between temperature and sea ice cover to be more linear, and the ice-albedo feedback in the Arctic to be weaker, than we previously thought. Tipping points where sea ice is beyond hope might not be such a problem. Therefore, we may still have a chance to limit damage to the ecosystem that experiences consequences of climate change earliest and strongest, and the polar bears might still make it. Nature News has a great summary for those who want more detail on the literature.

When the story showed up in my CBC News feed, however, I was bewildered at the angle they took:

Polar bears could be saved from extinction if greenhouse gas emissions are significantly reduced in the next decade or two, a study released Wednesday suggests.

As if that’s the most compelling reason to pursue mitigation…

Don’t get me wrong: it would be a shame to see the polar bears go. But it would be much worse to see agriculture in the subtropics go, or to see low-lying nations go. I believe that the public is wise enough to understand that sentimental notions about an oft-romanticized species are minuscule in their importance when compared to matters of human security.

Additionally, since polar bears reside at the top of the food chain, the ecological consequences of their loss – while certainly not trivial – would probably be less intense than if it were another species. Imagine the hypothetical scenario of termites going extinct – it would be much worse. Termites aren’t quite so cute and cuddly, though.

I continue to be amazed by choices that the mainstream media makes as to which studies to report on and which studies to ignore. Their picture of ordinary people’s priorities is baffling and somewhat insulting. I get it – I have a strong affinity for wildlife – but the species I care about the most is still Homo sapiens, despite its blatant shortcomings.

The Nature of Scientific Consensus

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Cross-posted from NextGen Journal

It is common for one to fail to grasp the difference between “consensus” and “unanimity”.

A consensus does not require agreement from absolutely every member involved. Rather, it is a more general measure of extremely high agreement, high enough to accept and base decisions on. It’s stronger than a majority-rules style of democracy, but does not necessarily equal unanimity. In fact, in the area of science, where the concept of consensus is particularly important, unanimity is nearly impossible.

With the exception of pure mathematics, scientific theories cannot be proven beyond a doubt. Every physical process that researchers study has some amount of irreducible uncertainty – because there is always, no matter how small, a chance that our understanding could be completely wrong. Additionally, science is never “settled”, because there is always more to learn, whatever the field. Even a law as basic as gravity is still being studied by physicists, and it turns out that it gets more complicated the more you look at it.

Despite this inherent uncertainty, scientists have developed consensuses around all sorts of topics. The Earth is approximately oblate-spherical in shape. Smoking cigarettes increases one’s risk of lung cancer. HIV causes AIDS. There’s a tiny chance that these statements are incorrect, but researchers can still have confidence in their accuracy. Incomplete knowledge is not the same as no knowledge.

However, when there is room for doubt, there will usually be doubters. Physicist Richard Lindzen continues to dispute the health risks of smoking (a conversation is recounted in a recent book by James Hansen). Peter Duesberg, an active molecular and cell biologist, prominently opposes the link between HIV and AIDS. Believe it or not, the Flat Earth Society was alive and well until the death of its leader in 2001 – and signs of the society’s renewal are emerging.

As these examples suggest, for a layperson to wait for scientific unanimity before accepting a topic would be absurd. When consensus reaches a certain point, the null hypothesis shifts: the burden of proof is on the contrarians, rather than the theory’s advocates.

Another case study that may seem surprising to many is that of anthropogenic global warming. A strong scientific consensus exists that human activity, mainly the burning of fossil fuels, is exerting a warming influence on the planet’s temperature, which is already beginning to show up in the instrumental record. This phenomenon is contested by less than 3% of publishing climatologists, a negligible amount of peer-reviewed scientific studies (so few that not one showed up in a 2004 survey’s random sample of almost one thousand papers), and no major scientific societies internationally. Additionally, scientists who dispute the existence or causes of climate change tend to have lower academic credibility than those who do not. It becomes apparent that this scientific question warrants “consensus” standing: never quite settled, never quite unanimous, but certainly good enough to go by. The mainstream media does not always reflect this consensus accurately, but it nonetheless exists.

As world leaders meet in Cancun this week to discuss a global policy to prevent or limit future climate change – a prospect that looks less likely by the day – science can only offer so much advice. Climatologists can approximate what levels of emissions cuts are required to prevent unacceptable consequences, but only when the governments of the world decide which consequences they are willing to accept. Can we deal with worldwide food shortages? Rising sea levels? What about a mass extinction? Even after we define “dangerous consequences”, scientists are unsure of exactly how much temperature change will trigger these consequences, as well as how much greenhouse gas emissions will need to be cut, and how quickly, to prevent the temperature change. All they can offer is a range of probabilities and most likely scenarios.

But remember, incomplete and uncertain knowledge is not the same as no knowledge. Of one thing climate scientists are sure: the more greenhouse gas emissions we emit, the more the world will warm, and the harder it will be to deal with the consequences. There’s no reason for you and I to doubt that simple correlation any longer.