Feeds:
Posts
Comments

Posts Tagged ‘canada’

I was scanning my blog stats the other day – partly to see if people were reading my new post on the Blue Mountains bushfires, partly because I just like graphs – when I noticed that an article I wrote nearly two years ago was suddenly getting more views than ever before:

The article in question highlights the scientific inaccuracies of the 2004 film The Day After Tomorrow, in which global warming leads to a new ice age. Now that I’ve taken more courses in thermodynamics I could definitely expand on the original post if I had the time and inclination to watch the film again…

I did a bit more digging in my stats and discovered that most viewers are reaching this article through Google searches such as “is the day after tomorrow true”, “is the day after tomorrow likely to happen”, and “movie review of a day after tomorrow if it is possible or impossible.” The answers are no, no, and impossible, respectively.

But why the sudden surge in interest? I think it is probably related to the record cold temperatures across much of the United States, an event which media outlets have dubbed the “polar vortex”. I prefer “Arctic barf”.

Part of the extremely cold air mass which covers the Arctic has essentially detached and spilled southward over North America. In other words, the Arctic has barfed on the USA. Less sexy terminology than “polar vortex”, perhaps, but I would argue it is more enlightening.

Greg Laden also has a good explanation:

The Polar Vortex, a huge system of swirling air that normally contains the polar cold air has shifted so it is not sitting right on the pole as it usually does. We are not seeing an expansion of cold, an ice age, or an anti-global warming phenomenon. We are seeing the usual cold polar air taking an excursion.

Note that other regions such as Alaska and much of Europe are currently experiencing unusually warm winter weather. On balance, the planet isn’t any colder than normal. The cold patches are just moving around in an unusual way.

Having grown up in the Canadian Prairies, where we experience daily lows below -30°C for at least a few days each year (and for nearly a month straight so far this winter), I can’t say I have a lot of sympathy. Or maybe I’m just bitter because I never got a day off school due to the cold? But seriously, nothing has to shut down if you plug in the cars at night and bundle up like an astronaut. We’ve been doing it for years.

Read Full Post »

At public hearings on the environmental impacts of proposed oil pipelines, Canadians are no longer allowed to discuss climate change: any testimonials concerning how the oil was produced (“upstream effects”) and what will happen when it is burned (“downstream effects”) are considered inadmissible. This new policy was part of a 2012 omnibus bill by the federal government.

So if we refuse to consider the risks, they don’t exist? Or does this government just not care? I’m not sure I want to know the answer.

See the very thoughtful article by Andy Skuce, a geologist who formerly worked in the Alberta oil sands.

Read Full Post »

On Monday evening, a Canadian research helicopter in northwest Nunavut crashed into the Arctic Ocean. Three men from the CGCS Amundsen research vessel were on board, examining the sea ice from above to determine the best route for the ship to take. All three were killed in the crash: climate scientist Klaus Hochheim, commanding officer Marc Thibault, and pilot Daniel Dubé.

The Amundsen recovered the bodies, which will be entrusted to the RCMP as soon as the ship reaches land. The helicopter remains at the bottom of the Arctic Ocean (~400 m deep); until it can be retrieved, the cause of the crash will remain unknown.

Klaus Hochheim

During my first two years of university, I worked on and off in the same lab as Klaus. He was often in the field, and I was often rushing off to class, so we only spoke a few times. He was very friendly and energetic, and I regret not getting to know him better. My thoughts are with the families, friends, and close colleagues of these three men, who have far more to mourn than I do.

Perhaps some solace can be found in the thought that they died doing what they loved best. All of the Arctic scientists I know are incredibly passionate about their field work: bring them down south for too long, and they start itching to get back on the ship. In the modern day, field scientists are perhaps the closest thing we have to explorers. Such a demanding job comes with immense personal and societal rewards, but also with risks.

These events remind me of another team of explorers that died while pursuing their calling, at the opposite pole and over a hundred years ago: the Antarctic expedition of 1912 led by Robert Falcon Scott. While I was travelling in New Zealand, I visited the Scott Memorial in the Queenstown public gardens. Carved into a stone tablet and set into the side of a boulder is an excerpt from Scott’s last diary entry. I thought the words were relevant to Monday night’s tragedy, so I have reproduced them below.

click to enlarge

We arrived within eleven miles of our old One Ton camp with fuel for one hot meal and food for two days. For four days we have been unable to leave the tent, the gale is howling about us. We are weak, writing is difficult, but, for my own sake, I do not regret this journey, which has shown that Englishmen can endure hardships, help one another, and meet death with as great a fortitude as ever in the past.

We took risks; we knew we took them. Things have come out against us, and therefore we have no cause for complaint, but bow to the will of providence, determined still to do our best to the last.

Had we lived I should have had a tale to tell of the hardihood, endurance, and courage of my companions which would have stirred the heart of every Englishman.

These rough notes and our dead bodies must tell the tale.

Read Full Post »

Now that the academic summer is over, I have left Australia and returned home to Canada. It is great to be with my friends and family again, but I really miss the ocean and the giant monster bats. Not to mention the lab: after four months as a proper scientist, it’s very hard to be an undergrad again.

While I continue to settle in, move to a new apartment, and recover from jet lag (which is way worse in this direction!), here are a few pieces of reading to tide you over:

Scott Johnson from Ars Technica wrote a fabulous piece about climate modelling, and the process by which scientists build and test new components. The article is accurate and compelling, and features interviews with two of my former supervisors (Steve Easterbrook and Andrew Weaver) and lots of other great communicators (Gavin Schmidt and Richard Alley, to name a few).

I have just started reading A Short History of Nearly Everything by Bill Bryson. So far, it is one of the best pieces of science writing I have ever read. As well as being funny and easy to understand, it makes me excited about areas of science I haven’t studied since high school.

Finally, my third and final paper from last summer in Victoria was published in the August edition of Journal of Climate. The full text (subscription required) is available here. It is a companion paper to our recent Climate of the Past study, and compares the projections of EMICs (Earth System Models of Intermediate Complexity) when forced with different RCP scenarios. In a nutshell, we found that even after anthropogenic emissions fall to zero, it takes a very long time for CO2 concentrations to recover, even longer for global temperatures to start falling, and longer still for sea level rise (caused by thermal expansion alone, i.e. neglecting the melting of ice sheets) to stabilize, let alone reverse.

Read Full Post »

You may have already heard that carbon dioxide concentrations have surpassed 400 ppm. The most famous monitoring station, Mauna Loa Observatory in Hawaii, reached this value on May 9th. Due to the seasonal cycle, CO2 levels began to decline almost immediately thereafter, but next year they will easily blow past 400 ppm.

Of course, this milestone is largely arbitrary. There’s nothing inherently special about 400 ppm. But it’s a good reminder that while we were arguing about taxation, CO2 levels continued to quietly tick up and up.


In happier news, John Cook and others have just published the most exhaustive survey of the peer-reviewed climate literature to date. Read the paper here (open access), and a detailed but accessible summary here. Unsurprisingly, they found the same 97% consensus that has come up over and over again.

Cook et al read the abstracts of nearly 12 000 papers published between 1991 and 2011 – every single hit from the ISI Web of Science with the keywords “global climate change” or “global warming”. Several different people categorized each abstract, and the authors were contacted whenever possible to categorize their own papers. Using several different methods like this makes the results more reliable.

Around two-thirds of the studies, particularly the more recent ones, didn’t mention the cause of climate change. This is unsurprising, since human-caused warming has been common knowledge in the field for years. Similarly, seismology papers don’t usually mention that plate tectonics cause earthquakes, particularly in the abstracts where space is limited.

Among the papers which did express a position, 97.1% said climate change was human-caused. Again, unsurprising to anyone working in the field, but it’s news to many members of the public. The study has been widely covered in the mainstream media – everywhere from The Guardian to The Australian – and even President Obama’s Twitter feed.


Congratulations are also due to Andrew Weaver, my supervisor from last summer, who has just been elected to the British Columbia provincial legislature. He is not only the first-ever Green Party MLA in BC’s history, but also (as far as I know) the first-ever climate scientist to hold public office.

Governments the world over are sorely in need of officials who actually understand the problem of climate change. Nobody fits this description better than Andrew, and I think he is going to be great. The large margin by which he won also indicates that public support for climate action is perhaps higher than we thought.


Finally, my second publication came out this week in Climate of the Past. It describes an EMIC intercomparison project the UVic lab conducted for the next IPCC report, which I helped out with while I was there. The project was so large that we split the results into two papers (the second of which is in press in Journal of Climate). This paper covers the historical experiments – comparing model results from 850-2005 to observations and proxy reconstructions – as well as some idealized experiments designed to measure metrics such as climate sensitivity, transient climate response, and carbon cycle feedbacks.

Read Full Post »

It seems that every post I write begins with an apology for not writing more. I’ve spent the past few months writing another set of exams (only one more year to go), building and documenting two simple climate models for term projects (much more on that later), and moving to Australia!

This (Northern Hemisphere) summer I have a job at the Climate Change Research Centre at the University of New South Wales in Sydney, which has a close partnership with the UVic Climate Lab (where I worked last summer). I am working with Dr. Katrin Meissner, who primarily studies ocean, carbon cycle, and paleoclimate modelling. We have lots of plans for exciting projects to work on over the next four months.

Australia is an interesting place. Given that it’s nearly 20 hours away by plane, it has a remarkably similar culture to Canada. The weather is much warmer, though (yesterday it dropped down to 15 C and everyone was complaining about the cold) and the food is fantastic. The birds are more colourful (Rainbow Lorikeets are so common that some consider them pests) and the bats are as big as ravens. Best of all, there is an ocean. I think I am going to like it here.

Read Full Post »

The back gardens of Mayflower, Arkansas aren’t looking too good:

spill

Yes, that’s oil. Canadian oil, no less. You’re welcome.

I’ve heard surprisingly little about this event, which occurred when an Exxon Mobil pipeline ruptured on Friday. It appears that the press have limited access while the cleanup crews are at work. National Geographic had a good piece, though.

Call me cynical, but I think the Canadian media are purposely keeping quiet on this one. It’s a very inconvenient time for a pipeline to burst, given that all levels of government and industry are pushing for Keystone, Northern Gateway, Energy East, etc., etc.

News of this event is largely relying on Mayflower citizens leveraging social media. There’s no way to verify their photos and videos, but they’re striking nonetheless. Here’s a video of the situation on a residential street – note the lack of cleanup crews.

The oil is going straight into the storm drain, the man in the video says, which makes me shudder. I don’t know anything about Mayflower’s stormwater system, but where I live those storm drains are about three steps removed from the Red River. Once oil got in there, I can’t imagine it ever getting out.

I find it puzzling that the negative impacts of pipelines are so often catalogued as “environmentalists’ problems” in the Canadian media – here’s a typical example. In reality, they’re everyone’s problems. Environmentalists (as much as I detest that label) are just the people who realize it. We are not a special interest group; we represent everyone. When it comes to disasters, from short-term spills like the one in Mayflower to millennial-scale impacts like climate change, Canadian oil will affect everyone indiscriminately.

Side note: Sorry I have been so absurdly quiet recently. I am busy building two climate models – just small ones for term projects, but so enjoyable that everything else is getting neglected. I’ll be posting much more on that in about a month.

Read Full Post »

This is the coldest time of year in the Prairies. Below -20 °C it all feels about the same, but the fuel lines in cars freeze more easily, and outdoor sports are no longer safe. We all become grouchy creatures of the indoors for a few months each year. But as much as I hate the extreme cold, I would rather be here than in Australia right now.

A record-breaking, continent-wide heat wave has just wrapped up, and Australia has joined the Arctic in the list of regions where the temperature is so unusually warm that new colours have been added to the map legends. This short-term forecast by the ACCESS model predicts parts of South Australia to reach between 52 and 54 °C on Monday:

For context, the highest temperature ever recorded on Earth was 56.7 °C, in Death Valley during July of 1913. Australia’s coming pretty close.

This heat wave has broken dozens of local records, but the really amazing statistics come from national average daily highs: the highest-ever value at 40.33 °C, on January 7th; and seven days in a row above 39 °C, the most ever, from January 2nd to 8th.

Would this have happened without climate change? It’s a fair question, and (for heat waves at least) one that scientists are starting to tackle – see James Hansen’s methodology that concluded recent heat waves in Texas and Russia were almost certainly the result of climate change.

At any rate, this event suggests that uninformed North Americans who claim “warming is a good thing” haven’t been to Australia.

Read Full Post »

Today my very first scientific publication is appearing in Geophysical Research Letters. During my summer at UVic, I helped out with a model intercomparison project regarding the effect of climate change on Atlantic circulation, and was listed as a coauthor on the resulting paper. I suppose I am a proper scientist now, rather than just a scientist larva.

The Atlantic meridional overturning circulation (AMOC for short) is an integral part of the global ocean conveyor belt. In the North Atlantic, a massive amount of water near the surface, cooling down on its way to the poles, becomes dense enough to sink. From there it goes on a thousand-year journey around the world – inching its way along the bottom of the ocean, looping around Antarctica – before finally warming up enough to rise back to the surface. A whole multitude of currents depend on the AMOC, most famously the Gulf Stream, which keeps Europe pleasantly warm.

Some have hypothesized that climate change might shut down the AMOC: the extra heat and freshwater (from melting ice) coming into the North Atlantic could conceivably lower the density of surface water enough to stop it sinking. This happened as the world was coming out of the last ice age, in an event known as the Younger Dryas: a huge ice sheet over North America suddenly gave way, drained into the North Atlantic, and shut down the AMOC. Europe, cut off from the Gulf Stream and at the mercy of the ice-albedo feedback, experienced another thousand years of glacial conditions.

A shutdown today would not lead to another ice age, but it could cause some serious regional cooling over Europe, among other impacts that we don’t fully understand. Today, though, there’s a lot less ice to start with. Could the AMOC still shut down? If not, how much will it weaken due to climate change? So far, scientists have answered these two questions with “probably not” and “something like 25%” respectively. In this study, we analysed 30 climate models (25 complex CMIP5 models, and 5 smaller, less complex EMICs) and came up with basically the same answer. It’s important to note that none of the models include dynamic ice sheets (computational glacial dynamics is a headache and a half), which might affect our results.

Models ran the four standard RCP experiments from 2006-2100. Not every model completed every RCP, and some extended their simulations to 2300 or 3000. In total, there were over 30 000 model years of data. We measured the “strength” of the AMOC using the standard unit Sv (Sverdrups), where each Sv is 1 million cubic metres of water per second.

Only two models simulated an AMOC collapse, and only at the tail end of the most extreme scenario (RCP8.5, which quite frankly gives me a stomachache). Bern3D, an EMIC from Switzerland, showed a MOC strength of essentially zero by the year 3000; CNRM-CM5, a GCM from France, stabilized near zero by 2300. In general, the models showed only a moderate weakening of the AMOC by 2100, with best estimates ranging from a 22% drop for RCP2.6 to a 40% drop for RCP8.5 (with respect to preindustrial conditions).

Are these somewhat-reassuring results trustworthy? Or is the Atlantic circulation in today’s climate models intrinsically too stable? Our model intercomparison also addressed that question, using a neat little scalar metric known as Fov: the net amount of freshwater travelling from the AMOC to the South Atlantic.

The current thinking in physical oceanography is that the AMOC is more or less binary – it’s either “on” or “off”. When AMOC strength is below a certain level (let’s call it A), its only stable state is “off”, and the strength will converge to zero as the currents shut down. When AMOC strength is above some other level (let’s call it B), its only stable state is “on”, and if you were to artificially shut it off, it would bounce right back up to its original level. However, when AMOC strength is between A and B, both conditions can be stable, so whether it’s on or off depends on where it started. This phenomenon is known as hysteresis, and is found in many systems in nature.

This figure was not part of the paper. I made it just now in MS Paint.

Here’s the key part: when AMOC strength is less than A or greater than B, Fov is positive and the system is monostable. When AMOC strength is between A and B, Fov is negative and the system is bistable. The physical justification for Fov is its association with the salt advection feedback, the sign of which is opposite Fov: positive Fov means the salt advection feedback is negative (i.e. stabilizing the current state, so monostable); a negative Fov means the salt advection feedback is positive (i.e. reinforcing changes in either direction, so bistable).

Most observational estimates (largely ocean reanalyses) have Fov as slightly negative. If models’ AMOCs really were too stable, their Fov‘s should be positive. In our intercomparison, we found both positives and negatives – the models were kind of all over the place with respect to Fov. So maybe some models are overly stable, but certainly not all of them, or even the majority.

As part of this project, I got to write a new section of code for the UVic model, which calculated Fov each timestep and included the annual mean in the model output. Software development on a large, established project with many contributors can be tricky, and the process involved a great deal of head-scratching, but it was a lot of fun. Programming is so satisfying.

Beyond that, my main contribution to the project was creating the figures and calculating the multi-model statistics, which got a bit unwieldy as the model count approached 30, but we made it work. I am now extremely well-versed in IDL graphics keywords, which I’m sure will come in handy again. Unfortunately I don’t think I can reproduce any figures here, as the paper’s not open-access.

I was pretty paranoid while coding and doing calculations, though – I kept worrying that I would make a mistake, never catch it, and have it dredged out by contrarians a decade later (“Kate-gate”, they would call it). As a climate scientist, I suppose that comes with the job these days. But I can live with it, because this stuff is just so darned interesting.

Read Full Post »

Since I last wrote, I finished my summer research at Andrew Weaver’s lab (more on that in the weeks and months to come, as our papers work through peer review). I moved back home to the Prairies, which seem unnaturally hot, flat and dry compared to BC. Perhaps what I miss most is the ocean – the knowledge that the nearest coastline is more than a thousand kilometres away gives me an uncomfortable feeling akin to claustrophobia.

During that time, the last story I covered has developed significantly. Before September even began, Arctic sea ice extent reached record low levels. It’s currently well below the previous record, held in 2007, and will continue to decline for two or three more weeks before it levels off:

Finally, El Niño conditions are beginning to emerge in the Pacific Ocean. In central Canada we are celebrating, because El Niño tends to produce warmer-than-average winters (although last winter was mysteriously warm despite the cooling influence of La Niña – not a day below -30 C!) The impacts of El Niño are different all over the world, but overall it tends to boost global surface temperatures. Combine this effect with the current ascent from a solar minimum and the stronger-than-ever greenhouse gas forcing, and it looks likely that 2013 will break global temperature records. That’s still a long way away, though, and who knows what will happen before then?

Read Full Post »

Older Posts »

Follow

Get every new post delivered to your Inbox.

Join 319 other followers