05/26/15

Canada’s moving climate target: the numbers

The Canadian government committed to reducing GHG emissions by 30% below 2005 levels by the year 2030. It was immediately derided by some observers as weak and others as ambitious. It is both: weak in terms of international equity, but ambitious given existing Canadian emissions policy, or lack thereof.

But there’s an even more fundamental problem.

Just what is the actual target?

Here’s the chart from Canada’s official submission to the United Nations, technically called an INDC:

canada-emissions-under-2030-target_600x319
The Carbon Brief brought attention to some confusion with the submission. The data in that graph does not include the key category of “land use, land use change and forestry”. Now, it is not that unusual to plot emissions without “LULUCF”, which can fluctuate from year-to-year based on forestry practices, weather, etc. However, the submission states that Canada intends to include LULUCF in calculating future emissions:

Canada intends to account for the land sector using a net-net approach, and to use a “production approach” to account for harvested wood products. Canada will exclude emissions from natural disturbances.

But that’s only the first problem with the data in the Canadian submission.

The graph uses historical data from the national emissions inventory completed in 2014, which includes data from 1990 through 2012 (data available from the UN). The latest Canadian inventory report, however, was published in April. Every time one of these reports is compiled, the historical emissions are recalculated based on changes in national and international methods.

Here’s the comparison of old and new, straight from the report (red line is the newest data):

Figure 8-1 Canada 2015 NIRLet’s be clear — the recalculation is not subterfuge. Revisiting past calculations is standard practice and takes legitimate effort.

The problem is Canada’s own INDC did not use Canada’s own most recent data. Given the recalculation and the confusion about whether LULUCF is included, the 2030 target is a bit fuzzy.

Here’s a comparison of the possible interpretations of 30% below 2005 levels by 2030.

UntitledThe target could be from 515 to 552 Mt. Semantics? No, the difference is more than half the current emissions from the oil sands. The government itself seems to be confused. Just today, the Environment Minister’s communication person stated the target based on the latest data (749 Mt – 225 Mt = 524 Mt) but excluded LULUCF, which seems incorrect.

There seems to be a basic gap in quality and effort between the very professionally done National Inventory Reports and the seemingly haphazard INDC prepared for the United Nations.

Given how challenging it will be for Canada to meet its target, and how little credibility Canada has right now on climate policy, the federal government needs to straighten all this out.

05/3/15

Weather, climate and the “limiting” nutrient in waterways

Nutrients are a good thing. They promote growth of cells in plants and animals. Food manufacturers love to advertise that their products, like breakfast cereals, are chock-full of “key” or “vital” or “healthy” nutrients.

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In waterways, however, you can have too much of a good thing. Load a lake or an estuary with too much of the nutrient that limits productivity and you might choke the system with algae – the process that scientists call eutrophication because we stink at naming things. All that algae eventually decomposes, or is consumed by other organisms that eventually decompose,  which uses up oxygen crucial to other organisms. That’s a rough explanation of what has happened in the Gulf of Mexico at the mouth of the Mississippi River. Nutrients, particularly nitrogen, leach off agricultural fields and empty into the continental shelf, driving the development of a large “hypoxic” or “dead” zone each summer.

The key issue for the algae is the stoichiometry (again, we stink at naming things) or the ratio of the nutrients: the relative availability of key chemical players like nitrogen (N), phosphorus (P) and silica (Si). Say the ratio of nitrogen to phosphorus in the water is greater than what most algae need; they typically 16 nitrogen”s” for every phosphorus. Then phosphorus becomes the “limiting nutrient”. Add more phosphorus and you should get more growth because there’s already enough nitrogen available. Add more nitrogen, no dice, as there’s not enough phosphorus to match the existing nitrogen levels.

Now, past research has shown that thanks to things like fertilizer loading agricultural soils and groundwater full of nutrients, the key determinant of how much actually ends up flowing down a agricultural river is the weather. For example, a study by myself and Don Scavia showed that a wet fall (which “recharges” the groundwater) in the Midwestern U.S. followed by a wet spring means a large flux of nitrogen down the Mississippi, and all else being equal, a large “dead” zone. But most of that type of runoff and nutrient analysis has focused on individual nutrients, when what really matters to the algae, is the ratio between the nutrients.

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Mississippi Delta and northern Gulf of Mexico

A recent paper led by my former student Doris Leong looked sensitivity of the nutrient ratios to variability in runoff, and hence rainfall. The idea was that, since N, P and Si come from different sources and have different solubilities and adsorptive properties, the flow of each nutrient in a watershed may respond differently to a change in rainfall and runoff*. We hypothesized that in an agricultural river basin, where there is a lot of nitrogen in a soluble form in the soils and groundwater, the N:P and N:Si ratio in the river should increase during wetter periods. An analysis using data from across the Mississippi River Basin confirmed the hypothesis, particularly for N:P:

A doubling of the discharge by the Mississippi and Atchafalaya Rivers to the Gulf of Mexico is found to increase the N:P by 10% and the N:Si by 4%. Analysis of data from upstream stations indicates that the N:P increases with discharge in subbasins with intensive row crop agriculture and high fertilizer application rates.

The effect suggests that the weather could influence nutrient limitation productivity downstream. It may also subtly influence the relative abundance of different primary producers (e.g. algae) in river or in the coastal zone. For example, research shows that if N:Si reaches well above 1:1, there can be a shift away from the production of diatoms, which require Si to build their shells.

The results of the paper suggest that, if all else is equal, a wetter climate in the central U.S. would mean higher N:P and N:Si in Mississippi water. It is important to note, however, that all else is unlikely to equal. Changes in agricultural practices, river management, erosion control, etc. will also influence the availability and movement of nutrients. From the conclusion:

The flux of nutrient ratios depends on multiple environmental characteristics of a watershed, including land use, land management, climate and geology, and the river network, and it is difficult to determine the relative importance of these different effects. The dominant nutrient species, sediment transport, presence of dams, as well as in-stream uptake of nutrients, all play a role in controlling the movement patterns of nutrients over the landscape and within rivers. High-resolution data and models that incorporate sediment and dissolved nutrient cycling are needed to understand the multiple factors that influence how nutrient ratios respond to changes in discharge. As future climate change drives an increase in hydrologic variability, the predictability of the response of nutrient ratios to discharge may be important to understanding ecosystem responses to climatic change.

* Technically speaking, we modeled the relationship between river discharge and nutrient load as a power law. Thus the hypothesis was that for a given watershed, the exponent in the power law would be different for N, P and Si.

04/26/15

Emissions of Convenience: The other side of oil spills

The fear of oil spills on Canada’s west coast was heightened by the recent small spill of bunker fuel, basically fuel oil, from a container ship parked in Vancouver’s harbour. Amidst all the furor over the recent spill, one question was missing: What would have happened to that fuel oil if it had not leaked into English Bay?VCRD129_Oil_Spill_20150409

It would have been burned, adding CO2 and a number of air pollutants to the atmosphere.

Transporting goods around the world via ships represents around 3% of global greenhouse gas emissions, roughly the same as air travel, or all of Canada. A recent study by Alice Bows-Larkin and others in Nature Climate Change concluded that shipping emissions are going to continue to grow at a rapid pace into the future despite the availability of technological advancements in ship design and energy sources.

The question of tackling greenhouse gas emissions from shipping will be up for debate at the upcoming meeting of the International Maritime Organization (IMO)’s Marine Environment Protection Committee (May 11-15th, 2015) thanks to a push from a surprising source: the Republic of the Marshall Islands. This small Pacific Islands country may sadly be best known to outsiders as the site of U.S. hydrogen bomb tests in the 1950s.

Why are the Marshall Islands leading the charge for regulation of shipping emissions?

Thanks to the weird system of international shipping in which vessels fly the flag of distant countries in order to avoid regulations, the Marshall Islands is legally the home port of 3,400 large vessels. If you live in Vancouver or another port city, look through some binoculars at the back of the supertankers and container vessels and you will likely see one of three names: Panama, Monrovia (the capital of Liberia), or Majuro, the capital of the Marshall Islands.

Unlike most economic sectors, shipping emissions are not part of the U.N. Framework Convention on Climate Change and thus not part of the emissions total for countries. Under the Kyoto Protocol negotiations, the responsibility for shipping emissions was handed to the IMO, similar to how aviation emissions were made the responsibility of the International Civil Aviation Organization.

Majuro

Flooding in Majuro, 2014 (rtcc.org)

The Marshall Islands is using the leverage of its large ship registry to push for a sector-wide emissions target. With most land less than 2-3m above sea-level, the coral atolls of the Marshall Islands are highly vulnerable to climate change. The damaging “king” tides from last year gave a glimpse of the future of the Marshallese. Here’s Minister of Foreign Affairs Tony de Brum:

We are an island nation and shipping is one of our lifelines – we cannot survive without it.  At the same time, carbon emissions, including those from shipping, pose an existential threat to our people and our country.

Right now, the Marshall Islands and others are jockeying for support within the IMO, especially from neighbouring Pacific Island countries. They could use support from places like Canada, which pays attention to shipping fuel only when it spills into our waters.

The federal government has spoken of making Canada a world leader in oil spill response. The recent budget included $13.9 million to fund research on effective response to oil spills, as well as money to help establish an International Maritime Centre in Vancouver.

The next step is to deal with the oil that ships actually burn.

03/16/15

The long-term threat of sea-level rise

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Road repair along Nippon Causeway, 2014

My recent article in Scientific American discusses how low-lying coral atolls, like the islands of Kiribati, are a lot more resilient to sea-level rise than dire stories in the media may have you think. But don’t let the nuances of reef island geology described in the article create any doubts about the reality of sea-level rise.

The oceans are rising, and the long-term picture for places like Kiribati is not pretty. This was brought home in the past few days by storm surges again damaging Tarawa atoll’s key causeway that links the most populated islet and international port to the rest of Tarawa.

Here’s a short sidebar of the science of sea-level rise which had to be cut from the article due to space considerations:

The oceans are rising, and the rate of that rise is increasing. Global average sea-level has risen 20 cm since the beginning of the last century, and may rise up to a metre or more by the end of this century.

We can blame greenhouse gas emissions and the basic physics of water.
The planet is absorbing extra heat thanks to the human enhancement of the natural greenhouse effect. The atmosphere gets all the attention, but actually receives only 1-2% of that extra heat. The majority – roughly 93% – goes into warming those deep pools of salt water covering two-thirds of the planet. When water warms up, it expands. That thermal expansion of the ocean is responsible for over half of sea-level rise since 1900.

The key issue for future sea-level is the 3% of the extra heat in the climate system going towards melting ice, especially the Greenland and West Antarctic ice sheets. The rate of melt from these great ice sheets, which hold enough water to raise sea-level by about 12 metres, will define the coasts of the future.

The most recent Intergovernmental Panel on Climate Change report concluded that sea-level would likely rise by 52 – 98 cm by the end of this century, but allowed that far greater changes were possible. It all depends on the complicated process of ice sheet melt.

We know that during periods of Earth’s history when temperatures and greenhouse gases were at levels expected for mid-century, ice sheet melt may have raised the oceans more than 5 metres above current sea-level. We don’t know exactly how long it takes for all that ice to break off or melt. Estimates run in the centuries or longer.

The long-term change is the existential concern for a place like Kiribati. From the article:

The fact that reef islands can grow in some cases and that adaptation measures can help will not save Kiribati forever, especially if the world fails to reduce greenhouse gas emissions. Climate models project that if we stay on the current emissions path, sea-level could be rising at the end of the century at more than five times today’s rate. Even in the unlikely case that islands are able to continue, on net, to accumulate material at their current rate, they may become narrower, steeper and possess less freshwater, making them prohibitively expensive to inhabit.

After a discussion of adaptation needs and ongoing initiatives in Kiribati, the article concludes with a thought I’ve had every time my local colleagues and I return to land from collecting data:

Tarawa's lagoon, visible in the distant clouds

Tarawa’s lagoon, visible to a trained eye in the distant clouds

As you travel out to sea in Kiribati, the flat islands quickly disappear below the horizon. In the old times, fishers navigated home by looking for the reflection of the shallow, greenish lagoon waters in the clouds. One day in the distant future, many of the islands of Kiribati could succumb to the sea. The people may leave, the trees may die and the land may become a submerged reef. The lagoons, still shallow in contrast to the deep open ocean, would remain green as before.

To outsiders, Kiribati would be gone. To the Kiribati people, the ghost of their former homeland would live on in the clouds.

02/23/15

Life as a climate change poster child: the new Scientific American article about Kiribati

???????????????????????????????I have a feature (“Fantasy Island”) in the latest issue of Scientific American and accompanying online slideshow about the reality of sea-level rise in Kiribati.

The article summarizes the complicated science of sea-level rise in coral islands and the even more complicated politics of being a poster child for the impacts of climate change on the developing world. In reflecting on years of research on the ground and on (and in) the water, I try to provide an antidote to all those well-meaning but generally inaccurate pieces of popular disaster porn written about remote island nations like Kiribati and Tuvalu.

If you are interested in what actually is happening in places like Kiribati, I encourage you to buy the issue. An excerpt:

A North American or European traveling to Kiribati may as
well be stepping through a wormhole into another universe. Combine
that naïveté with the reserved nature of the Kiribati people,
the custom of deferring to outsiders, the legacy of countless
past i-Matang asking about climate change and the lack of local scientific
capacity to verify claims, and a naturally flooding village
becomes a victim. Add in the geopolitics—the legitimate need for
a tiny country lacking agency on the world stage to raise awareness
of a threat to its existence—and the exaggeration about the
impacts of sea-level rise can look intentional, whether it is or not.
As my friend Claire Anterea of the Kiribati Climate Action Network
says, “This is not a story that you will just journalize in one
week or two weeks.”

The article is  a testament to all the wonderful people in Kiribati that I have interviewed and worked with over the years, as well as to Mark Fischetti and the editors at Scientific American, who were willing to embrace a story about the incredibly important but less glamourous nuances of climate change.

12/8/14

Corals suggest El Niño may become more frequent

By Jessica Carilli, Assistant Professor UMass Boston

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The author at work

In a warming world, key ocean-atmosphere processes, like the El Niño / Southern Oscillation, are expected to change. An important question is whether the frequency or nature of climate oscillations like El Niño will change in the future.

During El Niño, trade winds that normally blow warm surface waters from east to west across the equatorial Pacific Ocean weaken. The extra-warm surface waters that normally pile up in the west, called the Warm Pool, slosh back towards the east, shutting off upwelling off South America and reducing fishery productivity there. Rainfall patterns also change, moving to the east over the central Pacific and causing droughts in the west. El Niño also has global knock-on effects, like higher rainfall in California and drought in Australia.

In 2010, Simon Donner and I went to the Gilbert Islands, in the Republic of Kiribati, to collect core samples from large coral heads with the intent to learn how climate and the local coral reefs had changed over the past century.

Corals build their calcium carbonate skeletons from seawater, and in the process record changes in their environment – like water temperature and salinity – within the chemistry of their skeletons. Coral skeletons also have rings like trees, so assigning dates to the resulting skeletal environmental records is straightforward.

Gilbert Islands study region map

Butaritari is near the northern edge of the Gilbert group of Kiribati

The Gilbert Islands sit near the eastern edge of the Warm Pool, and are particularly sensitive to a recently discovered variant of El Niño, called El Niño Modoki or central Pacific El Niño. These events seem to be increasing in frequency, which makes this region particularly interesting.

Along with a team of researchers in Australia, we reconstructed water temperature and salinity at Butaritari, in the northern Gilbert Islands, from 1959-2010 and compared trends to other Pacific coral records. The gradient in water temperature from east to west across the Pacific is intrinsically linked to an atmospheric circulation cell called the Walker Circulation, comprised of the trade winds at the surface, rising warm air and rainfall in the west, and sinking, cool dry air in the east.

The records from Butaritari indicate that waters there have not warmed as much as water farther east along the equator. This means the west-east water temperature gradient has weakened over the past half century, and that the Walker Circulation – which breaks down during El Niño events – is weakening.

A weaker Walker Circulation in turn means that El Niño events will be more likely to occur. We could therefore be in for a future of increased El Niño events, which has consequences for fisheries, farming, and freshwater availability – not to mention increased likelihood of natural disasters like flooding and wildfire in some parts of the world.

The original publication can be accessed here or contact Jessica for a PDF.

12/4/14

Warming El Niños on a warming planet

According to the World Meteorological Organization, this year is on pace to be the warmest in recorded history. Whether or not 2014 is awarded the gold, silver or bronze in the global warming’s equivalent of the 100 m dash will probably depend on the temperature dataset. The precise placement of any one year on the medal standings is, of course, immaterial to the broader issue of the longer term trend, described beautifully by Eric RostonENSO-temps-v2-wTrends-638x431.

What is remarkable to many observers is that a record might be set without the help of a “full El Niño”, to use the WMO’s term. In the last few decades, global average surface temperature records have generally been set by a combination of the long-term warming trend and the bump from everyone’s favourite Latin American weather nickname. An increasingly common way to plot global average surface temperatures is with additional labels for El Niño, La Niña and neutral years, as was done in the WMO report and this figure from Skeptical Science. The take-home message – El Niño, La Niña, neutral, it is all warming.

The labeling is the tricky part, for two reasons. First, El Niños normally develop and peak over the “boreal” or northern hemisphere winter, which means they span two calendar years. There’s usually a few months lag between the development of El Niño and the global temperature effect. Thus, for the global temperature analysis purposes, the “El Niño” year is the year after the onset of the event. The best example is the 1997/98 event which helped bump 1998 to a warmest year gold medal.

Second, there’s no one perfect way to classify El Niño events. For example, in the Skeptical Science plot, 2005 is classified as an El Niño year. In a plot in the WMO report, 2005 is classified as a neutral year. These conflicts arise with “weak” El Niño years because different groups use different classification systems. The U.S. agencies NOAA and NASA disagreed as to whether 2004/05 was an El Niño event.

The suggestion that El Niño events be divided into types or flavours may address some of this potential disagreement. The recent paper led by my former student Sandra Banholzer concluded that the global average surface temperature is anomalously warm – statistically-speaking – during the canonical or traditional “Eastern Pacific” El Niño events like 1997/98, but not during “Central Pacific” events or “Mixefig2 - banholzer and donnerd” events. A more nuanced classification system allows 2004/05 to get status as El Niño-ish, but not a classic El Niño.

There are a variety of ways to perform the classifications and it is safe to say that the scientists involved do not agree on the “best” method. Whatever method is used, the underlying surface warming trend is the same. As is clear from this figure from the recent paper, the warming trend is robust.

NOTE: We will have a poster on this subject at AGU on the afternoon of Wednesday, December 15th, 2014.

12/3/14

A blast from the coral past

20141117_140418This blue coral specimen was collected during the U.S. Navy expedition to Bikini Atoll, in advance of the famous hydrogen bomb tests and forced evacuation of the Bikinians.

After years essentially collecting dust in someone’s basement, a group of corals from that expedition were donated to the California Academy of Sciences in San Francisco.

I took the photo during a recent visit to give a talk and to tour their incredible collections.

11/20/14

Message from communications research: Climate change is real. Repeat. Repeat again.

There is an ongoing feud about value in communicating the scientific consensus on climate change to the public. One side argues that we need to talk about the consensus in order to raise public awareness about climate change. A new review article by John Cook and Peter Jacobs (also described in the Guardian) reviews the evidence for “consensus messaging”.  The counterargument, proposed by Dan Kahan and others, is that talking about consensus will increase political polarization about climate change.

A recent paper by Kahan called “Climate Science Communication and the Measurement Problem” suggests the disagreement among communications researchers is related to the “contamination of education and politics with forms of cultural status competition”. It is a fascinating paper with a lot of important findings. But I wonder if, deep in the data, there may be evidence that the drumbeat of climate change news and outreach campaigns has actually been effective.

The core result of the paper is described by the following figure:

Kahan 2014 - Fig 7 - no legendIf people were rationally assessing scientific information, higher science comprehension would translate into higher perceived risk from climate change (left panel). Kahan’s experiments find the opposite for people on the right of the political spectrum (red, right panel). That’s been the headline: for conservatives, better knowledge of climate science might mean less concern about climate change.

In other words, when people go beyond the basics, opinions become polarized. That is not very surprising, given that someone on the right of the political spectrum with greater interest and/or ability in science who looks for information about climate change may head to right-wing media and blogs, which often house an alternate universe of “facts” about climate change.

What is more surprising are the results for people with low “science comprehension”.

Why are people with low science comprehension on both the left and the right of the political spectrum perceiving moderate to high risk from climate change? If people’s views on climate change are defined more by their cultural identity than by the facts of the case, why would people on the right of the spectrum with low science comprehension have even moderate concern about climate change?

This opinion about the risk from climate change must derive from something. It isn’t a detailed knowledge of the science, or the problem. Otherwise, the people would fall elsewhere on the graph. It also isn’t their community. Their community, if defined correctly, generally believes the risk from climate change to be low.

What’s happening? Perhaps there has been enough mention of climate change in the public domain, whether on the news, in private conversations, etc., that even those who pay scant little attention to science have been able to develop some level of concern about climate change.

It may be that, current polarization aside, the much-maligned information deficit model has actually worked, at least with very basic information, and in the way political messaging works. Years of repeating the general facts of the case – climate change is real, caused by humans, and poses a risk to the future – appears to have created a basic public consciousness about climate change.

11/12/14

US-China climate deal places pressure on Canada

The proposed climate agreement between the U.S. and China will put the Canadian government’s promise to harmonize with U.S. policy to the test.

Under the new agreement, the U.S. would limit greenhouse gas emissions to 26-28% below 2005 levels by the year 2025. That is a step beyond the existing U.S. target, shared by Canada, of 17% below 2005 levels by the year 2020.

The U.S. is roughly on pace to meet its 2020 target, with emissions for 2012, the most recent year available, only 8% above the target and further reductions possible due to automobile regulation, coal regulations and the shift from coal to natural gas for energy.

Canada is not; emissions were 13% above the 2020 target in 2012 and are projected to increase over the next two decades largely because of activities in the oil sands sector. According to the Environment Canada projections, Canada’s emissions are projected to reach 762 Mt of CO2e by the year 2020,  9% above the 2012 level and 25% above the 2020 target. 

The new agreement will increase the gap between U.S. and Canadian ambitions. Canadian greenhouse gas emissions are projected to be one third above the new target for the year 2025 agreed to by President Obama (assuming the Environment Canada projection for 2025 is halfway between the 2020 – 762 Mt – and 2030 – 815 Mt).

The core of the gap is the oil sands. This is not environmental rhetoric. This is math, based on the government’s own projections, submitted to the United Nations according to international reporting agreements. Roughly three-quarters of the projected growth in Canadian emissions by 2030 comes from the oil sands sector, with the remaining growth in industries like rail and heavy-duty trucks that can be related to the oil and gas activity.

Without addressing the expected growth in greenhouse gas emissions from the oil sands, Canada will not come close to even stabilizing emissions in the next couple decades, let alone keeping up with action by the U.S. and the rest of the developed world. At some point, our leaders need to address the elephant in the room.