Monday, September 30, 2013

The oceans, on acid. And bacon.

The new IPCC report reminds that through the fits and starts of climate warming, we continue to steadily carbonate the ocean. From the Summary for Policymakers:

Measurements of CO2 partial pressure and pH from three stations
...atmospheric concentrations of carbon dioxide (CO2), methane, and nitrous oxide have increased to levels unprecedented in at least the last 800,000 years. CO2 concentrations have increased by 40% since pre-industrial times, primarily from fossil fuel emissions and secondarily from net land use change emissions. The ocean has absorbed about 30% of the emitted anthropogenic carbon dioxide, causing ocean acidification...
Ocean acidification is quantified by decreases in pH. The pH of ocean surface water has decreased by 0.1 since the beginning of the industrial era (high confidence), corresponding to a 26% increase in hydrogen ion concentration.

The chemical conditions are unlike anything that the vast majority of organisms living in the surface of the ocean have ever regularly experienced. The changes are predicted to continue:

Ensemble mean surface pH from suite of earth system models
Climate change will affect carbon cycle processes in a way that will exacerbate the increase of CO2 in the atmosphere (high confidence). Further uptake of carbon by the ocean will increase ocean acidification... Earth System Models project a global increase in ocean acidification for all RCP scenarios. The corresponding decrease in surface ocean pH by the end of 21st century is in the range of 0.06 to 0.07 for RCP2.6, 0.14 to 0.15 for RCP4.5, 0.20 to 0.21 for RCP6.0 and 0.30 to 0.32 for RCP8.5

The RCP2.6 scenario, one in which the world rapidly moves to limit carbon emissions, would likely avoid some of the worst damage to coral reefs and other marine ecosystems.

The RCP8.5 scenario, the current "business as usual", could be considered the "few corals" scenario. To use IPCC parlance, this would be stated with medium or high confidence.  Perhaps we should add bacon to this scenario. They say everything tastes better with bacon.

(with thanks to research assistant Matthew Wagstaff)


Thursday, September 26, 2013

The pause in public understanding of climate change

The Fifth IPCC assessment report on the physical science of climate change will be released tomorrow. It is probably the largest, most comprehensive scientific assessment in history.  Not just of climate change, but of any scientific subject. Really. Try to think of any scientific report with more contributors, more citations, more reviewers, more pages, and more preparation time.

Unfortunately, the report is being overshadowed by confusion about a perceived slowdown in the rate of global warming. The graph at right, is based on the GISS estimates of global average surface temperatures since the early 1970s. There is a clear signal of rising temperatures amidst the noise of natural variability.

The slowdown in surface temperature change is part of that natural variability.  The planet is still gaining extra heat due to human enhancement of the natural greenhouse effect. As Stephan Rahmstorf summarized nicely on RealClimate, the difference is that over the past decade or so, a larger proportion of that heat than normal has gone into the deep ocean. In a few years, the yin of deep ocean heating will give way to the yang of surface temperature warming. When conditions in the Pacific Ocean again allow the development of a strong, traditional El Nino event - a la 1997/8, or 1982/3 - we'll see new global surface temperature records. We should not mistake a landing for the top of the stairwell, as Richard Muller wisely analogized at the end of an article that otherwise is so obtuse I'm reluctant to give it mention here.

The media noise surrounding the perceived slowdown is part of the  natural variability of public understanding of climate change. Our research has shown that public attitudes about climate change in the United States ebb and flow with the climate. After a cool period, people tend to be less convinced and less concerned about climate change.

It's worth imagining different labels on the axes of the temperature graph. The public conversation about climate warming follows a similarly noisy trajectory. There is a long-term trend towards greater public understanding, better reporting, and better informed discussion at the political level. There is also variability, due to the natural ups and downs of the climate, current events, etc.

This is the natural process of knowledge acquisition. We're learning more about more about how the planet works over time. The path, however, is not smooth. There are also periods when the knowledge in the scientific community or the public barely changes, or even goes in the wrong direction before jumping back onto an upward trajectory. There is plenty of evidence for brief periods of  "negative learning" in the recent history, including scientific understanding of the causes of ozone destruction.

Years from now, we'll look back at this temporary slowdown in the rate of surface temperature warming and shake our heads. This is a temporary landing in the middle of the stairwell of rising air temperatures and rising public acceptance of the magnitude of the human role in climate change.


Thursday, September 19, 2013

Did climate scientists make a mistake in predicting the decline of Arctic sea ice?

Each spring, the ice on the lake near the family cottage meets its demise.

As the days lengthen and warm, the ice gets thinner and thinner. No one ventures onto the lake for fear of breaking through. One sunny day, usually in early April, the ice disappears.

This death spiral of lake ice each spring is familiar to people across Canada and the northern United States. From above, the lakes look completely frozen during most of the melt process. The real sign of ice melt is the rapid drop in thickness or volume.

Thanks to climate change, the Arctic sea ice is in the throes of its own death spiral. The volume of sea ice in the Arctic, the key measure of ice change, has been declining rapidly for decades. There is now roughly 75% less summer ice in the Arctic than three decades ago.

Yet you don't hear about the volume of ice in the news. Journalists, activists and scientists normally highlight the very visible decline in area of ice during the summer.

There's a valid argument for talking on the more immediately relevant area of ice. Last September, area of ice cover dropped to only 3.4 million km2, less than half that in the 1980s. This dramatic melt was visible in satellite images. It was visible to the many boats transiting the once-forbidden Northwest Passage.

As with our small lake, the area of ice is not the best measure of the ice pack. Last summer's open water froze over the winter, forming a layer of ice thinner than what you'd find on our small lake during the height of winter. Due to natural variability in the weather, much of that thin Arctic ice survived the summer. Though the area of ice is still far lower than that of decades past, it is roughly 30% greater than last year.

This year's ice area has been manna for ardent climate change contrarians. Bold claims about the rebound of Arctic sea ice proving climate scientists wrong now abound on the internet.

In some cases, the claims about data are technically correct. In all cases, they miss the big picture.

The death spiral of Arctic ice continues. According to the Polar Science Center at the University of Washington, the volume of summer sea ice has declined by roughly 75% in the past few decades. The monthly ice volume figure (right) from their Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) actually looks like a spiral, with the ice volume for each month of the year declining over time.

Scientists' only mistake was not talking more about ice thickness or volume. This long-term change in ice volume, rather than the annual summer ice area, is the best harbinger of the future. Those boasting about the Arctic "rebound" this year should heed caution. They are standing on very thin ice.


Monday, September 16, 2013

False claims by contrarians, not scientists, caused Matt Gurney's cynicism about climate change

On Friday, Matt Gurney in the National Post blasted climate scientists, arguing that "repeated false claims have had the effect of turning a lot of people, including my fellow agnostics and I, into climate change cynics, if not yet outright skeptics".

He's right about the false claims. He's wrong about the source.

The false claims that are making Gurney and others "skeptics" come from contrarians, not the scientists.

Gurney's source material is not any actual science, it is an error-filled piece by Daily Mail columnist David Rose that has been torn to shreds by scientists.

In that column, Rose not only misinterpreted the findings in a leaked IPCC report, he flat out made up numbers. For one, the estimated rate of warming since 1950 dropped from 0.13 deg C/decade in the last report to 0.12 deg C /decade in the upcoming report -- not from 0.2 to 0.12, as claimed by Rose. Apparently there are no fact checkers at the Daily Mail, nor many people good at math, because Rose's easily debunked claim garnered the headline "Global warming is just half of what we said".

I'm sympathetic to Gurney's argument that alarmism, on any subject, can alienate the public and impede progress on solutions. We can make up legitimate arguments for and against different climate policies. We can't make up facts.


Tuesday, September 10, 2013

Drought was beyond Syria's "capacity as a country"

Another assessment of the role of drought in the Syrian conflict from long-time foreign policy expert William Polk:

The domestic Syrian refugees immediately found that they had to compete not only with one another for scarce food, water and jobs, but also with the already existing foreign refugee population.  Syria already was a refuge for quarter of a million Palestinians and about a hundred thousand people who had fled the war and occupation of Iraq.  Formerly prosperous farmers were lucky to get jobs as hawkers or street sweepers. And in the desperation of the times, hostilities erupted among groups that were competing just to survive.

Survival was the key issue.  The senior UN Food and Agriculture Organization (FAO) representative in Syria turned to the USAID program for help. Terming the situation “a perfect storm,” in November 2008, he warned  that Syria faced “social destruction.” He noted that the Syrian Minister of Agriculture had “stated publicly that [the]  economic and social fallout from the drought was ‘beyond our capacity as a country to deal with.’”  But, his appeal fell on deaf ears:  the USAID director commented that “we question whether limited USG resources should be directed toward this appeal at this time.”  (reported on November 26, 2008 in cable 08DAMASCUS847_a to Washington and “leaked” to Wikileaks )

Whether or not this was a wise decision, we now know that the Syrian government made the situation much worse by its next action. Lured by the high price of wheat on the world market, it sold its reserves. In 2006, according to the US Department of Agriculture, it sold 1,500,000 metric tons or twice as much as in the previous year.  The next year it had little left to export; in 2008 and for the rest of the drought years it had to import enough wheat to keep its citizens alive.

So tens of thousands of frightened, angry, hungry and impoverished former farmers flooded constituted a “tinder” that was ready to catch fire.  The spark was struck on March 15, 2011  when a relatively small group gathered in the town of Daraa to protest against government failure to help them.  Instead of meeting with the protestors and at least hearing their complaints, the government cracked down on them as subversives.


Thanks to Heidi Cullen of Climate Central for bringing this to our attention.


Monday, September 09, 2013

Flying flags of convenience in climate change debates

This is an updated post from two years ago:

One of the perverse thrills of paddling in Vancouver is cozying up to the massive container ships parked out in English Bay. A little while back, I paddled past one rusting behemoth with the word "Monrovia" painted in white on the red hull. Each letter was about the size of my little kayak.

Monrovia is the capital of Liberia, the country where that vessel is registered. There is no thriving trade between Liberia and western Canada. Merchant ships merely register in Liberia in order to avoid regulations and to reduce costs. Liberia is the flag of convenience.

As a scientist, I sometimes find the challenge of communicating about climate change similar to that of operating a ship according to the rules of your native country while the "competitors" take advantage of the lawless wilds of other nations.

People opposing the basic science of climate change in the public sphere need not adhere to the slow, rigorous method of hypothesis testing or building coherent arguments over time based on the balance of published evidence. That provides contrarians or "deniers" the rhetorical advantage of adopting whatever "flag" or argument is convenient that week, whether about sunspots, a one sentence error in a 900+ page IPCC report, or year-to-year variability in the area of Arctic sea ice. If the argument is proven false in the court of public opinion, you adopt another flag. The sequence of arguments does not have to be logically consistent. The goal of the organized sceptic movement* is simply to keep the ship sailing.

The temptation for scientists to adopt the practices of the opponents in the debate is what the late Steve Schneider described as "double ethical bind" in a famously mis-used quote:

On the one hand, as scientists we are ethically bound to the scientific method, in effect promising to tell the truth, the whole truth, and nothing but – which means that we must include all doubts, the caveats, the ifs, ands and buts. On the other hand, we are not just scientists but human beings as well. And like most people we’d like to see the world a better place, which in this context translates into our working to reduce the risk of potentially disastrous climate change. To do that we need to get some broad based support, to capture the public’s imagination. That, of course, means getting loads of media coverage. So we have to offer up scary scenarios, make simplified, dramatic statements, and make little mention of any doubts we might have. This “double ethical bind” we frequently find ourselves in cannot be solved by any formula. Each of us has to decide what the right balance is between being effective and being honest. I hope that means being both

The response to that honest, clear assessment of the communications challenge says enough. For years, that one line about offering up "scary scenarios" was itself a Liberia to many of Schneider's opponents.

It can be challenging to stay level-headed about communication in the face of often unscrupulous opposition. That's why I find that the keys to communication about climate change are not the usual suspects of understanding the audience, technical expertise, passion, ability to drop jargon, etc. etc. In my experience, successfully communicating about climate change takes, more than anything else, patience and humility.

* Note: It's important to separate the funded movement from individual people's doubts about the science of climate change, which can be grounded in science, culture, religion, politics, moral values, you name it. And there are vocal sceptics who rely on a consistent line of argumentation; perhaps Richard Lindzen's earlier arguments about the water vapour feedback could fall in this category, though it's fair to say that ship has since migrated to other shores.


Tuesday, September 03, 2013

Has climate change played a role in the Syrian conflict?

The Syrian conflict has become a humanitarian tragedy incomparable to others in recent history. Over 2 million people, 10% of the country, have fled during the ongoing conflict according to the UN.

While the proximate drivers of the Syrian conflict are a reaction to an oppressive government, the wave of Arab Spring protests, and other political, social and economic factors, a number of experts have argued that climate change, or at least climate, has served as a "multiplier".

Links between climate change and the Arab Spring have been suggested for the past couple of years. High wheat prices in 2010-11, driven by droughts in Russia and China, may have contributed to the unrest in Egypt and the overall timing of the Arab Spring protests. In Syria, add on the fact that a severe drought over the past decade has devastated farmers.

From a UN Office of Disaster Risk Reduction report:

Poor and erratic rainfall since October 2007 has caused the worst drought to strike Syria in four decades. Approximately one million people are severely affected and food insecure, particularly in rainfed areas of the northeast – home to Syria’s most
vulnerable, agriculture-dependant families.

Since the 2007/2008 agriculture season, nearly 75 percent of these households suffered total crop failure. Depleted vegetation in pastures and the exhaustion of feed reserves have forced many herders to sell their livestock at between 60 and 70 percent below cost. Syria’s drought break point was the season 07/08 which extended for two more seasons, affecting farming regions in the Middle north, Southwestern and Northeastern of the country, especially the northeastern governorate of Al Hassakeh. 

The drought drove internal migration to the cities, depopulating some rural areas:

The drought is causing a high drop-out rate, families left in the area who cannot afford, or do not want, to move are suffering. Some figures estimated the people lifted their villages to be more than one million people. Thousands of Syrian farming families have been forced to move to cities in search of alternative work after two years of drought and failed crops followed a number of unproductive years. The field survey that conducted by ACSAD/MoLA/UNDP in January 2011 showed that most of the houses on villages are left empty and less than 10% are occupied by old people and children, The younger generations left for thousands of kilometers seeking work.

While the Syrian drought, like any individual event, cannot be definitively attributed to climate change, the Middle East and the Mediterranean region is one place where climate models agree that drought is becoming or will become more frequent due to human-induced climate change. From Hoerling et al. (2012):

The amplitude of the externally forced [ED-meaning "human-caused"], area-averaged Mediterranean drying signal (estimated from the ensemble mean of CMIP3 simulations) is roughly one-half the magnitude of the observed drying, indicating that other processes likely also contributed to the observed drying.
Naturally, these connections need to be viewed with caution. Climate change is not solely responsible for the Syrian drought, as natural climate variability and ill-conceived land use and agricultural policy clearly also contributed. And the drought itself is only one of many stressors that led to the crisis in Syria. The fact is we will never be able to precisely calculate the contribution of climate change to a geopolitical event or a humanitarian crisis.

Does the inability to provide a precise answer - 44% due to climate change - matter?

Inability to attribute events to climate change may make adaptation seem impossible. A solution is to not view adaptation as separate from other development activities. For example, the large aid institutions  recommend marrying climate change adaptation and disaster risk reduction. In other words, when working on a program or system to reduce future droughts, consider how climate change may alter the likelihood and nature of future disasters.

Right now, any of that would be a luxury in Syria. Dealing with the everyday humanitarian crisis is paramount. Hopefully, in time the crisis will abate enough to work on rebuilding people's lives and improving the capacity to deal with future droughts.