Have We Already Tipped? My growing concern about the challenges we face.


The scientists at the Scripps Institution of Oceanography who manage one of the two sets of instruments atop Mauna Loa (NOAA manages the other set) announced on April 20th that concentrations of CO2 exceeded 409 ppm for the first time in recorded history.  While concentrations will soon fall slightly as a summer of photosynthesis commences in the northern hemisphere, they are unlikely to dip below 400 ppm again until we significantly reduce emissions.  Meanwhile, the rate of increase of the overall level is faster than it has ever been.  Looking at things more broadly, the planet has not seen levels of CO2 this high for several million years.

March 2016 global temp NOAA

Like a raging infection – the planet’s fever just keeps on going.  Image courtesy NOAA.

Temperatures are also at record highs.  NOAA’s latest monthly global analysis reports that the combined land and ocean temperature in March 2016 was the warmest on record (since 1880) at 1.22oC above the late 20th century average, and that it exceeded the previous record March (set only last year) by the largest increase (0.32oC) ever for any month of the year, beating out February 2016, the prior record holder.  Further, March 2016 is the 11th consecutive month of record high temperature, the longest such run in history.  Record warmth was present in the northern and in the southern hemisphere, on land and in the ocean and in most individual countries.  The combined temperature over the first three months of 2016 is also the highest on record.

While the record temperatures are partly a consequence of the now-weakening el Niño, which is itself turning out to be the longest, and possibly also the strongest el Niño ever recorded, they are also a reflection of our continued emissions of CO2.  We are doing a very effective job of warming the planet, and along with the warming come other changes.  The drought in California and other parts of the US south-west continues despite some good rains courtesy of el Niño.  The rains just were not good enough and snowpack in the Sierra Nevada was just 87% of average levels when it peaked in late March.  Despite the fact that aquifers have not yet come close to being replenished, demands to lift the water conservation measures introduced are becoming louder – Californians need to wash their cars.  Aljazeera has written of a “state of chronic drought” in the American south-west.  In the Arctic, for the second year in a row, ice formation this winter has fallen short and the maximum extent is a new low.  The National Snow and Ice Data Center has announced that the maximum extent was achieved on 24th March at 14.52 million km2, 13 thousand km2 less than the previous record set just last year.  With more open water, the Arctic warms more rapidly.  I think we are beginning to see a pattern here – a world warming rapidly out of control.

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Sea ice in the Arctic, summer 2015.  Image © Stefan Hendricks

Record coral bleaching

The el Niño has now ushered in the longest continuous global coral bleaching episode in history, and bleaching is not over yet.  I covered the bleaching of the northern Great Barrier Reef in my last post.  While the heavily damaged Great Barrier Reef is now experiencing less warm conditions, bleaching has recently started on the western Australian reefs, and can be expected to march through the Indian Ocean over the next few months, before cropping up again in the Caribbean and northern Pacific this summer.  One begins to wonder if there will ever again be a pause – a month or two with no bleaching on any reef anywhere – before the last of our coral reefs succumb.

The el Niño can also be blamed for severe forest fires in the Philippines, Malaysia and particularly Indonesia.  One consequence of these fires (which are largely human-set, but aided by the dry conditions set in place by el Niño) is an enhanced rate of CO2 emissions, a spike in atmospheric CO2, and yet more warming.  Oh yes, the melting of glaciers proceeds, and may now be unstoppable.

And then there are the other environmental stresses

In the oceans, sea level is rising faster, and pH is falling as CO2 leaks in from the atmosphere.  Coastal dead zones are not going away, and there are signs that the oxygen minimum layer of the open ocean is expanding as waters warm.  Anoxia and low pH have been features of the oceans in every prior mass extinction event, and the oceans have typically taken several million years to recover.

On land, we continue to eliminate forests.  While FAO, always being optimistic, is quick to point out that the rate of deforestation has fallen significantly in the past 25 years, the world lost 129 million ha of forest since 1990.  That is an area almost the size of South Africa.  The actual loss of natural forest (including regenerated as well as old growth) was nearly double this (239 million ha) because a lot of natural forest is being replaced by other forms of treed land including palm oil plantations.  Current deforestation rates generate 1.5 Gt CO2 in emissions each year, and the total amount of forested land is 3.2% less than in 1990 with most of these losses in the tropics.  If we could grow our forested land, we could create a significant new sink for CO2.  We also continue to overuse freshwater supplies, overfish many fishery stocks, and continue to pollute air, land, and water.  Needless to say, the threat to biodiversity is undiminished, but I doubt many people will see biodiversity loss as troubling until we get a lot further down that particular slippery slope.


Corcovado, Costa Rica.  Forests are a major refuge for biodiversity.  Photo © Matthew Karsten

Our population and economic growth

Currently 7.4 billion of us live on this planet.  Our global growth rate has continued to fall since 1962, when it stood at 2.1% per year, but despite this, we expect to number an additional billion in 2030, reach 9.5 billion by 2050, and 10.9 billion by 2100 – that is a 47% increase in numbers between now and then.  Most of this increase is coming in Africa, South and Southeast Asia.  We can be cheerfully optimistic about the declining rate of increase and the fact that global population is expected to peak sometime around 2100, or pessimistic about the growing demands on our environment that 3.5 billion more people will impose.

Our global economy is also growing, in part simply because of population growth.  Global per capita GDP is also growing, however, as individuals on average become slightly richer.  While per capita GDP scarcely grew at all during the 1000 years prior to 1950, it has been growing more or less continuously ever since with the world average now about $8000 per year.  Economic theory vested in ensuring positive GDP growth is in wide use.  The standard economic argument is based on the premise that economic competition inevitably increases economic efficiency, so that goods of more value are created with less labor and materials.  In order to ensure continued employment, it is therefore necessary for societies to ensure growing economic production so that the amount of labor required does not diminish.  If the population is also growing, maintenance of employment requires still more economic growth, and if there is a trend towards increasing income inequality, the rate of economic growth needs to be kept even higher to ensure that the 99% do not become disillusioned with their lot in life and prone to social unrest and violence.  So long as we continue to live within this paradigm, we are condemning ourselves to an increasingly fruitless search for increased economic activity, with all the additional stresses which that growing economy places on the environment.

From the perspective of environmental science, I see the growth in population and economic activity as major impediments to any attempts to bring our unsustainable use of the environment under control.  Our global economy is now sufficiently large that it results in the emission of about 36 Gt CO2 per year to the atmosphere.  As the two graphs below show, emissions due to our global economy seem to have only just leveled off despite the fact that emissions intensity has declined about 30% since 1990.  While results for 2014 and 2015 make me optimistic that we are starting to divorce economic growth from emissions (decarbonizing), two points do not make a trend, and I do not think we are able to claim that emissions from economic activity are now declining.  The projected 47% growth in our population during the remainder of this century is going to demand at least that much growth in the global economy, even setting aside any desire for continued growth in individual wealth.  (In this increasingly unequal world, there will either be substantial wealth redistribution or an effort to ensure continued increase in per capita GDP, so I am betting we are looking for an overall growth in excess of 47% for global GDP by 2100.)

CO2 emissions due to energy use global

CO2 emissions due to economic activity have been strongly linked to GDP growth over the years, however reduction in carbon intensity (decarbonization) due to the shift away from use of fossil fuels, and to the shift in the economy away from resource-intensive manufacturing is now making it possible for emissions to grow less quickly than the economy.  Figure © Global Carbon Project.

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Graph showing the improvement in emissions intensity of the global economy since 1990, and the growth of emissions over the same period.  We would have to reduce emissions intensity far more than this to counteract the anticipated growth in the size of the economy during the remainder of the century.  Figure © Nature Climate Change.

At the present time, increasing global GDP by 47% must result in a substantial (though less than 47%) increase in the energy required to sustain that activity.  Doing this while simultaneously bringing CO2 emissions down to near zero appears to be a gargantuan task.

The growing population and growing economy do not just impact the environment through CO2 emissions.  There is the 47% more food, 47% more potable water, and 47% more living space required for the larger population, never mind the increased demand for other resources to sustain the economic growth.  Looking at our situation from this perspective is almost enough to cause me to roll myself up in a tight ball in a shady corner and try not to think about reality.  And yet, we do need to look at our situation in its totality, and recognize just how great a task we have in front of us.

For a start, I believe that the world community should be ramping up efforts to speed up the demographic transition in those parts of the world where fertility remains high.  Far better for all of us to “fail” to achieve a world population of 10.9 billion by 2100 by accelerating the decline of fertility than by subjecting millions of people to the inhuman hardship of abject poverty in a world economy that is unable to grow fast enough to raise their standards of living.  Such a “failure” might permit us to live with dignity in a global economy that is not half again as large as it is now, and an economy that has found effective ways to make money on activities that repair the ecosystems on which we depend, in place of the economy which thrives on environmental despoliation.  In any event, our environmental challenge (which is only partly a climate challenge) must be viewed in the context of our population growth and our global economy, both of which make the challenge a good bit bigger.

Nations do not yet understand the true extent of our environmental challenge

The true message of climate change has not got through to the rank and file of the political class, never mind the masses of ordinary people.  Scientists who present truly alarming long-term projections of such things as glacier melting are dismissed as “extremists” while scientists who present their results more cautiously, and with an optimistic tone, are seen as talking about “environmental” issues – issues that are important, but not as important as jobs, energy, national security.  Environmental issues are not existential.

Most people who are not scientists can remember that we have solved many environmental problems in the past, and will surely solve such problems in the future as well.  Few people who are not environmental scientists recognize how deeply entwined environmental problems can be with our lives.  For example, our growing population suggests we will need more arable land to provide food for the extra 3.5 billion people expected by 2100.  A sea level rise of 2 meters will wipe out vast areas of currently fertile lowlands, and the changing climate will increase aridity in many agricultural regions.  These problems have a nasty habit of coming together to make things really, really difficult.  The notion that things might become so difficult that a desirable solution is not attainable does not seem prominent among most who think casually about such things.

Trudeau signing Paris accord 22 Apr 16 Mary Altaffer-AP

Canada’s Justin Trudeau signing the Paris Accord, Earth Day 2016.  Photo © Mary Altaffer/AP

On Earth Day 2016, there was a big ceremonial signing of the Paris Accord at the UN offices in New York.  Many world leaders were present to add their names and say a few inspirational words.  Most nations will have to ratify these signatures over coming months.  It was a wonderful photo op, but it did nothing for our climate except to add a few more tonnes of CO2 to the atmosphere as all those dignitaries flew to New York and back home again.  Canada’s new climate-positive Prime Minister was there trying to show that with the change of government last October we have got our groove back on the environmental front.

But have we?  Canada’s Intended Nationally Determined Contribution (INDC) to reducing emissions under the Paris Accord is a 30% cut in emissions from 2005 levels by 2030.  It was determined during the Harper administration, has been widely criticized as one of the weakest commitments among major emitters, and is a commitment for which we do not yet have adequate policy in place.  Currently, we are on track to fail to achieve the timid goals set by the Harper government, and Justin Trudeau’s new government knows that.  I hope he, and his Minister for Environment and Climate Change, Catherine McKenna, do lie awake some nights wondering how they are going to bring the nation kicking and screaming towards some actions that will meet, and then greatly exceed this goal, because failing to achieve Harper’s goal would be an ignominious defeat.

They will have their work cut out for them.  Leaders of some Provinces – British Columbia, Quebec, Ontario – feel they have done quite a bit already, and are not in the mood to do more before the rest of the country catches up.  Others – Alberta, Saskatchewan – are pleading for compassion while they cope with economies in considerable disarray following the collapse of the oil boom, and talking optimistically about how things will be better once oil comes back.  Rachel Notley, the leftist Premier of Alberta, who came to power as the oil boom was collapsing, has moved rapidly to the right, struggling to put in place some measures to curtail CO2 emissions, while still protecting the damaged, but politically powerful oil sector.  (She did not move as far to the right as the government she replaced, but her response to the need for a price on carbon has been timid, so far.)  Taxes on emissions during production of tar sands crude are coming, but slowly and gently, because everyone in Alberta, apparently including Notley, is under the illusion that growth in the tar sands will begin again soon.

Canada has to reduce its emissions by 30% by 2030, but the pace of reduction must continue and be rapid enough to bring emissions to just 20% of 2005 levels by 2050 if the goal of keeping warming to no more than 2oC is to be achieved.  These calculations assume that the world will continue to allow Canada to “use” its current, overly large share of “emissions space”, rather than a smaller share appropriate to its population (and countries like India and China may have some thoughts on that matter).  Any hope of getting to the aspirational 1.5oC maximum temperature increase (which Catherine McKenna, to her credit, pushed for in Paris), requires that Canada bring emissions down effectively to zero by 2050.  (See my earlier post on the challenge Canada faces, and also the excellent analysis by Drs. Simon Donner (UBC) and Kirsten Zickfeld (Simon Fraser U).)  Bringing emissions to zero by 2050 is not compatible with being gentle on the oil and gas sector during their time of travail.  The quicker Canada’s fossil fuel industry winds down the better.

If Canadians can pull their heads out of the tar sands for just a moment and look around, it should be clear.  The train has left the station.  There will be some recovery in the Canadian oil sector, but it will not boom because tar sands oil is too expensive to extract, and demand is going away.  Either that, or there is going to be a boom just before we finally tip into climate catastrophe.  Since I do not want catastrophe, I will continue to argue that we have all the pipeline capacity we need for the oil sector of the future, and I’ll also advocate for a national carbon tax that 1) establishes a carbon price no less than the average of the British Columbian and Quebec prices, 2) that is broadly based to capture all sectors and uses, and 3) is one that increments annually.  This tax should be reduced or waived completely in those parts of the country which have a comparable price in place.  Without the price, we Canadians are simply not going to reduce our emissions.

I’ve frequently commented on the similarities between Australia and Canada.  Australia should have one advantage over Canada in coming to grips with the need to reduce CO2 emissions.  It cares for, and deeply values, the Great Barrier Reef.  Yet, in Australia, in the midst of the worst bleaching the GBR has ever encountered, governments are actively promoting the coal industry and shipping and dredging to get the coal through the GBR to India and China.  The current bleaching on the Great Barrier Reef is turning out to be the worst bleaching experienced there, and has been particularly surprising (and deeply disappointing) to scientists because the worst-affected region has been the far north, that part of the reef system that is most remote, least impacted by tourism, fisheries or on-shore pollution, and therefore most likely to be able to resist warm temperatures successfully.  Yet the Australian press is filled with pious assurances from political leaders about their concern for, and recognition of responsibility to care for the reef, similarly pious claims to climate purity, and proud announcements of major new international agreements to mine and export large quantities of coal, shipping the coal through newly built ports along the Queensland coast.

To a Canadian, the Australian governmental claims re climate have an eerie Harperian tone, while the claims about caring for the reef sound much like the words any not-particularly-green politician spouts on opening a new recreational area, national trail, or wildlife reserve.  Nice green words.  What is interesting about Australia from my perspective is that they are getting increasingly close to a national election, and the coverage of the destruction on the Great Barrier Reef has been extensive.  Will it make a difference, and will Australia begin its march back towards environmental responsibility.  Time will tell.

Finally, we should reflect very briefly on the political circus just south of Canada.  The world’s capacity to reduce CO2 emissions sufficiently absolutely requires that the USA play a leadership role.  Its 6.9 GtCO2 per year mean that the USA cannot be ignored, and the rest of the world cannot keep the planet within 2oC without the USA playing its part.  Yet, the USA seems to have ample people still in total denial, including a majority of both houses of the Congress.  One leading candidate for President believes CO2 is harmless or good (Cruz), another (Trump) has no coherent climate policy, others would rather not talk about it, and Congress and many States are actively attempting to block the imposition of modest CO2 caps on power plants.  Unlike Canada, the USA has been making steady if modest progress in decarbonizing its economy, but progress on the climate front has been driven by a committed President who has faced obstruction at every turn.  There will be an election in the USA in November.  Who they choose as President will be important, but equally vital will be the composition of the Senate and the House of Representatives.  Our global struggle to keep the planet habitable could be aided, or brought to an abrupt halt by what happens in millions of polling booths across the USA this November.  Just a little scary, right?

So, have we already tipped?

I began by asking if we had already tipped or not.  In the real world, there are tasks that turn out to be too difficult to accomplish.  The task of wrenching the atmosphere back to the state it was in in the mid- to late 1980s (with CO2 at 350ppm) could be one of these.  It is a gargantuan task that cannot be done by a single actor, a single team, a single nation acting alone.  It is a task with definite societal costs as well as opportunities, and progress to date does not inspire confidence that the world community is up for it.  If we fail, the Anthropocene will prove to be a very different kind of place and we will come to look back at the Holocene with nostalgia.  We will also likely have to settle for a less equal world, and a world in which even the best laid plans by the most honorable of people will sometimes fail because the environment, far from being the stage on which we people act out our lives, will be a violently thrashing entity, tossing us about like the puny primates we are.  We will likely survive, but culture, civilization, and humanity will all be severely strained.  I hope we have not tipped onto that dismal path.  Time will tell.

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Categories: Arctic, Canada's environmental policies, Changing Oceans, Climate change, Coal, Economics, In the News, Politics | 2 Comments

What Does the Bleaching of Vast Areas of the Northern Great Barrier Reef Really Mean?


On March 30th, I briefly commented on the bleaching now taking place on the northern Great Barrier Reef.  Today I want to talk about what this really means.

Catlin off Lizard Island 2900

XL Catlin Seaview Survey divers over bleached coral at Lizard Island, March 2016.  Photo © AFP/Getty

Reports so far indicate that there has been major damage and considerable coral death, and it has been widely reported in the media.  The Australian science community is making a major effort to document the damage, in ways that should provide answers to important questions – like is there any evidence that corals are evolving a greater tolerance of warmed water.  But all the media coverage has focused on the event, its scale and seriousness for corals on the Great Barrier Reef (GBR).  I think a much wider perspective is in order.

Back in September, I devoted space on this blog to the current el Niño, which now looks like it will definitely prove to be stronger and longer than the 1997-98 event, until now the most extreme el Niño in recent history.  What is now happening off the northeastern Australian coast is just one aspect of the effect of this huge el Niño on coral reefs around the world, but in calling for a wider perspective, I am not just referring to the on-going global bleaching event.  I will talk about what the GBR bleaching means for reefs, what it means for our appreciation of global climate change, what it means for our understanding of the task ahead if we are to bring climate change under control, what it means, in particular, for Australia’s understanding of the changes that country needs to make if it truly values the GBR, and, finally, what this all means for our collective relationship with and stewardship of this planet of which we are a part.  Wish me luck; let’s get started.

What bleaching of the northern GBR means for reefs

The meaning for reefs is simple:  “We told you so, many times”.  Extensive mass coral bleaching was first observed along the Pacific coast of Panama and in the Galapagos in 1982-3.  Peter Glynn, the coral ecologist who documented the occurrence, noted that there was a particularly strong el Niño that summer, inferred that the exceptionally warm water that resulted was the stressor causing the bleaching, and predicted that climate change would make bleaching an event that would recur and become more prevalent in subsequent years.  In all respects, Peter Glynn was right.  Unfortunately.

Since 1983, there have been multiple reports of mass bleaching from coral reefs throughout the tropics.  During 1997-98, in the presence of what was then the most intense el Niño in the recent past, the world observed the first pan-tropical mass bleaching event ever, and the mortality of coral representing approximately 16% of all live coral cover on reefs worldwide.

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Most of the fish disappear soon after the reef has bleached.  Photo © O. Hoegh-Guldberg

Bleaching has now become a permanent feature of summer somewhere in the tropics, and for the last 18 years, reef scientists have been variously reporting on bleaching, studying factors leading to bleaching or traits favoring survival of warm water without bleaching, and projecting likely consequences if climate change continues to warm the oceans.  One major question has been whether, and the degree to which, corals and/or their dinoflagellate symbionts will be able to evolve adaptations to survive warmer water.  Along the way, there have been glimmers of good news along with a lot of bad news.

One of those glimmers is that in nearly all bleaching events, some corals survive unbleached, and these remain available to drive some recovery even if the great majority of bleached corals succumb.  That some do not bleach provides evidence of the inherent variation among individuals that is required for adaptation to evolve.  However, the majority of reef biologists who have commented are skeptical of the ability of corals to evolve adaptations to warming water, because of the long generation times of corals and the rapid rate at which the world is warming.

(For adaptation to evolve, it is necessary for warm water to cause some mortality, and then for the survivors (presumably corals with genetics that favor resistance to high temperatures) to reproduce successfully.  In that way, these more heat-tolerant types will become more prevalent in the population.  But when temperatures are rising so rapidly, corals are likely to be bleached repeatedly, by ever warmer water, leaving little time for the reproduction of favored types.  Clearly, the long-term outlook for coral reefs is very grim if warming is occurring too quickly to permit effective adaptation.)

Another glimmer of good news came in 2009-10, in the form of two studies, one on the GBR and one in the Florida Keys, in which water quality as well as the beaching of corals was documented during a period of warm water.  In both cases, it was possible to show that corals living in less polluted waters did not bleach until temperatures rose higher than was the case for corals in nearby, but more polluted water.  In other words, the stress of living in waters over-enriched with nutrients due to run-off made corals less tolerant of warm water, and they bleached more easily than would otherwise have been the case.  These two studies provided that essential fragment of evidence to support the otherwise tenuous argument that reefs will likely be more tolerant of warm water if they are well managed with respect to other stressors – overfishing, pollution, sedimentation, physical destruction, and so on.  This was an important argument, because otherwise the depressing news about coral bleaching could lead to a general malaise among reef managers and others, and a deterioration of reefs due to other stressors.  “Why waste time looking after the reefs; they are all going to bleach anyway.”  Over the years, managers have not given up, and the overall management of local stressors on coral reefs may have improved.  But still they bleach.

While investigating the science of bleaching, reef scientists have done their best to raise awareness over what has been happening, and to stress the importance of coral reefs, and the value that will be lost if they are gone.  About one fifth of the human population lives within 100km of a tropical coast, and many of these people are directly dependent on those coastal waters, frequently dotted with reefs, for their food and livelihood.  In addition, reefs have immense economic value in the coastal protection they provide and the fisheries and tourism they support, and further non-economic cultural, spiritual and biodiversity value.

The northern GBR is remote.  North of Cooktown there are few roads, fewer settlements, no agriculture other than some grazing, and one of the last, large, truly remote places on this planet.  That this portion of the GBR has bleached as severely as it has, confirms the worst fears of reef scientists.  Pristine reefs are now being bleached and killed by climate change.  This is serious and the future looks grim.

What this bleaching should mean for our appreciation of climate change

I write ‘should mean’ because I fear that, bad as it is, the bleaching of the northern GBR is not impacting most of us the way it should.  Despite all the effort by reef scientists and by many in the media, the bleaching of coral reefs has never really captured the attention of the mass of us the way scientists hoped it would.  Phrases like ‘canary in the mineshaft’, ‘jewels of the sea’, and ‘biodiversity storehouses of immense ecological and evolutionary importance’ have all been used along with some beautiful and other heart wrenching images, and coverage has been sufficient that few people have not heard that coral reefs are having difficulties.  But only a tiny fraction of people have understood just what is at stake.  Losing a substantial fraction of coral reefs worldwide is akin to throwing away a major fraction of marine biodiversity, but few people grasp what losing biodiversity means for the planet.  Losing the coastal protection services, or the fisheries resources of coral reefs will have profound impacts on the lives of many already marginalized people, but most scanners of the media do not know any of those people personally.  At best, most people who have heard that coral reefs are bleaching think that their opportunities for snorkeling in colorful locations may be dimmed in the future.  The bleaching of reefs is ‘too bad’ but it is not a signal of existential change for humanity on this planet.  Except that it is.

The repeated statements by informed scientists, ever since Peter Glynn first published his report of the 1982-3 bleaching in Panama, that bleaching is a clear sign that climate change has serious environmental consequences, and that bleaching will likely become more extensive and more frequent as climate warms have failed to generate the kind of widespread concern that motivates a desire to act to bring climate change under control.  Yet now we are witnessing the bleaching of some of the most pristine reefs on the planet.  If the northern GBR lacks the resilience to resist warming, what real hope is there for any coral reef if climate is permitted to continue to warm?  And given that the most dire predictions about reefs seem to be coming true, why are we not much more alarmed than we are?  I fear the efforts of reef scientists to communicate have simply not been sufficiently skillful to cut through the noise and the barrage of disinformation about climate (and, yes, I count myself among those unskilled communicators).

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Aerial view of bleached reef, north Queensland, March 2016.  Image © ARC Centre for Coral Reef Studies

In my view, the claim by some among the reef science community that we must provide hope by focusing on the glimmers of good news, rather than “preach doom and gloom” has been an error.  We reef scientists need to be telling it like it is; telling the story accurately, projecting cautiously, but pointing to the near inevitability of the total loss of coral reefs under business as usual.  And we need to be doing a much better job of linking the bleaching of coral reefs to all the other manifestations that suggest humanity is pushing the biosphere towards existentially dangerous thresholds.  Roger Bradbury attempted to do this in an Op Ed in the New York Times in 2012; many of his colleagues condemned him for being too strident.

I do not even believe we have done a good job of effectively relating bleaching to all the other things going on on coral reefs.  This February, Rebecca Albright and Ken Caldeira of the Carnegie Institution’s Global Ecology Department at Stanford University, along with 16 colleagues, published an important paper in Nature on effects of ocean acidification on coral reefs.  Their study was a simple field experiment that took advantage of a unidirectional tidal flow across a reef flat at One Tree Reef, southern GBR, to temporarily adjust the pH and alkalinity of water flowing past a natural reef community.  By briefly shifting pH back to where it was in pre-industrial times (one hour per day over 22 days), they obtained a 6.9% increase in calcification rate across that strip of reef habitat.  While a short-term response to altered conditions (less than one hour per day during a falling tide) may not represent the long-term response if corals were growing continually under elevated pH, these results complement earlier work (2014, by Jacob Silverman and colleagues, including Ken Caldiera) at Lizard Island, GBR, showing that net calcification rates there have fallen by 27-49% since the mid-1970s, a rate that is consistent with the known change in pH.  They also complement still earlier work (2009) by Glenn De’ath and colleagues that revealed a marked slow-down in growth of Porites sp. corals on the GBR in recent years – a change they inferred was due to acidification.  Ocean acidification is proceeding in lock-step with warming, and there are clear indications that both impact coral reefs severely – both problems have to be solved, along with local pollution, sedimentation, physical destruction, and overfishing (see this recent paper on this topic).  Keeping reefs functional is a lot more challenging than just solving the warming.

To be fair to my colleagues, there are serious discussions of the multiple ways in which we are impacting this planet, and the plight of coral reefs was used very effectively to get the oceans into the IPCC and other discussions of climate change.  A few years ago one might have believed that climate change only affects terrestrial systems.  That has now changed.  But our messages about coral bleaching have remained too much about the corals.

To paraphrase American political adviser, James Carville,
“It’s not about corals, it’s about our ability to continue to live on this planet, stupid.”

As I am writing this, the media are reporting the new paper in Nature by Robert DeConto, U. Massachusetts, Amherst, and David Pollard, Penn State University, concerning likely rates of Antarctic melting and resultant sea level rise this century.  Using different methods than Jim Hansen, whose paper was discussed in my last post, they explore how Antarctic ice might melt, and predict global sea level rise of almost two meters by 2100, with Antarctica providing 1.05 ± 0.3 meters of that total under the IPCC RCP8.5 scenario for how we deal with CO2 emissions.  This is double the rise IPCC projected in the latest (2014) Assessment Report.  DeConto and Pollard began by noting that present models do not do a good job of representing the changes in sea level at two past times – the Pliocene and the late Pleistocene when conditions were similar in many ways to now.  They modified the models to take account of two aspects of glacier melting: how warm ocean waters will undercut grounded ice leading to the rapid break-up of ice shelves around Antarctica’s shore, and how surface melting leads to water drilling down through the glacier causing further melting inside.  (These were also considered by Hansen).  With these adjustments their models replicated these past events appropriately, so they then applied the models to currently projected warming patterns and got their nearly two meters of sea level rise.  (Undark Magazine has an interesting account of how Hansen’s paper was received by the press – telling it like it seems to be, rather than softening the bad news with a focus on hope, can get a scientist pilloried by some.)

The messages that are not getting delivered effectively to people are that climate change is simultaneously causing multiple changes to our world, and that the impacts of climate change add to, or even enhance, the negative effects of a number of other things we are doing to our planet.  While corals are being bleached in the tropics, ice is rapidly melting at the poles, and we are going to have to deal with the consequences of both these trends, while also dealing with overfishing, rainforest destruction, desertification, rampant pollution of air, water and soil, and so on.  The science community is mostly aware of these multiple stressors on our world, the general public far less so.  And many politicians are still operating in a mindset that equates negotiations over climate to any other type of negotiations among nations – you talk for a while, you reach a compromise, everyone is happy, even though nobody got what they really wanted (I posted some more extensive comments on this issue last December).  Politicians seem not to have got the message that Nature does not negotiate, and the messaging on coral reefs does not seem to be helping much in the effort to deliver this message.  And this brings me to my next point.

What the GBR bleaching should mean for the task ahead

Even before the ink was dry on the Paris Agreement, in fact before the Paris conference started, it was clear that the agreement reached, while historic and a definite move forward, was going to be woefully inadequate if the world was serious about combating climate change.  Most national INDCs are timid, and waiting until 2020 to strengthen them is just kicking the can down the road.  (Canada’s INDC, developed by the previous, notoriously anti-climate action, Harper government, has yet to be strengthened despite all the positive words coming out of the new, pro-climate action, Trudeau government.  Will Canada wait till 2020 to do something about it?)

Big world small planet CQz9MFQU8AAU3Mk

The new book by Johan Rockstrom and Mattias Klum provides a readable account of the problems we face, and why the world has to change.

The response is inadequate with respect to IPCC science, yet IPCC has consistently been a cautious body as it reviews current science, making that inadequacy doubly so.  IPCC’s need for consensus has meant that it has consistently underestimated the seriousness or the pace of climate change, and been overly optimistic about the ease with which the world community can bring this particular beast under control.  Thus, IPCC stated in its 5th Assessment report (2014) that global sea level would rise 0.52 to 0.98 meters by 2100 under its most extreme (business as usual) scenario RCP8.5, despite the fact that many climate scientists expected that the increase would be significantly more.  IPCC did acknowledge that our understanding of how glaciers melt was in some flux, but reinforced the impression of only moderate sea level change by stating “the collapse of marine-based sectors of the Antarctic ice sheet, if initiated, could cause global mean sea level to rise substantially above the likely range during the 21st century.  However, there is medium confidence that this additional contribution would not exceed several tenths of a meter of sea level rise during the 21st century”.  (To translate the IPCC-speak, the ‘likely’ range (.52-.98 meters) is the range within which reality is expected to fall two-thirds or more of the time, and ‘medium confidence’ means IPCC has a middling level of confidence that this statement is correct – so ice sheet melt could make a bigger contribution.)

This tendency to favor less extreme departures from current conditions has probably helped maintain the widespread complacency about climate change.  Yes, it is a problem, but no, I do not have to radically revise my plans for my life to help deal with it.  And yet, if you read the IPCC reports carefully, they are pretty clear in spelling out the extent of the reduction in CO2 emissions that has got to be achieved by mid-century if we want to keep climate warming to 2oC.  The absolute need to keep nuclear power as a part of the electricity supply for at least a few decades longer, in order to be able to phase out fossil fuels, and the near certain need to develop effective new technology for carbon capture and sequestration, not to enable continued use of fossil fuels, but to strip carbon out of the atmosphere — these needs are not gaining the attention of political leaders or the industrial sector the way they should be.  That Alberta is waiting patiently for the oil boom to start back up is perhaps forgivable, if misguided.  That Canada’s national government is enabling them in this fantasy, by further delaying stricter environmental controls, and continuing the discussions about Canada’s need for additional pipelines is just unfortunate (a recent post on this topic is here).

It is not surprising that in the months following the Paris meeting there would be a pause to celebrate a significant achievement.  My fear is that the pause, like an unwelcome dinner guest, is settling in for a long stay.  Meanwhile, the global situation worsens and our chance of a good outcome in the global battle gets more remote.  The bleaching of the northern Great Barrier Reef should be causing a lot of us to remember we are engaged in a battle, and to get on with it.  I do not think it is doing that, no more than the other bits of climate news that assault us daily.

CO2 concentration at Mauna Loa in the last week of March was 405.41ppm, 123ppm higher than it was that week in 1800.  February 2016 was the warmest February on record, as was January 2016, as were each of the previous 9 months.  February 2016 also surpassed the previous warmest February (2015) by the largest margin ever.  On 21st March, in releasing a report on the extreme weather in 2015, the World Meteorological Organization’s Secretary General is quoted as saying “The future is happening now.  The alarming rate of change we are now witnessing in our climate as a result of greenhouse gas emissions is unprecedented in modern records.”  The statement identified shattered temperature records, intense heatwaves, exceptional rainfall, devastating drought, unusual tropical cyclone activity, unabated ocean warming and sea level rise, shrinking sea ice extent, and other extreme weather events around the world, and noted that the extreme weather was continuing into 2016.  Climate change is here, and it is worsening faster than most climate scientists expected.  And yet, for most people, life goes on, and climate change issues have been moved to a back shelf for a while, because we all did such a good job in Paris.

We remain blissfully unaware of how much more than Paris we have to do.  We keep forgetting that there are other affronts to natural systems that also must be acted on.  And population is the elephant in the room, even if the science community, every now and then attempts to make the elephant visible.  In its 25th February issue, Nature included an essay by John Bongaarts, Vice-president of the Population Council, New York, titled ‘Slow down population growth’.  He pointed to the more than 50% expansion predicted between now and 2100, when the global population is estimated to become 11.2 billion, and stated that most of this growth will occur in the least developed parts of the planet.  Rapid population growth is a major impediment to economic and societal development, and can even pull developing countries back from the brink of success (when millions are lifted out of poverty and a viable economy can take hold).  Simultaneously, rapid population growth has severe environmental effects, and can make efforts to transition away from wasteful, polluting, CO2-emitting economic structures.  We would all be far better off if population growth could be curtailed, and it may not even be possible to bring climate change under control if we do not address our population problem more aggressively as well.

This bleaching of the northern GBR should be one more splash of cold water across our faces, to wake us to the reality the science community has been trying to warn about for far too long.  And since the media are not using it like a splash of cold water, we scientists have got to step up and tell it clearly, and repeatedly, in simple language – people, this is how it really is; we are dangerously close to going over a cliff.  I fear the alarms are being sounded too gently; future generations will look back and wonder how we could be so blind to our peril.

What coral bleaching should mean for Australia

Australia is a country much like Canada, blessed with a small, but talented population, and a land rich in natural resources, it has developed an economy in which the extraction and export of those mineral resources is  a major part.  Australia is particularly rich in coal, and China and India are tantalizingly close neighbors who need energy resources.  Unlike Canada, Australia also has the world’s largest coral reef region, and these reefs have had far less mistreatment by people simply because the reefs are so large and so many and the people are so few.  Australia has recognized since the late 1970s that the Great Barrier Reef can provide immense economic value through its tourism and fisheries, is a powerhouse of marine biodiversity, an iconic natural wonder, and a feature that provides enormous spiritual and cultural value to Australians and to visitors from overseas.  Since the 1980s, Australia has mostly done a very good job of protecting the Great Barrier Reef while using it sustainably — exceptional, really, when compared to the usual management of reefs globally.  But too much of Australia’s coal is in Queensland, and the logical pattern for extraction is to ship it to ports along the Queensland coast and thence out through the reef and on to Asia.

Australia uses massive amounts of energy to extract the coal and ship it.  Eventually, the coal gets burnt and while the CO2 emissions are not technically Australia’s problem, they add to the global emissions problem that Australia and all other countries are ostensibly trying to reduce.  Furthermore, the development and maintenance of commercial ports along the Queensland coast requires dredging and other activities that contribute directly to poor water quality on parts of the GBR.  While I was finishing this post, the Queensland government announced it was approving the proposed Carmichael coal mine, to be developed by the Indian mining company Adani – the same Queensland government that was recently criticizing the federal Australian government for foot-dragging on CO2 emissions abatement.  That mine is slated to produce 60 million tonnes of coal a year, and export it via ports and ship travel through the GBR.

Australia really cannot have it both ways.  If the commitment to sustain the Great Barrier Reef in perpetuity is genuine, the bleaching now taking place on its most remote northern third has to be interpreted as a clear and unambiguous message.  The climate has now reached the point where all coral reefs are at serious risk; the need to reduce CO2 emissions is real and urgent; supplying other countries with coal is an enabling gesture that is incompatible with sustaining the GBR.  Surely Australians are capable of building an economy that does not rely on digging up dangerous stuff and shipping it overseas to whoever wants to buy it?  But, come to think of it, I’ve asked exactly the same question of my own country.  True, Canada does not claim to be caring sustainably for a coral reef, and we have yet to recognize that our Arctic lowlands may turn out to be nearly as sensitive to climate change as is the GBR.  Australia’s coal and Canada’s tar sands oil have to stay in the ground.

What this all means for our relationship to the biosphere.

When we were few, and with limited technology, we still did some damage to this world, because we are intelligent, and saw how we could use fire to shape ecosystems to our benefit, and how we could create tools to allow us to hunt large animals on land and in the ocean.  But because we were few, and relatively weak, our impacts were local and often trivial, and if we did cause damage, we could always move away.  Now there are 7 billion of us, we are immensely powerful, and there is no longer any away to move to.

Unfortunately, we have, if anything, lost some of our awareness of our essential dependence on the biosphere, and we rarely consider the long-term, cumulative effects of our impacts, especially when there is money to be made.  As well as revitalizing our so far puny efforts to combat climate change, we must rebuild our links to nature, and cultivate once more a sense of responsibility for caring for nature.

What is happening right now on the northern GBR is just one more in a long list of object lessons.  But so far, they are object lessons that for the most part are being ignored.  Greed, thoughtlessness, short-term thinking, and a widespread lack of appreciation of the extent to which our lives are interwoven with the rest of the biosphere are trumping reason.  I fear the size of the jolt that is going to be required to wake us up to the perilousness of our condition.  Meanwhile, more coral bleaches.

Hamilton Island reef-aerial

The Great Barrier Reef – we need to save it to save ourselves.  Image © Hamilton Island Enterprises

Categories: Climate change, Coal, coral reef science, In the News, Politics | 7 Comments

Ice, Coral, el Niño, and Worsening Climate Change


The very strong el Niño which has been driving global weather over the past year is now showing signs of weakening (I’ve been following it since 2014).  The monthly diagnostic discussion released by NOAA’s Climate Prediction Center on 10th March reported that surface temperatures in the tropical Pacific have moderated slightly and deeper water temperatures have fallen significantly – signs that it is coming to an end, although it remains strong at present.  Models generally predict a flip into la Niña conditions by late summer or fall; however, just as the start of this el Niño was delayed by nearly a year, its termination may also surprise us.  It has proved to be very close to as strong as the 1997-98, one if not stronger.

The local winter has been strongly affected with generally mild temperatures except when the polar vortex managed to break out and plunge south.  Thus we had a couple of periods in February when it was bitterly cold, reminiscent of last year, but mild and sunny days in between.  My lake did not finally freeze over until late on 9th January, and is already threatening to thaw.  (Meaning that it has opened up for a few days in the center, but is now frozen over again – won’t be long now.)  So far we have had negligible run-off, a consequence of the milder winter with much melting of snow during the warmer times and little snow pack build-up.  In fact, we are just completing a winter that will likely become a lot more common as we move on into this century and CO2 levels in the atmosphere rise further.  The local Muskoka Watershed Council has just released a report describing the most likely climate here at mid-century and discussing its likely impacts, and actions we need to take.  And this winter is a harbinger.

While the focus of most people discussing recent weather has been squarely on the el Niño, all that the el Niño has done is to temporarily amplify the warming of our climate, which continues inexorably as we continue our releases of greenhouse gases.  Climate warming may even be responsible for the considerable strength and persistence of this el Niño, but, regardless, once we subside into la Niña next year, the overall long-term warming will have progressed and the world will be that much closer to any tipping points that are out there.  In one sense, el Niño now gives us a glimpse ahead to the climate that is coming.  It’s not a pretty sight.

While I tend to notice the effects of el Niño on my local weather, el Niño has had far larger, more severe impacts in parts of the world a little closer to the tropical Pacific.  Winter has been substantially milder than usual in western North America, and there has been some significant rain in California.  Coral reefs around the world have been impacted by warm water and have been bleaching one by one.  And Arctic sea ice has been slow to form this winter.

This el Niño is killing lots of coral

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Severe coral bleaching near Heron Island, southern Great Barrier Reef this February.
Photo © XL Catlin Seaview Survey.

As I write, scientists coordinated by the James Cook University-based Coral COE (for coral reef research center of excellence) have been running a massive aerial survey of bleaching reefs in the northern third of the Great Barrier Reef.  While data collected in the aerial surveys will provide a rapid, region-wide assessment of the extent of bleaching, field teams are being directed to specific locations based on the aerial surveys to collect more detailed analyses of extent of the bleaching, and extent of coral mortality.  Australia is one of very few tropical countries with the capacity to mount such a large monitoring effort, and the results, when compared to data from previous bleaching events should help answer some critical questions about the capacity of corals to adapt to warming seas.

On 19th March, Dr. Terry Hughes of James Cook University, the scientist leading the current monitoring effort, posted this message on coral-list, an e-mail list serving the global coral reef research and management community:

“Unfortunately, the northern section of the Great Barrier Reef is now severely bleached.  In preparation for the risk of coral bleaching, we convened the National Coral Bleaching Network last November to plan a coordinated response across Australia’s research and reef management community. The ARC Centre has allocated approximately $1million to respond to the 2016 bleaching on the GBR and elsewhere on tropical and sub-tropical reefs around Australia.  We’re focusing on the GBR, the Coral Sea, coastal and offshore reefs in WA, and sub-tropical reefs on both the east and west coast.

“In the next few days, I’ll conduct ten aerial transects (3-6 hour flights) throughout the 1000km region between Cairns and PNG that is most severely impacted by bleaching.  Thereafter, we plan to expand these surveys to cover elsewhere in the GBR Marine Park south of Cairns.  To eliminate observer-bias, the aerial surveys in Queensland will be conducted by myself and James Kerry.

“We have relocated JCU’s research vessel, the Kirby, from Townsville to Cairns, and it will operate from today in the northern GBR and Torres Strait for the next month.  It will be joined shortly by two other vessels from the ARC Centre and the Australian Institute for Marine Science (AIMS).  The GBR research stations, on Lizard and Orpheus Island in particular, are also fully engaged in the bleaching event.  We are working very closely with the GBR Marine Park Authority and other management agencies in QLD, NSW and WA.

“Thankfully, the southern GBR looks to be in the clear.”

This is a major monitoring effort, being mounted through the efforts of the research community in Australia, rather than by the management agency of the federal Australian government, although, in fairness, the government has put some new money into the project.

One of the critical as yet unanswered questions about coral bleaching is whether repeated events (as reefs can expect as the seas continue to warm) will cause corals to adapt, becoming more tolerant of high temperatures.  Some scientists believe that ‘of course’ this will happen, but others are concerned that the pace at which the oceans are warming is very fast compared to the generation time of corals, and that this will make significant adaptation very difficult to achieve.

(Adaptation is an evolutionary change, and it requires opportunities for individual organisms to be stressed and for the more tolerant ones to then be more successful at reproducing so that their genes become the dominant ones in the population.  If the stress – the bleaching – is happening too frequently, animals may simply get killed from repeated bleaching long before they reproduce.  One complication that keeps scientists arguing about this possibility is that the coral animals are in a symbiosis with single-celled dinoflagellates of the genus Symbiodinium as their partners.  The dinoflagellates have much shorter generation times and perhaps they could adapt to the warmer water.  After all, bleaching is really the collapse of this symbiosis, and just as it takes two to tango, it takes two to end a partnership.)

late March 2016 northern GBR NOAA cur_b05kmnn_max_r07d_baa_gbr_930x580

The bleaching risk for north-eastern Australia as projected by NOAA Coral Reef Watch on 28 March 2016.  Not surprising that extensive bleaching is now being documented on the northern Great Barrier Reef.  Figure courtesy NOAA Coral Reef Watch.

One goal of the present monitoring effort will be to look critically for evidence that corals are proving more resistant to bleaching this time than those same corals were when they last experienced significantly warmed water in 1998 and in 2002.  Maybe there will be some good news to report on this front, to stack up against the bad news of yet more coral mortality.  Incidentally, Terry Hughes’ final comment refers to the fact that the waters were warming up and down the 2500 km length of the Great Barrier Reef, and severe bleaching was expected along its length.  However, the last few weeks have been predominantly cloudy further south on the reef, keeping surface waters moderated, and now, with the end of summer approaching, a general cooling down is anticipated.  Great news, but it tells us something important when we realize we have to hope for overcast weather to prevent wholesale damage to coral reefs.

The bleaching now going on in Australia is just the latest in a series of bleaching events around the world that has been occurring since the el Niño started in earnest early in 2015.  On 8th October 2015, NOAA’s Coral Reef Watch program declared the third global coral bleaching event on record had commenced during the summer of 2014 and was likely to continue into early 2017.  The first reports of significant bleaching came from Hawaii, both around the main islands and at reefs in the remote Papahanaumokuakea Marine National Monument in the north-western Hawaiian chain, in August 2014.  Significant bleaching was also reported that year in the Marianas, Guam, the Marshalls, Kiribati, and Florida.  Then bleaching conditions moved to the southern hemisphere, and reports of bleaching came in from the Solomon Islands, Vanuatu, Tuvalu, Fiji and the Samoas.  By early 2015, there were reports of bleaching from the British Indian Ocean Territory, south of the Maldives, and there was further extensive bleaching in Hawaii during summer of 2015, the first reported occurrence of two successive years of bleaching in Hawaii.  Since then, as the el Niño continued and the seasonal cycle moved locations for warm water around the globe, there have been reports of bleaching from many Pacific locations, from the Indian Ocean, and from the Caribbean.  Fiji had back-to-back bleachings in early 2015 and early 2016.  Now, as I write, scientists are surveying the damage across hundreds of kilometers of the northern Great Barrier Reef.  And NOAA has announced that this will be the longest continuous global coral bleaching event ever.

Lest it be forgotten, it has even been necessary for Australian scientists to point out that the el Niño is only exacerbating and hastening the damage that will inevitably occur to coral reefs as global temperature continues its climb.  While I am trying to leave politics out of this post, the need to point out that bleaching is a response to rising ocean temperatures, not a response to a routine weather oscillation that has been going on, presumably, for hundreds or thousands of years, arises simply because the Australian government currently is seriously schizophrenic  when it comes to protecting the Great Barrier Reef.  Yes, the reef must be protected, but yes, the Australian coal mining and exporting industry (which creates dirty CO2-emitting fuel, while its export degrades reef waters) must be encouraged and supported.  One might think that politicians who get to form national governments in mature nation states would be able to follow short chains of logic.  Judging by what I see on Twitter or in the media, the current Liberal-Country Party leadership of Australia lacks that capacity.

Meanwhile back in the Arctic

The el Niño has also been impacting sea ice formation in the Arctic, and this year’s ice accumulation is running well below average for the last several years.  The latest data from the National Snow and Ice Data Center (NSIDC) at University of Colorado, Boulder, shows a total area of 14.9 million km2 of ice present on 25th March, compared to ~15.3 million km2 in a typical year.  One very likely consequence is that we are likely to see a record low level of ice remaining when September comes around.

Arctic ice NSIDC 25 March 2016

Arctic sea ice extent as of 25th March 2016 (blue line) is running 2SD lower than the average extent over 1981 to 2010.  This may well mean another very low coverage following next summer’s melt.  We’ll check back in September.  Image courtesy of the National Snow and Ice Data Center, University of Colorado, Boulder.

What does this generally low level of sea ice mean?  Well, it has no impact on sea level rise, because this is floating sea ice, not continental ice.  And, yes, it does bode well for those cruise ship operators itching to have their ships wallowing through the Arctic filled with tourists eating in the restaurants, exercising their arms at the slot machines, wallowing in the pool (I’ve found it quite rare to see a non-wallower in a cruise ship pool), and just occasionally peering out to sea to see the Arctic in all its splendor.  Who knows … maybe Royal Dutch Shell will reverse its most recent decision and once more announce plans to prospect for oil in Arctic waters; if they do not, some other resource companies will, and if not oil, it will be some other resource that they believe they can extract from deep cold Arctic waters with ‘minimal environmental impact’.

Who-owns-the-Arctic cartoon

Melting of Arctic sea ice is encouraging a ramp-up of national territorial claims, flag plantings, and minerals exploration.  Will we act wisely and first learn sufficiently about this ecosystem to manage our exploitation of it?  That would be a first!  Image © Wednesday-Night

But what does the lack of ice mean for the environment?  Perhaps the greatest change is the greater albedo of open water compared to ice, and therefore, the greater rate of warming of Arctic waters because less sea ice is around.  Here we have a positive feedback loop, because while it may have been an el Niño that has made this a low-ice year, the fact that the ice is less prevalent means rate of warming now increases, and if warming increases enough, we will not need any more el Niños to give an extra push.  The Arctic will become ice-free in a few more years.  And, if I understand the Polar vortex sufficiently, a warmer Arctic Ocean means more instability in the weather, and climates in mid-northern latitudes that become ever more variable.  (That’s a polite way of saying that eastern North America can expect to see lots of winters as unpredictably crazy as this one has been – especially south of here in Virginia and North Carolina and Alabama and Mississippi – or more so.)

Ice is Amazing

I’ve recently been pondering the incredible unlikeliness of life.  On a cosmic level, we know of nowhere in this universe that is within reach of our relatively puny transport, and that we could go to and survive outside a controlled environment system such as a space suit, an orbiter, or a sealed, pressurized surface module.  Forget images of the astronaut, standing, legs apart, six feet tall, dressed head to toe in his gloriously white, sleek, Calvin Klein-created space suit, helmet under one arm, and his blond hair blowing in the wind on a strange planet with two moons.  Even apart from the sexism, it ain’t likely to happen, because planets like that do not exist in our corner of the universe.

Never mind life like us, we have not yet been able to find conclusive evidence of any type of life anywhere in the universe beyond our small planet.  Life surely exists elsewhere, even intelligent life, because our universe is impossibly big.  But life is incredibly unlikely, improbable.  Some people see God in that improbability; I just see the utterly unexpected wondrousness of the natural world.  The very rarity of life elsewhere is a sign of how wonderful our home planet really is; teeming with life, in every habitat no matter how severe, even deep within the rocks of the Earth, or clustered at those scaldingly hot, chemically noxious, hydrothermal vents deep in the ocean.  You’d think we might value it more.

hydrothermal vent tube worms WGBH Educational image-01-large

Tube worms and a fish at a hydrothermal vent prove that life can occur anywhere on our planet.  Photo © WGBH educational Foundation.

And water has a lot to do with life.  This simple molecule is essential for life on this planet, and is a major component of every living thing.  Among the many important, and unusual, properties of water are the fact that its solid form, ice, is less dense than the liquid, and the fact that the process of melting or freezing involves such a high latent heat.  In fact, compared to other common substances, water has the highest specific heat, at one calorie per gram, the highest latent heat of fusion, 80 calories per gram, and the highest latent heat of evaporation, 540 calories per gram.  These unusual properties mean that the oceans can contain an immense quantity of heat, that the melting of ice or the evaporation of water requires a further immense quantity of heat, and that any ice which forms will float on the surface of a body of water.  If just the latter feature were to be replaced with the more usual situation (the solid form is more dense than the liquid), freezing on lakes or the ocean would take a lot longer because the entire mass of water would have to be lowered to the freezing point before any freezing occurred, but then the entire mass would freeze, condemning aquatic creatures to an interestingly restricted existence.  Spring and summer thawing might never extend deeper than the upper few dozen meters of water, and aquatic life would have to evolve to live in ponds of liquid water on the surface of a permanently frozen block of ice, if it evolved at all.

But, I digress.  That is not how the world is.  Ice is lighter than water, sea ice floats at the surface, and ice is whiter and more reflective than open water.  It is these unusual physical properties of water which underlie the paper by James Hansen of Columbia University Earth Institute, and colleagues there, at the Goddard Institute for Space Studies, and at a number of other environmental and climate research centers, now published in Atmospheric Chemistry and Physics, volume 16, on 22nd March.  I had earlier discussed this paper when it was posted on-line for public peer-review, an unusual procedure and perhaps a sign of the times in scientific research.  It was first on-line last July, and there have been numerous comments, queries and corrections to it during the intervening months.  Still, the final version is scarcely changed in overall thrust, and undoubtedly a stronger product as a result of the scrutiny.  Perhaps the biggest changes between the initial and final manuscripts have been a change of title, and a reorganization of the sequence of topics considered.

Originally titled “Ice Melt, Sea Level Rise and Superstorms: Evidence from Paleoclimate Data, Climate Modeling, and Modern Observations that 2°C Global Warming is Highly Dangerous”, the paper has become “Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2oC global warming could be dangerous.”  “is highly” is a value-judgement, and “could be” is the more circumspect way in which scientists usually signal their value judgements.  The reorganization of subject matter makes the sequence of arguments easier to follow and appreciate.  There are numerous additional citations to document claims, but no substantive retraction of what was originally reported, and the abstract is substantially longer and more detailed (a tacit recognition of the fact that too many of us read only the abstract of most papers we scan).  Hansen’s message can be summed up as follows (all extracted from the abstract):

“The modeling, paleoclimate evidence, and ongoing observations together imply that 2oC global warming above the preindustrial level could be dangerous.  Continued high fossil fuel emissions this century are predicted to yield (1) cooling of the Southern Ocean, especially in the Western Hemisphere; (2) slowing of the Southern Ocean overturning circulation, warming of the ice shelves, and growing ice sheet mass loss; (3) slowdown and eventual shutdown of the Atlantic overturning circulation with cooling of the North Atlantic region; (4) increasingly powerful storms; and (5) nonlinearly growing sea level rise, reaching several meters over a timescale of 50–150 years.  These predictions, especially the cooling in the Southern Ocean and North Atlantic with markedly reduced warming or even cooling in Europe, differ fundamentally from existing climate change assessments.  We discuss observations and modeling studies needed to refute or clarify these assertions.”

I find this article no less alarming than I did when it referred to a 2oC warming as ‘highly’ dangerous.  Effectively, Hansen and colleagues are arguing that evidence to date is consistent with the hypothesis that we have already passed, or are very close to, a tipping point at which melting of glaciers becomes essentially unstoppable, and that, over a period that will likely go into the 22nd century, sea levels will rise substantially and the temperature differential between the tropics and poles will become greater, leading in turn to much more violent weather than we now experience.  Do we really want to test this hypothesis by continuing to emit greenhouse gases?


And so, there is a major coral bleaching event under way that is currently damaging the reefs of the northern Great Barrier Reef.  It is the third global-scale bleaching event in history, occurring 6 years after the second, which occurred 11 years after the first.  This time, some reefs are experiencing serious bleaching two years in succession.  There will be more, and each one seems to take out substantial areas of reef permanently (NOAA’s current estimate for this one, once completed, is about 15 thousand km2 of reef globally, about 6% of the world’s total, to be killed).  The cause of this worsening situation is our emissions of greenhouse gases.

nemo & bleached coral Justin Marshall CenkJlgWIAAEWZa

Coral bleaching is not just bad for corals.  These fish were seen recently in their bleached anemone host near Lizard Island, Great Barrier Reef.  Photo © Justin Marshall

These same emissions are largely responsible for the record low level of sea ice in the Arctic, and Jim Hansen’s paper provides convincing evidence for the suggestion that our emissions have already, or perhaps almost, brought the glaciers of the world to a tipping point beyond which melting will continue until sea level is several meters higher than today some 50 to 150 years from now.  Does the global community really want to go to that future?

With these messages from the Arctic and the tropics, the Paris agreement reached less than four months ago seems very inadequate indeed, and the near cessation of efforts by governments to move beyond Paris, or even to bring their emissions into compliance with their commitments made there, must be seen as truly alarming.  Every country that produces significant greenhouse gases – certainly including the top ten in 2015: in rank order China, USA, India, Russia, Japan, Germany, Korea, Canada, Iran, Brazil, and Indonesia – should be making substantial efforts to cut them much faster than committed to at Paris.  In Canada, the Trudeau government’s first budget, released on 22nd March, had several components that will aid the shift towards reduced carbon pollution – tax measures to encourage investment in clean technology, significant funding to ensure a more effective National Energy Board, and Canadian Environmental Assessment Agency, and a $2 billion Low Carbon Economy Fund.  However, the budget missed the opportunity to more aggressively phase out coal or oil, and failed to signal a determination to go beyond the climate commitments made at COP21 (commitments shaped by the previous government and widely condemned as inadequate).  As for Australia, just a few positions down below the top ten emitters, difficult as it may seem to some politicians, that coal has got to stay in the ground.

Categories: Arctic, Climate change, coral reef science, In the News | Comments Off on Ice, Coral, el Niño, and Worsening Climate Change