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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.

Arctic sea ice 2015 Stefan Hendricks 160421085209_1_900x600

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.

emissions intensity trend 1990-2015 Guardian 1105

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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2 thoughts on “Have We Already Tipped? My growing concern about the challenges we face.”

    1. I don’t usually reply to unsigned comments. I’m not even sure whether the link you provided is to your own commentary, or to that of someone else. Nevertheless, I did not say that over population was the main problem. I said that overpopulation and a growing economy were problems that needed to be addressed if we are to be able to solve our environmental problems.

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