2015 in review: Critical Angle and Skeptical Science

2015 in review: Critical Angle and Skeptical Science

The  most-read piece of the year on Critical Angle was The history of emissions and the Great Acceleration where I looked at data from the Carbon Dioxide Information Analysis Center and in which I discovered some surprising (at least to me) factoids about emissions. For example:

  • Cumulative emissions from land-use changes since 1750 were bigger than cumulative emissions from all fossil fuels combined up to 1978.
  • Using an ultra-simple 40% atmospheric fraction carbon-cycle model yields a good match between observations of atmospheric CO2 concentrations and emissions statistics.
  • The Great Acceleration in almost everything, which happened in the years after 1950, brought forward the climate crisis by 20 years. That’s a shorter time than the world has wasted since the Rio Earth Summit in 1992.

I must like trilogies, since I wrote two of them this year. In January I did a series on fracking, focussing mainly on the UK:

  1. Spot the charlatan
  2. There’s no endorsement of fracking from Skeptical Science or climate experts
  3. Quantity has a quality all of its own.

Later in the year I wrote about the road to the two degrees target:

  1. Feasible emissions pathways, burying our carbon and bioenergy
  2. Are the experts being candid about our chances?
  3. Equity, inertia and fairly sharing our carbon budget.

I was pleased to be asked by the Corporate Knights Magazine to provide some pieces for their website and for the quarterly hardcopy magazine that is distributed with the Globe and Mail and the Washington Post: Why the 97% consensus on climate change still gets challenged (Summer 2015 Issue); Are we overestimating our global carbon budget? (website only) and; B.C. lowballing fugitive methane emissions from natural gas industry (Fall 2015 Issue). There’s another article (on CCS) scheduled for the Winter 2015 issue of the magazine, due out in January 2016.

All of this pales beside the combined output of my colleagues at Skeptical Science who have contributed hugely with numerous academic articles, conference presentations, pieces in the mainstream and social media, as well as a University of Queensland supported Massive Open Online Course.

Skeptical Science is run without significant funding, except for a tip jar to pay for Internet hosting. Everyone who contributes there does so as a volunteer, mostly in spare time from day jobs.There are a lot of valuable supporters whose names don’t appear on articles, but who keep the website running and the comments moderated.

I should add that much of what I write benefits from reviews and comments made by my Skeptical Science colleagues.

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My interview on KKRN community radio

Last week, presenter Doug Bennett  asked me to do an interview on KKRN Community Radio based in Round Mountain, California. It was supposed to be a phone-in show as well, but in the event they only put one caller through. The main subject of the conversation was the 2°C target and what we have to do to get there, especially with regard to carbon capture and storage, and bioenergy carbon capture and storage. We also ranged a little off-topic onto population growth.

You can listen to it here or on the KKRN site linked above.


Apparently, I say “um” a lot. I’m going to have to work on that.

NASA November temperature update: the heat is still on

There has been little doubt for several months, but now it is certain: 2015 will be the hottest year on record by far.


Data from NASA, with my guesswork from July 2015 shown in dashed and dotted lines.

November would have set another monthly record, except that October was revised upwards by two-hundredths of a degree. As it is, this is the hottest November on record. For 2015 not to be a record year, December would have to come in with a below-zero anomaly and that is not happening.

Note to readers: my guesswork is not an expert forecast, but a what-if exercise I did a few months ago in an attempt to predict average anomalies for 2015 and 2016. I will not be updating my guesses as reality proves them wrong. But I would welcome improved forecasts from readers who understand the El Niño and surface temperature dynamics better than I do.

The annual anomaly chart below shows the projection (which assumes that December is as warm as November) by the red x, 0.862 °C above the  1951-1980 baseline. My guess from July 2015 for 2015 is shown as the red square and for 2016 by the orange dot.


It is now certain that we have set two record years in a row, something that last happened in 1980-1981. It is even possible, given a persistent El Niño, that 2016 will be hotter than 2015, which would give three record years in a row, something that has not happened since at least 1880. Continue reading

The Road to Two Degrees, Part Three: Equity, inertia and fairly sharing the remaining carbon budget

The Road to Two Degrees, Part Three: Equity, inertia and fairly sharing the remaining carbon budget

Previously published at Skeptical Science on December 9th, 2015

In the first part of this series, I examined the implications of relying on CCS and BECCS to get us to the two degree target. In the second part, I took a detailed look at Kevin Anderson’s arguments that IPCC mitigation scenarios aimed at two degrees are biased towards unproven negative-emissions technologies and that they consequently downplay the revolutionary changes to our energy systems and economy that we must make very soon. In this last part, I’m going to look at the challenges that the world faces in fairly allocating future emissions from our remaining carbon budget and raising the money needed for climate adaptation funds, taking account of the very unequal past and present.

Until now, economic growth has been driven and sustained largely by fossil fuels. Europe and North America started early with industrialization and, from 1800 up to around 1945, this growth was driven mainly by coal. After the Second World War there was a period of rapid (~4% per year) economic growth in Europe, N America and Japan, lasting about thirty years, that the French refer to as Les Trente Glorieuses, The Glorious Thirty. This expansion was accompanied by a huge rise in the consumption of oil, coal and natural gas. After this there was a thirty-year period of slower growth (~2%) in the developed economies, with consumption fluctuations caused by oil-price shocks and the collapse of the Soviet Union. During this time, oil and coal consumption continued to grow, but not as steadily as before. Then, at the end of the twentieth century, economic growth took off in China, with a huge increase in the consumption of coal.

Source of the emissions data is from the CDIAC. See the SkS post The History of Emissions and the Great Acceleration for further details.

If we are to achieve a stable climate, we will need to reverse this growth in emissions over a much shorter time period, while maintaining the economies of the developed world and, crucially, allowing the possibility of economic growth for the majority of humanity that has not yet experienced the benefits of a developed-country middle-class lifestyle.

Here are the the annual emissions sorted by country and region:

From Chancel and Piketty (2015) Continue reading

The three R’s of Paris: Rejoice, Ratify, Ratchet

It’s all too easy to carp about the Paris COP agreement. There’s no global carbon tax. It is all pledges and good intentions. The sum total of those promises falls far short of the 2 C goal and far, far short of the 1.5 C aspirational target. The agreement contains some provisions for measuring progress in transparent ways, but it is not legally binding. There is no provision for sanctioning governments that fail to deliver. As my MP, Elizabeth May, has said of environmental treaties in general: “Trade treaties have teeth, environmental treaties only gums”.

Still, there is much to celebrate.


This is what a turning point looks like. This is what a first step in the right direction looks like. We have waited for a long time for this, too long of course, but now that it has happened we should cheer this agreement. It brings together all of the governments of the world, in a diplomatic agreement focussed on the monumental problem of climate change. The French convenors deserve our thanks and praise for their stamina and patience in herding all of these cats to a common goal.

Now it’s up to the national governments to implement their promises. Continue reading

The Road to Two Degrees, Part Two: Are the experts being candid about our chances?

The Road to Two Degrees, Part Two: Are the experts being candid about our chances?

Originally published at Skeptical Science on November 26th, 2015

The first part of this three-part series looked at the staggering magnitude and the daunting deployment timescale available for the fossil fuel and bioenergy carbon capture and storage technologies that many 2°C mitigation scenarios assume. In this second part, I outline Kevin Anderson’s argument that climate experts are failing to acknowledge the near-impossibility of avoiding dangerous climate change under current assumptions of the political and economic status quo, combined with unrealistic expectations of untested negative-emissions technologies.

In plain language, the complete set of 400 IPCC scenarios for a 50% or better chance of meeting the 2 °C target work on the basis of either an ability to change the past, or the successful and large-scale uptake of negative-emission technologies. A significant proportion of the scenarios are dependent on both. (Kevin Anderson)

Kevin Anderson has just written a provocative article titled: Duality in climate science, published in Nature Geoscience (open access text available here). He contrasts the up-beat pronouncements in the run-up to the Paris climate conference in December 2015 (e.g. “warming to less than 2°C” is “economically feasible” and “cost effective”; “global economic growth would not be strongly affected”) with what he see as the reality that meeting the2°C target cannot be reconciled with continued economic growth in rich societies at the same time as the rapid development of poor societies.  He concludes that: “the carbon budgets associated with a 2 °C threshold demand profound and immediate changes to the consumption and production of energy”.

His argument runs as follows: Integrated Assessment Models, which attempt to bring together, physics, economics and policy, rely on highly optimistic assumptions specifically:

o   Unrealistic early peaks in global emissions;
o   Massive deployment of negative-emissions technologies.

He notes that of the 400 scenarios that have a 50% or better chance of meeting the 2 °C target, 344 of them assume the large-scale uptake of negative emissions technologies and, in the 56 scenarios that do not, global emissions peak around 2010, which, as he notes, is contrary to the historical data.

I covered the problems of the scalability and timing of carbon capture and storage and negative emissions technologies in a previous article.

From Robbie Andrew, adjusted for non-CO2 and land-use emissions.Note that thesemitigation curves assume no net-negative emissions technologies deployed in the latter part of the century.

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The Road to Two Degrees, Part One: Feasible Emissions Pathways, Burying our Carbon, and Bioenergy

The Road to Two Degrees, Part One: Feasible Emissions Pathways, Burying our Carbon, and Bioenergy

Originally posted at Skeptical Science on November 16th, 2015

This post looks at the feasibility of the massive and rapid deployment of Carbon Capture and Storage and negative-emissions Bioenergy Carbon Capture and Storage technologies in the majority of IPCC scenarios that avoid dangerous global warming. Some observers question whether the deployment of these technologies at these scales and within the required time frames is achievable. This is Part One of a three-part series on the challenge of keeping global warming under 2 °C.

The various emissions models that have been used to produce the greenhouse gas concentration pathway to 2°Celsius vary considerably, but the majority of them require huge deployment of Carbon Capture and Storage (CCS) as well as net-negative global emissions in the latter part of the twenty-first century. The only negative emissions methods generally considered in these scenarios are bioenergy capture and storage (BECCS) and land-use changes, such as afforestation. For there to be net-negative emissions, positive emissions have to be smaller than the negative emissions.

Kevin Anderson (2015) (open-access text) reports that of the 400 scenarios that have a 50% chance or greater of no more than 2 °C of warming, 344 assume large-scale negative emissions technologies. The remaining 56 scenarios have emissions peaking in 2010, which, as we know, did not happen.

Sabine Fuss et al. (2014) (pdf) demonstrate that of the 116 scenarios that lead to concentrations of 430-480 ppm of CO2 equivalent, 101 of them require net negative emissions. Most scenarios that have net-negative emissions have BECCS providing 10-30% of the world’s primary energy in 2100.

From Fuss et al. (2014), showing the historical emissions (black), the four RCPs (heavy coloured lines) and 1089 scenarios assigned to one of the RCPs (light coloured lines). Continue reading