The chance of staying below two degrees: INDCs and the Seven Ifs

There is an easy-to-follow video published by Climate Interactive titled How Could Paris Climate Talks Ratchet Up To Success? It runs quickly through a series a of what-if scenarios to calculate what the effects of various emissions promises could have on global temperatures to 2100. It starts with the Intended Nationally Determined Contributions (INDCs) pledged for the Paris COP, which in many cases only have targets up to 2030, and  extends them using various assumption out to 2100.

The numbers are based on the C-ROADS model, described here.

The presenter, Andrew Jones, shows how we can go from business-as-usual emissions to get to a fifty-fifty chance of staying below two degrees Celsius.  There are a lot of “ifs” along the way, I counted seven. You could easily count more. I assume that the expected warming for various scenarios is the median value, 50/50, derived from climate models. Continue reading

NASA October temperature update: a new monthly record

Wow. Just in time for Paris.

My guesswork now looks a little lame as the Nasa October land-ocean temperature anomaly shoots upwards to a new record of 1.04 degrees Celsius.


Monthly anomalies for selected hot years since 1998. My guesswork forecasts are shown in dashed and dotted lines. Data from NASA.

A clear all-time temperature record for 2015 is now assured, because November and December anomalies would now have to be less than 0.34 degrees, a level not seen for those months since 2000, for 2014 to retain the warmest year record.

My original anomaly forecast for the year was 0.82 degrees C , which is unchanged below, but is clearly now conservative and is shown  by the red square. The red cross (0.86 degrees C) is a projection based on November and December averaging the same anomaly as October.2015-11-16_17-41-51

As Michael Caine put it: Continue reading

Not all Christians are like Roy Spencer, thank God

Dr Roy Spencer of the University of Alabama is one of the few scientists who minimize the importance of the human contribution to recent climate change. He is also an ardent Christian and a member of the advisory board of the  Cornwall Alliance, a group that thinks that God’s fingers control the global thermostat. He’s an evolution “doubter”, “contrarian” or “skeptic”, as well.

Previously, he  has likened those of us who are concerned about climate change to Nazis.

Today, in the wake of the dreadful terrorist attacks in Paris, he posted this on Facebook.

As a response from a Christian to the human suffering in Paris, I would have expected something better than sarcasm and ideological point-scoring. You know, something like compassion for the victims, even forgiveness for the perpetrators. Instead Spencer serves up snarky comments about SUVs and gun control. He should be ashamed of himself.

However, we must be careful not to judge all Christians by the behaviour of one deranged extremist.

So long, Keystone XL

After an approval process that lasted longer than World War Two, President Obama finally said “No” to the Keystone XL pipeline.

This is undoubtedly a major victory for climate activists who had a lot staked on the outcome. Obviously, this is a defeat for the oil sands industry, but it is also something of a blow to the Serious People who are in favour of action on climate, but who consider protesting against the construction of infrastructure to be naïve at best and, at worst, a counterproductive distraction from the real action of international negotiations and policy wonkery.

If you haven’t done so already, read David Roberts who writes most of what I’m going to, but does it better.

What the Serious People say

  • One pipeline is not going to make much difference to global emissions.
  • Oil sands’ emissions have been overstated.
  • Coal.
  • What matters is reducing demand, not restricting supply.
  • There are transportation alternatives to pipelines, like railways, and they are more environmentally risky.
  • It’s a distraction.

This is all true, more or less. But it is also beside the point. Continue reading

Consensus on plate tectonics and climate science



From Cook et al. 2013

One of the surprises I had when I was involved in the Cook et al (2013) paper was how many abstracts there were that hardly mentioned anthropogenic global warming, despite having been selected using the key words global climate change and global warming, about two-thirds of all of the abstracts. When we got to the stage of tabulating and plotting the ratings over the 1991-2011 period, what was even more surprising, to me, was that the proportion of abstracts that took No Position (NP) actually rose from about 50% in the early 1990s to about 65% in 2002, after which that proportion stayed more or less the same for nine years. It wasn’t immediately obvious to me how this squared with the increasing knowledge and generally reduced uncertainties expressed in successive IPCC reports.


From Cook et al. 2013

The other investigation we did was to ask the authors of the articles to rate their papers on the same scale. Here the overall percentage of NP was lower, about 35%. Not all authors responded to our email queries, so the sample size is smaller than for the abstracts. Also, it was harder to track down email addresses for researchers in the early 1990s, so the sample is particularly small then. Nevertheless, the rising proportion of NP papers is if anything a little more marked here, rising from around 20% in the 1994-1999 period to around 35-40% in the 2001-2011 period.

The difference between abstract and paper NP proportions is not surprising: the abstracts are reserved for key results and space there tends not to be wasted telling everyone what the prevailing paradigm is. Also, as confidence in the paradigm grows over time, a larger proportion of  papers might consider the attribution of global warming to be an established fact and not something that needs to be endorsed even in the body of the paper itself. We might well expect to see the same thing in other subjects: for example, life scientists no longer need to affirm evolution through natural selection, it has become settled science; geologists take plate tectonics for granted today, although they would not have in the 1960s when there was a scientific revolution underway. Rising NP proportions in climate science papers might well signify rising confidence among researchers that human emissions are a main cause of global warming—something that just does not have to be reaffirmed every time the subject of changing modern climates is discussed. Continue reading

The thermometer needle and the damage done


A recent paper published in Nature by Marshall Burke, Solomon M. Hsiang and Edward Miguel Global non-linear effect of temperature on economic production argues that increasing temperatures will cause much greater damage to the world economy than has been previously predicted. Furthermore, these losses will be distributed very unequally, with tropical countries getting hit very hard and some northern countries actually benefitting.

Let me attempt a highly simplified summary to explain what they did. I’m not an economist and their analysis is not straightforward, so beware. If I confuse you, try Dana Nuccitelli’s take or Seth Borenstein’s or Bloomberg’s.

Firstly, Burke et al. looked at factors like labour supply, labour performance and crop yields and how they relate to daily temperature exposure. Generally these show little variation up to temperatures in the high twenties Celsius, at which point they fall off quickly. Secondly, those trends were aggregated to predict the relationship between annual average temperatures and the annual impact on economic output. Thirdly, they looked at annual economic output and average annual temperatures for individual countries for the period 1960-2010. Note that they only compared the economic effects of temperature change on individual countries, they did not correlate one country with another. They were able to see how the observations compared with their predicted aggregate curve.


From Burke et al. (2015).

This work showed that the GDP of countries with an annual average temperature of 13°C were the least sensitive to temperature changes. Colder countries on the left side of the hump would benefit from an increase in temperature, whereas warmer countries would see their output suffer as temperature increases. Note that the figure does not show that a certain temperature predetermines the level of wealth of a country (China, despite recent rapid growth is poorer than the US and Japan even though average annual temperatures are similar). Rather, it illustrates how susceptible countries are to increases or decreases in productivity relative to their annual average temperature.

There is some evidence that rich countries are slightly less affected by changes in temperature (the curve is a little flatter for them). There are few hot and wealthy countries examined in the study, so any general conclusions about them cannot be certain, but the evidence still points to them being more prone to damage from rising temperature than rich, cooler countries. No matter how rich you are, extra heat hurts the warm lands more than it does the temperate and the cool. You can’t buy your way out of the effects of global warming, except by moving away from the Equator or up into the highlands. Continue reading

Volkswagen Got Caught Cheating Emissions Reporting. Will B.C.?

Originally published at DeSmog Canada on October 7th, 2015.

Volkswagen has admitted to cheating on emissions tests of some of its diesel vehicles. The full story has not yet been made public, but Volkswagen seems not to be an isolated case. There are indications of widespread gaming of emissions testing in the European automobile industry, with regulators and governments turning a blind eye to cheats and being reluctant to introduce testing procedures that would measure actual emissions in real-world conditions.

There are some parallels with the estimation of emissions in the natural gas industry in British Columbia, where officially-sanctioned emissions rates are far lower than in other jurisdictions, compliance inspections are non-existent and methodologies do not include state-of-the art field measurements.

Volkswagen gamed the system

Anyone from North America driving a modern diesel car while on vacation in Europe must have wondered why these economical and high-performance vehicles were not more popular back home. Now we know. Volkswagen introduced a line of diesel vehicles to the U.S. and Canada, but the company only managed to meet nitrogen oxides (NOx) emissions tests by cheating, using so-called defeat devices — software that changed the vehicle’s settings when it sensed that a test was underway. Low NOx emissions are technically feasible, but they entail trade-offs with higher vehicle costs, reduced performance and increased fuel consumption.

As the scandal unfolds, we are starting to learn how Volkswagen — and probably other manufacturers as well — has been gaming vehicle-testing procedures in Europe, not just with NOx emissions, but also with carbon-particle and carbon dioxide emissions. Tests done in unrealistic laboratory-type settings do not reflect real-world performance on the road. Continue reading