Tag Archives: global warming

Hindering the Hothouse

It’s been over a year since I posted on climate issues (last post here after Trump’s withdrawal from the Paris Agreement). A recent study by a group of scientists warned that even if the carbon emission reductions called for in the Paris Agreement are met, there is a risk of Earth entering “Hothouse Earth” conditions. A “Hothouse Earth” climate will in the long term stabilize at a global average of 4-5°C higher than pre-industrial temperatures with sea level 10-60 m higher than today according to the scientists.

Human emissions of greenhouse gas are not the sole determinant of temperature on Earth. Our study suggests that human-induced global warming of 2°C may trigger other Earth system processes, often called “feedbacks”, that can drive further warming – even if we stop emitting greenhouse gases,” says lead author Will Steffen from the Australian National University and Stockholm Resilience Centre, adding that “avoiding this scenario requires a redirection of human actions from exploitation to stewardship of the Earth system”.

The best-selling author of “Sapiens” and “Homo Deus”, Yuval Noah Harari, makes the observation that “the hand of the market is blind as well as invisible, and left to its own devices, it may fail to do anything at all about the threat of global warming or the dangerous potential of artificial intelligence”. This is one of the themes he returns vigorously to in his new book “21 Lessons for the 21st Century”, a collection of previously published essays.

It is therefore heartening to see such an influential and intelligent financial professional as Jeremy Grantham of GMO pushing the issue as an important one for investors to consider in our daily activities. This talk from Grantham and the accommodating presentation are well worth spending some time on. His arguments are articulated further in this August GMO white paper, The Race of Our Lives Revisited, an update on his 2013 paper.

Grantham states that “the truth is we’ve wasted 40 or 50 years since the basic fact about manmade serious climate damage became known” and “we’re moving so slowly that by the time we’ve fully decarbonized our economy, the world will have heated up by 2.5ºC to 3ºC, and a great deal of damage will have been done”.

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Grantham highlights the declining costs of alternative energy like solar and wind and the advances made in battery costs. Notwithstanding these advances, progress is too slow, as the graphs below show.

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Depressingly Grantham concludes that “in all probability we will reach our 2ºC target by 2050, and we will be fighting tooth and nail – with any luck, with carbon taxes and an improved attitude – to keep it below 3ºC by 2100”. Compounding the climate issue is continued population growth, declining agricultural productivity and increased soil erosion.

Like Harari, Grantham argues that “the greatest deficiency of capitalism is its complete inability to deal with any of these things that we are talking about even though it can handle the millions of more mundane factors that go into producing a workable economy, far better than planned economies”. Grantham makes a passionate argument for investors to divest themselves of negative climate impact firms, such as the oil producers, and to do more in our personal lives to promote green changes, like buying electric cars.

In the absence of real political leadership in our world, which looks likely to continue for some years yet as the populist and nationalistic political dead end we are currently travelling on plays out, voting with our actions seems the only thing we can do. As Grantham concludes, we all need to “get to it”.

IPCC Risk & Uncertainty

I haven’t had time to go into the latest WGIII IPCC report in detail (indeed I haven’t had much time recently to spend on blogging) but I had a quick browse through the report and there is an excellent chapter on “Integrated Risk and Uncertainty Assessment of Climate Change Response Policies” which goes through many of the key elements of current risk management theory and practise and how they can be applied to climate change.

A previous post highlighted the difficulties of making predictions given the uncertainties involved. The report highlights the “large number of uncertainties in scientific understanding of the physical sensitivity of the climate to the build‐up of GHGs” and acknowledges that these “physical uncertainties are multiplied by the many socioeconomic uncertainties that affect how societies would respond to emission control policies”. The report calls these socioeconomic uncertainties “profound” and lists examples as the development and deployment of technologies, prices for major primary energy sources, average rates of economic growth and the distribution of benefits and costs within societies, emission patterns, and a wide array of institutional factors such as whether and how countries cooperate effectively at the international level.

The IPCC gives a medium rating (50% probability) to the statement that the “current trajectory of global annual and cumulative emissions of GHGs is inconsistent with widely discussed goals of limiting global warming at 1.5 to 2 degrees Celsius above the preindustrial level”.

Included in Chapter 2 are the graphs below. According to the report “the representative concentration pathways (RCPs) are constructed by the IPCC on the bases of plausible storylines while insuring (1) they are based on a representative set of peer reviewed scientific publications by independent groups, (2) they provide climate and atmospheric models as inputs, (3) they are harmonized to agree on a common base year, and (4) they extend to the year 2100”. The 3 scenarios (A2, A1B and B1) are multi-model global averages of surface warming (relative to 1980–1999) shown as continuations of the 20th century simulations. Shading is the plus/minus one standard deviation range of individual model annual averages and the orange line is where concentrations were held constant at year 2000 values. Time permitting; it demonstrates that the conclusions and scenarios presented in the latest report are worth finding out more about.

click to enlargeIPCC global surface temperature scenarios from RCPs

Although each scenario is likely at the mercy of the uncertainties highlighted above, the open and thoughtful way the report is presented, including highlighting the underlying weaknesses, doesn’t mean that they (or the report) can be ignored. Indeed, the recent output from the IPCC will hopefully provide the basis for informed thinking on the subject in the coming years.

The report includes a reference to Kahneman-Tversky’s certainty effect where people overweight outcomes they consider certain, relative to outcomes that are merely probable. That implies that a 50% probability of the temperature blowing through 2 degrees celsius may not be enough to force real action. Unfortunately the underlying scientific and socioeconomic uncertainties inherent in making forecasts on temperature change over the next 30 to 50 years may mean that the required level of certainty cannot ever be achieved (until of course it’s too late).