Peak fossil fuel won’t stop climate change – but it could help

26 02 2015

The Conversation

Peak fossil fuel means it’s unlikely the worst climate scenario will come to pass. Gary Ellem explains.

What happens to coal in China will play a big role in deciding which climate road we’re all on. Han Jun Zeng/Flickr, CC BY-SA

Fossil fuels are ultimately a finite resource – the definition of non-renewable energy. Burning of these fuels – coal, oil and gas – is the main driver of climate change. So could the peak of fossil fuels help mitigate warming?

The short answer is maybe … but perhaps not how you might think.

In a paper published this month in the journal Fuel, my colleagues and I suggest that limits to fossil fuel availability might take climate Armageddon off the table, although we will still need to keep some fossil fuels in the ground for the best chance of keeping warming below 2C.

But more importantly, the peak of Chinese coal use is changing the face of global alternative energy industry development, and is soon likely to impact on international positioning for a low-emissions future.

Now for the long answer.

Predicting climate change

Predicting future climate change is dogged by two fundamental uncertainties: the dosage of greenhouse gas that human civilisation will add to the atmosphere, and how Earth’s climate and feedback systems will respond to it.

In the absence of a crystal ball for the future of emissions, the Intergovernmental Panel on Climate Change (IPCC) has adopted a scenario-based approach which highlights four representative concentration pathways (or RCPs). These are named after how much extra heating they add to the earth (in watts per square metre).

The relationship between emissions, and temperature projections. IPCC
Click to enlarge

From these scenarios the IPCC has developed temperature scenarios. So the RCP2.6 scenario is expected to restrict climate change to below 2C, whereas RCP8.5 represents catastrophic climate change of around 4C by the end of this century, rising to perhaps 8C in the ensuing centuries.

Fossil fuels forecast

The key thing to note here is that the emissions scenarios are demand-focused scenarios that have been developed to reflect possibilities for potential fossil fuel consumption. They explore a range of scenarios that include increasing global population and living standards, as well as the possible impact of new alternative energy technologies and global emissions-reduction agreements.

Instead of examining demand scenarios for fossil fuels, our work has focused on supply constraints to future fossil fuel production. Our work is not a forecast of future fossil fuel production and consumption, but rather seeks to determine the upper bounds of the geological resource and how it might be brought to market using normal supply and demand interactions.

We developed three projections based on different estimates of these Ultimately Recoverable Resources (URR). URR is the proportion of total fossil fuel resources that can be viably extracted now, and in the future (this accounts for some resources that are technologically inaccessible now becoming extractable in the future). The low case used the most pessimistic literature resource availability estimates, whereas the high case used the most optimistic estimates.

We also included a “best guess” estimate by choosing country-level resource values that we considered most likely. We then compared the resulting emissions profiles for the three upper bounds to the published IPCC emissions scenarios, as shown in the figure below.

Our projections for fossil fuel supply (black) matched with emissions scenarios (colours). RCP8.5 is the worst, RCP2.6 the best. Gary Ellem
Click to enlarge

In comparison to the published emissions scenarios, we found that it was very unlikely that enough fossil fuels could be brought to market to deliver the RCP8.5 scenario and we would recommend that this be removed from the IPCC scenarios in future assessment reports.

Mining out the optimistic fossil fuel supply base could perhaps deliver the RCP6 scenario, however, our best guess limit to fossil fuel availability caps the upper limit of emissions exposure to the RCP4.5 scenario (roughly equivalent to a median estimate of 2C warming).

But even under the low resource availability scenario, it will be necessary to leave some fossil fuels untapped if we are to meet the conditions for the RCP2.6 scenario or lower (to have more than a 90% chance of avoiding 2C temperature rise).

To sum up, our supply side assessment suggests that even if the climate Armageddon of the RPC8.5 scenario were desirable, it is unlikely that enough new fossil fuel resources could be discovered in time and brought to market to deliver it. To be clear, there is still much to worry about with the RPC4.5 and RPC6 scenarios which are still possible at the limits of likely fossil fuel resources.

So a simple reflection on global fossil fuel limitation won’t save us … but nations don’t face peak fuels at the same time. A country-level analysis of peak fuels suggests the possibility of a very different future.

How China could shake the world

As part of our assessment we looked closely at the fossil fuel production projections for four countries including China, Canada, the United States and Australia. Of these, China is by far the most intriguing.

China has little in the way of oil and gas resources and so has established its remarkable industrial growth on exploiting its substantial coal resources. Our projections indicate that the rapid expansion in Chinese coal mining is rapidly depleting this resource, with Chinese peak coal imminent in the mid-2020s under even the high fossil fuel scenario, as seen in the projections below.

Various scenarios for China’s fossil fuel supply. Gary Ellem
Click to enlarge

China is well aware of this and is currently scrambling to cap coal consumption and develop alternative energy projects and industries. Its leaders understand that the alternative energy sector is really an advanced manufacturing sector, and have moved to position themselves strategically as the world leader in solar, wind, hydro, battery and nuclear technology construction and manufacturing.

As fossil fuels start to fail China as a path to economic and energy security, China will join other regions in a similar position, such as the European Union nations, which have largely depleted their fossil fuel reserves.

For these nations focused on alternative energy investment for energy and economic security, global action on climate change is strategically aligned with their industrial strength. We can therefore expect them to pressure for increasing global action as a method of improving their strategic global trading position. We may see the beginnings of this transition at this year’s international climate talks in Paris this year, but it will take a few more years for the Chinese shift to play out as they exploit the remainder of their coal resource and gain confidence in the ability of their alternative energy sector to scale.

The question then becomes “can the USA manufacturing sector afford to be out of these global alternative energy markets?”. Our guess is “no” and a global tipping point will have been reached in the alternative energy switch.

This is perhaps the most profound way that peak fuels may contribute to a low-emissions future.



6 responses

26 02 2015

Interesting. His idea of the most pessimistic forecasts of fossil fuel production must come from the mainstream (non-peakist) community. I have commented at The Conversation and I hope it leads somwhere. The paper is behind a paywall.

26 02 2015

Is not the two degrees already well blown? We are about 0.8 of a degree above preindustrial already, there are significant lags in the climate system, there are feedbacks already underway that have further to go without additional CO2 (albedo changes to the arctic due to ice loss, methane from the permamelt) and finally there is aerosol masking of about half of the effect of CO2 we have added. These aerosols will wash out nearly completely within twelve months, making the problem very quickly worse.

It is far too late to save it all, but it is not too late to save something. An extinction event is locked in already and it will be difficult for mankind to survive. A few more decades of BAU and we will have an extinction event that mankind cannot survive, an extinction event that will take tens of millions of years for the biosphere to recover from. BAU will not only make the extinction event worse, but bring forward the worst effects.

WE are chin deep in the doo doo, do you really want to add another foot?

26 02 2015

With so many factors influencing the outcome, not the least of which is the unknown quantity of fossil fuels that will be burned in the future, the only way to sort it all out is by running climate models on the various scenarios. The first chart in the article is the result of just that, and for the RCP 2.6 scenario shows that will increase temperatures to 1.0°C above 1986-2005 levels by 2050, and very slowly decreasing after that (as the oceans continue to absorb CO2).

There are actually 31 “official” climate models that are all considered valid at the moment (that is, they all give correct results when run on historical data), and the range of predictions for 2100 are 0.1 – 1.9°C. So your assertion that more than 2 degrees is already locked in is not supported by the models in an RCP 2.6 scenario.

It is Gary Ellem’s contention that the RCP 8.5 scenario can be discounted because of Peak Fossils. He does however admit that this only sets an upper bound on the outcome. It is my contention that RCP 2.6 can be discarded too, for the same reason. The difference is because he is only considering mainstream forecasts, while I am considering “peakist” scenarios, where BAU is impossible anyway.

Yes, every tonne of coal being burned is making things worse, but it surely obvious by now that “a few more decades of BAU” cannot happen. It will probably turn out that Peak Fossils will save Gaia in the nick of time, in which case we might wonder whether Gaia knew this all along. But Homo sapiens certainly isn’t wise enough to change course ahead of disaster. That’s why the end of the Age of Cheap Energy is going to be a crash scenario and not a power-down scenario.

26 02 2015

You typically omit the unknown effects of CH4 emissions which are growing quite dramatically…. some climatologists studying CH4 emissions are very concerned, as are the glaciologists who see the planet’s albedo worsening, whether or not we burn more FFs….

26 02 2015

Yes, I typically omit unknown effects, because they are unknown.

The RCP mechanism was invented for IPCC’s AR5 to allow people who want to test alternative scenarios to do so. A scenario consists of values every decade for 40 GHGs, of which CH4 is the second most important. In practice, the scenario has to be checked by IPCC to make sure it is logically consistent and can be sensibly compared to other scenarios, and so only scenarios published in the peer-reviewed literature can be submitted.

While that rules me out from submitting a Peak Fossils scenario, it wouldn’t rule out Arctic climate researchers from submitting a “RCP 2.6 + high CH4” scenario if they have published solid data on that. I haven’t heard that they have done that, but I would be very interested to see it if they did.

Failing that though, it’s all just speculation. I imagine it will be a while before Arctic methane measurements can tie down any comprehensive figures.

26 02 2015

I do doubt the models. Eemian CO2 was no more than 300 ppm and temperature was at least 1 degree higher than today. We are at 400ppm a level not seen in at least 5 million years.

Glaciologists admit not fully understanding the mechanisms of glacier movement. If the base knowledge is uncertain the models cannot capture the full range of possibilities.

Finally I would also question the independence of the models, multiple runs with multiple models smooth the significant events that do occur in single runs. The changes will not be smooth.

Models are useful, but inevitably wrong. The variables and the unknowns are too significant to have absolute faith in the results. Modelers are scary, paleo-climatologists are scarier.

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