Climate Catastrophe

In an earlier post (1) some of the characteristics of climate denial were examined. This was an introductory piece and we will look at this in more detail in coming months, in the meantime it is worth examining the beliefs of those at the other end of the spectrum. These are the folks who believe the current trajectory will (or will very likely) lead to truly catastrophic and irreversible environmental impacts. A quick summary (2) of the logic that underpins this belief is that :

Actions to reduce anthropogenic CO2 emissions are failing and as a consequence temperatures will continue to rise.
This will trigger irreversible “tipping points” such as the release of methane and CO2 currently contained in Arctic permafrost
Before the end of the current century, temperatures rapidly spike to greater than 4C above the average of the last century
Agriculture and marine based food production fails massively leading to famine and starvation
Destabilisation of the jet stream and the elimination of monsoon rainfall renders a wide swathe of the globe uninhabitable.
Human population will be restricted to the far northern latitudes and a few isolated pockets in the southern hemisphere.
The earth’s human population will drop from over 7.8 billion to somewhere between 1 billion and 500 million – a reduction of around 90%

That’s right – war, famine and disease will see the global population decrease by 90% with the carrying capacity of the earth so depleted that there will be no recovery. Furthermore this is not an extreme, worst case scenario – for some this is the base case, most likely outcome.

Many readers will be asking “can this really be possible?” Reassuringly, this type of extreme forecast is far from the base case of the IPCC meaning it is outside the current scientific consensus. Worryingly, there are some academics who endorse this line of thinking meaning there is a climate activist faction who genuinely believe their children and grandchildren will inherit a blighted and mostly inhospitable world.

This highlights the huge gulf between climate deniers who reject the entire anthropogenic climate thesis and those who see something close to human extinction starting to play out in the current decade. This gulf, with multiple intermediate shades of grey, frames the challenges facing those who are seeking to win a political mandate for their particular approach to climate, energy and decarbonisation.

For those looking for a more rosy prognosis and hoping the climate apocalypse forecast will be proven false what signs of hope should they be looking for?

The first is more progress in reducing the rate of anthropogenic CO2 generation. Emissions in absolute terms are continuing to rise, though on a per capita basis they have been stable for the past 8 years as shown in the figure below(3). In other words, modest efforts in decarbonisation are being negated by population growth. Looked at from a regional basis, emissions reductions in the US and Europe are being balanced by increases in Asia. If, or hopefully when, we see emissions start to decline then we should start to feel a little more confident in our rejection of an impending catastrophe. As an aside, Australia’s per capita CO2 emissions are four times the global average, an examination of which seems like a good topic for the next article in journeytozerocarbon

Note: data is for CO2 emissions (not CO2e)

Secondly, we should be monitoring and hoping to avoid “tipping points” which are potential abrupt and irreversible changes in key physical systems such as those controlling the amount of polar sea ice, the structure and formation of clouds, the storage of methane in arctic

permafrost and the maintenance of marine coral reefs. The map below summarises some of the regions where scientists are looking for evidence of sudden changes being triggered by rising temperatures (4).

Thus far threats from accelerating sea level rise, permafrost thawing and loss of agricultural output continue to be perceived as low probability (but obviously with high consequences) in most published scenarios (and apparently by most central governments). Events like the recent bushfires in Australia will be rightly used to challenge this thinking though a quick google search suggests global food production still seems pretty robust (5) as shown in the graph below which shows no evidence that global wheat production is declining .

Wheat output (tonnes/ha) from major global producing regions

Lastly, if the human population is to avoid a population catastrophe, we should look for adaption programs intended to respond to issues like rising temperatures and sea levels as well as changing yields and growing seasons for key agricultural products. Extreme climate scenarios tend to be based on an assumption that the globe will sleep walk into disaster – not doing anything over multiple decades to either reduce CO2 or prepare for a warmer future. While the seeming lack of action on reducing GHG emissions supports this thinking, I believe this is misleading. The impact of modern, low cost renewable generation has only just started and an aggressive introduction of electric vehicles is surely not too far away. From a climate adaptation perspective expect to hear more about drought resistant crops, changes to diet and increased climate resilience in China and India (whose populations must be among the most vulnerable under an extreme climate scenario).

My reaction to extreme climate scenarios is to consider the raft of new business opportunities that are being created by the transition away from fossil fuels and the need to adapt to a warmer future. Some accuse capitalism and the pursuit of profit and financial gain as contributing to the climate challenges we face – perhaps they have a point but this doesn’t mean these forces won’t also be a powerful engine to deliver the decarbonisation and climate products and technologies that will make us more resilient to the impact of warming. We will see a generation of Elon Musks competing with existing corporations, all seeking new ways to make money. With well targeted government regulation and support we should see development of solutions such as battery storage, smart metering systems, electric and probably autonomous vehicles and drones, atmospheric carbon capture and storage and improved crops. I am an optimist, believing that solutions will continue to be developed and growing public demand and political pressure demand will insist on their implementation.