Low Carbon Pulse Edition 38

Every tonne of well mixed GHG emitted contributes to an increase in average global atmospheric temperature. Stated another way, the root cause of climate change is the increase in temperature caused by increased mass of GHGs in the climate system, increasing the concentration of GHGs in the climate system, principally CO₂, CH₄ and N₂O.

The CO₂ concentrations are higher than at any time in the last two million years, and concentrations of CH₄ and N₂O are higher than at any time in at least 800,000 years.

The Paris Agreement:

CO₂-e (carbon dioxide equivalent) recognises that different GHGs have different global warming effects, with the use of CO₂-e allowing a like-for-like comparison taking account of potency and time retained in the climate system. What is clear however is that CO₂ is the GHG on which GHG reduction and GHG removal initiatives need to concentrate because globally, by mass, it is, by far, the most emitted GHG. At the same time, there needs to be a near term concentration on the reduction of CH₄. 

The key provisions of the Paris Agreement are as follows:

2: What the reader needs to know:

2.1 Overarching theme: 

In the weeks leading up to COP-26 some countries increased and accelerated their NDCs. During COP-26 further commitments were made. Edition 30 of Low Carbon Pulse reported on the work and conclusions of the good folk at Climate Tracker to model the impact of those further commitments. See graphic.

After COP-26, as reported by Climate Tracker, the best case scenario arising from the announced increased NDCs would be to hold the increase in global warming to 1.8^OC, assuming implementation of those increased NDCs. This was positive, certainly more positive than the Catastrophic Pathway. It did not, however, and it does not, provide certainty of a 45% reduction in GHG emissions by 2030. See graphic on projected greenhouse gas emissions in 2030.

From COP-26 a number of themes emerged (see Edition 30 of Low Carbon Pulse), but the overarching theme was the need to increase levels of action to address climate change, and to accelerate the reduction in GHG emissions. 

The overarching theme from COP-26 is carried forward in both the IPCC WGIII Report and WETO 2022, each emphasising that by the end of the current decade considerably more action needs to have been taken than is represented by the current combined NDCs of each country party to the Paris Agreement. 

2.2: Fundamental choices need to be made, quickly:

Each of the IPCC WGIII Report and WETO 2022 are clear – the world faces fundamental choices that will determine whether global warming is limited to 1.5^OC or 2^OC, or not. The IPCC WGIII Report contemplates a worst case outcome of a 3.2^OC increase, beyond the Catastrophic Pathway. Time is a luxury, and collectively our carbon budget does not allow any luxuries.

2.3: Increased and accelerated reductions in NDCs are required, quickly: 

It is known that increased and accelerated reductions in GHG emissions by 2030 and 2040 are required, particularly reductions in methane (CH₄), to achieve lower peak GHG emissions, and lower peak warming (which will happen after peak GHG emissions). This will place less reliance on GHG removal (including negative GHG emission initiatives).

2.4: None of this is new:

It is important to note that none of this is new. What is new is the increasing realisation that the choices available to us are narrowing, and there is a real risk that neither the 1.5^OC nor 2^OC limit on global warming will be achieved. 

Section 3: The Headlines:

3.1: Peaking GHG emissions:

Many of the headlines reporting on the IPCC WGIII Report do not seem to reflect the sage advice described in Section 1.2 above. In context, as reported in previous editions of Low Carbon Pulse, and as noted above, there is a gap between the NDCs of countries that are party to the Paris Agreement and the level, and rate, of reductions in GHG emissions required to limit global warming to 1.5^OC or 2^OC. At the moment, GHG emissions are increasing, as is the rate of increase, and as such it is difficult to discern when peak GHG emissions will be reached. 

Given the current rate of GHG emissions, we can discern the mass of GHG emissions in the atmosphere that will result in a 1.5^OC increase in average temperature compared to pre-industrial times. Below, a simple scenario (under section 4.1.7) is provided that would allow us to limit the temperature increase to 1.5^OC by 2100, assuming reductions of a level and at a rate consistent with achieving net-zero by 2050. Depending on the mass of GHGs emitted, by 2100 the increase may exceed 3^OC compared to pre-industrial time (a worst case scenario is a 3.2^OC increase). 

3.2: Key message:

The key message from the IPCC WGIII Report is that, starting now, increased and accelerated reductions in GHG emissions are required across all sectors, using multiple means. It is imperative that this happens. If it does not happen it seems highly unlikely that keeping the increase in average global temperatures to 1.5^OC will be achieved. 

As Mr Bill Gates said, in How to Avoid A Climate Disaster, reducing GHGs to net-zero by 2050 "will be hardest thing humanity's ever done". But it is technically feasible. The basis for Mr Gate's book is that: "There are two numbers you need to know about climate change. The first is 51 billion. The other is zero". The IPCC WGIII Report increases the first number to between 54 and 66 GtCO₂ (reflecting the mass of GHG emissions emitted in 2019). It is harder!

3.3: What needs to be done is known: 

The scale of the task is known, the degree of difficulty is known. Objectively viewed, the fundamental choices are clear, and decisions should be easy, but execution is the hardest thing humanity's ever done. 

In short, in the words of the Co-Chair of the IPCC WGIII, Mr Jim Skea: "It's now or never" to make and to act upon those fundamental choices. 

In a quote used on a number of occasions in Low Carbon Pulse, "What's past is prologue", taken, without any intended cynicism or irony, from The Tempest, by William Shakespeare. The phrase is emblematic. 

To the ever-optimistic author, this means that it is time to draw a line under the past, and move on, as quickly as possible, to increase the level and to accelerate the rate of reductions in GHG emission by all means practicable.

Section 4: What is past is prologue

4.1.1: Carbon budget to the end of 2019:

The IPCC WGIII Report states that:

"Historical cumulative net CO₂ emissions from 1850 to 2019 were 2,400 ± 240 GtCO₂ (high confidence). Of these, more than half (58%) occurred between 1850 and 1989 [1,400 ± 195] GtCO₂, and about 42% between 1990 and 2019 1,000 ± 90 GtCO₂". 

See graphic on 'Global net anthropogenic GHG emissions by region (1990 – 2019)' and another graphic titled 'Global net anthropogenic emissions have continued to rise across all major groups of greenhouse gases'.

The focus of the IRENA WETO 2022 is GHG emissions arising from the energy sector. The following pie-chart and infographic illustrate the mass of GHG emissions arising (36.9 GtCO₂) and the means by which those emissions are to be reduced. The infographic and accompanying narrative represents the required reduction in the mass of GHG emissions by 2030. 

4.1.2: Reduction in GHG emissions and impact:

The mass of GHG emissions arising each year, and more importantly the global warming potential of those GHG's, will inform the rate at which global warming occurs, and as such at what point we will reach a 1.5^OC increase and, possibly, a 2^OC increase in global average temperatures around which the Paris Agreement is framed. 

In this context, considerable work has been done to determine the rate at which GHG emissions can be emitted before the 1.5_OC limit or 2_OC limit is reached. The IPCC WGIII Report indicates that in 2019, 59 GtCO₂ (plus or minus 6.6 Gt) of GHG emissions arose. This is relevant for the purposes of the carbon budget.

4.1.3: Carbon budget from 2020 onwards:

The IPCC WGIII Report states that:

"Remaining carbon budgets depend on the amount of non-CO₂ mitigation (± 220 GtCO₂) and are further subject to geophysical uncertainties. Based on central estimates only, cumulative net CO₂ emissions between 2010-2019 compared to about four fifths of the size of the remaining carbon budget from 2020 onwards for a 50% probability of limiting global warming to 1.5^OC and about one third of the remaining carbon budget for a 67% probability to limit global warming to 2^OC. Based on central estimates only, historical cumulative net CO₂ emissions between 1850-2019 amount to about four firths of the total carbon budget for a 50% probability of limiting global warming to 1.5^OC (central estimate 2,900 GtCO₂, and to about two thirds of the total carbon budget for a 67% probability to limit global warming to 2^OC (central estimate about 3,350 GtCO₂)."

What emerged clearly from COP-26 was an understanding of the criticality of staying as close as possible to a 1.5^OC increase in average global temperatures (see Editions 29 and 30 of Low Carbon Pulse). 

What has emerged since COP-26 is that the rate of GHG emissions is increasing at a faster rate than was thought (including because of an under-recognition of CH₄ emissions), and the point of peak GHG emissions, and the level of the peak, is further into the future, and at a higher mass of GHG emissions at peak level, than thought. These dynamics explain the reason for the expression of urgency. 

4.1.4: Where we are now - in summary:

Based on an assumed mass of GHG emissions of say 60 GtCO₂ a year, it is possible to estimate how much is left in the carbon budget before we reach global warming of 1.5^OC (or 2^OC), but, as will be explained, is not possible to determine exactly when the carbon budget will be depleted, because this depends on the mass of net GHG emissions. 

Various models and reports indicate that four fifths of the carbon budget is 2,400 GtCO₂ to limit global warming to 1.5^_OC has been used. Leaving a fifth remaining, or 600 GtCO₂. Once the remaining fifth is used, we will need to remove CO₂ from the atmosphere to be able limit global warming to 1.5^OC. This is not new (see Article 4 of the Paris Agreement).

In simple terms, at the current rate of GHG emissions during 2019, by 2030 we will have depleted the carbon budget. This is one part of the equation. 

The other parts of the equation include knowing when peak GHG emissions will occur, and at what level of GHG emissions, and the rate of reduction in GHG emissions after reaching peak GHG emissions. These other parts to the equation will determine the extent to which we "overdraw" from the carbon budget, and, as a result, the mass of CO₂ that will need to be removed from the atmosphere, and the rate at which this will have to occur.

4.1.5: Understanding peak emissions and the level of peak emissions: 

It is not simple to determine is when GHG emissions will peak, and at what mass of GHG emissions will peak. More than this, it is critical to note that once peak GHG emissions are reached, the aggregate of all GHG emissions emitted to peak GHG emissions, and the rate of the decrease in GHG emissions after reaching peak GHG emissions, will determine the peak of global warming. 

As such, assuming that we reach net zero GHG emissions by 2050, this does not mean that the rate of global warming will slow, or that global warming will reverse, this will depend upon the period of time taken for the global warming effect of GHGs emitted to dissipate, and the use of carbon removal (including negative greenhouse emission reduction initiatives).

4.1.6: Recurring headline illustrates the core issue:

One of the recurring headlines arising from the IPCC WGIII Report has been that to be able to have a chance of limiting global warming to 1.5^OC it will be necessary to achieve peak GHG emissions by the end of 2025. 

The basis for this headline is that if we were to achieve peak GHG emissions by 2025 (assuming no increase in the mass of GHG emissions arising each year before 2025), this will leave 300 GtCO₂ left in the carbon budget (at the current assumed rate of GHG emission, 60 GtCO₂ a year). Clearly if the level of GHG emissions increase, we will use up the carbon budget at a faster rate. 

But, and it is a big but, for global warming not to exceed 1.5_^OC, the cumulative mass of GHG emissions arising from the end of 2025 (assuming the peak GHG emissions arise then) to the time at which we achieve net-zero emissions should not exceed 300 GTCO₂. 

This is not going to happen, but what is?

While headlines are intended to capture our attention, the recurring headline described above leads us to the core of the issue, and, it is hoped, explains why policy makers are adamant that steep reductions in GHG emissions are required by 2030 and 2040. To explain this thinking, the following simple scenario may help. 

4.1.7: A simple scenario (from the author):

If a 50% reduction in GHG emissions was to be achieved by 2030, GHG emissions would have to have reduced to 30 GtCO₂ in 2030. If the rate of reduction was say 6 GtCO₂ a year from an assumed peaking of GHG emissions in 2025 at 60 GtCO₂. This would result in 280 GtCO₂ being emitted (from 2025 to 2030). Out of the 300 GtCO₂ carbon budget,  about 90 GtCO₂ would be left i.e. 300 GtCO₂ less 210 GtCO₂ of GHG emissions (noting that this takes no account of dissipation of GHG emission in the atmosphere). (This would not guarantee limiting global warming to 1.5^OC, but it would make the task of removing CO₂ a lesser task than might otherwise be the case.) 

Continuing with the simple scenario. If during the period 2030 to 2040, GHG emissions could be reduced at a rate of 2 GtCO₂ a year, by 2040 the carbon budget of 300 GtCO₂ carbon budget would have been used, and it would be 70 GtCO₂ "overdrawn" (i.e. positive integer 90 GtCO₂ less 160 GtCO₂ of GHG emissions) against the carbon budget that would limit global warming to a 1.5^OC increase.

Assuming that from 2040 to 2050 GHG emissions are reduced at a rate of 1.2 GtCO₂ a year to reach net zero GHG emissions by 2050, we would be 105 GtCO₂ "overdrawn" by (i.e. negative integer 70 GtCO₂ plus 35 GtCO₂ of GHG emissions) against the 1.5^OC carbon budget, but the task of removing CO₂ from the atmosphere would be a lesser task than what might otherwise be the case, and, more likely than not, would allow us to limit global warming to 1.5^OC by the end of the 21st century.

In putting numbers to a concept, it is hoped that this simple scenario provides a firm basis for what follows. From one simple scenario, to multiple scenarios. 

The IPCC WGIII Report and the WETO 2022 provide a range of scenarios, some of which will allow us to limit global warming to 1.5^OC by the end of the 21st century, others that will not. 

4.2 What might the future hold:

4.2.1: From 2020 to peak GHG emissions:

Of course, the mathematics in the simple scenario work only if GHG emissions start to slow before and decrease at an appropriate rate after peak GHG emissions are reached. 

The IPCC WGIII Report notes that the mathematics will not work given the announced NDCs pre-COP-26, and, as noted above, the best scenario immediately post-COP-26 (taking into account increased NDCs) is a 1.8^OC increase in average global temperatures. 

The IPCC WGIII Report states that based on pre-COP-26 NDCs it is likely that global warming will exceed 1.5^OC during the 21st century, and that limiting global warming to below 2^OC would require accelerated mitigation efforts after 2030. 

Even allowing for the increased NDCs before, during and after COP-26, the rate of GHG emissions is increasing, not decreasing. 

It is accepted broadly that GHG emissions need to reduce by between 45 to 50% by 2030 for there to be a chance of limiting global warming to 1.5^OC. This is not new, and the core of the issue is explained above.

The graphic below, and accompanying analysis, provides a good sense of the GHG reductions that need to be achieved, and the range of outcomes that may arise if those GHG reductions are not achieved. See graphic.

4.2.2: Fossil fuels:

Consistent with a plethora of reports finding that countries are not taking into account in setting their NDCs for continued use of fossil fuels (see Editions 29 and 30 of Low Carbon Pulse), the IPCC WGIII Report notes that without additional reductions to take account of continued use of fossil fuels (both existing and currently planned) projected reductions will not be achieved. Again, this is not new. 

The narrative and reporting around the phasing out of fossil fuels remains challenging, both in terms of a reduction in revenue (direct for national oil companies, indirect for Governments currently receiving royalties and taxes from the production and sale of fossil fuels, and customs and duties from downstream import and sale of fossil fuels, and indeed any carbon tax) and the level of revenue required to allow Governments to support the development of infrastructure to allow progress to the achievement of net-zero emissions, and the fiscal incentives that Governments are giving, and are likely to have to continue to give, to allow continued progress to the achievement of net-zero emissions. 

Governments in many countries are facing a "fiscal squeeze" (and will continue to do so), as the expectations of the funding support that Government will provide to achieve progress towards net-zero emissions increases, while at the same time the Governments face a diminishing lower fiscal base with the phase out of fossil fuel. This "fiscal squeeze" needs to be understood, and overcome.

Both the IPCC WGIII Report and the WETO 2022 are clear about the need to phase out fossil fuels. The author notes that pragmatism, and good sense, is required in this context.

The table provides a summary on a page of a range of outcomes canvassed in the IPCC WGIII Report. To the author, it is pretty much an ideal summary. See table and another graphic on 'The range of assessed scenarios results in a range of 21st century projected global warming'. 

Section 5: What needs to be done:

5.1: What needs to be done in a general sense?

The IPCC WIII Report notes that all models that limit global warming to 1.5^OC assume that peak GHG emissions will be achieve by 2025, and that all models that limit global warming to 2^OC assume immediate action to achieve the model GHG emission reductions. 

5.2: What will the consequences be if what needs to be done is not done?

Without implementing policy settings that address the short-comings of the pre-COP-26 NDCs, peaking GHG emissions will not be achieved by 2025, rather GHG emissions will continue to increase after 2025. Again, this is not new, nor is the projection that global warming may reach 3.2^OC if action is not taken to achieve appropriate levels and rates of reduction in GHG emissions.

As a general statement, the IPCC WGIII Report contemplates the need for immediate increased and accelerated GHG emission reductions across all sectors. 

5.3: The means of reductions are known: 

5.3.1: IPCC WGIII Report: 

The IPCC WGIII Report provides considerable narrative on the following needs: to develop and to deploy renewable electrical energy; to transition from fossil fuels (that do not use CCS) to transition to very low or no carbon energy fuels; to achieve effective demand management, including to achieve efficient use of energy and reduced use of energy; to reduce CH₄ emissions; and to develop and to deploy carbon dioxide removal (CDR) methods. 

In this context, the IPCC WGIII Report provides Illustrative Mitigation Pathways (IMPs) 

5.3.2: WETO 2022: 

In addition to the ubiquitous need for countries that are parties to the Paris Agreement to increase the level and rate of GHG emission reductions, WETO 2022 builds on the six technological means to reducing emissions identified in WETO 2021: those means being renewable electrical energy, energy efficiency, electrification, hydrogen and hydrogen-based fuels, fossil fuel based CCS and bio-energy based CCS. These means are covered in detail in WETO 2021, and summarised, amongst others, in Edition 21 of Low Carbon Pulse. 

The focus of WETO 2022 is the 2030 priorities are as follows:

1. replacing coal-fired power stations with clean power generation;

2. phasing out fossil fuels in tandem with market development and reform to incentivise net-zero transition;

3. increasing the rate of development and deployment of renewable electrical energy and "aggressive energy efficiency" strategies;

4. infrastructure development and expansion, and upgrading, to assure, or to increase infrastructure and system, integrity and reliability to allow timely deployment of renewable electrical energy;

5. green hydrogen to become mainstream by 2030; 

6. triple the supply and demand for bio-energy by 2030, requiring considerable work to collect and to allow use of bio-energy feedstock arising from waste streams; 

7. the majority of car sales should be electric by 2030; 

8. new buildings must be energy efficient and renovation rates of existing buildings must be increased (including to avoid production of cement for concrete and iron and steel for construction); 

9. demand side management initiatives to ensure efficiency, including recycling and repurposing; and 

10. policy settings that cover all avenues that technology development may take. 

5.4: Nothing new under the sun:

There is nothing new in the IPCC WGIII Report or the WETO 2022. This said, were one reading news items and commentary on each report, one could be forgiven for concluding that carbon dioxide removal was new, and that conclusions in respect of it were new. 

As is apparent from Article 4 of the Paris Agreement, CDR has always been contemplated. The issue now is that CDR should be accelerated. 

While not new (see Editions 28 of Low Carbon Pulse, under NZE not enough CDR required now), there is a new emphasis on the need for CDR now: boiling down to the essentials, there is a need to commence CDR (including negative GHG emission initiatives (NGHGEIs)) as soon as possible. 

In the blur of headlines, a number of commentators and participants have expressed a range of views on CDR, and its role in IMPs. CDR is used in a broad sense to include carbon capture arising from Bioenergy with CCS (BECCS) and Direct Air Carbon Capture and Storage (DACCS), and negative emission reduction initiatives in the AFOLU sector. 

While understandable, some commentators and participants have overstated the findings in the IPCC WGIII Report on the use of particular means of achieving CDR.

The good thing is that it is recognised that CDR needs to be developed and deployed at the same time as GHG emission reductions. This recognises the reordering of the three means of achieving the outcomes contemplated in the Paris Agreement: from RPR – Reduction, Peaking and Removal, to RRP – Reduction, Removal and Peaking. (See the Anniversary Edition of Low Carbon Pulse.)

5.5: Means to reduce GHG emissions:

The following graphic illustrates the range of means for reducing GHG emissions identified by the IPCC WGIII. See graphic on 'Overview of emission mitigation options and their cost and potential for the year 2030' and another graphic on 'Net zero CO₂ and net zero GHG emissions are possible through different modelled mitigation pathways'. 

5.7: Reductions in GHG emissions sector by sector:

In the context of the following sectors the IPCC WGIII Report identifies the following principal means of mitigation by sector:

• AFOLU: the greatest mitigation will arise from conservation and preservation, reforestation, restoration of grasslands, peatlands, savannas and wetlands, reduced and then cessation of deforestation. In the context of cultivated or farmed land, improved and sustainable crop and livestock management, and carbon sequestration in agriculture, including soil carbon management, agroforestry and biochar use, will be key.
  
  It is noted that AFOLU mitigation actions cannot compensate for delayed reductions in GHG emissions across other sectors.
  This is a key theme from both the IPCC WGIII Report, and the WETO 2022 – all policy settings, all means of mitigation need to be developed and deployed as quickly as possible and as broadly as possible.
• Built environment: In the context of the continued growth in population and increasing urbanisation, changing and reducing energy demand, increased electrification (using renewable electrical energy), and use of CCS are identified as key IMPs.
• Industry: demand side management, energy and materials efficiency, circular material flows, as well as abatement technologies and changes to production processes are required.
• Transport: electric vehicles, sustainable bio-fuels, low emission hydrogen and synthetic fuels may mitigate CO₂ emissions arising in the aviation, heavy-vehicle land transport and shipping, but for wide, and timely, adoption require improved production processes, including to achieve reductions in cost.

 The author of (and researcher for) each edition of Low Carbon Pulse is Michael Harrison.