When’s the best time to plant a tree?

Twenty years or more ago would have been the best time for us all to have started the transformation to decarbonize our global economy, and more specifically to have started weaning ourselves off carbon intensive fossil fuels.

However, hindsight is a wonderful thing, and the fact remains that the metaphorical tree of decarbonization wasn’t planted twenty years ago. Reflecting on the COP26 conference, just a few weeks ago, it is important to keep reminding ourselves in no uncertain terms that now is the time to act.

Twenty years or more ago would have been the best time for us all to have started the transformation to decarbonize our global economy, and more specifically to have started weaning ourselves off carbon intensive fossil fuels.

However, hindsight is a wonderful thing, and the fact remains that the metaphorical tree of decarbonization wasn’t planted twenty years ago. Reflecting on the COP26 conference, just a few weeks ago, it is important to keep reminding ourselves in no uncertain terms that now is the time to act.

The changing narrative on 2 degrees

Having been researching and working on sustainability for approaching two decades, I was recently reflecting on the dialogue around “2 degrees.” Throughout the 2000s, the climate dialogue was around the importance of limiting global temperature rise to no more than “2 degrees” above pre-industrial levels. Then, as we slipped into the 2010s, the talk of “2 degrees” seemed to stop, as if the climate community had silently resigned itself to the fact that this was an unachievable goal.

After several years of what seemed like silence, along came COP21 in October 2015, and with the Paris Agreement, “2 degrees” was very much back on the table as the maximum safe limit with an accepted aspiration that globally we should strive for no more than “1.5 degrees.”

So, what has happened at this COP? Well, against a starting points of previous government carbon pledges from around the world, which in summation might be expected to lead to 2.4^oC of global heating, COP26 delivered enhanced government carbon pledges. In total, these pledges would be expected to deliver global heating of around 1.8^oC. While these pledges do not get to 1.5^oC, they are notable because it is the first time that the pledges have crossed the 2^oC threshold.

However, a pledge is nothing more than that without the aligned government policy in place to deliver the pledge. This policy-pledge gap is nothing new; while the previous pledges were adding up to 2.4^oC degrees, an analysis of government policies leads to a calculation that the expected outcome might be expected might be closer to 3^oC of global heating. Consequently, these new pledges, while welcome, now need governments to urgently implement policies commensurate with their stated ambitions.

The mathematics of the Paris Agreement and COVID

All this reinforces the need for urgent and radical need of decarbonization. The mathematics of the Paris Agreement are clear; global carbon emissions need to half this decade, halve again in the 2030s, and reach a net zero balance by the end of the 2040s. Step one of this three-decade journey means reducing global emissions by 7.6% every year from 2020 to 2030.

With cruel irony, the COVID19 pandemic has highlighted just the enormous magnitude of this challenge. When the carbon effects of all the global 2020 lockdowns are combined, the impact on annual CO₂ emissions from fossil fuel and industry was a reduction of approximately 2.4GtCO_2, or 7% compared to 2019. With all the disruption and human tragedy associated with the pandemic, COVID19 had almost delivered us the carbon savings we needed for the first year of the Paris pathway.

The chart above shows how global carbon emissions reduced, at peak around 18% in April at the height of the COVID lockdowns. Clearly, this is not a sustainable approach to decarbonization in any way, but it does highlight the scale of the challenge. Even after the impacts of COVID, when combined with the impacts of land-use change, human-caused CO₂ emissions in 2020 totaled around 40Gt.

Current estimates suggest that in 2021 global carbon emissions will rebound by about 5% on 2020, and consequently global emissions this year are likely to be 2–3% below 2019, a far cry from the 15.2% called for by the Paris Agreement.

It’s absolute emissions that matter

Reinforcing this analysis, this year’s Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), was described by the UN Secretary-General António Guterres as a clear “code red for humanity.” Among the nearly 4,000 pages of analysis, Table SPM.2 is perhaps one of the clearest reminders of the seriousness and scale of our collective challenge.

Ultimately, the key message of Table SPM.2 is that it is absolute concentration of carbon emissions in the atmosphere that matter. It is the absolute level of carbon that impacts global heating.  Consequently, while reductions in annual emissions are important, the critical figure that really needs attention is the overall CO₂ concentration figure. Currently this figure sits around 412 ppm (parts per million), driven up from the pre-industrial level of around 280 ppm by the estimated cumulative emission of 2,400 billion tons of CO₂ from 1850 to 2019.

The critical number in the table is 300.

Three hundred is the estimated number of gigatons of additional CO₂ that can be added to the atmosphere if we are to have an 83% chance of limiting global heating to 1.5^oC. Three-hundred GtCO₂ can be seen as our global budget from 2020 onwards. Increase those emissions to 500 GtCO₂ (broadly the Paris pathway), and the likelihood of limiting heating to 1.5^oC drops to 50:50.

It is also worth remembering that around 80 GtCO₂ of those 300 GtCO₂ have already been emitted this year and last, and so at current levels of emissions, we can afford less than six more years of business-as-usual carbon emissions. If we are prepared to settle for 1.7^oC of global heating, significantly higher than the ambition of the Paris Agreement, the budget rises to 470 GtCO₂ (550Gt less the 80Gt emitted in 2020 and2021) about 12 years at business-as-usual emissions.

It’s important also to note here that these projections are based on significant and parallel reductions in non-CO₂ greenhouses gases. For brevity, I have not discussed non-CO₂ emissions in this analysis, but as the final column of the table indicates the magnitude in savings of these non-CO₂ greenhouses gases will significantly impact the analysis and likely outcomes.

So, in summary, what the world needs remain nothing short of a carbon revolution. As we wrote in Capgemini’s Sustainable Business Revolution report in the run up to COP25, two years ago now, the “radical reinvention of business models, open collaboration and sustainability-driven technology choices are urgently needed to stem the destructive impact of carbon emissions on our planet.” This remains as true now as it was in 2019, and indeed it was reflected by our CEO when giving the keynote at the World Climate Summit (watch it here), the leading business forum at the COP. The discussion and agreements at COP26 only reinforce the need for action, and the need for action is now.

If you’re interested in reading more post—COP26 reflections, here are a few links you might find interesting:

• Aiman Ezzat, Capgemini’s CEO, calls for the private sector to spearhead the carbon revolution in his opinion piece
• James Forrest, our energy and utilities expert, summarized 4 steps to achieving energy transformation in his blog post