Mangrove trees, belonging to the Rhizophoraceae family, thrive in coastal ecosystems with their ... [+]
The world is not going to achieve net zero without implementing every tool available and nature-based climate solutions are going to play a critical role in mitigating climate change. For companies trying to achieve net zero with integrity however, the complexities of what to invest in and where are legion.
Nature based solutions are a critical tool in addressing nature loss and climate change - they are already being deployed at scale but much more is needed. In 2021 the World Economic Forum research estimated that they could provide around a third of the climate mitigation needed to achieve the Paris climate goals. That’s around 7 Gigatons of carbon removal, and at a lower cost than other forms of CO2 removal. A new study in Nature Climate Change explores what is really understood about the GHG mitigation potential of different approaches – specifically addressing the potential for nature-based climate solutions or NbCS.
What has proved challenging has been generating the funding needed to facilitate action at the scale needed, with part of the problem being an unmet demand for clear, transparent, rigorous science underpinning the tools and levers that different actors can trust to be part of the climate solution. This new research is about to change that, with an assessment of the efficacy of existing approaches – it provides the first peer-reviewed scientific assessment of over 40 of the nature-based climate solutions that have so far been implemented or proposed for use in the carbon markets.
Assessing the science understanding nature-based carbon removals
The study was developed by 27 authors from 11 institutions, including the Environmental Defense Fund, The Nature Conservancy and Columbia University, and explored what Doria Gordon, one of the lead authors and lead senior scientist at EDF, describes as “the many different nature-based climate solutions which have proliferated in the marketplace in recent years and the underlying scientific confidence we have in each of them.”
The research identifies the four nature-based climate solutions with the most robust scientific foundations. These turned out to be tropical forest conservation; temperate forest conservation; tropical forest reforestation; and temperate forest reforestation – these have the greatest certainty in carbon mitigation potential. In fact tropical and temperate forest conservation and restoration reached near consensus across the experts with respect to the scientific foundations regarding management and GHG accounting.
The research also identified which approaches need urgent additional research before their role as a climate solution is understood. The study explicitly looked at the scientific basis of, and expert confidence in, solutions for climate benefit, not the implementation of individual projects, carbon crediting methodologies or co-benefits.
As Peter Ellis, global director of natural science at TNC and co-author says, “Science is about bringing intelligence to action. That is exactly what we do in this paper: review the best available information to determine which nature-based climate solutions are ready for primetime.”
Using the carbon markets to fund nature-based climate solutions
Carbon finance, the use of carbon credits to finance action and to enable countries and companies to move towards net zero, has played a significant role in developing nature-based solutions. The challenge for many in the private sector however is the scandals that have rocked the carbon markets. Companies have bought carbon credits in good faith, only to discover that the amount of carbon sequestered is not accurate, or that local communities have been taken advantage of, giving rise to significant reputational risk and making reaching net zero targets questionable.
Methodologies and mechanisms have been questioned, with research from Berkeley showing REDD+ credits to have been generated from ineffective projects with over-inflated credit issuance. Yet the research suggests that REDD+ approaches are well substantiated by the science, so it’s the clearly the implementation that needs to be improved.
Even with that being the case, few credit buyers have the resources to fully understand the technical details of various projects or even the knowledge to ask the right questions. Crucial doubts have remained around the verifiability, sustainability and permanence of the quality of the carbon credits e.g. do they represent real reductions or removals, including issues such as additionality; permanence; double-counting and, of course, social safeguards and impacts.
At the same time, the research shows that that 70% of nature-based carbon credits generated by the four major registries have come from the four solutions with the highest scientific confidence. This suggests that the majority of carbon market investment is going to solutions with strong scientific foundations. That suggests that capital is going to the right places - clearly what is necessary is to redefine how projects are implemented and rebuild trust in the markets.
Impact – and integrity - matters
What the research enables is the understanding of which programs to conserve, protect and restore forests – when implemented well - will result in real emissions reductions that benefit the climate, that can be accurately measured and accounted for. The study is focused on the scientific evidence base underpinning each intervention, not the mechanism used to monitor and measure – an important distinction.
The research also makes clear that there are many unknowns about a variety of nature-based solutions, from wetland protection to mangrove or seagrass restoration, and that without clear confidence in the science, purchases of related carbon credits could be ineffective or inefficient in terms of carbon sequestration. There may be strong co-benefits in terms of biodiversity, local communities etc but these need to be understood distinctly from carbon removals.
Around 90% of the approaches assessed don’t yet have a sufficiently robust scientific basis on how to measure or account for carbon removal or the extent to which they are likely to provide long term mitigation. That is not decrying the enormous numbers of other benefits, which can range from biodiversity, to habitat conservation, to water quality to livelihood provision. These are all immensely valuable, it's just that the quantification of their climate impacts is currently uncertain.
As Mark Moroge, vice president of natural climate solutions at EDF points out there are two clear takeaways for companies. The first is to be thoughtful and cautious about the types of credit being purchased. The second is that it’s vital to understand what’s been proven to be effective scientifically. He says: “First you will ensure that your credits are coming from areas and ecosystems of high scientific certainty and second, because there are still important implementation questions, you can look to guidance that helps solve for those kinds of questions and your purchase.” There is a growing body of guidance around how to ascertain the integrity of credits, and Moroge points to the Tropical Forest Credit Integrity (TFCI) Guide and the ART TREES standard as examples.
Moving nature-based climate solutions forward
Challenges remain around how NbCS credits will be used and accounted for but the research identifies the nature-based climate solutions in which we have sufficient scientific confidence that we can quantify and understand the climate benefit. It also identifies a research roadmap that needs to be rapidly addressed in order to scale up to the third of necessary mitigation potential that nature offers. That provides the basis for a rapid scaling up of effective action as a means of achieving emissions removals.
There are a growing number of guardrails and parameters around implementation that will help to address the accounting challenges for nature-based solutions. What this research identifies is where the most rapid and effective mitigation potential lies, and where the science robustly supports the effectiveness of climate action. With little or no time to lose, there is an urgent need for climate action but those actions have got to work, and be seen to be effective.
As Doria Gordon says: “The intent is to identify where people should have confidence now, and where we anticipate confidence to be growing as we move forward.” Trust the science, invest sensibly and pay attention to implementation - that’s what’s needed to develop a nature-based climate solutions market at scale.
