 Good morning, good afternoon and good evening. It is a great privilege and pleasure for me to participate in this FTA science conference and to share some of my thoughts on reforestation as a nature or biodiversity-based solution. During the annual World Economic Forum meeting in Davos earlier this year, the forum launched their initiative to plant one trillion trees worldwide with the goal to restore biodiversity and fight climate change. And that was of course not the first or the last tree planting campaign. There have in fact been many tree planting and forest restoration initiatives at both the national and international levels in recent years. For example, the trillion trees is a joint venture between BirdLife International WCS and WWF with the goal to protect and restore one trillion trees by 2050. And the hashtag team trees is another one that has been quite successful and well supported by some famous people including Elon Musk. Given the high profile of many of these campaigns, it is not surprising that there have been some pushbacks. People are starting to question whether the climate mitigation benefits of tree planting may have been overstated. And some others have raised concerns about the constraints and tradeoffs of indiscriminately planting trees everywhere. While these debates are happening in the popular media, a parallel drama has been unfolding in the scientific domain. Most of us would have read this paper published in Science last year, which raised several eyebrows. The bone of contention comes from its rather audacious claim that tree restoration is the most effective climate change solution to date. For better or worse, that study and the headlines and sound bites it has generated have had a strong influence on policy and decision-making across different segments of society worldwide. Suddenly, everyone is jumping on the tree planting bandwagon. Now, I think all of us here understand that even if a parcel of land is biophysically suitable for reforestation, there often are many other context-dependent factors beyond biophysical suitability that need to be considered for a reforestation project to have any chance of long-term success and to deliver its benefits to society. For example, these so-called degraded lands that are being targeted for reforestation may in fact be used by local communities as smallholder farms or home gardens. Allocating or appropriating these lands for reforestation efforts could compromise the livelihoods, food security, and land rights of these land users. Furthermore, the long-term security of carbon stocks within regenerating or reforested lands may require constant site maintenance and protection, as well as some degree of ecological resilience against threats such as tree directs, logging, and forest fires. These considerations of land use, operational, and financial constraints can limit the potential feasibility and success of tree planting and reforestation projects. To illustrate these impacts that these constraints may have on reforestation and its efficacy as a climate solution, my team from the Centre for Nature-Based Climate Solutions at the National University of Singapore recently conducted an analysis for the region of Southeast Asia. As a baseline scenario, we first mapped the biophysical suitability of land for reforestation based on aboveground biomass, the potential for natural vegetation, and by excluding obvious unsuitable land use or land cover, such as industrial agriculture, urban areas, or bare limestone. We find that 121 million hectares of degraded forests, peat swamp forests, and mangroves in Southeast Asia are biophysically suitable for reforestation. We also calculated the climate mitigation potential of reforestation on these lands based on the rates of aboveground carbon sequestration and the avoided emissions from further forest degradation. And we find that the reforestation of these lands could contribute to climate mitigation at a rate of about 3.4 gigatons of carbon dioxide every year from now through 2030. Next, we applied different layers of land use, operational and financial constraints that may need to be considered when implementing reforestation projects on the ground. We find that the most limiting scenario would reduce the amount of lands for reforestation to less than 8 million hectares across the region. Most of these feasible lands would be located in parts of Sumatra, West and Central Kalimantan, and Papua. And in this scenario, reforestation would remove less than a quarter of a gigaton of carbon dioxide every year. Now, of course, a wide range of other environmental, sociocultural, and geopolitical factors not considered in this study could also influence decision making during different phases of the reforestation process. The intent of our analysis is not to produce precise estimates of the climate mitigation potential of reforestation, but rather to illustrate through a scenario analysis how this potential can quickly diminish when such constraints are considered in the Southeast Asian context. In other words, what our analysis shows is that when we look carefully at reforestation through multiple layers of practical considerations and constraints, we may find that only a fraction of the climate mitigation potential of reforestation is actually achievable. The barriers to reforestation we identified are not insurmountable. With strong government commitment, smart policies, and financial support from private industries, a reduction in the opportunity costs of reforestation projects, which is a major constraint, can be achieved, for example, by transitioning smallholder farms to an agroforestry system. We find that even a moderate reduction in these opportunity costs can almost double the realizable climate mitigation potential of reforestation efforts. Reforestation is a hugely important nature-based solution, not only for climate mitigation, but also for the multiple co-benefits it provides, including biodiversity conservation, clean air and water, and poverty alleviation. Indeed, reforestation is embedded in key international initiatives, such as the sustainable development goals, the bond challenge, and the IEG targets. Nevertheless, our study suggests that a more complete and nuanced consideration of both the potential and the limits of reforestation as a climate solution is needed to inform climate policies and decisions that are scientifically sound, economically feasible, and socially acceptable. Thank you very much for your time and attention.