In the case of social bonds, for example, the European Platform on Sustainable Finance has been working on a proposal for a social taxonomy, but this area evolves very quickly and more dimensions need to be included, such as diversity, equity and inclusion. In addition, the focus of sustainable finance is widening from climate to include nature and the environment because climate change and biodiversity loss are interconnected and mutually reinforcing. 7  Central banks are starting to analyse the consequences of the loss of biodiversity for the financial system. The Network for Greening the Financial System (NGFS) has set up a task force on biodiversity loss and nature-related risks. We need to research and learn more about the transmission channels from nature loss to the economy and the financial system, as we are already doing in relation to climate change.7 Thus, we have a further challenge here, and probably next year there will be a session at this conference focusing on biodiversity. In the meantime, to conclude, we can see that the issuance of green bonds is recovering in 2023. However, other bonds in the sustainable finance family are seeing less interest from investors. The challenges are several: i) the lack of common definitions, ii) the voluntary aspect of the European green bond standard, and iii) the lack of verification of sustainabilitylinked bonds. In addition, a higher degree of transparency and a global disclosure standard would contribute to the development of sustainable bond markets and a reduction in greenwashing. 7  See NGFS (2022).

- Green bond issuance saw the largest increase, comparing with the previous quarter and with the same quarter a year earlier. Financials and governments remained the largest issuers with a share of over 73 percent in 2023 Q1. Indeed, new sovereign issuance increased sharply in 2023 Q1, the European Commission issuing € billion of NextGenerationEU green bonds in its fourth syndicated transaction for 2023. 1  See IMF (2023). Climate Finance Monitor Q1 2023. May. 1  - Conversely, the issuance of most other types of bonds declined. For example, sustainability-linked instruments saw slower growth in the first quarter of the year, which, according to the IMF, “may reflect market participants’ perceptions around greenwashing and the credibility of the asset class to drive companies to meet sustainability targets”. Focusing on the euro area, according to the experimental indicators on sustainable finance developed by the Eurosystem: - The outstanding amount of sustainable debt securities issued in the euro area has more than doubled in the last two years. Securities designed to finance green and social projects, which account for the majority of the market, have seen a particularly strong increase. - Over the same period, sustainability-linked bonds recorded the highest growth rate. However, the relevance of these instruments in the overall debt securities market remains minor. Another interesting aspect highlighted by these experimental indicators is holdings. Since the beginning of 2021, euro area holdings of sustainable debt securities have grown continuously, following a similar trend to the one observed for euro area issuances.