a careful and timely transition will also open up opportunities, associated with the development of new renewable energy and innovative products, investment in energy saving, new infrastructure and new jobs. the transformation of the global economy towards decarbonisation cannot but have a positive net outcome. long - term value creation is a matter of effective climate risk management and transition to a zero - carbon economy4. for this reason, central banks support transparency and the disclosure of data that will enable markets to lead the transition5 so that, with the right information, they can price in the cost of doing business, the climate risk, and, most importantly, evaluate new business opportunities. the proper assessment and supervision of the financial risks stemming from the transition to a zero - carbon economy are important factors in promoting sustainable development and safeguarding the smooth functioning of the financial system6. in addition, commercial banks can play an important role in moving towards a low - carbon economy by reducing their exposures to high - carbon investment, while banking supervisors could take into account sustainability considerations in the calculation of bank capital requirements7. the transformation of cities represents another significant challenge from the perspective of sustainability. as put by amina mohammed, un deputy secretary - general, “ it is clear that it is in cities where the battle for sustainability will be won or lost ” 8. today, over 80 % of the global gdp is generated in urban areas, which are hubs of collaboration and progress, innovation, culture, science, productivity, exchange of ideas, goods and services, and societal development. urban development in a manner that cities can continue to generate jobs, prosperity, social and economic gains without drying up land and resources, is a crucial bet as it is projected that twothirds of the world ’ s population will be living in urban or suburban areas by 2050. this concentration will exacerbate the existing problems and add new ones, unless best practices are adopted that will make our cities sustainable and inclusive, with highly interconnected networks and “ smart ” infrastructures, quality services and low environmental and energy footprint. the advances in technology, innovation and science, which are the driving force of growth through total factor productivity, as well as a catalyst for a sustainable future, also pose a significant challenge. technological progress and the digital age have created a new landscape, that of the 4th industrial revolution, in which digital technology helps to raise productivity, 2 / 4 bis central bankers'speeches reduces the costs of production – parts of which are now demater

##rrencies preserving the two distinguishing attributes of cash, namely anonymity and peer - to - peer exchangeability within a digitized platform, had proven to be significantly challenging until the distributed ledger technology offered in 2008 the key to assure in a decentralized way than one could never spend twice her withholding ( the “ double spending problem ” ). there is a lot of excitement in the air about cryptocurrencies. everyone has heard about bitcoin, whose market capitalization as of the first quarter of 2018 exceeded 110 billion us $, increasing by a factor of ten within a year. the above observation raises many questions, while it is true that cryptocurrencies represent only a negligible fraction of all world payments. there has been a raging debate about the effects on the financial system of introducing virtual currencies, digital currencies and related innovations. the imf has recently recognized that digital currencies might offer potential benefits, including greater speed and efficiency in making payments and transfers – particularly across borders2. offsetting the promised benefit of low payment processing costs, which is expected when the technology in this field matures, is the extreme volatility of cryptocurrencies ’ prices. “ crypto ” means anonymity and anonymity can be abused in a world of crime, terrorism and evasion. the ecb has been considering monetary policy implications resulting from the introduction of cryptocurrencies since at least 2012. in its recent study, it suggested that due to its high price volatility and low acceptance rate, the bitcoin could not be regarded as a full form of money from an economic perspective3. more recently, the issue has been discussed in the g - 20 meeting and in the latest communique of finance ministers and central bank governors ( buenos aires 19 - 20 march 2018 ) where it was stated that crypto - assets lack the key attributes of sovereign currencies, although at some point they could have financial stability implications. so, in the current state, digital currencies leave monetary transmission mechanisms largely unaffected. 2 / 6 bis central bankers'speeches however, it is almost a cliche to say that the only certainty about the future of cryptocurrencies is uncertainty. risks to financial stability may eventually emerge since the impact of the digital currencies on the monetary transmission mechanism ultimately depends on whether firms and households broadly accept them. therefore, supervisory authorities are monitoring all developments in the