The fifth challenge is to emerge from a mood that can be called “irrational pessimism.” In the same way that “irrational optimism” creates a bubble, “irrational pessimism” will certainly not have positive effects on economic activity either.
(2019), “ Finance and carbon emissions” , Working Paper Series, No 2318, ECB,  September; Popov, A. (2020), “ Does financial structure affect the carbon footprint of the economy?” , Financial Integration and Structure in the Euro Area, ECB, March. 9 In 2017, Europe had 76% more patents in the digital-green domain than the United States and over four times  more than China.