Lufthansa’s boss struck an optimistic tone on Thursday as he revealed the firm’s results for the past year, but said considerable uncertainty lay ahead for the flagship German airline. “We are very certain that air traffic will experience a strong upswing this year,” chief executive Carsten Spohr said on Thursday. However, major uncertainties surrounding the developments in Ukraine, the consequences of the conflict as well as the uncertain course of the pandemic did not allow for a detailed financial forecast. The board did not commit to a position on whether Lufthansa would return to profit i…