Will Europe Manage without Immigrants?

The World Economic Forum says that "Europeans must not see refugees and migrants purely as a threat to national politics or EU internal unity. It could be a great opportunity for an ageing continent. By 2030, the EU countries will have 16 million fewer people of working age (even with steady net migration)." However, to be successful countries need to integrate migrants quickly in order for them to get jobs and start paying taxes. On the mentioned web page there is a graph showing "Economic impact of refugees in Germany", and even the most pessimistic line shows a positive trend in a couple of years. Consequently, language training as a crucial part of integration will need a boost.