New Delhi World Book Fair opens today at Pragati Maidan in the national capital. Organised by the National Book Trust in association with India Trade Promotion Organisation, the main theme of this year's fair is environment and climate change. The European Union is the focus country this time. Our correspondent reports, more than 40 countries including Belgium, Canada, China, Denmark, Egypt, France, Germany, and the United Kingdom are participating in the book fair. The annual event will come to an end on 14th of this month.