With a major environmental conference such as green week 2015, during which thousands of participants are zig-zagging between fascinating sessions on aspects of EU biodiversity policy for three days, it's difficult to single out one event above the others.
This is a crucial year for our nature policies, and green week will be looking at what works, what can be improved, and how we can make sure it all fits together.
But the week isn't just about nature - it will also highlight other aspects of EU environment policy, with the launch of the process to find a European green capital for 2018, for example.
In one of the great demographic shifts of modern times, city dwellers now far outnumber rural populations, with nearly two out of three Europeans living in an urban environment. That means that towns and cities are the places where emerging environmental challenges impact most on people's health and wellbeing.
The European green capital award, now in its ninth year, publicly recognises cities that are rising to the challenge, actively creating a sustainable future for their citizens.
The UK city of Bristol holds this year's title. Last year's recipient was Copenhagen, and next year's award will go to Ljubljana.
These cities are at the top of their game where a good environment is concerned: they are places where urban decision-makers understand that when citizens say they want clean air, green spaces, safe cycle paths and a well-run public transport system, they mean it, because it matters to them and to their families.
They are places that have found the right balance between preserving and innovating, between respecting citizens' demands for their environment, and attracting investment to provide the prosperity and employment opportunities on which any modern city depends.
The green capital award - like its recent offshoot, the European green leaf, aimed at smaller cities, which is about to enter its second year 0 is anything but window-dressing.
It is a policy tool used by the European commission to draw attention to urban environment challenges and to the fact that decision-makers in cities can empower themselves to bring about durable solutions.
Winning the title boosts tourism, investment potential and the city's reputation, but equally important for the commission is building up a stock of leading proponents for sustainable city living - city authorities - committed to enhancing urban life.
Green capital winners also commit to sharing what they have learned and act as ambassadors to inspire others to strive for a cleaner, greener and healthier future for their citizens.
Cities differ enormously, and sharing examples of what a green capital can look like is set to become ever more interesting, with a growing variety of contenders competing for the award.
The network of city-based 'ambassadors' includes not only the winners, but also the best-performing runners-up, providing a rich panoply of different examples - big, less big, coastal, riverside, post-industrial and others. The green capital works and this is a message that can also extend beyond Europe.
Cities with populations below the green capital threshold - 100,000 - also seek EU recognition for their efforts and commitment in the areas of sustainability and environment. In response, the commission has launched the new European green leaf initiative.
It is already growing in popularity, so the lower threshold - which was 50,000 for the 2015 pilot year - will be 20,000-100,000 inhabitants for the 2016 competition. The green leaf motto says it all: 'towns and cities - growing greener'.
These urban schemes are particularly relevant this year, because one of the sustainable development goals expected to be agreed by the UN in September concerns the urban environment.
Given the increasing number of people living in cities worldwide, European metropolises have an opportunity to share their experience in building better urban futures with poorer regions. In that context, and given the huge numbers of people attracted to cities in developing countries, careful monitoring of both European and international efforts to reach the sustainable development goals is called for.
The EU and its member states can share experience on urban design, innovative solutions - for example, in addressing fresh water and waste management problems - and pioneering approaches that would enable poorer regions to avoid some of the errors made in European cities at earlier stages of their development.
After nearly 10 years of the European green capital award, much has been learned from how cities function and change.
EU environment policy - which aims to safeguard people's health as much as it does the environment - can only be successful when properly implemented.
One of the best ways to quicken the pace of change is to make sure that residents, communities, businesses and tourists are all made aware of what is at stake, becoming more involved in projects and decisions on all aspects of environmental sustainability.
This is the key to keeping a city green and sustainable, and I think that it's the hallmark of our European green capital initiative.
One final thing: green week will reveal many things, but it won't tell you the name of the next winning city for 2017. That will be revealed - as will the first green leaf winner - in Bristol, on 18 June.